/* ============================================================
   CODE TUTORIUM — Global Stylesheet
   Primary: #1e3a6e (deep navy blue)  |  Accent: #2f5eb3  |  Background: #ffffff
   ============================================================ */

/* ── RESET & BASE ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --blue-900: #0d1f3c;
  --blue-800: #1e3a6e;
  --blue-700: #254d92;
  --blue-600: #2f5eb3;
  --blue-500: #4472c9;
  --blue-400: #6d96d9;
  --blue-200: #b8cff0;
  --blue-100: #dce8f8;
  --blue-50:  #f0f5fc;

  --white:    #ffffff;
  --gray-50:  #f8f9fb;
  --gray-100: #eef1f6;
  --gray-200: #dde2ec;
  --gray-400: #8d97ab;
  --gray-600: #4f5a6e;
  --gray-800: #1c2333;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 3px rgba(30,58,110,.08), 0 1px 2px rgba(30,58,110,.06);
  --shadow-md: 0 4px 16px rgba(30,58,110,.10), 0 2px 6px rgba(30,58,110,.06);
  --shadow-lg: 0 12px 40px rgba(30,58,110,.14);

  --transition: 160ms ease;
}

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

body {
  font-family: 'Outfit', system-ui, sans-serif;
  font-weight: 400;
  color: var(--gray-800);
  background: var(--white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
ul { list-style: none; }


/* ── NAVIGATION ── */
.lesson-mega-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--blue-800);
  border-bottom: 1px solid var(--blue-700);
}

.lesson-nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lesson-nav-logo {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--white);
  letter-spacing: -.02em;
}

.lesson-nav-logo span {
  color: var(--blue-400);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--blue-200);
  padding: 0.5rem 0.875rem;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

.nav-links a:hover {
  background: rgba(255,255,255,.08);
  color: var(--white);
}

.nav-links a.active {
  background: rgba(255,255,255,.12);
  color: var(--white);
  font-weight: 600;
}

.search-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius-sm);
  color: var(--blue-200);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.search-btn:hover {
  background: rgba(255,255,255,.16);
  color: var(--white);
}


/* ── HERO ── */
.hero {
  position: relative;
  overflow: hidden;
  background: var(--blue-800);
  padding: 6rem 2rem 5rem;
  text-align: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 0%, rgba(47,94,179,.5) 0%, transparent 70%);
  pointer-events: none;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero-content {
  position: relative;
  max-width: 680px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.1);
  border: 1px solid rgba(255,255,255,.2);
  color: var(--blue-200);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  padding: 0.375rem 1rem;
  border-radius: 100px;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: clamp(2rem, 5vw, 3.25rem);
  line-height: 1.15;
  color: var(--white);
  letter-spacing: -.03em;
  margin-bottom: 1.25rem;
}

.hero-sub {
  font-size: 1.125rem;
  color: var(--blue-200);
  max-width: 480px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 0.875rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  background: var(--white);
  color: var(--blue-800);
  font-weight: 600;
  font-size: 0.925rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-md);
  transition: background var(--transition), box-shadow var(--transition), transform var(--transition);
}

.btn-primary:hover {
  background: var(--blue-50);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  background: transparent;
  color: var(--blue-200);
  font-weight: 500;
  font-size: 0.925rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255,255,255,.2);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.btn-ghost:hover {
  background: rgba(255,255,255,.08);
  color: var(--white);
  border-color: rgba(255,255,255,.35);
}


/* ── SECTION SHARED ── */
#learning-paths {
  max-width: 1200px;
  margin: 0 auto;
  padding: 5rem 2rem 6rem;
}

.section-label {
  font-size: 0.775rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--blue-600);
  margin-bottom: 0.75rem;
}

.section-title {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  line-height: 1.2;
  color: var(--blue-900);
  letter-spacing: -.025em;
  margin-bottom: 1rem;
}

.section-sub {
  font-size: 1.0625rem;
  color: var(--gray-600);
  max-width: 520px;
  margin-bottom: 3.5rem;
}


/* ── LEARNING PATH CARDS ── */
.learning-paths-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-bottom: 4rem;
}

.learning-path-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}

.learning-path-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: var(--blue-200);
}

.path-header {
  background: var(--blue-800);
  padding: 1.5rem 1.5rem 1.25rem;
}

.path-info h3 {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--white);
  margin-bottom: 0.25rem;
}

