/* ========================================
   PYTHON LEARNING SITE - BLUE/TEAL THEME
   ======================================== */

/* ========================================
   MOBILE DEVICE TEMPLATE - SIMPLIFIED LAYOUT
   ======================================== */
.mobile-device {
  /* Reset everything for mobile */
  overflow-x: hidden !important;
  overflow-y: auto !important; /* Enable vertical scrolling */
  max-width: 100vw !important;
  width: 100% !important;
  height: auto !important;
  min-height: 100vh !important;
  -webkit-overflow-scrolling: touch !important; /* Smooth scrolling on iOS */
  touch-action: pan-y !important; /* Allow vertical panning */
}

.mobile-device html {
  overflow-x: hidden !important;
  overflow-y: auto !important;
  height: auto !important;
  -webkit-overflow-scrolling: touch !important;
  touch-action: pan-y !important;
}

.mobile-device body {
  overflow-x: hidden !important;
  overflow-y: auto !important;
  height: auto !important;
  min-height: 100vh !important;
  -webkit-overflow-scrolling: touch !important;
  touch-action: pan-y !important;
}

.mobile-device * {
  max-width: 100% !important;
  box-sizing: border-box !important;
  touch-action: auto !important; /* Allow default touch actions */
}

/* Disable all fixed/absolute positioning that could cause issues */
.mobile-device body::before,
.mobile-device body::after {
  display: none !important;
}

.mobile-device [class*="fixed"],
.mobile-device [class*="absolute"] {
  position: relative !important;
}

/* Simplify header */
.mobile-device .site-header {
  position: sticky !important;
  top: 0 !important;
  z-index: 100 !important;
  width: 100% !important;
  max-width: 100vw !important;
  padding: 0 !important;
}

.mobile-device .container {
  width: 100% !important;
  max-width: 100vw !important;
  padding-left: 16px !important;
  padding-right: 16px !important;
  margin: 0 auto !important;
}

/* Simplify navigation */
.mobile-device .mobile-toggle {
  display: flex !important;
  flex-direction: column !important;
  gap: 5px !important;
  padding: 10px !important;
  background: transparent !important;
  border: 2px solid var(--border) !important;
  border-radius: 8px !important;
  cursor: pointer !important;
  z-index: 101 !important;
  position: relative !important;
  min-width: 44px !important;
  min-height: 44px !important;
  align-items: center !important;
  justify-content: center !important;
}

.mobile-device .mobile-toggle span {
  width: 24px !important;
  height: 3px !important;
  background: var(--text) !important;
  display: block !important;
  border-radius: 3px !important;
  transition: all 0.3s ease !important;
}

.mobile-device .primary-nav .menu {
  position: fixed !important;
  top: 70px !important;
  left: 0 !important;
  right: 0 !important;
  width: 100vw !important;
  max-width: 100vw !important;
  margin: 0 !important;
  padding: 20px 16px !important;
  background: var(--panel) !important;
  border-bottom: 3px solid var(--border) !important;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15) !important;
  transform: translateY(-150%) !important;
  opacity: 0 !important;
  pointer-events: none !important;
  transition: transform 0.3s ease, opacity 0.3s ease !important;
  z-index: 100 !important;
  display: flex !important;
  flex-direction: column !important;
  gap: 8px !important;
  list-style: none !important;
  max-height: calc(100vh - 70px) !important;
  overflow-y: auto !important;
  -webkit-overflow-scrolling: touch !important;
}

.mobile-device .primary-nav[aria-expanded="true"] .menu {
  transform: translateY(0) !important;
  opacity: 1 !important;
  pointer-events: auto !important;
}

.mobile-device .primary-nav .menu li {
  width: 100% !important;
  margin: 0 !important;
  padding: 0 !important;
}

.mobile-device .primary-nav .menu a,
.mobile-device .primary-nav .menu button {
  display: block !important;
  width: 100% !important;
  padding: 14px 16px !important;
  text-align: left !important;
  border-radius: 8px !important;
  font-size: 16px !important;
  min-height: 44px !important;
  border: none !important;
  background: transparent !important;
}

.mobile-device .primary-nav .menu a:hover,
.mobile-device .primary-nav .menu button:hover {
  background: var(--bg-elevated) !important;
}

.mobile-device .primary-nav .has-dropdown {
  position: relative !important;
}

.mobile-device .primary-nav .dropdown {
  position: relative !important;
  top: 0 !important;
  left: 0 !important;
  right: 0 !important;
  width: 100% !important;
  margin-top: 8px !important;
  padding-left: 16px !important;
  background: var(--bg-elevated) !important;
  border-radius: 8px !important;
  display: none !important;
}

.mobile-device .primary-nav .has-dropdown[aria-expanded="true"] .dropdown {
  display: block !important;
}

.mobile-device .primary-nav .dropdown li {
  width: 100% !important;
}

.mobile-device .primary-nav .dropdown a {
  padding: 12px 16px !important;
  font-size: 15px !important;
}

/* Stack everything vertically */
.mobile-device .hero-grid,
.mobile-device .features-grid,
.mobile-device .units-grid,
.mobile-device .testimonials,
.mobile-device .cofounders-grid,
.mobile-device .founders-showcase {
  display: flex !important;
  flex-direction: column !important;
  gap: 20px !important;
}

/* Simplify course layout */
.mobile-device .layout-course {
  display: flex !important;
  flex-direction: column !important;
  gap: 16px !important;
}

.mobile-device .course-sidebar {
  position: relative !important;
  width: 100% !important;
  max-width: 100% !important;
  order: 2 !important;
  margin-top: 20px !important;
}

.mobile-device .course-main {
  order: 1 !important;
  width: 100% !important;
}

/* Make all links safe - only clickable on text */
.mobile-device a {
  display: inline-block !important;
  position: relative !important;
  z-index: 1 !important;
  pointer-events: auto !important;
  max-width: 100% !important;
  word-wrap: break-word !important;
}

.mobile-device a:not(.btn) {
  padding: 4px 0 !important;
  margin: 0 !important;
}

/* Buttons are safe */
.mobile-device .btn {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  padding: 14px 20px !important;
  min-height: 44px !important;
  width: 100% !important;
  max-width: 100% !important;
  margin: 8px 0 !important;
  z-index: 100 !important;
  position: relative !important;
  pointer-events: auto !important;
}

/* Prevent any element from overflowing */
.mobile-device .section,
.mobile-device main,
.mobile-device header,
.mobile-device footer {
  width: 100% !important;
  max-width: 100vw !important;
  overflow-x: hidden !important;
  overflow-y: visible !important; /* Allow content to flow */
  padding-left: 0 !important;
  padding-right: 0 !important;
}

.mobile-device main {
  overflow-y: visible !important;
  height: auto !important;
  min-height: auto !important;
}

/* Simplify content areas */
.mobile-device .lesson-content,
.mobile-device .content-section {
  width: 100% !important;
  max-width: 100% !important;
  padding: 0 16px !important;
}

/* Remove complex positioning */
.mobile-device .hero-visual,
.mobile-device .orb-1,
.mobile-device .orb-2 {
  position: relative !important;
  transform: none !important;
}

/* Make images responsive */
.mobile-device img {
  max-width: 100% !important;
  height: auto !important;
}

/* Simplify tables */
.mobile-device table {
  display: block !important;
  overflow-x: auto !important;
  width: 100% !important;
  max-width: 100% !important;
}

/* Code blocks */
.mobile-device pre,
.mobile-device code {
  max-width: 100% !important;
  overflow-x: auto !important;
  word-wrap: break-word !important;
}

/* Forms */
.mobile-device input,
.mobile-device textarea,
.mobile-device select {
  width: 100% !important;
  max-width: 100% !important;
  box-sizing: border-box !important;
}

/* Remove animations that could cause issues, but keep scroll smooth */
.mobile-device * {
  animation: none !important;
  transition: opacity 0.2s ease, transform 0.2s ease !important;
}

/* Ensure scrolling works properly */
.mobile-device html,
.mobile-device body {
  -webkit-overflow-scrolling: touch !important;
  overscroll-behavior-y: auto !important;
  overscroll-behavior-x: none !important;
}

/* Ensure nothing is off-screen */
.mobile-device * {
  left: auto !important;
  right: auto !important;
  margin-left: 0 !important;
  margin-right: 0 !important;
}

.mobile-device [style*="left"],
.mobile-device [style*="right"],
.mobile-device [style*="margin-left"],
.mobile-device [style*="margin-right"] {
  left: auto !important;
  right: auto !important;
  margin-left: 0 !important;
  margin-right: 0 !important;
}

/* ========================================
   END MOBILE TEMPLATE
   ======================================== */

/* Global Theme Tokens - Light Blue/Teal Palette */
:root {
  --bg: #F0F9FF;
  --bg-elevated: #E0F2FE;
  --panel: #FFFFFF;
  --text: #0F172A;
  --text-strong: #020617;
  --muted: #475569;
  --border: #CBD5E1;
  --primary: #0EA5E9;
  --primary-strong: #0284C7;
  --accent: #14B8A6;
  --accent-alt: #06B6D4;
  --shadow: 0 8px 24px rgba(15, 23, 42, 0.1);
  --shadow-strong: 0 12px 32px rgba(15, 23, 42, 0.15);
  --ring: 0 0 0 4px rgba(14, 165, 233, 0.15);
  --gradient: linear-gradient(135deg, #0EA5E9 0%, #06B6D4 100%);
  --gradient-soft: linear-gradient(135deg, #06B6D4 0%, #14B8A6 100%);
  --font-scale: 1;
}

[data-theme="dark"] {
  --bg: #0F172A;
  --bg-elevated: #1E293B;
  --panel: #1E293B;
  --text: #F1F5F9;
  --text-strong: #FFFFFF;
  --muted: #94A3B8;
  --border: #334155;
  --primary: #38BDF8;
  --primary-strong: #0EA5E9;
  --accent: #5EEAD4;
  --accent-alt: #22D3EE;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-strong: 0 12px 32px rgba(0, 0, 0, 0.5);
  --ring: 0 0 0 4px rgba(56, 189, 248, 0.25);
  --gradient: linear-gradient(135deg, #38BDF8 0%, #22D3EE 100%);
  --gradient-soft: linear-gradient(135deg, #22D3EE 0%, #5EEAD4 100%);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
html { 
  scroll-behavior: smooth;
  overflow-x: hidden; /* Prevent horizontal scroll */
  max-width: 100vw; /* Prevent viewport overflow */
}
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: calc(16px * var(--font-scale, 1));
  position: relative;
  overflow-x: hidden; /* Prevent horizontal scroll */
  max-width: 100vw; /* Prevent viewport overflow */
  width: 100%; /* Ensure body doesn't exceed viewport */
}

/* Python-themed decorative backgrounds - Subtle animated elements only */
body {
  background: var(--bg);
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.08;
  background-image: 
    /* Animated snake paths - very subtle */
    url("data:image/svg+xml,%3Csvg width='500' height='400' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M0 200 Q 100 100, 200 200 T 400 200 T 500 200' stroke='%230EA5E9' fill='none' stroke-width='16' opacity='0.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3Cpath d='M50 250 Q 150 150, 250 250 T 450 250' stroke='%2306B6D4' fill='none' stroke-width='12' opacity='0.35' stroke-linecap='round'/%3E%3Ccircle cx='150' cy='120' r='12' fill='%230EA5E9' opacity='0.4'/%3E%3Ccircle cx='350' cy='280' r='10' fill='%2314B8A6' opacity='0.35'/%3E%3C/svg%3E");
  background-size: 1200px 900px;
  background-position: -200px -150px;
  animation: none;
  filter: blur(3px);
  max-width: 100vw; /* Prevent overflow */
  overflow: hidden; /* Prevent overflow */
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.06;
  background-image: 
    /* Subtle code text patterns - very faint */
    url("data:image/svg+xml,%3Csvg width='350' height='280' xmlns='http://www.w3.org/2000/svg'%3E%3Ctext x='30' y='40' font-family='monospace' font-size='18' fill='%230EA5E9' opacity='0.5' font-weight='bold'%3Edef calculate():%3C/text%3E%3Ctext x='30' y='70' font-family='monospace' font-size='18' fill='%2314B8A6' opacity='0.45'%3E    return sum(x)%3C/text%3E%3Ctext x='30' y='100' font-family='monospace' font-size='18' fill='%2306B6D4' opacity='0.4'%3Eclass Python:%3C/text%3E%3C/svg%3E");
  background-size: 700px 550px;
  background-position: 70% 45%;
  animation: none;
  filter: blur(4px);
  max-width: 100vw; /* Prevent overflow */
  overflow: hidden; /* Prevent overflow */
}

