/* ============================================================
   IT-Tea.org — Design System
   System-aware Dark/Light mode · Mobile-First
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

/* ---------- CSS Custom Properties (Light — mobile-first default) ---------- */
:root {
  /* Surface – Light */
  --bg-primary: #f8fafb;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-glass: rgba(0, 0, 0, 0.03);
  --bg-code: #f1f5f9;
  --border: rgba(0, 0, 0, 0.07);
  --border-hover: rgba(0, 0, 0, 0.14);

  /* Text */
  --text-primary: #1a1d23;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  --text-inverse: #f0f6fc;

  /* Accents */
  --accent-tea: linear-gradient(135deg, #0d9488, #06b6d4);
  --accent-hero: linear-gradient(135deg, #0d9488, #0891b2);
  --accent-python: linear-gradient(135deg, #10b981, #06b6d4);
  --accent-cs: linear-gradient(135deg, #6366f1, #a855f7);
  --accent-warm: linear-gradient(135deg, #f97316, #ef4444);
  --accent-blue: linear-gradient(135deg, #3b82f6, #6366f1);
  --accent-rose: linear-gradient(135deg, #e11d48, #f43f5e);

  /* Solid */
  --clr-tea: #0d9488;
  --clr-tea-light: #14b8a6;
  --clr-python: #10b981;
  --clr-cs: #8b5cf6;
  --clr-orange: #f97316;
  --clr-blue: #3b82f6;
  --clr-rose: #e11d48;
  --clr-link: #0d9488;
  --clr-float: #f59e0b;
  --clr-logic: #8b5cf6;
  --clr-lmc: #ef4444;

  /* Spacing */
  --space-2xs: 0.125rem;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Typography */
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-code: 'JetBrains Mono', 'Fira Code', monospace;
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 2rem;
  --fs-3xl: 2.5rem;
  --fs-4xl: 3.25rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.10);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 40px rgba(13, 148, 136, 0.10);

  /* Transitions */
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --header-height: 64px;
  --container-max: 1200px;
}

/* ---------- System-aware Dark Mode ---------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-primary: #0c1017;
    --bg-secondary: #141820;
    --bg-card: rgba(20, 24, 32, 0.85);
    --bg-glass: rgba(255, 255, 255, 0.04);
    --bg-code: #1a1f2e;
    --border: rgba(255, 255, 255, 0.07);
    --border-hover: rgba(255, 255, 255, 0.14);

    --text-primary: #eef2f7;
    --text-secondary: #8b949e;
    --text-muted: #5c6370;
    --text-inverse: #0c1017;

    --clr-link: #2dd4bf;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(13, 148, 136, 0.15);
  }
}

/* Manual toggle overrides */
[data-theme="dark"] {
  --bg-primary: #0c1017;
  --bg-secondary: #141820;
  --bg-card: rgba(20, 24, 32, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.04);
  --bg-code: #1a1f2e;
  --border: rgba(255, 255, 255, 0.07);
  --border-hover: rgba(255, 255, 255, 0.14);

  --text-primary: #eef2f7;
  --text-secondary: #8b949e;
  --text-muted: #5c6370;
  --text-inverse: #0c1017;

  --clr-link: #2dd4bf;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px rgba(13, 148, 136, 0.15);
}

[data-theme="light"] {
  --bg-primary: #f8fafb;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-glass: rgba(0, 0, 0, 0.03);
  --bg-code: #f1f5f9;
  --border: rgba(0, 0, 0, 0.07);
  --border-hover: rgba(0, 0, 0, 0.14);

  --text-primary: #1a1d23;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  --text-inverse: #f0f6fc;

  --clr-link: #0d9488;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.10);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 40px rgba(13, 148, 136, 0.10);
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--clr-link);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  opacity: 0.85;
}

img {
  max-width: 100%;
  display: block;
}

::selection {
  background: rgba(13, 148, 136, 0.25);
  color: var(--text-primary);
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-xl);
  }
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 1000;
  display: flex;
  align-items: center;
  padding: 0 var(--space-md);
}

@media (min-width: 768px) {
  .site-header {
    padding: 0 var(--space-xl);
  }
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-primary);
  font-weight: 800;
  font-size: var(--fs-lg);
  letter-spacing: -0.02em;
}

.logo-icon {
  font-size: 1.4rem;
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-text {
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-dot {
  -webkit-text-fill-color: var(--text-muted);
  font-weight: 500;
}

/* Nav */
.header-nav {
  display: none;
  align-items: center;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .header-nav {
    display: flex;
  }
}