.path-info p {
  font-size: 0.875rem;
  color: var(--blue-300, var(--blue-200));
  line-height: 1.5;
}

.path-courses {
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.path-course {
  display: flex;
  align-items: center;
  padding: 0.75rem 1rem;
  background: var(--gray-50);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-md);
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.path-course:hover {
  background: var(--blue-50);
  border-color: var(--blue-200);
  transform: translateX(3px);
}

.course-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.course-info strong {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--blue-800);
}

.course-info span {
  font-size: 0.8rem;
  color: var(--gray-400);
}

.path-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--gray-100);
  background: var(--gray-50);
}

.path-duration {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--blue-700);
  background: var(--blue-100);
  padding: 0.25rem 0.75rem;
  border-radius: 100px;
}

.path-action {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--blue-600);
  transition: color var(--transition), letter-spacing var(--transition);
}

.path-action:hover {
  color: var(--blue-800);
  letter-spacing: .01em;
}


/* ── QUICK START ── */
.quick-start-section {
  border-top: 1px solid var(--gray-200);
  padding-top: 3.5rem;
}

.quick-start-section h3 {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--blue-900);
  margin-bottom: 1.5rem;
}

.quick-start-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.quick-start-card {
  display: block;
  padding: 1.375rem 1.5rem;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
}

.quick-start-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--blue-200);
  transform: translateY(-2px);
}

.quick-start-card.featured {
  background: var(--blue-800);
  border-color: var(--blue-700);
}

.quick-start-card.featured:hover {
  background: var(--blue-700);
  border-color: var(--blue-600);
}

.quick-start-card h4 {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--blue-900);
  margin-bottom: 0.375rem;
}

.quick-start-card p {
  font-size: 0.875rem;
  color: var(--gray-600);
  line-height: 1.55;
}

.quick-start-card.featured h4 {
  color: var(--white);
}

.quick-start-card.featured p {
  color: var(--blue-200);
}


/* ── FOOTER ── */
#footer-grid {
  background: var(--blue-900);
  padding: 4rem 2rem 2.5rem;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid rgba(255,255,255,.08);
}

.footer-col h3 {
  font-family: 'Syne', sans-serif;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--white);
  letter-spacing: .04em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}

.footer-col p {
  font-size: 0.9rem;
  color: var(--blue-400);
  line-height: 1.7;
  max-width: 300px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-col ul li a {
  font-size: 0.9rem;
  color: var(--blue-400);
  transition: color var(--transition);
}

.footer-col ul li a:hover {
  color: var(--white);
}

.copyright {
  text-align: center;
}

.copyright p {
  font-size: 0.8rem;
  color: rgba(255,255,255,.3);
}


/* ── SEARCH OVERLAY ── */
.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10,18,35,.6);
  backdrop-filter: blur(4px);
  z-index: 999;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding-top: 10vh;
}

.search-overlay.open {
  display: flex;
}

.search-box {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-xl);
  width: min(640px, 92vw);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.search-header {
  padding: 0.875rem 1.25rem;
  border-bottom: 1px solid var(--gray-100);
}

.search-input-wrap {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.search-icon-svg {
  color: var(--gray-400);
  flex-shrink: 0;
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  font-family: 'Outfit', sans-serif;
  font-size: 1rem;
  color: var(--gray-800);
  background: transparent;
}

.search-input::placeholder {
  color: var(--gray-400);
}

.search-esc {
  font-size: 0.75rem;
  font-family: 'DM Mono', monospace;
  color: var(--gray-400);
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm);
  padding: 0.2rem 0.5rem;
  cursor: pointer;
}

.search-results {
  padding: 1rem 1.25rem;
  min-height: 80px;
}

.search-hint {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.search-hint-row {
  font-size: 0.875rem;
  color: var(--gray-400);
}


/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }
}

@media (max-width: 640px) {
  .lesson-nav-container { padding: 0 1rem; }

  .nav-links a:not(.active) { display: none; }

  .hero { padding: 4rem 1.25rem 3.5rem; }

  #learning-paths { padding: 3.5rem 1.25rem 4rem; }

  .learning-paths-grid { grid-template-columns: 1fr; }

  .quick-start-grid { grid-template-columns: 1fr 1fr; }

  .footer-grid { grid-template-columns: 1fr; gap: 1.75rem; }

  .hero-actions { flex-direction: column; align-items: center; }
}

@media (max-width: 420px) {
  .quick-start-grid { grid-template-columns: 1fr; }
}