@keyframes bgFloat {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  33% { transform: translate(50px, -40px) rotate(2deg); }
  66% { transform: translate(-30px, 30px) rotate(-1deg); }
}

@keyframes bgDrift {
  0% { transform: translate(0, 0); }
  100% { transform: translate(300px, 250px); }
}

/* Typography Scale */
h1, .h1, .headline { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: clamp(36px, 6.5vw, 68px); 
  line-height: 1.1; 
  letter-spacing: -0.02em; 
  margin: 0 0 12px;
  font-weight: 700;
  color: var(--text-strong);
}
h2, .h2 { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: clamp(28px, 4vw, 42px); 
  line-height: 1.15; 
  letter-spacing: -0.015em; 
  margin: 0 0 10px;
  font-weight: 600;
  color: var(--text-strong);
}
h3, .h3 { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 24px; 
  line-height: 1.3; 
  letter-spacing: -0.01em; 
  margin: 0 0 8px;
  font-weight: 600;
}
h4, .h4 { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 20px; 
  line-height: 1.3; 
  margin: 0 0 6px;
  font-weight: 600;
}
p { margin: 0 0 12px; }

/* Layout */
.container { 
  width: min(1120px, 92%); 
  margin: 0 auto; 
  position: relative; 
  z-index: 1;
  max-width: 100vw; /* Prevent overflow */
  padding-left: 4%;
  padding-right: 4%;
  box-sizing: border-box;
}
.container.narrow { width: min(880px, 92%); }

/* Full-width containers for main content sections */
main .container,
.section .container {
  width: 100%;
  max-width: 100%;
  padding-left: 40px;
  padding-right: 40px;
}

@media (min-width: 1400px) {
  main .container,
  .section .container {
    padding-left: 60px;
    padding-right: 60px;
  }
}

@media (min-width: 1600px) {
  main .container,
  .section .container {
    padding-left: 80px;
    padding-right: 80px;
  }
}

/* Remove container constraints for course layout */
.container.layout-course {
  width: 100% !important;
  max-width: 100% !important;
  padding: 0 32px 0 24px !important;
  margin: 0 !important;
}

/* Header */
.site-header {
  position: sticky; 
  top: 0; 
  z-index: 50;
  background: var(--panel);
  border-bottom: 3px solid var(--border);
  box-shadow: 0 4px 12px rgba(44, 36, 22, 0.08);
}
.site-header .container {
  width: 100%;
  max-width: 100%;
  padding-left: 40px;
  padding-right: 40px;
}

@media (min-width: 1400px) {
  .site-header .container {
    padding-left: 60px;
    padding-right: 60px;
  }
}

@media (min-width: 1600px) {
  .site-header .container {
    padding-left: 80px;
    padding-right: 80px;
  }
}

.nav { display: flex; align-items: center; justify-content: space-between; padding: 16px 0; }

.brand { 
  display: inline-flex; 
  align-items: center; 
  gap: 12px; 
  text-decoration: none; 
  color: var(--text-strong); 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-weight: 700; 
  font-size: 22px;
  letter-spacing: -0.01em;
}
.brand .logo { 
  display: inline-block; 
  width: 36px; 
  height: 36px; 
  border-radius: 10px; 
  object-fit: contain;
  vertical-align: middle;
}
.brand .logo.small { width: 28px; height: 28px; }
.brand.small { gap: 10px; font-size: 18px; }

.primary-nav .menu { display: flex; align-items: center; gap: 4px; list-style: none; margin: 0; padding: 0; }
.primary-nav a, .primary-nav button { 
  appearance: none; 
  border: 0; 
  background: none; 
  font: inherit; 
  color: var(--text); 
  text-decoration: none; 
  padding: 10px 16px; 
  border-radius: 8px;
  font-weight: 600;
  transition: background-color 150ms ease, color 150ms ease;
}
.primary-nav a:hover, .primary-nav button:hover { 
  background: var(--bg-elevated); 
  color: var(--primary);
}
.primary-nav a { position: relative; }
.primary-nav a::after { 
  content: ""; 
  position: absolute; 
  left: 16px; 
  right: 16px; 
  bottom: 6px; 
  height: 3px; 
  background: var(--primary); 
  transform: scaleX(0); 
  transform-origin: left; 
  transition: transform 250ms ease; 
  border-radius: 2px; 
}
.primary-nav a:hover::after { transform: scaleX(1); }
.primary-nav a.active { 
  color: var(--primary); 
  background: color-mix(in srgb, var(--primary) 12%, transparent); 
}

.mobile-toggle { 
  display: none; 
  flex-direction: column; 
  gap: 5px; 
  padding: 10px; 
}

/* Always show mobile toggle on mobile devices */
.mobile-device .mobile-toggle {
  display: flex !important;
}
.mobile-toggle span { width: 24px; height: 3px; background: var(--text); display: block; border-radius: 3px; }

.has-dropdown { position: relative; }
.dropdown-toggle { display: inline-flex; align-items: center; gap: 6px; }
.has-dropdown .dropdown {
  position: absolute; 
  top: 120%; 
  left: 0; 
  min-width: 200px; 
  padding: 8px; 
  border-radius: 12px; 
  background: var(--panel); 
  box-shadow: var(--shadow-strong); 
  border: 2px solid var(--border);
  opacity: 0; 
  transform: translateY(-8px) scale(0.98); 
  pointer-events: none; 
  transition: 250ms ease;
}
.has-dropdown[aria-expanded="true"] .dropdown { 
  opacity: 1; 
  transform: translateY(0) scale(1); 
  pointer-events: auto; 
}
.dropdown li { list-style: none; }
.dropdown a { display: block; padding: 10px 12px; border-radius: 8px; }
.dropdown a:hover { background: var(--bg-elevated); }
.dropdown a::before,
.dropdown a::after,
.dropdown li::before,
.dropdown li::after {
  display: none !important;
  content: none !important;
}

/* Footer */
.site-footer { 
  padding: 48px 0; 
  border-top: 3px solid var(--border); 
  background: var(--bg-elevated); 
  margin-top: 80px; 
  position: relative;
  z-index: 1;
}
.footer-grid { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.footer-links { list-style: none; display: flex; gap: 16px; margin: 0; padding: 0; }
.footer-links a { color: var(--muted); text-decoration: none; font-weight: 600; }
.footer-links a:hover { color: var(--primary); }

/* Global Progress */
.progress-global { 
  position: relative; 
  height: 8px; 
  background: var(--bg-elevated); 
  border-radius: 999px; 
  overflow: hidden; 
  margin: 0 0 12px; 
  border: 2px solid var(--border); 
}
.progress-global .bar { 
  position: absolute; 
  inset: 0 auto 0 0; 
  width: 0%; 
  background: var(--gradient); 
  border-radius: 999px; 
  transition: width 500ms cubic-bezier(.2,.7,0,1); 
}

/* Mobile Warning Banner */
.mobile-warning-banner {
  display: none; /* Hidden by default, shown only on mobile */
  background: linear-gradient(135deg, #FEF3C7 0%, #FDE68A 100%);
  border-bottom: 2px solid #F59E0B;
  padding: 12px 0;
  position: sticky;
  top: 0;
  z-index: 200;
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.2);
}

.mobile-device .mobile-warning-banner {
  display: block !important;
}

.mobile-warning-content {
  display: flex;
  align-items: center;
  gap: 12px;
  position: relative;
}

.mobile-warning-content svg:first-child {
  flex-shrink: 0;
  color: #D97706;
}

.mobile-warning-content p {
  margin: 0;
  flex: 1;
  font-size: 14px;
  line-height: 1.5;
  color: #92400E;
}

.mobile-warning-content strong {
  font-weight: 600;
  color: #78350F;
}

.mobile-warning-close {
  flex-shrink: 0;
  background: transparent;
  border: none;
  padding: 4px;
  cursor: pointer;
  color: #92400E;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  transition: background-color 0.2s ease;
  min-width: 28px;
  min-height: 28px;
}

.mobile-warning-close:hover {
  background: rgba(217, 119, 6, 0.1);
}

.mobile-warning-close:active {
  background: rgba(217, 119, 6, 0.2);
}

/* Hero */
.announcement-banner {
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
  text-align: center;
  position: relative;
}

.announcement-banner p {
  margin: 0;
  font-size: 15px;
  color: var(--text);
  font-weight: 400;
  line-height: 1.5;
}

.announcement-banner a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

.announcement-banner a:hover {
  color: var(--accent);
  text-decoration: underline;
}

.hero { 
  padding: 60px 0 80px; 
  position: relative; 
  overflow: hidden;
  background: linear-gradient(180deg, transparent 0%, rgba(14, 165, 233, 0.02) 50%, transparent 100%);
}
.hero-grid { 
  display: grid; 
  grid-template-columns: 1.2fr 1fr; 
  gap: 48px; 
  align-items: start; 
}
.hero .illustration { 
  position: absolute; 
  inset: -20px auto auto -40px; 
  width: 400px; 
  opacity: 0.15; 
  pointer-events: none; 
  z-index: 0;
}
.hero .illustration svg { width: 100%; height: auto; display: block; }
.subhead { 
  margin: 0 0 28px; 
  color: var(--muted); 
  font-size: 20px; 
  line-height: 1.7;
  font-weight: 400;
  max-width: 600px;
}
.cta { display: flex; gap: 16px; margin: 32px 0 28px; flex-wrap: wrap; }
.badges { display: flex; gap: 12px; flex-wrap: wrap; }
.badge { 
  display: inline-flex; 
  padding: 8px 14px; 
  border-radius: 999px; 
  color: var(--primary-strong); 
  background: color-mix(in srgb, var(--primary) 14%, transparent); 
  font-weight: 700; 
  font-size: 13px;
  border: 2px solid color-mix(in srgb, var(--primary) 20%, transparent);
}

.hero-visual { position: relative; height: 480px; }
.orb { 
  position: absolute; 
  width: 200px; 
  height: 200px; 
  border-radius: 50%; 
  filter: blur(60px); 
  opacity: 0.25; 
  animation: none; 
  z-index: 0;
}
.orb-1 { background: radial-gradient(circle, var(--primary), transparent); top: -40px; right: 10%; }
.orb-2 { background: radial-gradient(circle, var(--accent), transparent); bottom: -60px; left: 5%; animation-delay: -4s; }
.screen { 
  position: absolute; 
  top: 0; 
  right: 0; 
  left: auto; 
  width: min(95%, 920px); 
  max-width: 920px; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 20px; 
  box-shadow: var(--shadow-strong); 
  z-index: 1;
}
.screen-header { 
  display: flex; 
  align-items: center; 
  gap: 10px; 
  padding: 12px 14px; 
  border-bottom: 3px solid var(--border); 
  background: var(--bg-elevated); 
  border-top-left-radius: 20px; 
  border-top-right-radius: 20px; 
}
.screen-header .dot { width: 10px; height: 10px; border-radius: 50%; }
.screen-header .dot:nth-child(1) { background: #ef4444; }
.screen-header .dot:nth-child(2) { background: #f59e0b; }
.screen-header .dot:nth-child(3) { background: #10b981; }
.code { 
  margin: 0; 
  padding: 20px; 
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; 
  font-size: 14px; 
  color: var(--text); 
  line-height: 1.6;
}
.floating { animation: none; }

/* Code blocks */
pre.code, pre code { 
  background: var(--bg-elevated); 
  color: var(--text);
}
pre.code { border-radius: 12px; border: 2px solid var(--border); }
pre code { display: block; overflow-x: auto; }

/* Sections & Spacing */
.section { 
  padding: 40px 0; 
  position: relative; 
  z-index: 1;
}
.stack-4 > * + * { margin-top: 4px; }
.stack-8 > * + * { margin-top: 8px; }
.stack-12 > * + * { margin-top: 12px; }
.stack-16 > * + * { margin-top: 16px; }
.stack-24 > * + * { margin-top: 24px; }
.section-head { 
  display: grid; 
  gap: 12px; 
  margin-bottom: 40px; 
  text-align: center;
}
.section-head h2 {
  margin-bottom: 0;
}
#curriculum.section { padding-top: 0; padding-bottom: 40px; }
.features.section { padding-top: 40px; padding-bottom: 60px; }
#testimonials.section { padding-top: 50px; padding-bottom: 60px; }

.page-title { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: clamp(36px, 7vw, 72px); 
  line-height: 1.05; 
  letter-spacing: -0.02em; 
  margin: 0 0 12px; 
  color: var(--text-strong);
  font-weight: 700;
}
.page-subtitle { color: var(--muted); margin: 0 0 20px; font-size: 18px; }
.gradient-text { 
  background: var(--gradient); 
  -webkit-background-clip: text; 
  background-clip: text; 
  color: transparent; 
}