.header-nav a {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
}

.header-nav a:hover {
  color: var(--text-primary);
  opacity: 1;
}

.teacher-area-link {
  display: inline-flex !important;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md) !important;
  background: var(--accent-tea) !important;
  color: #fff !important;
  border-radius: var(--radius-full);
  font-weight: 600 !important;
  font-size: var(--fs-sm) !important;
  transition: transform var(--transition), box-shadow var(--transition) !important;
}

.teacher-area-link:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.3);
  opacity: 1 !important;
}

/* Theme Toggle */
.theme-toggle {
  background: var(--bg-glass);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: var(--radius-full);
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition);
  font-size: var(--fs-base);
}

.theme-toggle:hover {
  border-color: var(--border-hover);
  background: var(--bg-card);
  transform: rotate(20deg);
}

/* Language Switcher */
.lang-switcher {
  display: inline-flex;
  gap: 2px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  padding: 2px;
}

.lang-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition);
  letter-spacing: 0.03em;
}

.lang-btn:hover {
  color: var(--text-primary);
}

.lang-btn.active {
  background: var(--accent);
  color: #fff;
}

/* Mobile Hamburger */
.menu-toggle {
  display: flex;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: var(--space-sm);
  font-size: var(--fs-xl);
}

@media (min-width: 768px) {
  .menu-toggle {
    display: none;
  }
}

/* Mobile Nav Expanded */
.header-nav.open {
  display: flex;
  flex-direction: column;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: var(--space-lg);
  gap: var(--space-md);
  animation: slideDown 0.3s ease;
  z-index: 999;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   UTILITY
   ============================================================ */
.gradient-text {
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.main-full {
  padding-top: var(--header-height);
  min-height: 100vh;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  padding: var(--space-3xl) var(--space-md) var(--space-2xl);
  text-align: center;
  overflow: hidden;
}

@media (min-width: 768px) {
  .hero {
    padding: 6rem var(--space-xl) var(--space-3xl);
  }
}

.hero-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(13, 148, 136, 0.12) 0%, rgba(6, 182, 212, 0.06) 40%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-md);
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-xl);
  animation: fadeInUp 0.6s ease;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, var(--fs-4xl));
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-lg);
  animation: fadeInUp 0.6s ease 0.1s both;
}

.hero h1 i {
  font-size: 0.85em;
}

.hero-subtitle {
  font-size: var(--fs-md);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto var(--space-2xl);
  line-height: 1.7;
  animation: fadeInUp 0.6s ease 0.2s both;
}

@media (min-width: 768px) {
  .hero-subtitle {
    font-size: var(--fs-lg);
  }
}

.hero-tags {
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
  animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--text-secondary);
  transition: border-color var(--transition);
}

.hero-tag:hover {
  border-color: var(--border-hover);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

/* ============================================================
   SECTION HEADERS
   ============================================================ */
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-header h2 {
  font-size: var(--fs-2xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

.section-header h2 i {
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-header p {
  font-size: var(--fs-md);
  color: var(--text-secondary);
}

/* ============================================================
   LO OF THE DAY
   ============================================================ */
.lo-of-day {
  padding: var(--space-xl) 0 var(--space-2xl);
}

.lo-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-2xl);
  padding: var(--space-xl);
  backdrop-filter: blur(12px);
  overflow: hidden;
  transition: all var(--transition);
}

@media (min-width: 768px) {
  .lo-card {
    padding: var(--space-2xl);
  }
}

.lo-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-tea);
}

.lo-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
}

.lo-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--clr-tea);
  margin-bottom: var(--space-md);
}

.lo-title {
  font-size: var(--fs-xl);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-lg);
}

@media (min-width: 768px) {
  .lo-title {
    font-size: var(--fs-2xl);
  }
}

.lo-objectives {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.lo-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-glass);
  border-radius: var(--radius-lg);
  font-size: var(--fs-sm);
  line-height: 1.6;
}

.lo-code {
  flex-shrink: 0;
  font-family: var(--font-code);
  font-size: var(--fs-xs);
  font-weight: 600;
  padding: 2px var(--space-sm);
  background: rgba(13, 148, 136, 0.12);
  color: var(--clr-tea);
  border-radius: var(--radius-sm);
}

.lo-meta {
  display: flex;
  gap: var(--space-lg);
  flex-wrap: wrap;
  font-size: var(--fs-xs);
  color: var(--text-muted);
  font-weight: 500;
}

.lo-meta span {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

/* ============================================================
   INTERACTIVE LAB
   ============================================================ */
.interactive-lab {
  padding: var(--space-2xl) 0 var(--space-3xl);
}

.lab-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

@media (min-width: 576px) {
  .lab-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .lab-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.lab-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  backdrop-filter: blur(12px);
  transition: all var(--transition);
  cursor: pointer;
  overflow: hidden;
}

