/* ════════════════════════════════════════════════════════════════════
   LAYOUT.CSS  – Header, Hero, Sections, Footer
   ════════════════════════════════════════════════════════════════════ */

/* ─── HEADER ──────────────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background var(--transition-slow), box-shadow var(--transition);
}

[data-theme="dark"] .site-header {
  background: rgba(19, 25, 41, 0.85);
}

.header-inner {
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

/* ─── BRAND ──────────────────────────────────────────────────────── */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.brand:hover { text-decoration: none; }

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-latin);
  font-weight: 800;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-bounce), box-shadow var(--transition);
}

.brand:hover .brand-mark {
  transform: rotate(-6deg) scale(1.1);
  box-shadow: var(--shadow-glow);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.brand-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--color-text);
  transition: color var(--transition);
}

.brand-subtitle {
  font-size: 0.72rem;
  color: var(--color-text-muted);
  font-family: var(--font-latin);
}

/* ─── NAV ────────────────────────────────────────────────────────── */
.header-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  position: relative;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  transition: color var(--transition), background var(--transition);
  overflow: hidden;
}

.nav-link::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--color-primary-soft);
  border-radius: inherit;
  opacity: 0;
  transition: opacity var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
  text-decoration: none;
}

.nav-link:hover::after,
.nav-link.active::after {
  opacity: 1;
}

/* ─── DARK MODE TOGGLE ───────────────────────────────────────────── */
.theme-toggle {
  position: relative;
  width: 48px;
  height: 26px;
  border: none;
  border-radius: 100px;
  background: var(--color-surface-muted);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--color-primary);
}

.theme-toggle-knob {
  position: absolute;
  top: 3px;
  right: 3px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  transition: transform var(--transition-bounce), background var(--transition);
  line-height: 1;
}

[data-theme="dark"] .theme-toggle-knob {
  transform: translateX(-22px);
}

/* ─── HERO ───────────────────────────────────────────────────────── */
.hero {
  position: relative;
  background: var(--hero-gradient);
  border-bottom: 1px solid var(--color-border);
  padding: 80px 0 72px;
  overflow: hidden;
}

/* Decorative blobs */
.hero::before,
.hero::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  animation: float 6s ease-in-out infinite;
}

.hero::before {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, var(--color-primary-glow) 0%, transparent 70%);
  top: -150px;
  left: -100px;
  animation-delay: 0s;
}

.hero::after {
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, rgba(217, 119, 6, 0.12) 0%, transparent 70%);
  bottom: -100px;
  right: -80px;
  animation-delay: 3s;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--wide-width);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.3fr 0.7fr;
  gap: 56px;
  align-items: center;
}

.hero-content {
  animation: fadeIn 0.6s ease both;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  background: var(--color-accent-soft);
  border: 1px solid rgba(217, 119, 6, 0.25);
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 22px;
  animation: slideInRight 0.5s 0.1s ease both;
}

[data-theme="dark"] .hero-eyebrow {
  border-color: rgba(251, 191, 36, 0.3);
}

.hero-eyebrow::before {
  content: '✦';
  font-size: 0.65em;
  animation: spin-slow 4s linear infinite;
  display: inline-block;
}

.hero-title {
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 800;
  color: var(--color-text);
  line-height: 1.25;
  margin-bottom: 18px;
  animation: fadeIn 0.6s 0.15s ease both;
}

.hero-title span {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  max-width: 540px;
  margin-bottom: 36px;
  line-height: 1.8;
  animation: fadeIn 0.6s 0.25s ease both;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  animation: fadeIn 0.6s 0.35s ease both;
}

/* ─── HERO PANEL (Stats) ─────────────────────────────────────────── */
.hero-panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-lg);
  animation: fadeInScale 0.65s 0.2s ease both;
  transition: background var(--transition-slow), border-color var(--transition);
}

[data-theme="dark"] .hero-panel {
  background: var(--color-surface);
  box-shadow: var(--shadow-lg), 0 0 60px rgba(129, 140, 248, 0.08);
}

.hero-panel-title {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 22px;
  font-family: var(--font-latin);
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero-panel-title::before {
  content: '';
  display: inline-block;
  width: 20px;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: 2px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.stat-card {
  background: var(--color-surface-muted);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 20px 14px;
  text-align: center;
  transition: transform var(--transition-bounce), box-shadow var(--transition),
              background var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transition: transform var(--transition);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.stat-card:hover::before {
  transform: scaleX(1);
}

.stat-value {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

/* ─── SECTIONS ───────────────────────────────────────────────────── */
.section {
  padding: 80px 0;
}

.section:nth-child(even) {
  background: var(--color-surface);
  transition: background var(--transition-slow);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-teal);
  letter-spacing: 0.08em;
  margin-bottom: 10px;
  font-family: var(--font-latin);
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 800;
  color: var(--color-text);
  margin-bottom: 12px;
}

.section-desc {
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto;
  font-size: 1rem;
}

/* ─── STEPS (How It Works) ───────────────────────────────────────── */
.steps-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  position: relative;
}

.steps-row::before {
  content: '';
  position: absolute;
  top: 28px;
  right: calc(33.33% - 10px);
  left: calc(33.33% - 10px);
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  opacity: 0.3;
  z-index: 0;
}

.step-item {
  position: relative;
  z-index: 1;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: 32px 24px;
  text-align: center;
  transition: transform var(--transition-bounce), box-shadow var(--transition),
              border-color var(--transition), background var(--transition);
}

.step-item:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  font-weight: 800;
  margin: 0 auto 20px;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-bounce), box-shadow var(--transition);
}

.step-item:hover .step-number {
  transform: scale(1.15) rotate(-5deg);
  box-shadow: var(--shadow-glow);
}

.step-item h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 10px;
}

.step-item p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ─── LESSONS GRID ───────────────────────────────────────────────── */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 24px;
}

/* ─── FOOTER ─────────────────────────────────────────────────────── */
.site-footer {
  background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
  color: rgba(255, 255, 255, 0.9);
  padding: 48px 24px;
  margin-top: 40px;
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: -60px; left: -60px;
  width: 200px; height: 200px;
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
  pointer-events: none;
}

.site-footer::after {
  content: '';
  position: absolute;
  bottom: -80px; right: -80px;
  width: 250px; height: 250px;
  border-radius: 50%;
  background: rgba(255,255,255,0.04);
  pointer-events: none;
}

.footer-inner {
  max-width: var(--wide-width);
  margin: 0 auto;
  text-align: center;
  position: relative;
  z-index: 1;
}

.footer-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.footer-text {
  font-size: 0.85rem;
  opacity: 0.7;
}

/* ─── RESPONSIVE ─────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .hero-desc { margin: 0 auto 36px; }
  .hero-actions { justify-content: center; }
  .hero-eyebrow { margin-left: auto; margin-right: auto; display: flex; width: fit-content; }

  .steps-row {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .steps-row::before { display: none; }
}

@media (max-width: 600px) {
  .header-nav { display: none; }
  .lessons-grid { grid-template-columns: 1fr; }
  .hero { padding: 52px 0 48px; }
}