/* Features */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature {
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 20px; 
  padding: 32px 28px; 
  box-shadow: var(--shadow); 
  transition: all 0.3s ease; 
  position: relative;
  overflow: hidden;
}
.feature:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-strong);
  border-color: color-mix(in srgb, var(--primary) 30%, transparent);
}
.feature::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 300ms ease;
}
.feature:hover::before {
  transform: scaleX(1);
}
.feature:hover { 
  transform: translateY(-4px);
  box-shadow: var(--shadow-strong);
  border-color: color-mix(in srgb, var(--primary) 30%, transparent);
}
.feature .icon { 
  font-size: 14px; 
  font-weight: 800; 
  margin-bottom: 8px; 
  padding: 8px 12px;
  background: var(--gradient);
  color: #fff;
  border-radius: 8px;
  display: inline-block;
  letter-spacing: 0.05em;
}

/* Units Grid */
.units-grid { 
  display: grid; 
  grid-template-columns: repeat(5, 1fr); 
  gap: 20px; 
}
.units-grid .unit-card {
  min-width: 0; /* Allow grid items to shrink below content size */
}
.unit-card { 
  display: grid; 
  gap: 8px; 
  padding: 16px; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 16px; 
  text-decoration: none; 
  color: var(--text); 
  box-shadow: var(--shadow); 
  position: relative; 
  overflow: hidden; 
  transition: box-shadow 200ms ease, border-color 200ms ease; 
}
.unit-card::before { 
  content: ""; 
  position: absolute; 
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: var(--gradient-soft);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 400ms ease;
}
.unit-card:hover::before {
  transform: scaleX(1);
}
.unit-card::after { 
  content: "View details"; 
  position: absolute; 
  right: 12px; 
  bottom: 10px; 
  font-weight: 800; 
  font-size: 10px; 
  color: var(--primary); 
  background: var(--bg-elevated); 
  border: 2px solid var(--border); 
  padding: 4px 10px; 
  border-radius: 999px; 
  opacity: 0; 
  transform: translateY(8px); 
  transition: opacity 200ms ease, background-color 200ms ease; 
}
.unit-card:hover { 
  box-shadow: var(--shadow-strong); 
}
.unit-card:hover::after { opacity: 1; transform: translateY(0); }
.unit-card h3 { 
  margin: 0; 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-weight: 700;
  font-size: 18px;
  line-height: 1.3;
  word-wrap: break-word;
  overflow-wrap: break-word;
}
.unit-card p { 
  margin: 0 0 10px 0; 
  color: var(--muted);
  line-height: 1.5;
  font-size: 14px;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.unit-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 2px;
}
.unit-ribbon { 
  position: absolute; 
  top: -14px; 
  right: -14px; 
  width: 60px; 
  height: 60px; 
  border-radius: 16px; 
  background: var(--gradient); 
  color: #fff; 
  display: grid; 
  place-items: center; 
  font-weight: 800; 
  box-shadow: var(--shadow-strong); 
  transform: rotate(12deg); 
  border: 3px solid var(--panel);
}

/* Progress Ring */
.progress-ring { width: 40px; height: 40px; display: inline-grid; place-items: center; position: absolute; top: 10px; left: 10px; }
.progress-ring svg { width: 40px; height: 40px; transform: rotate(-90deg); }
.progress-ring circle.track { stroke: color-mix(in srgb, var(--muted) 25%, transparent); }
.progress-ring circle.indicator { stroke: var(--primary); transition: stroke-dashoffset 600ms ease; }
.progress-ring .label { position: absolute; font-size: 11px; font-weight: 800; color: var(--text); }

/* Buttons */
.btn { 
  display: inline-flex; 
  align-items: center; 
  justify-content: center; 
  gap: 8px; 
  text-decoration: none; 
  padding: 14px 24px; 
  border-radius: 12px; 
  font-weight: 700; 
  border: 3px solid transparent; 
  transition: background-color 150ms ease, color 150ms ease; 
  position: relative; 
  overflow: hidden; 
  font-size: 16px;
  z-index: 10;
  pointer-events: auto;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
.btn:focus-visible { outline: none; box-shadow: var(--ring); }
.btn-primary { 
  background: var(--gradient); 
  color: #fff; 
  border-color: var(--primary-strong);
  box-shadow: var(--shadow);
}
.btn-primary:hover {
  box-shadow: var(--shadow-strong);
  filter: brightness(1.05);
}
.btn-ghost { 
  background: var(--panel); 
  color: var(--text); 
  border-color: var(--border);
  box-shadow: var(--shadow);
}
.btn-ghost:hover {
  background: var(--bg-elevated);
  border-color: var(--primary);
  color: var(--primary);
}

/* Button ripple */
.btn .ripple { 
  display: none;
}

/* Panels & Controls */
.panel { 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 16px; 
  box-shadow: var(--shadow); 
  padding: 16px; 
  display: grid; 
  gap: 12px; 
}
.panel-row { 
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  gap: 16px; 
  padding: 14px 12px; 
  border-radius: 12px; 
}
.panel-row:hover { background: var(--bg-elevated); }
.muted { color: var(--muted); }
.hint { margin-top: 14px; color: var(--muted); }

/* Text links */
.text-link { 
  color: var(--primary); 
  text-decoration: none; 
  border-bottom: 2px solid color-mix(in srgb, var(--primary) 40%, transparent); 
  padding-bottom: 2px; 
  font-weight: 600;
  transition: border-color 200ms ease;
}
.text-link:hover { border-bottom-color: var(--primary); }

.segmented { 
  display: grid; 
  grid-template-columns: 1fr 1fr 1fr; 
  background: var(--bg-elevated); 
  padding: 6px; 
  border-radius: 999px; 
  border: 2px solid var(--border); 
  gap: 6px; 
}
.segmented label { display: contents; }
.segmented input { display: none; }
.segmented span { text-align: center; padding: 8px 12px; border-radius: 999px; cursor: pointer; font-weight: 600; }
.segmented input:checked + span { background: var(--panel); border: 2px solid var(--border); box-shadow: var(--shadow); }

.switch { position: relative; display: inline-block; width: 56px; height: 32px; }
.switch input { display: none; }
.switch .slider { 
  position: absolute; 
  inset: 0; 
  background: var(--bg-elevated); 
  border: 3px solid var(--border); 
  border-radius: 999px; 
  transition: 250ms ease; 
}
.switch .slider::after { 
  content: ""; 
  position: absolute; 
  width: 22px; 
  height: 22px; 
  top: 50%;
  left: 3px; 
  transform: translateY(-50%);
  background: var(--panel); 
  border: 2px solid var(--border); 
  border-radius: 50%; 
  box-shadow: var(--shadow); 
  transition: 250ms ease; 
}
.switch input:checked + .slider { 
  background: color-mix(in srgb, var(--primary) 25%, var(--bg-elevated)); 
  border-color: var(--primary); 
}
.switch input:checked + .slider::after { 
  transform: translateY(-50%) translateX(24px); 
}

/* Page Transition */
#page-transition { display: none; }
body.route-leaving { filter: saturate(0.96) blur(2px); opacity: 0.85; transition: opacity 180ms ease, filter 180ms ease; }

/* Reveal Animations */
.reveal { opacity: 0; transform: translateY(20px) scale(.98); }
.reveal.revealed { opacity: 1; transform: none; transition: opacity 300ms ease; }
.reveal-up { opacity: 0; transform: translateY(24px); }
.reveal-up.revealed { opacity: 1; transform: none; transition: opacity 300ms ease; }
/* Fallback: show content if JS fails */
.no-js .reveal-up,
.reveal-up:not(.revealed) {
  animation: fadeInFallback 0.5s ease forwards;
}
@keyframes fadeInFallback {
  to { opacity: 1; transform: none; }
}
.reveal-left { opacity: 0; transform: translateX(-24px); }
.reveal-right { opacity: 0; transform: translateX(24px); }
.reveal-scale { opacity: 0; transform: scale(.96); }
.reveal-left.revealed,
.reveal-right.revealed,
.reveal-scale.revealed { opacity: 1; transform: none; transition: opacity 300ms ease; }

/* Utils */
.grid { display: grid; }
.hidden { display: none !important; }

/* Responsive */
@media (max-width: 980px) {
  /* Prevent horizontal overflow and invisible clickable areas */
  html, body {
    overflow-x: hidden !important;
    max-width: 100vw !important;
    width: 100% !important;
  }
  
  /* Ensure all containers respect viewport */
  .container,
  .section,
  main,
  header,
  footer,
  .site-header,
  .site-footer {
    max-width: 100vw !important;
    overflow-x: hidden !important;
  }
  
  /* Prevent fixed/absolute elements from creating invisible clickable areas */
  body::before,
  body::after {
    max-width: 100vw !important;
    left: 0 !important;
    right: 0 !important;
  }
  
  /* Constrain all positioned elements */
  [class*="fixed"],
  [class*="absolute"] {
    max-width: 100vw !important;
  }
  
  .hero-grid { grid-template-columns: 1fr; }
  .hero-visual { height: 400px; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .units-grid { grid-template-columns: repeat(2, 1fr); }
  .primary-nav .menu { 
    position: fixed; 
    inset: 70px 16px auto 16px; 
    background: var(--panel); 
    border: 3px solid var(--border); 
    border-radius: 20px; 
    box-shadow: var(--shadow-strong); 
    padding: 12px; 
    flex-direction: column; 
    gap: 4px; 
    transform: translateY(-10px); 
    opacity: 0; 
    pointer-events: none; 
    transition: 250ms ease; 
  }
  .mobile-toggle { 
    display: inline-flex; 
    min-width: 44px;
    min-height: 44px;
    align-items: center;
    justify-content: center;
  }
  .primary-nav[aria-expanded="true"] .menu { 
    transform: translateY(0); 
    opacity: 1; 
    pointer-events: auto; 
  }
  .has-dropdown .dropdown { 
    position: static; 
    transform: none; 
    opacity: 1; 
    pointer-events: auto; 
    border: 0; 
    box-shadow: none; 
    padding-left: 10px; 
  }
  .has-dropdown .dropdown a {
    padding: 12px 16px;
    min-height: 44px;
  }
  .primary-nav .menu {
    max-height: calc(100vh - 100px);
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
}

/* Keyframes */
@keyframes hover { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }
@keyframes float { 0%, 100% { transform: translate(0, 0); } 50% { transform: translate(6px, -12px); } }

/* Toasts */
.toast-container { position: fixed; right: 20px; bottom: 20px; display: grid; gap: 10px; z-index: 200; }
.toast { 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 16px; 
  padding: 14px 16px; 
  box-shadow: var(--shadow-strong); 
  transform: translateY(10px); 
  opacity: 0; 
  transition: opacity 200ms ease, background-color 200ms ease; 
  color: var(--text); 
  font-weight: 600;
}
.toast.show { transform: translateY(0); opacity: 1; }

/* Remove wave dividers */
.divider { display: none; }

/* Accordions */
.accordion { display: grid; gap: 14px; }
.accordion-item { 
  border: 3px solid var(--border); 
  border-radius: 16px; 
  background: var(--panel); 
  box-shadow: var(--shadow); 
  overflow: hidden; 
}
.accordion-header { 
  list-style: none; 
  cursor: pointer; 
  display: flex; 
  align-items: center; 
  gap: 12px; 
  padding: 16px 18px; 
  font-weight: 700; 
  position: relative; 
}
.accordion-header::after { 
  content: "\25BC"; 
  position: absolute; 
  right: 16px; 
  font-size: 14px; 
  color: var(--muted); 
  transition: transform 250ms ease; 
}
.accordion-item[open] .accordion-header::after { transform: rotate(180deg); }
.accordion-header::-webkit-details-marker { display: none; }
.accordion-item > summary { outline: none; }
.accordion-item[open] .accordion-header { background: var(--bg-elevated); border-bottom: 2px solid var(--border); }
.accordion-content { padding: 16px 18px 18px; }
.accordion .badge { 
  min-width: 32px; 
  height: 32px; 
  border-radius: 10px; 
  background: var(--gradient); 
  color: #fff; 
  display: grid; 
  place-items: center; 
  font-weight: 800; 
  font-size: 14px;
}
.accordion .cbadge { 
  display: inline-flex; 
  align-items: center; 
  justify-content: center; 
  height: 32px; 
  padding: 0 12px; 
  border-radius: 10px; 
  background: var(--gradient); 
  color: #fff; 
  font-weight: 800; 
  font-size: 13px; 
  line-height: 1; 
  min-width: 40px; 
}