.lab-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  opacity: 0;
  transition: opacity var(--transition);
}

.lab-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

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

.lab-card[data-accent="python"]::before {
  background: var(--accent-python);
}

.lab-card[data-accent="float"]::before {
  background: linear-gradient(135deg, #f59e0b, #fbbf24);
}

.lab-card[data-accent="logic"]::before {
  background: var(--accent-cs);
}

.lab-card[data-accent="lmc"]::before {
  background: var(--accent-warm);
}

.lab-card-icon {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-xl);
  margin-bottom: var(--space-md);
}

.lab-card[data-accent="python"] .lab-card-icon {
  background: rgba(16, 185, 129, 0.12);
  color: var(--clr-python);
}

.lab-card[data-accent="float"] .lab-card-icon {
  background: rgba(245, 158, 11, 0.12);
  color: var(--clr-float);
}

.lab-card[data-accent="logic"] .lab-card-icon {
  background: rgba(139, 92, 246, 0.12);
  color: var(--clr-logic);
}

.lab-card[data-accent="lmc"] .lab-card-icon {
  background: rgba(239, 68, 68, 0.12);
  color: var(--clr-lmc);
}

.lab-card h3 {
  font-size: var(--fs-md);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.01em;
}

.lab-card p {
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-lg);
}

.lab-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lab-tag {
  font-size: var(--fs-xs);
  font-weight: 600;
  padding: var(--space-2xs) var(--space-sm);
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  color: var(--text-muted);
}

.lab-card-footer i {
  color: var(--text-muted);
  font-size: var(--fs-sm);
  transition: transform var(--transition), color var(--transition);
}

.lab-card:hover .lab-card-footer i {
  transform: translateX(4px);
  color: var(--clr-tea);
}

/* ============================================================
   ASSESSMENT HUB
   ============================================================ */
.assessment-hub {
  padding: var(--space-2xl) 0 var(--space-3xl);
  background: var(--bg-glass);
}

.assessment-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .assessment-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.assessment-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-2xl);
  padding: var(--space-xl);
  backdrop-filter: blur(12px);
  overflow: hidden;
  transition: all var(--transition);
}

@media (min-width: 768px) {
  .assessment-card {
    padding: var(--space-2xl);
  }
}

.assessment-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}

.assessment-card.mock-exams::before {
  background: var(--accent-warm);
}

.assessment-card.resources::before {
  background: var(--accent-blue);
}

.assessment-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.assessment-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-xl);
  margin-bottom: var(--space-md);
}

.mock-exams .assessment-icon {
  background: rgba(249, 115, 22, 0.12);
  color: var(--clr-orange);
}

.resources .assessment-icon {
  background: rgba(59, 130, 246, 0.12);
  color: var(--clr-blue);
}

.assessment-label {
  font-size: var(--fs-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-xs);
}

.assessment-card h3 {
  font-size: var(--fs-xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.assessment-card p {
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-lg);
}

.assessment-badges {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-bottom: var(--space-lg);
}

.assessment-badge {
  font-size: var(--fs-xs);
  font-weight: 600;
  padding: var(--space-2xs) var(--space-sm);
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  color: var(--text-secondary);
}

.assessment-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: 600;
  transition: all var(--transition);
}

.mock-exams .assessment-btn {
  background: rgba(249, 115, 22, 0.12);
  color: var(--clr-orange);
}

.mock-exams .assessment-btn:hover {
  background: rgba(249, 115, 22, 0.2);
  opacity: 1;
}

.resources .assessment-btn {
  background: rgba(59, 130, 246, 0.12);
  color: var(--clr-blue);
}

.resources .assessment-btn:hover {
  background: rgba(59, 130, 246, 0.2);
  opacity: 1;
}

/* ============================================================
   SYLLABUS SECTION
   ============================================================ */
.syllabus {
  padding: var(--space-2xl) 0 var(--space-4xl);
}

/* Filter Tabs */
.syllabus-tabs {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: var(--space-2xl);
}

.syllabus-tab {
  padding: var(--space-sm) var(--space-lg);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: var(--fs-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.syllabus-tab:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.syllabus-tab.active {
  background: var(--accent-tea);
  border-color: transparent;
  color: #fff;
}

/* Grade Block */
.syllabus-grade {
  margin-bottom: var(--space-2xl);
  transition: all var(--transition);
}

.syllabus-grade.hidden {
  display: none;
}

.grade-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--border);
}

.grade-header i {
  font-size: var(--fs-xl);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
}

.syllabus-grade[data-grade^="g11-cs"] .grade-header i,
.syllabus-grade[data-grade^="g12-cs"] .grade-header i {
  background: rgba(139, 92, 246, 0.12);
  color: var(--clr-cs);
}