/* Certifications page */
.tip { 
  display: flex; 
  align-items: center; 
  gap: 14px; 
  padding: 16px 18px; 
  border-radius: 16px; 
  border: 3px solid var(--border); 
  background: var(--bg-elevated);
  box-shadow: var(--shadow);
}
.tip .icon { 
  padding: 6px 10px;
  border-radius: 8px; 
  background: var(--gradient); 
  color: #fff; 
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 800; 
  font-size: 12px;
  letter-spacing: 0.05em;
  flex-shrink: 0;
}
.unit-chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 10px; }
.unit-chip { 
  display: inline-flex; 
  align-items: center; 
  gap: 8px; 
  padding: 8px 14px; 
  border-radius: 999px; 
  background: var(--panel); 
  border: 2px solid var(--border); 
  text-decoration: none; 
  color: var(--text); 
  font-weight: 700; 
  transition: background-color 150ms ease, color 150ms ease;
}
.unit-chip:hover {
  border-color: var(--primary);
  color: var(--primary);
}
.unit-chip .num { 
  width: 22px; 
  height: 22px; 
  border-radius: 50%; 
  background: var(--gradient); 
  color: #fff; 
  display: grid; 
  place-items: center; 
  font-size: 12px; 
  font-weight: 800;
}

/* Stagger helper */
.stagger > * { opacity: 0; transform: translateY(12px); }
.stagger.revealed > * { opacity: 1; transform: none; transition: opacity 300ms ease; }

/* Checklists */
.checklist { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.checklist li { 
  display: flex; 
  align-items: flex-start; 
  gap: 12px; 
  padding: 14px 16px; 
  border: 2px solid var(--border); 
  border-radius: 12px; 
  background: var(--panel); 
  box-shadow: var(--shadow);
  font-size: 17px;
  line-height: 1.6;
}
.checklist .icon { 
  width: 20px; 
  height: 20px; 
  border-radius: 50%; 
  background: var(--bg-elevated); 
  display: flex; 
  align-items: center;
  justify-content: center;
  color: var(--text); 
  font-weight: 600; 
  line-height: 1; 
  font-size: 12px; 
  flex-shrink: 0;
  margin-top: 2px;
  border: 1px solid var(--border);
}
.meta { display: inline-flex; gap: 10px; align-items: center; }
.pill { 
  display: inline-flex; 
  align-items: center; 
  gap: 4px; 
  padding: 4px 8px; 
  border-radius: 999px; 
  font-size: 11px; 
  border: 2px solid var(--border); 
  background: var(--bg-elevated); 
  color: var(--text); 
  font-weight: 600;
}
.pill .dot { width: 5px; height: 5px; border-radius: 50%; background: currentColor; opacity: .7; }

/* Testimonials */
.testimonials { 
  display: grid; 
  grid-template-columns: repeat(2, minmax(320px, 520px)); 
  gap: 20px; 
  justify-content: center; 
  justify-items: center; 
  max-width: 1120px; 
  margin-left: auto; 
  margin-right: auto; 
}
.testimonial { 
  position: relative; 
  padding: 32px; 
  border-radius: 20px; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  box-shadow: var(--shadow); 
  display: grid; 
  gap: 16px; 
  transition: all 0.3s ease;
}
.testimonial:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-strong);
  border-color: color-mix(in srgb, var(--primary) 30%, transparent);
}
.testimonial .who { display: flex; align-items: center; gap: 12px; }
.avatar { 
  width: 44px; 
  height: 44px; 
  border-radius: 50%; 
  background: var(--gradient); 
  color: #fff; 
  display: grid; 
  place-items: center; 
  font-weight: 800; 
  box-shadow: var(--shadow); 
  font-size: 18px;
}
.quote { 
  color: var(--text); 
  position: relative; 
  padding-left: 32px; 
  font-size: 17px;
  line-height: 1.6;
}
.quote::before { 
  content: "\201C"; 
  position: absolute; 
  left: 0; 
  top: -8px; 
  font-size: 40px; 
  color: color-mix(in srgb, var(--primary) 50%, var(--text)); 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.stars { color: #fbbf24; letter-spacing: 3px; font-size: 16px; }
.role { color: var(--muted); font-size: 13px; font-weight: 600; }

/* Certification badges */
.certs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.cert { 
  display: flex; 
  align-items: center; 
  gap: 12px; 
  padding: 14px 16px; 
  border-radius: 16px; 
  border: 3px solid var(--border); 
  background: var(--panel); 
  text-decoration: none; 
  color: var(--text); 
  box-shadow: var(--shadow);
  transition: box-shadow 200ms ease, border-color 200ms ease;
}
.cert:hover {
  box-shadow: var(--shadow-strong);
}
.cert .badge { 
  min-width: 36px; 
  height: 36px; 
  border-radius: 10px; 
  background: var(--gradient); 
  color: #fff; 
  display: grid; 
  place-items: center; 
  font-weight: 800; 
  font-size: 16px;
}

@media (max-width: 980px) {
  .testimonials { grid-template-columns: 1fr; }
  .certs { grid-template-columns: 1fr 1fr; }
}

/* About page */
.about-grid { grid-template-columns: 1.1fr 1.1fr; gap: 24px; }
.about-grid .feature { padding: 24px; }
.about-header { 
  display: flex; 
  align-items: center; 
  gap: 12px; 
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}

.about-header h3 {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-size: 22px;
  font-weight: 700;
  color: var(--text-strong);
  letter-spacing: -0.01em;
}
.profile { display: flex; align-items: center; gap: 18px; margin-bottom: 16px; }
.profile-photo { 
  width: 140px; 
  height: 140px; 
  object-fit: cover; 
  border-radius: 20px; 
  border: 4px solid var(--border); 
  box-shadow: var(--shadow-strong); 
}
/* Co-founders Section */
/* Mission Statement */
.mission-statement {
  max-width: 1000px;
  margin: 0 auto 0 auto;
  padding: 24px 36px;
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  text-align: center;
  position: relative;
  overflow: hidden;
}


.mission-title {
  margin: 0 0 16px 0;
  font-size: clamp(26px, 3.5vw, 32px);
  font-weight: 700;
  color: var(--primary);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  letter-spacing: -0.02em;
}

.mission-text {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-strong);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-weight: 400;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

@media (max-width: 768px) {
  .mission-statement {
    padding: 36px 28px;
  }
  
  .mission-text {
    font-size: 17px;
    line-height: 1.7;
  }
  
  .mission-title {
    margin-bottom: 20px;
  }
}

.founder-section {
  margin-bottom: 32px;
}

/* Team Disclaimer */
.team-disclaimer {
  max-width: 900px;
  margin: 16px auto 32px auto;
  padding: 20px 28px;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 12px;
  text-align: center;
}

.team-disclaimer p {
  margin: 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
}

.team-disclaimer strong {
  color: var(--text-strong);
  font-weight: 600;
}

/* Co-founders Layout */
.cofounders-layout {
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.cofounders-cards-wrapper {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  max-width: 1200px;
  margin: 0 auto 24px auto;
  align-items: start;
  transition: grid-template-columns 0.3s ease;
}

.prahas-card {
  grid-column: 1 / -1;
  max-width: 600px;
  margin: 0 auto;
  transition: all 0.5s ease-in-out;
}

.cofounders-layout.details-expanded .cofounders-cards-wrapper {
  grid-template-columns: 1fr;
}

.founder-card-wrapper {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.adam-card {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.ritesh-card {
  transition: all 0.5s ease-in-out;
}

.ritesh-card-expanded {
  display: none;
  max-width: 600px;
  margin: 0 auto;
  transition: all 0.5s ease-in-out;
}

.cofounders-layout.details-expanded .ritesh-card,
.cofounders-layout.details-expanded .prahas-card {
  opacity: 0;
  height: 0;
  overflow: hidden;
  pointer-events: none;
  transition: opacity 0.5s ease-in-out, height 0.5s ease-in-out;
}

.cofounders-layout.details-expanded .ritesh-card-expanded {
  display: block;
  animation: slideDown 0.5s ease;
}

.cofounders-layout.ritesh-details-expanded .adam-card,
.cofounders-layout.ritesh-details-expanded .prahas-card {
  opacity: 0;
  height: 0;
  overflow: hidden;
  pointer-events: none;
  transition: opacity 0.5s ease-in-out, height 0.5s ease-in-out;
}

.cofounders-layout.ritesh-details-expanded {
  grid-template-columns: 1fr;
  transition: grid-template-columns 0.5s ease-in-out;
}

.cofounders-layout.prahas-details-expanded .adam-card,
.cofounders-layout.prahas-details-expanded .ritesh-card {
  opacity: 0;
  height: 0;
  overflow: hidden;
  pointer-events: none;
  transition: opacity 0.5s ease-in-out, height 0.5s ease-in-out;
}

.cofounders-layout.prahas-details-expanded {
  grid-template-columns: 1fr;
  transition: grid-template-columns 0.5s ease-in-out;
}

.cofounders-layout.prahas-details-expanded .prahas-card {
  max-width: 600px;
  margin: 0 auto;
  transition: all 0.5s ease-in-out;
  animation: slideDown 0.5s ease;
}

.prahas-details-side {
  margin-top: 24px;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease;
}

.cofounders-layout.prahas-details-expanded .prahas-details-side {
  margin-top: 0;
  margin-bottom: 32px;
}

.cofounders-layout.ritesh-details-expanded .cofounders-cards-wrapper {
  grid-template-columns: 1fr;
  max-width: 600px;
  margin: 0 auto 24px auto;
}

.cofounders-layout.ritesh-details-expanded .ritesh-card {
  max-width: 600px;
  margin: 0 auto;
  transition: all 0.5s ease-in-out;
  animation: slideDown 0.5s ease;
}

.cofounders-layout.ritesh-details-expanded .founder-card-wrapper.ritesh-card {
  max-width: 600px;
  margin: 0 auto;
  width: 100%;
}

.ritesh-card-wrapper-expanded {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.founder-details {
  max-width: 1200px;
  margin: 0 auto;
}

.cofounders-layout.details-expanded .founder-details {
  margin-top: 0;
  margin-bottom: 32px;
}

.ritesh-details {
  margin-top: 32px;
  max-width: 1200px;
  margin: 32px auto 0 auto;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease;
}

.ritesh-details-side {
  margin-top: 24px;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease;
}

.cofounders-layout.ritesh-details-expanded .ritesh-details-side {
  margin-top: 0;
  margin-bottom: 32px;
}

@media (max-width: 768px) {
  .cofounders-cards-wrapper {
    grid-template-columns: 1fr;
  }
  
  .cofounders-layout.details-expanded .cofounders-cards-wrapper {
    grid-template-columns: 1fr;
  }
}

.details-toggle-wrapper {
  width: 100%;
  margin: 0;
  display: flex;
  justify-content: center;
  align-self: flex-end;
}

.details-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 24px;
  background: var(--primary);
  color: white;
  border: 2px solid var(--primary);
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-size: 16px;
  font-weight: 600;
  min-width: 200px;
}

.details-toggle:hover {
  background: var(--primary-strong);
  border-color: var(--primary-strong);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.details-toggle .dropdown-arrow {
  transition: transform 0.3s ease;
  flex-shrink: 0;
  color: white;
}

.details-toggle .dropdown-arrow.rotated {
  transform: rotate(180deg);
}

.founder-details {
  animation: slideDown 0.3s ease;
}

.cofounders-section {
  margin-bottom: 48px;
}

.cofounders-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 32px;
  max-width: 1000px;
  margin: 0 auto;
}

.section-title {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  color: var(--text-strong);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.about-card { 
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 20px; 
  padding: 32px 24px 24px 24px; 
  border-radius: 24px; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.about-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.about-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-strong);
  border-color: var(--primary);
}

.about-card:hover::before {
  opacity: 1;
}

.about-avatar { 
  width: 160px; 
  height: 160px; 
  border-radius: 50%; 
  overflow: hidden; 
  border: 4px solid var(--primary); 
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  flex-shrink: 0;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
}

.about-card:hover .about-avatar {
  transform: scale(1.05);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.2);
}

.about-avatar img { 
  width: 100%; 
  height: 100%; 
  object-fit: cover; 
  display: block;
  transition: transform 0.3s ease;
}

.about-card:hover .about-avatar img {
  transform: scale(1.05);
}

.about-meta { 
  display: grid; 
  gap: 8px;
  width: 100%;
}

.cofounder-name {
  margin: 0;
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  color: var(--text-strong);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  letter-spacing: -0.01em;
}

.cofounder-title {
  color: var(--primary);
  font-weight: 600;
  font-size: 18px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.about-meta .sub { 
  color: var(--muted); 
  font-size: 17px;
  margin-top: 4px;
}

.cofounder-bio {
  margin: 12px 0 0;
  color: var(--text);
  font-size: 17px;
  line-height: 1.6;
  max-width: 100%;
}

/* Academics Dropdown */
.academics-dropdown {
  width: 100%;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 2px solid var(--border);
}

.academics-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-strong);
}

.academics-toggle:hover {
  background: var(--panel);
  border-color: var(--primary);
  transform: translateY(-1px);
}

.academics-toggle span {
  flex: 1;
  text-align: left;
}

.dropdown-arrow {
  transition: transform 0.3s ease;
  flex-shrink: 0;
  margin-left: 12px;
  color: var(--primary);
}

.academics-toggle[aria-expanded="true"] .dropdown-arrow {
  transform: rotate(180deg);
}

.academics-toggle .dropdown-arrow.rotated {
  transform: rotate(180deg);
}

.academics-content {
  margin-top: 16px;
  padding: 20px 20px 16px 20px;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 16px;
  animation: slideDown 0.3s ease;
}

.academics-content .muted {
  margin-bottom: 0;
  padding-bottom: 0;
}

/* Certifications Horizontal Box */
.certifications-box {
  margin-top: 40px;
  padding: 28px;
  background: var(--panel);
  border: 3px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.certifications-title {
  margin: 0 0 20px 0;
  font-size: 24px;
  font-weight: 700;
  color: var(--text-strong);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}

.certifications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.cert-item {
  padding: 16px;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 12px;
  transition: all 0.2s ease;
}

.cert-item:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.cert-item h4 {
  margin: 0 0 6px 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-strong);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
}

.cert-item p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.4;
}

@media (max-width: 768px) {
  .certifications-grid {
    grid-template-columns: 1fr;
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.page-about .section { padding: 24px 0; }
.page-about .section:first-of-type { padding-top: 24px; }
.page-about .section:has(.mission-statement) { padding-bottom: 0 !important; }
.page-about .section#about-cofounders { padding-top: 0 !important; }

.page-about .features-grid {
  margin-top: 24px;
}

.page-about .feature {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about .feature:hover {
  transform: translateY(-2px);
}

.page-about .feature p {
  font-size: 17px;
  line-height: 1.6;
}

.page-about .feature h4 {
  font-size: 19px;
}

.page-about .feature .muted {
  font-size: 16px;
}

.page-about .feature > *:last-child,
.page-about .feature .badge-list:last-child,
.page-about .feature .checklist:last-child,
.page-about .feature .stack-16:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
}

.page-about .feature .stack-16 > div:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
}

.contact-section {
  background: var(--bg-elevated);
  border-radius: 16px;
  padding: 24px !important;
}

.contact-section .text-link {
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  transition: color 0.2s ease;
}

.contact-section .text-link:hover {
  color: var(--primary-strong);
  text-decoration: underline;
}

@media (max-width: 768px) {
  .cofounders-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .about-card {
    padding: 24px 20px;
  }
  
  .about-avatar {
    width: 140px;
    height: 140px;
  }
}
.projects-gallery { 
  display: grid; 
  grid-template-columns: repeat(2, minmax(280px, 1fr)); 
  gap: 16px; 
  margin-top: 16px; 
  justify-content: center; 
}
.projects-gallery figure { 
  margin: 0; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 16px; 
  overflow: hidden; 
  box-shadow: var(--shadow); 
  display: grid; 
  grid-template-rows: 1fr auto; 
  height: 240px; 
  max-width: 380px; 
  transition: box-shadow 200ms ease, border-color 200ms ease;
}
.projects-gallery figure:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-strong);
  border-color: var(--primary);
}
.projects-gallery img { width: 100%; height: 100%; object-fit: cover; display: block; }
.projects-gallery figcaption { 
  padding: 10px 12px; 
  font-size: 13px; 
  color: var(--muted); 
  background: var(--bg-elevated); 
  font-weight: 600;
}

@media (max-width: 980px) { 
  .projects-gallery { grid-template-columns: 1fr 1fr; justify-content: center; } 
}

.stat-row { 
  display: grid; 
  grid-template-columns: repeat(2, minmax(0,1fr)); 
  gap: 16px; 
  margin: 16px 0 12px; 
}
.stat-row.single { grid-template-columns: 1fr; justify-items: center; }
.stat-row.single .stat { max-width: 440px; width: 100%; }
.stat { 
  background: var(--bg-elevated); 
  border: 2px solid var(--border); 
  border-radius: 16px; 
  padding: 20px 16px; 
  text-align: center;
  box-shadow: var(--shadow);
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  opacity: 0;
  transition: opacity 0.2s ease;
}

.stat:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.stat:hover::before {
  opacity: 1;
}

.stat .label { 
  color: var(--muted); 
  font-size: 13px; 
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 8px;
}
.stat .value { 
  font-size: 28px; 
  font-weight: 800; 
  letter-spacing: -0.02em; 
  color: var(--text-strong);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, sans-serif;
}
.badge-list { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; margin-bottom: 0; }
.badge-chip { 
  display: inline-flex; 
  align-items: center; 
  gap: 8px; 
  padding: 10px 16px; 
  border-radius: 999px;
  font-size: 16px; 
  background: var(--panel); 
  border: 2px solid var(--border); 
  font-size: 13px; 
  font-weight: 600;
}
.badge-chip .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--primary); }

@media (max-width: 980px) {
  .about-grid { grid-template-columns: 1fr; }
}

/* Course layout (Khan-style) */
.layout-course { 
  display: grid; 
  grid-template-columns: 260px 1fr; 
  gap: 32px;
  max-width: 100%;
  margin: 0;
  padding: 0 32px 0 24px;
  position: relative;
}

/* Sidebar with spacing from left */
.course-sidebar {
  position: sticky;
  top: 80px;
  align-self: start;
  width: 260px;
  max-width: 260px;
}

/* Content area stretches */
.course-main {
  width: 100%;
  max-width: none;
}

/* Wider content on large screens */
@media (min-width: 1400px) {
  .layout-course {
    grid-template-columns: 240px 1fr;
    gap: 40px;
    padding: 0 32px 0 24px;
    max-width: 100%;
  }
  
  .course-sidebar {
    width: 240px;
    max-width: 240px;
  }
  
  .course-main {
    width: 100%;
    max-width: none;
  }
  
  .course-main .lesson-content {
    max-width: none;
    margin: 0;
    width: 100%;
  }
}

@media (min-width: 1600px) {
  .layout-course {
    grid-template-columns: 220px 1fr;
    gap: 48px;
    padding: 0 32px 0 24px;
    max-width: 100%;
  }
  
  .course-sidebar {
    width: 220px;
    max-width: 220px;
  }
  
  .course-main {
    width: 100%;
    max-width: none;
  }
  
  .course-main .lesson-content {
    max-width: none;
    margin: 0;
    width: 100%;
  }
}
.course-sidebar { 
  position: sticky; 
  top: 80px; 
  align-self: start; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  border-radius: 20px; 
  box-shadow: var(--shadow); 
  padding: 16px; 
  height: fit-content;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  overflow-x: hidden;
  width: 100%;
  max-width: 260px;
}

@media (min-width: 1400px) {
  .course-sidebar {
    max-width: 240px;
  }
}

@media (min-width: 1600px) {
  .course-sidebar {
    max-width: 220px;
  }
}
.course-sidebar h3 { 
  margin: 0 0 12px; 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif; 
  font-weight: 700;
  position: sticky;
  top: 0;
  background: var(--panel);
  z-index: 1;
  padding-bottom: 8px;
}
.course-sidebar nav {
  overflow: visible;
}
.course-sidebar nav ul { 
  list-style: none; 
  padding: 0; 
  margin: 0; 
  display: grid; 
  gap: 6px;
  overflow: visible;
}

/* Custom scrollbar for course sidebar */
.course-sidebar::-webkit-scrollbar {
  width: 8px;
}
.course-sidebar::-webkit-scrollbar-track {
  background: transparent;
  border-radius: 10px;
}
.course-sidebar::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 10px;
}
.course-sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--muted);
}
.course-sidebar nav li {
  display: flex;
  align-items: center;
}
.course-sidebar nav a { 
  display: flex; 
  align-items: center;
  padding: 10px 12px 10px 16px; 
  border-radius: 12px; 
  color: var(--text); 
  text-decoration: none; 
  font-weight: 600;
  transition: background-color 150ms ease, color 150ms ease;
  flex: 1;
  position: relative;
  /* Prevent invisible clickable areas */
  min-width: 0;
  max-width: 100%;
}
.course-sidebar nav a::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  border: 1.5px solid var(--border);
  margin-right: 10px;
  flex-shrink: 0;
  display: inline-block;
  vertical-align: middle;
  position: relative;
}
.course-sidebar nav a:hover { background: var(--bg-elevated); }
.course-sidebar nav a.active { 
  background: color-mix(in srgb, var(--primary) 14%, transparent); 
  color: var(--primary); 
  font-weight: 700; 
  border: 2px solid color-mix(in srgb, var(--primary) 20%, transparent);
}
.course-main { 
  background: transparent; 
  max-width: none;
  width: 100%;
}

.sidebar-toggle { display: none; }

/* Collapsible sidebar */
.sidebar-closed .course-sidebar { transform: translateX(-300px); opacity: 0; pointer-events: none; }
.sidebar-closed .layout-course { grid-template-columns: 0 1fr; }
.sidebar-toggle-btn { 
  display: inline-flex; 
  align-items: center; 
  gap: 8px; 
  padding: 10px 14px; 
  border: 3px solid var(--border); 
  border-radius: 12px; 
  background: var(--panel); 
  cursor: pointer; 
  font-weight: 600;
  transition: background-color 150ms ease, color 150ms ease;
}
.sidebar-toggle-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

@media (max-width: 980px) {
  .layout-course { grid-template-columns: 1fr; }
  .course-sidebar { 
    position: fixed; 
    left: 16px; 
    right: 16px; 
    top: 76px; 
    z-index: 60; 
    transform: translateY(-120%); 
    transition: transform 250ms ease;
    /* Prevent clicks when hidden */
    pointer-events: none;
  }
  .sidebar-open .course-sidebar { 
    transform: none;
    pointer-events: auto;
  }
  .sidebar-toggle { display: block; margin-bottom: 12px; }
  
  /* Ensure sidebar links don't create invisible clickable areas */
  .course-sidebar nav a {
    flex: none;
    width: 100%;
    box-sizing: border-box;
  }
}

/* Lesson overview box */
.lesson-overview { 
  position: relative; 
  padding: 20px; 
  border-radius: 20px; 
  background: var(--panel); 
  border: 3px solid var(--border); 
  box-shadow: var(--shadow); 
  overflow: hidden; 
  margin-bottom: 24px;
}
.lesson-overview::before { 
  content: ""; 
  position: absolute; 
  inset: 0 0 auto 0; 
  height: 6px; 
  background: var(--gradient); 
  opacity: 1; 
}
.lesson-overview h2 { 
  margin: 4px 0 10px; 
  font-size: 20px; 
  letter-spacing: -0.01em; 
  color: var(--text-strong); 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}
.lesson-overview p { margin: 0; color: var(--text); line-height: 1.7; }
.lesson-overview .pill { 
  display: inline-flex; 
  align-items: center; 
  gap: 8px; 
  padding: 6px 12px; 
  border-radius: 999px; 
  background: color-mix(in srgb, var(--primary) 14%, transparent); 
  color: var(--primary); 
  font-weight: 700; 
  font-size: 13px; 
  margin-top: 12px;
}

/* Lesson header */
.lesson-head { display: flex; align-items: center; gap: 16px; margin-bottom: 10px; }
.icon-circle { 
  width: 44px; 
  height: 44px; 
  border-radius: 50%; 
  background: var(--bg-elevated); 
  border: 3px solid var(--border);
  display: grid; 
  place-items: center; 
}
.icon-circle span { font-weight: 800; color: var(--primary); font-size: 18px; }
.lesson-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.lesson-actions { display: flex; gap: 12px; margin-top: 16px; }

/* Next/Prev sticky bar */
.lesson-nav { 
  position: sticky; 
  bottom: 20px; 
  display: flex; 
  justify-content: space-between; 
  gap: 12px; 
  margin-top: 20px; 
  z-index: 10;
}