.syllabus-grade[data-grade^="g11-prog"] .grade-header i,
.syllabus-grade[data-grade^="g12-prog"] .grade-header i {
  background: rgba(16, 185, 129, 0.12);
  color: var(--clr-python);
}

.grade-header h3 {
  font-size: var(--fs-lg);
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* Term Group — collapsible wrapper */
.term-group {
  margin-bottom: var(--space-sm);
}

/* Term Label — clickable toggle */
.term-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  margin: var(--space-lg) 0 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--clr-tea);
  border-left: 3px solid var(--clr-tea);
  background: var(--bg-glass);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
  user-select: none;
}

.term-label:hover {
  background: rgba(13, 148, 136, 0.08);
}

.term-label i {
  font-size: 0.85em;
}

.term-chevron {
  margin-left: auto;
  font-size: 0.7em;
  color: var(--text-muted);
  transition: transform var(--transition);
}

.term-group.open .term-chevron {
  transform: rotate(180deg);
}

/* Term Content — collapsible */
.term-content {
  display: none;
  padding-top: var(--space-sm);
}

.term-group.open .term-content {
  display: block;
}

/* Topic links in syllabus */
.topic-block h4 a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition);
}

.topic-block h4 a:hover {
  color: var(--clr-tea);
  text-decoration: underline;
}

/* Unit Accordion */
.syllabus-unit {
  margin-bottom: var(--space-sm);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
}

.syllabus-unit:hover {
  border-color: var(--border-hover);
}

.unit-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: none;
  border: none;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  cursor: pointer;
  transition: background var(--transition);
  text-align: left;
}

.unit-toggle:hover {
  background: var(--bg-glass);
}

.unit-code {
  font-family: var(--font-code);
  font-size: var(--fs-xs);
  font-weight: 700;
  padding: 2px var(--space-sm);
  background: rgba(13, 148, 136, 0.12);
  color: var(--clr-tea);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.unit-name {
  flex: 1;
  font-weight: 600;
}

.unit-chevron {
  color: var(--text-muted);
  font-size: var(--fs-xs);
  transition: transform var(--transition);
}

.syllabus-unit.open .unit-chevron {
  transform: rotate(180deg);
}

/* Unit Content */
.unit-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.syllabus-unit.open .unit-content {
  max-height: 2000px;
}

/* Topic & LO List */
.topic-block {
  padding: var(--space-md) var(--space-lg);
  border-top: 1px solid var(--border);
}

.topic-block h4 {
  font-size: var(--fs-sm);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.topic-block h4::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--clr-tea);
  flex-shrink: 0;
}

.lo-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.lo-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  padding: var(--space-xs) 0;
}

.lo-list .lo-code {
  margin-top: 2px;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: var(--space-2xl) var(--space-md);
  text-align: center;
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
}

.footer-brand {
  font-size: var(--fs-lg);
  font-weight: 800;
  margin-bottom: var(--space-sm);
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
}

.footer-brand i {
  -webkit-text-fill-color: unset;
  background: var(--accent-tea);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.site-footer p {
  font-size: var(--fs-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

.footer-copy {
  font-size: var(--fs-xs);
  color: var(--text-muted);
}

/* ============================================================
   SCROLL ANIMATIONS (intersection observer)
   ============================================================ */
.animate-target {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.animate-target.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delays */
.stagger-1 {
  transition-delay: 0.05s;
}

.stagger-2 {
  transition-delay: 0.10s;
}

.stagger-3 {
  transition-delay: 0.15s;
}

.stagger-4 {
  transition-delay: 0.20s;
}

/* ============================================================
   RESPONSIVE FINE-TUNING
   ============================================================ */

/* Small phones */
@media (max-width: 374px) {
  :root {
    --fs-4xl: 2rem;
    --fs-3xl: 1.75rem;
    --fs-2xl: 1.5rem;
  }

  .syllabus-tabs {
    gap: var(--space-xs);
  }

  .syllabus-tab {
    padding: var(--space-xs) var(--space-md);
    font-size: var(--fs-xs);
  }
}

/* Tablet & up */
@media (min-width: 768px) {
  .lo-card {
    display: grid;
    grid-template-columns: 1fr;
  }

  .unit-toggle {
    padding: var(--space-lg) var(--space-xl);
  }

  .topic-block {
    padding: var(--space-md) var(--space-xl) var(--space-md) var(--space-2xl);
  }
}

/* Desktop */
@media (min-width: 1024px) {
  .hero {
    padding: 7rem var(--space-xl) var(--space-3xl);
  }

  .hero h1 {
    font-size: var(--fs-4xl);
  }

  .grade-header h3 {
    font-size: var(--fs-xl);
  }
}