/* Lesson entrance */
.lesson-overview { transform: translateY(8px); opacity: .98; animation: lessonIn .4s ease both; }
@keyframes lessonIn { from { transform: translateY(16px); opacity: 0; } }

/* Lesson Content Styles */
.lesson-content {
  margin-top: 40px;
  line-height: 1.8;
  max-width: none;
  width: 100%;
}

.content-section {
  margin-bottom: 56px;
  padding: 32px;
  background: var(--panel);
  border-radius: 20px;
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
}

.content-section:last-child {
  margin-bottom: 0;
}

.text-center {
  text-align: center;
}

.lesson-content > .content-section:first-child {
  background: linear-gradient(135deg, var(--panel) 0%, color-mix(in srgb, var(--primary) 5%, var(--panel)) 100%);
  border: 3px solid var(--primary);
  position: relative;
  overflow: hidden;
}

.lesson-content > .content-section:first-child::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient);
}

.lesson-content h2 {
  font-size: 28px;
  font-weight: 800;
  margin: 0 0 20px 0;
  color: var(--text-strong);
  line-height: 1.2;
  letter-spacing: -0.02em;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.content-section h2 {
  margin-top: 0;
}

.lesson-content h3 {
  font-size: 22px;
  font-weight: 700;
  margin: 32px 0 16px 0;
  color: var(--text-strong);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.lesson-content h4 {
  font-size: 18px;
  font-weight: 600;
  margin: 24px 0 12px 0;
  color: var(--text-strong);
}

.lesson-content p {
  margin: 0 0 20px 0;
  color: var(--text);
  line-height: 1.85;
  font-size: 16px;
}

.content-section p:last-child {
  margin-bottom: 0;
}

.lesson-content ul, .lesson-content ol {
  margin: 16px 0;
  padding-left: 24px;
}

.lesson-content li {
  margin: 8px 0;
  line-height: 1.7;
  color: var(--text);
}

.lesson-content strong {
  color: var(--text-strong);
  font-weight: 600;
}

/* Practice Boxes */
.practice-box {
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 10%, var(--panel)) 0%, var(--panel) 100%);
  border: 3px solid var(--primary);
  border-left: 8px solid var(--primary);
  border-radius: 20px;
  padding: 32px;
  margin: 40px 0;
  box-shadow: 0 8px 24px color-mix(in srgb, var(--primary) 20%, transparent);
  position: relative;
  overflow: hidden;
}

.practice-box::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, color-mix(in srgb, var(--primary) 15%, transparent) 0%, transparent 70%);
  pointer-events: none;
}

.practice-box.interactive {
  background: var(--panel);
  border: 3px solid var(--primary);
  box-shadow: 0 8px 32px color-mix(in srgb, var(--primary) 15%, transparent);
}

.practice-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
  position: relative;
  z-index: 1;
}

.practice-header h4 {
  margin: 0;
  color: var(--primary);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.practice-badge {
  background: var(--gradient);
  color: white;
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  box-shadow: 0 2px 8px color-mix(in srgb, var(--primary) 30%, transparent);
}

.practice-box p {
  margin: 0 0 16px 0;
}

.practice-box p:last-child {
  margin-bottom: 0;
}

.reflection-prompt {
  background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 12%, var(--panel)) 0%, var(--panel) 100%);
  padding: 18px 20px;
  border-radius: 12px;
  border-left: 5px solid var(--accent);
  margin: 20px 0;
  font-style: italic;
  font-size: 17px;
  line-height: 1.6;
  box-shadow: 0 2px 8px color-mix(in srgb, var(--accent) 10%, transparent);
}

.reflection-input {
  width: 100%;
  min-height: 140px;
  padding: 18px;
}

.exercise-section {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 3px solid var(--border);
}

.exercise-item {
  margin-bottom: 32px;
  padding: 24px;
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 16px;
}

.exercise-item h3 {
  color: var(--text-strong);
  margin-bottom: 12px;
  font-size: 20px;
  font-weight: 700;
}

.exercise-actions {
  display: flex;
  gap: 12px;
  margin-top: 20px;
  flex-wrap: wrap;
  align-items: center;
}

.exercise-actions .btn {
  padding: 10px 20px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
  z-index: 10;
  pointer-events: auto;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.exercise-actions .btn-save {
  background: var(--primary);
  color: white;
  border: 2px solid var(--primary);
}

.exercise-actions .btn-save:hover {
  background: var(--primary-strong);
  border-color: var(--primary-strong);
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.exercise-actions .btn-show-answer {
  background: var(--bg-elevated);
  color: var(--text);
  border: 2px solid var(--border);
}

.exercise-actions .btn-show-answer:hover {
  background: var(--border);
  border-color: var(--muted);
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

.saved-indicator {
  margin-left: 10px;
  color: var(--accent);
  font-weight: 600;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.saved-indicator.show {
  opacity: 1;
}

.correct-answer {
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 15px 20px;
  margin-top: 20px;
  display: none;
  flex-direction: column;
  gap: 10px;
}

.correct-answer.show {
  display: flex;
}

.correct-answer h4 {
  color: var(--primary);
  margin: 0;
  font-size: 18px;
}

.correct-answer-content {
  font-family: monospace;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--text-strong);
  font-size: 14px;
}

.answer-feedback {
  margin-top: 15px;
  padding: 10px 15px;
  border-radius: 8px;
  font-weight: 600;
  display: none;
  align-items: center;
  gap: 8px;
}

.answer-feedback.show {
  display: flex;
}

.answer-feedback.match {
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  color: var(--accent-strong);
  border: 1px solid var(--accent);
}

.answer-feedback.no-match {
  background: color-mix(in srgb, var(--primary) 15%, transparent);
  color: var(--primary-strong);
  border: 1px solid var(--primary);
}

.reflection-input {
  width: 100%;
  min-height: 140px;
  padding: 18px;
  border: 2px solid var(--border);
  border-radius: 12px;
  font-family: Inter, sans-serif;
  font-size: 15px;
  line-height: 1.7;
  background: var(--panel);
  color: var(--text);
  resize: vertical;
  margin: 16px 0;
  transition: opacity 200ms ease, background-color 200ms ease;
}

.reflection-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 15%, transparent), 0 4px 12px color-mix(in srgb, var(--primary) 10%, transparent);
  transform: translateY(-1px);
}

.hint-text {
  font-size: 13px;
  color: var(--muted);
  margin-top: 8px;
  font-style: italic;
}

/* Exercise Section */
.exercise-section {
  background: linear-gradient(135deg, var(--panel) 0%, color-mix(in srgb, var(--accent) 6%, var(--panel)) 100%);
  border: 3px solid var(--accent);
  border-radius: 24px;
  padding: 40px;
  margin: 56px 0;
  box-shadow: 0 12px 40px color-mix(in srgb, var(--accent) 15%, transparent);
  position: relative;
  overflow: hidden;
}

.exercise-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: var(--gradient-soft);
}

.exercise-section h3 {
  margin-top: 0;
  color: var(--accent);
  font-size: 28px;
  margin-bottom: 32px;
  font-weight: 800;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 12px;
}

.exercise-section h3::before {
  content: "";
  width: 40px;
  height: 40px;
  background: var(--gradient-soft);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
}

.exercise-item {
  margin-bottom: 40px;
  padding: 28px;
  background: var(--panel);
  border-radius: 16px;
  border: 2px solid var(--border);
  box-shadow: 0 4px 12px color-mix(in srgb, var(--text) 5%, transparent);
  transition: opacity 200ms ease, background-color 200ms ease;
}

.exercise-item:hover {
  border-color: var(--accent);
  box-shadow: 0 6px 20px color-mix(in srgb, var(--accent) 15%, transparent);
  transform: translateY(-2px);
}

.exercise-item:last-child {
  margin-bottom: 0;
}

.exercise-item h4 {
  color: var(--text-strong);
  margin-bottom: 16px;
  font-size: 20px;
  font-weight: 700;
}

/* Info Callout */
.info-callout {
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 12%, var(--panel)) 0%, var(--panel) 100%);
  border-left: 5px solid var(--primary);
  border-radius: 12px;
  padding: 20px 24px;
  margin: 24px 0;
  box-shadow: 0 4px 12px color-mix(in srgb, var(--primary) 10%, transparent);
  border: 2px solid color-mix(in srgb, var(--primary) 20%, transparent);
}

.info-callout p {
  margin: 0 0 8px 0;
  color: var(--text);
  line-height: 1.7;
}

.info-callout p:last-child {
  margin-bottom: 0;
}

.info-callout ul {
  margin: 8px 0 0 0;
  padding-left: 24px;
}

.info-callout li {
  margin: 6px 0;
  line-height: 1.6;
}

/* Tables */
.lesson-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 32px 0;
  background: var(--panel);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 6px 20px color-mix(in srgb, var(--text) 8%, transparent);
  border: 2px solid var(--border);
}

.lesson-content table th {
  background: linear-gradient(135deg, var(--bg-elevated) 0%, color-mix(in srgb, var(--primary) 10%, var(--bg-elevated)) 100%);
  padding: 16px 20px;
  text-align: left;
  font-weight: 700;
  color: var(--text-strong);
  border-bottom: 3px solid var(--primary);
  font-size: 15px;
  letter-spacing: 0.3px;
}

.lesson-content table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  line-height: 1.6;
}

.lesson-content table tr:last-child td {
  border-bottom: none;
}

.lesson-content table tr:hover {
  background: color-mix(in srgb, var(--primary) 5%, var(--panel));
  transform: scale(1.01);
  transition: background-color 150ms ease, color 150ms ease;
}

/* Code blocks in lesson content */
.lesson-content pre.code {
  margin: 20px 0;
}

.lesson-content pre.code code {
  padding: 16px 20px;
  font-size: 14px;
  line-height: 1.6;
  background: var(--bg-elevated) !important;
  color: var(--text) !important;
}

.lesson-content code:not(pre code) {
  background: var(--bg-elevated);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.9em;
  color: var(--primary);
  border: 1px solid var(--border);
}

/* Interactive Code Editor */
.interactive-editor {
  margin: 24px 0;
  border: 3px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  background: var(--panel);
  box-shadow: 0 4px 16px color-mix(in srgb, var(--text) 6%, transparent);
}

.editor-toolbar-small {
  display: flex;
  gap: 10px;
  padding: 14px 16px;
  background: linear-gradient(135deg, var(--bg-elevated) 0%, color-mix(in srgb, var(--primary) 8%, var(--bg-elevated)) 100%);
  border-bottom: 2px solid var(--border);
}

.btn-run, .btn-reset, .btn-check, .btn-solution {
  padding: 10px 20px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: var(--panel);
  color: var(--text);
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
  transition: opacity 200ms ease, background-color 200ms ease;
  font-family: Inter, sans-serif;
  letter-spacing: 0.3px;
  position: relative;
  z-index: 10;
  pointer-events: auto;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.btn-run {
  background: var(--gradient);
}

.btn-check {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border-color: #10b981;
}

.btn-check:hover {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-solution {
  background: var(--bg-elevated);
  color: var(--text);
  border-color: var(--border);
}

.btn-solution:hover {
  background: var(--panel);
  border-color: var(--primary);
}

.exercise-feedback {
  margin-top: 16px;
  padding: 16px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.6;
  display: none;
}

.exercise-feedback.show {
  display: block;
}

.exercise-feedback.correct {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(5, 150, 105, 0.1) 100%);
  border: 2px solid #10b981;
  color: #059669;
}

.exercise-feedback.incorrect {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.1) 0%, rgba(220, 38, 38, 0.1) 100%);
  border: 2px solid #ef4444;
  color: #dc2626;
}

.exercise-feedback h5 {
  margin: 0 0 8px 0;
  font-size: 16px;
  font-weight: 700;
}

.exercise-feedback.correct h5 {
  color: #059669;
}

.exercise-feedback.incorrect h5 {
  color: #dc2626;
}

.exercise-feedback ul {
  margin: 8px 0 0 20px;
  padding: 0;
}

.exercise-feedback li {
  margin: 4px 0;
}

.btn-run:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px color-mix(in srgb, var(--primary) 40%, transparent);
}

.btn-reset:hover {
  background: var(--bg-elevated);
  border-color: var(--primary);
  transform: translateY(-1px);
}

.btn-clear {
  padding: 10px 20px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: var(--panel);
  color: var(--muted);
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  transition: opacity 200ms ease, background-color 200ms ease;
  font-family: Inter, sans-serif;
  letter-spacing: 0.3px;
}

.btn-clear:hover {
  background: var(--bg-elevated);
  border-color: var(--muted);
  color: var(--text);
  transform: translateY(-1px);
}

.btn-clear-small {
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-elevated);
  color: var(--muted);
  font-weight: 600;
  font-size: 12px;
  cursor: pointer;
  transition: background-color 150ms ease, color 150ms ease;
  font-family: Inter, sans-serif;
  margin-top: 8px;
  display: inline-block;
}

.btn-clear-small:hover {
  background: var(--panel);
  border-color: var(--muted);
  color: var(--text);
}

.code-editor-small {
  width: 100%;
  min-height: 150px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 14px;
  border: none;
  padding: 16px;
  background: var(--bg-elevated);
  color: var(--text);
  resize: vertical;
}

.editor-output {
  min-height: 70px;
  padding: 18px 20px;
  background: var(--bg);
  border-top: 2px solid var(--border);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 13px;
  line-height: 1.6;
}

.output-placeholder {
  color: var(--muted);
  font-style: italic;
  text-align: center;
  padding: 12px;
}

.output-loading {
  color: var(--primary);
  text-align: center;
  padding: 12px;
}

.output-line {
  margin-bottom: 8px;
}

.output-label {
  font-weight: 700;
  color: var(--primary);
  margin-right: 8px;
}

.output-text {
  color: var(--text);
  margin: 4px 0 0 0;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: inherit;
}

.output-line.error .output-label {
  color: #ef4444;
}

.output-line.error .output-text {
  color: #ef4444;
}

.output-error {
  color: #ef4444;
  text-align: center;
  padding: 12px;
}

/* Code Example Box */
.code-example {
  margin: 28px 0;
  border: 3px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  background: var(--panel);
  box-shadow: 0 4px 16px color-mix(in srgb, var(--text) 8%, transparent);
}

.code-example pre.code,
.code-example pre.code code {
  background: var(--bg-elevated) !important;
  color: var(--text) !important;
}

.code-header {
  background: linear-gradient(135deg, var(--bg-elevated) 0%, color-mix(in srgb, var(--primary) 8%, var(--bg-elevated)) 100%);
  padding: 12px 20px;
  font-size: 12px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 1px;
  border-bottom: 2px solid var(--border);
  display: flex;
  align-items: center;
  gap: 8px;
}

.code-header::before {
  content: "";
  font-size: 10px;
}

/* Info Cards */
.info-card {
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 12%, var(--panel)) 0%, color-mix(in srgb, var(--accent) 8%, var(--panel)) 100%);
  border: 2px solid var(--primary);
  border-left: 6px solid var(--primary);
  border-radius: 16px;
  padding: 24px;
  margin: 24px 0;
  box-shadow: 0 4px 12px color-mix(in srgb, var(--primary) 15%, transparent);
  position: relative;
  overflow: hidden;
}

.info-card::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, color-mix(in srgb, var(--primary) 10%, transparent) 0%, transparent 70%);
  pointer-events: none;
}

.info-card h4 {
  margin: 0 0 12px 0;
  color: var(--primary);
  font-size: 20px;
  font-weight: 700;
  position: relative;
  z-index: 1;
}

.info-card p {
  margin: 0;
  color: var(--text);
  position: relative;
  z-index: 1;
  line-height: 1.7;
}

/* Uses Grid */
.uses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
  margin: 28px 0;
}

.use-item {
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  text-align: center;
  font-weight: 600;
  color: var(--text);
  transition: opacity 200ms ease, background-color 200ms ease;
  position: relative;
  overflow: hidden;
}

.use-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient);
  transform: scaleX(0);
  transition: transform 300ms ease;
}

.use-item:hover {
  border-color: var(--primary);
  background: color-mix(in srgb, var(--primary) 8%, var(--panel));
}

.use-item:hover::before {
  transform: scaleX(1);
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  margin: 32px 0;
}

.feature-card {
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  transition: box-shadow 200ms ease, border-color 200ms ease;
  position: relative;
  overflow: hidden;
}

.feature-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient);
  transform: scaleX(0);
  transition: transform 400ms ease;
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-strong);
}

.feature-card:hover::after {
  transform: scaleX(1);
}

.feature-card h4 {
  margin: 0 0 14px 0;
  color: var(--primary);
  font-size: 20px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.feature-card h4::before {
  content: "";
  color: var(--accent);
  font-weight: 800;
}

.feature-card p {
  margin: 0;
  color: var(--text);
  line-height: 1.7;
}

/* Process Steps */
.process-steps {
  margin: 32px 0;
  padding: 24px;
  background: var(--bg-elevated);
  border-radius: 16px;
  border: 2px solid var(--border);
}

.step {
  display: flex;
  gap: 24px;
  margin-bottom: 28px;
  align-items: flex-start;
  padding: 20px;
  background: var(--panel);
  border-radius: 12px;
  border: 2px solid var(--border);
  transition: opacity 200ms ease, background-color 200ms ease;
}

.step:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-strong);
}

.step:last-child {
  margin-bottom: 0;
}

.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 20px;
  flex-shrink: 0;
  box-shadow: 0 4px 12px color-mix(in srgb, var(--primary) 30%, transparent);
}

.step-content {
  flex: 1;
  padding-top: 4px;
}

.step-content h4 {
  margin: 0 0 8px 0;
  color: var(--text-strong);
  font-size: 19px;
  font-weight: 700;
}

.step-content p {
  margin: 0;
  color: var(--text);
  line-height: 1.7;
}

/* CodeMirror in lesson editors */
.interactive-editor .CodeMirror {
  border: none;
  border-radius: 0;
  height: 150px;
  font-size: 14px;
}

.interactive-editor .CodeMirror-scroll {
  min-height: 150px;
}

[data-theme="dark"] .interactive-editor .CodeMirror {
  background: var(--bg-elevated);
}

/* OS Tabs */
.os-tabs, .terminal-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  border-bottom: 2px solid var(--border);
}

.os-tab, .terminal-tab {
  padding: 12px 24px;
  border: none;
  background: transparent;
  color: var(--muted);
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  border-bottom: 3px solid transparent;
  transition: background-color 150ms ease, color 150ms ease;
  font-family: Inter, sans-serif;
  margin-bottom: -2px;
}

.os-tab:hover, .terminal-tab:hover {
  color: var(--text);
  background: var(--bg-elevated);
}

.os-tab.active, .terminal-tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.os-instructions, .terminal-instructions {
  display: none;
}

.os-instructions.active, .terminal-instructions.active {
  display: block;
}

.installation-steps, .terminal-guide {
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin: 24px 0;
}

.step-list {
  margin: 16px 0;
  padding-left: 24px;
}

.step-list li {
  margin: 12px 0;
  line-height: 1.7;
}

.important-box {
  background: color-mix(in srgb, var(--primary) 12%, var(--panel));
  border: 2px solid var(--primary);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 12px 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.important-box input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: not-allowed;
}

.important-box label {
  font-weight: 600;
  color: var(--text-strong);
  cursor: default;
}

/* Link Cards */
.link-card {
  background: var(--panel);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin: 20px 0;
  text-align: center;
}

.external-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--primary);
  text-decoration: none;
  font-size: 16px;
  font-weight: 600;
  padding: 12px 20px;
  background: color-mix(in srgb, var(--primary) 10%, transparent);
  border-radius: 8px;
  transition: background-color 150ms ease, color 150ms ease;
}

.external-link:hover {
  background: color-mix(in srgb, var(--primary) 15%, transparent);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px color-mix(in srgb, var(--primary) 20%, transparent);
}

.link-icon {
  font-size: 14px;
  opacity: 0.7;
}

.link-note {
  margin: 12px 0 0 0;
  font-size: 13px;
  color: var(--muted);
  font-style: italic;
}

/* Command Box */
.command-box {
  background: var(--bg-elevated);
  border: 2px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin: 16px 0;
}

.command-item {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  padding: 12px;
  background: var(--panel);
  border-radius: 8px;
}

.command-item:last-child {
  margin-bottom: 0;
}

.command-label {
  font-weight: 600;
  color: var(--text-strong);
  min-width: 80px;
}

.command {
  background: var(--bg);
  padding: 8px 12px;
  border-radius: 6px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 14px;
  color: var(--primary);
  border: 1px solid var(--border);
  flex: 1;
}

/* Success Box */
.success-box {
  background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 12%, var(--panel)) 0%, var(--panel) 100%);
  border: 2px solid var(--accent);
  border-left: 5px solid var(--accent);
  border-radius: 12px;
  padding: 20px;
  margin: 20px 0;
}

.success-box p {
  margin: 0 0 8px 0;
}

.success-box p:last-child {
  margin-bottom: 0;
  font-size: 14px;
  color: var(--muted);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  /* Improved button sizes for touch */
  .btn:not(.btn-small):not(.btn-run):not(.btn-reset):not(.btn-check):not(.btn-solution):not(.btn-clear):not(.btn-clear-small) {
    padding: 14px 20px;
    min-height: 44px;
    font-size: 16px;
    z-index: 100 !important;
    pointer-events: auto !important;
    position: relative;
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(14, 165, 233, 0.2);
  }
  
  /* Keep exercise buttons reasonable size */
  .exercise-actions .btn {
    padding: 12px 18px;
    min-height: 44px;
    font-size: 15px;
    z-index: 100 !important;
    pointer-events: auto !important;
    position: relative;
    touch-action: manipulation;
  }
  
  /* Code editor buttons */
  .btn-run, .btn-reset, .btn-check, .btn-solution {
    padding: 12px 18px;
    min-height: 44px;
    font-size: 14px;
    white-space: nowrap;
    flex-shrink: 0;
    z-index: 100 !important;
    pointer-events: auto !important;
    position: relative;
    touch-action: manipulation;
  }
  
  /* Ensure all buttons are clickable */
  button,
  button.btn,
  .btn[type="button"],
  input[type="button"],
  input[type="submit"],
  .btn-primary,
  .btn-ghost {
    z-index: 100 !important;
    pointer-events: auto !important;
    position: relative;
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(14, 165, 233, 0.2);
  }
  
  /* Button groups */
  .exercise-actions,
  .code-example-header,
  .interactive-editor-header {
    flex-wrap: wrap;
    gap: 8px;
    position: relative;
    z-index: 5;
  }
  
  .exercise-actions .btn,
  .code-example-header .btn,
  .interactive-editor-header .btn {
    flex: 1 1 auto;
    min-width: 0;
    z-index: 101 !important;
  }
  
  /* Prevent overlays from blocking buttons */
  .code-example-header,
  .interactive-editor-header,
  .practice-box,
  .lesson-nav {
    position: relative;
    z-index: 5;
  }
  
  /* Ensure buttons in these containers are above */
  .practice-box .btn,
  .lesson-nav .btn {
    z-index: 101 !important;
  }
  
  .primary-nav a, .primary-nav button {
    padding: 14px 16px;
    min-height: 44px;
  }
  
  /* Better spacing */
  .hero {
    padding: 40px 0 50px;
  }
  
  .subhead {
    font-size: 18px;
    line-height: 1.7;
  }
  
  .headline {
    font-size: clamp(32px, 8vw, 48px);
  }
  
  .feature-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .uses-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
  
  .practice-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .step {
    flex-direction: column;
    gap: 12px;
  }
  
  .step-number {
    align-self: flex-start;
  }
  
  /* Better input field sizes */
  input[type="text"],
  input[type="email"],
  input[type="number"],
  textarea,
  select {
    font-size: 16px;
    padding: 14px 16px;
    min-height: 44px;
  }
  
  /* Improved mobile menu */
  .primary-nav .menu {
    max-height: calc(100vh - 100px);
    overflow-y: auto;
  }
  
  /* Better code block readability */
  .code {
    font-size: 13px;
    padding: 16px;
    overflow-x: auto;
  }
  
  /* Improved card spacing */
  .feature {
    padding: 24px 20px;
  }
  
  .testimonial {
    padding: 24px 20px;
  }
  
  /* Better section spacing */
  .section {
    padding: 40px 0;
  }
  
  .section-head {
    margin-bottom: 32px;
  }
  
  /* Improved CTA buttons */
  .cta {
    flex-direction: column;
    gap: 12px;
  }
  
  .cta .btn {
    width: 100%;
    justify-content: center;
    max-width: 100%;
  }
  
  /* Lesson navigation buttons */
  .lesson-nav {
    flex-direction: column;
    gap: 12px;
  }
  
  .lesson-nav .btn {
    width: 100%;
    max-width: 100%;
  }
  
  /* Prevent zoom on input focus (iOS) */
  input[type="text"],
  input[type="email"],
  input[type="number"],
  textarea,
  select {
    font-size: 16px !important;
  }
  
  /* Prevent invisible clickable areas on mobile */
  /* Only make links clickable on their actual content area */
  nav a,
  .menu a,
  .course-sidebar nav a,
  .footer-links a {
    /* Don't expand beyond content */
    flex: none !important;
    width: auto !important;
    min-width: 0 !important;
    max-width: 100% !important;
    /* Reduce padding to make clickable area smaller */
    padding-left: 12px !important;
    padding-right: 12px !important;
  }
  
  /* Make breadcrumb links smaller and less clickable */
  nav[aria-label="Breadcrumb"] a {
    padding: 4px 6px !important;
    margin: 0 2px !important;
    display: inline-block !important;
    min-width: auto !important;
  }
  
  /* Ensure sidebar links don't create large clickable zones */
  .course-sidebar nav li {
    margin-bottom: 4px !important;
  }
  
  .course-sidebar nav a {
    padding: 8px 10px 8px 12px !important;
    margin: 0 !important;
    width: 100% !important;
    box-sizing: border-box !important;
  }
  
  /* Ensure hidden/transformed elements don't capture clicks */
  .course-sidebar:not(.sidebar-open) {
    pointer-events: none !important;
  }
  
  /* Prevent accidental clicks on navigation when scrolling */
  .primary-nav a,
  .primary-nav button {
    min-height: 44px !important;
    padding: 12px 14px !important;
  }
  
  /* Better badge spacing */
  .badges {
    gap: 8px;
  }
  
  .badge {
    padding: 10px 16px;
    font-size: 14px;
  }
  
  /* Improved lesson navigation */
  .lesson-nav {
    flex-direction: column;
    gap: 12px;
  }
  
  .lesson-nav .btn {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }
  
  /* Better table responsiveness */
  table {
    font-size: 14px;
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  /* Improved sidebar scrolling */
  .course-sidebar {
    max-height: calc(100vh - 120px);
  }

  .os-tabs, .terminal-tabs {
    flex-direction: column;
    gap: 4px;
  }

  .os-tab, .terminal-tab {
    width: 100%;
    text-align: left;
    border-bottom: 2px solid var(--border);
    border-radius: 8px 8px 0 0;
  }

  .os-tab.active, .terminal-tab.active {
    border-bottom-color: var(--border);
    border-bottom: 3px solid var(--primary);
  }
}

/* Breadcrumb navigation */
nav[aria-label="Breadcrumb"] {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  margin-bottom: 16px;
  padding: 8px 0;
  flex-wrap: wrap;
}

nav[aria-label="Breadcrumb"] a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: background-color 150ms ease, color 150ms ease;
  padding: 2px 4px;
  border-radius: 4px;
}

nav[aria-label="Breadcrumb"] a:hover {
  color: var(--primary-strong);
  background: color-mix(in srgb, var(--primary) 10%, transparent);
  text-decoration: underline;
}

nav[aria-label="Breadcrumb"] .separator {
  color: var(--muted);
  margin: 0 2px;
  font-weight: 400;
}

nav[aria-label="Breadcrumb"] .current {
  color: var(--text);
  font-weight: 500;
  pointer-events: none;
}

/* Lesson title styles */
.eyebrow { 
  text-transform: uppercase; 
  letter-spacing: .16em; 
  font-weight: 700; 
  font-size: 12px; 
  color: var(--muted); 
  margin-bottom: 6px; 
}
.lesson-title { 
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-size: 32px; 
  line-height: 1.15; 
  letter-spacing: -0.02em; 
  margin: 0 0 10px; 
  color: var(--text-strong);
}

/* Inline code */
code { 
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; 
  background: var(--bg-elevated); 
  border: 2px solid var(--border); 
  border-radius: 8px; 
  padding: 2px 8px; 
  font-size: .92em; 
  color: var(--primary-strong);
  font-weight: 600;
}

/* Settings implementations */

/* Compact layout */
body.compact-layout .section {
  padding: 40px 0;
}
body.compact-layout .panel-row {
  padding: 10px 12px;
}
body.compact-layout .feature,
body.compact-layout .unit-card {
  padding: 16px;
}
body.compact-layout .btn {
  padding: 10px 18px;
}
body.compact-layout .stack-16 > * + * { margin-top: 12px; }
body.compact-layout .stack-24 > * + * { margin-top: 16px; }

/* Focus mode - hide distracting elements */
body.focus-mode::before,
body.focus-mode::after {
  opacity: 0 !important;
  display: none !important;
}
body.focus-mode .hero .illustration,
body.focus-mode .orb {
  opacity: 0.05;
}
body.focus-mode .badge:not(.important),
body.focus-mode .feature .icon {
  opacity: 0.7;
}
body.focus-mode .site-footer {
  border-top: 1px solid var(--border);
}

/* Code editor theme */
pre.code[data-theme="light"],
[data-code-theme="light"] pre.code {
  background: #F8F9FA !important;
  color: #212529 !important;
  border-color: #DEE2E6 !important;
}
pre.code[data-theme="light"] code,
[data-code-theme="light"] pre.code code {
  background: transparent !important;
  border: none !important;
  color: #212529 !important;
}

pre.code[data-theme="dark"],
[data-code-theme="dark"] pre.code {
  background: #1E293B !important;
  color: #F1F5F9 !important;
  border-color: #334155 !important;
}
pre.code[data-theme="dark"] code,
[data-code-theme="dark"] pre.code code {
  background: transparent !important;
  border: none !important;
  color: #F1F5F9 !important;
}

/* Sidebar behavior */
[data-sidebar="hidden"] .layout-course {
  grid-template-columns: 1fr !important;
  gap: 0 !important;
  padding: 0 40px !important;
}

[data-sidebar="hidden"] .course-sidebar {
  display: none !important;
}

[data-sidebar="hidden"] .course-main {
  width: 100% !important;
  max-width: 100% !important;
}

[data-sidebar="hidden"] .course-main .lesson-content {
  max-width: 100% !important;
  width: 100% !important;
}

@media (min-width: 1400px) {
  [data-sidebar="hidden"] .layout-course {
    padding: 0 60px !important;
  }
}

@media (min-width: 1600px) {
  [data-sidebar="hidden"] .layout-course {
    padding: 0 80px !important;
  }
}

/* Sandbox Styles */
.sandbox-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 24px;
  margin-top: 24px;
  min-height: 600px;
}

.sandbox-sidebar {
  background: var(--panel);
  border: 3px solid var(--border);
  border-radius: 20px;
  padding: 20px;
  box-shadow: var(--shadow);
  height: fit-content;
  max-height: calc(100vh - 200px);
  overflow-y: auto;
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}

.sidebar-header h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  color: var(--text-strong);
}

.btn-small {
  padding: 6px 12px;
  font-size: 13px;
}

.projects-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.project-item {
  padding: 12px;
  border-radius: 12px;
  border: 2px solid var(--border);
  background: var(--bg-elevated);
  cursor: pointer;
  transition: background-color 150ms ease, color 150ms ease;
}

.project-item:hover {
  border-color: var(--primary);
  background: var(--panel);
  transform: translateX(4px);
}

.project-item.active {
  border-color: var(--primary);
  background: color-mix(in srgb, var(--primary) 10%, transparent);
}

.project-item-content {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.project-item-content strong {
  font-size: 14px;
  color: var(--text-strong);
}

.project-meta {
  font-size: 12px;
  color: var(--muted);
}

.sandbox-main {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.editor-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: var(--panel);
  border: 3px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
}

.toolbar-left,
.toolbar-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.project-select {
  padding: 8px 12px;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: var(--bg-elevated);
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  min-width: 200px;
}

.project-status {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 6px;
}

.project-status.saved {
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 15%, transparent);
}

.project-status.unsaved {
  color: #f59e0b;
  background: color-mix(in srgb, #f59e0b 15%, transparent);
}

.editor-container {
  background: var(--panel);
  border: 3px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
  min-height: 400px;
}

.editor-container .CodeMirror {
  height: 400px;
  font-size: 14px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

[data-theme="dark"] .editor-container .CodeMirror {
  background: #1e293b;
  color: #f1f5f9;
}

.output-container {
  background: var(--panel);
  border: 3px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  min-height: 150px;
  max-height: 300px;
  overflow-y: auto;
}

.output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  border-bottom: 2px solid var(--border);
}

.output-header h4 {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-strong);
}

.output-content {
  padding: 16px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 13px;
  line-height: 1.6;
}

.output-line {
  margin-bottom: 8px;
}

.output-label {
  font-weight: 700;
  color: var(--primary);
  margin-right: 8px;
}

.output-text {
  color: var(--text);
  margin: 0;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

.output-content pre {
  margin: 0;
  padding: 0;
  background: transparent;
  border: none;
  font-family: inherit;
}

.output-line.error .output-label {
  color: #ef4444;
}

.output-line.error .output-text {
  color: #ef4444;
}

@media (max-width: 980px) {
  .sandbox-layout {
    grid-template-columns: 1fr;
  }
  
  .sandbox-sidebar {
    max-height: 300px;
  }
}

[data-sidebar="always"] .layout-course {
  grid-template-columns: 260px 1fr !important;
}

[data-sidebar="always"] .course-sidebar {
  display: block !important;
  transform: none !important;
  opacity: 1 !important;
  pointer-events: auto !important;
}

[data-sidebar="always"] .sidebar-closed {
  grid-template-columns: 260px 1fr !important;
}

@media (min-width: 1400px) {
  [data-sidebar="always"] .layout-course {
    grid-template-columns: 240px 1fr !important;
  }
}

@media (min-width: 1600px) {
  [data-sidebar="always"] .layout-course {
    grid-template-columns: 220px 1fr !important;
  }
}

/* Keyboard shortcuts enabled */
[data-shortcuts="on"] .btn:focus-visible,
[data-shortcuts="on"] a:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
}

[data-shortcuts="off"] *:focus-visible {
  outline: none;
}

/* Notifications - visual feedback */
[data-notifications="on"] .unit-card:has(.progress-ring[data-complete="true"]) {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--primary) 20%, transparent);
}

/* Auto-save indicator */
[data-autosave="on"] .lesson-overview::after {
  content: "Auto-saving...";
  position: absolute;
  bottom: 8px;
  right: 12px;
  font-size: 11px;
  color: var(--muted);
  opacity: 0;
  transition: opacity 200ms;
}

[data-autosave="on"] .lesson-overview.saving::after {
  opacity: 1;
}

/* Study reminders - subtle indicator */
[data-reminders="on"] .site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient);
  opacity: 0.6;
}

/* Founders CTA Section */
.founders-cta {
  padding: 60px 0;
  text-align: center;
  background: linear-gradient(180deg, transparent 0%, rgba(14, 165, 233, 0.02) 50%, transparent 100%);
}

.testimonials-founders-layout {
  padding: 40px 0;
}

.testimonials-founders-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr 1fr;
  gap: 48px;
  align-items: start;
  max-width: 1400px;
  margin: 0 auto;
}

.testimonial-side {
  margin: 0;
  align-self: stretch;
  display: flex;
  flex-direction: column;
}

.testimonial-side .quote {
  flex-grow: 1;
  margin-bottom: auto;
}

.founders-cta-content {
  text-align: center;
}

.founders-cta-title {
  font-size: 2.75rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.founders-cta-subtitle {
  font-size: 1.125rem;
  color: var(--muted);
  margin-bottom: 40px;
  font-weight: 500;
}

.founders-showcase {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 56px;
  flex-wrap: wrap;
  margin-bottom: 32px;
  padding: 20px 0;
}

.founder-showcase-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  transition: transform 0.3s ease;
}

.founder-showcase-item:hover {
  transform: translateY(-4px);
}

.founder-showcase-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--border);
  background: var(--panel);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  box-shadow: var(--shadow);
}

.founder-showcase-item:hover .founder-showcase-avatar {
  border-color: var(--primary);
  box-shadow: 0 12px 32px rgba(14, 165, 233, 0.2);
  transform: scale(1.05);
}

.founder-showcase-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.founder-showcase-fallback {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary);
  background: var(--bg-elevated);
}

.founder-showcase-name {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
}

.founder-showcase-role {
  font-size: 0.9375rem;
  color: var(--muted);
  font-weight: 500;
}

@media (max-width: 1024px) {
  .testimonials-founders-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  
  .testimonial-side {
    max-width: 500px;
    margin: 0 auto;
  }
}

@media (max-width: 768px) {
  .founders-cta-title {
    font-size: 2rem;
  }
  
  .founders-showcase {
    gap: 32px;
  }
  
  .founder-showcase-avatar {
    width: 100px;
    height: 100px;
  }
  
  .founder-showcase-fallback {
    font-size: 2.5rem;
  }
}