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

:root {
  --bg: #0a0a0f;
  --bg2: #111118;
  --bg3: #1a1a24;
  --text: #e4e4ed;
  --text2: #9494a8;
  --primary: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --accent: #22d3ee;
  --accent2: #a78bfa;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ====== Buttons ====== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 600; border-radius: 10px; cursor: pointer;
  transition: all var(--transition); border: none; font-size: 15px;
  text-decoration: none; white-space: nowrap;
}
.btn-sm { padding: 8px 18px; font-size: 14px; }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent2));
  color: #fff; box-shadow: 0 4px 16px rgba(99,102,241,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(99,102,241,0.5);
}
.btn-outline {
  background: transparent; color: var(--text);
  border: 1.5px solid rgba(255,255,255,0.2);
}
.btn-outline:hover { border-color: var(--primary); color: var(--primary-light); }
.btn-ghost {
  background: rgba(255,255,255,0.06); color: var(--text);
  border: 1px solid rgba(255,255,255,0.1);
}
.btn-ghost:hover { background: rgba(255,255,255,0.1); }

/* ====== Nav ====== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(10,10,15,0.8); backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: all var(--transition);
}
.nav.scrolled { background: rgba(10,10,15,0.95); }
.nav-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.nav-logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.logo-icon { font-size: 24px; }
.nav-links { display: flex; gap: 32px; }
.nav-links a { font-size: 14px; color: var(--text2); transition: color var(--transition); }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.nav-toggle span {
  display: block; width: 22px; height: 2px; background: var(--text);
  margin: 5px 0; border-radius: 2px; transition: all var(--transition);
}

/* ====== Hero ====== */
.hero {
  position: relative; min-height: 100vh; display: flex; align-items: center;
  padding: 100px 24px 60px; overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; overflow: hidden; }
.hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(99,102,241,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99,102,241,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-glow {
  position: absolute; border-radius: 50%; filter: blur(120px); opacity: 0.4;
  animation: float 8s ease-in-out infinite;
}
.hero-glow-1 { width: 500px; height: 500px; background: var(--primary); top: -10%; left: -5%; }
.hero-glow-2 { width: 400px; height: 400px; background: var(--accent); top: 40%; right: -10%; animation-delay: -3s; }
.hero-glow-3 { width: 300px; height: 300px; background: var(--accent2); bottom: -5%; left: 30%; animation-delay: -5s; }

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(20px, -20px) scale(1.05); }
  66% { transform: translate(-15px, 15px) scale(0.95); }
}

.hero-content { position: relative; max-width: 560px; z-index: 2; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(99,102,241,0.1); border: 1px solid rgba(99,102,241,0.2);
  border-radius: 100px; padding: 6px 16px; font-size: 13px; color: var(--primary-light);
  margin-bottom: 24px;
}
.badge-dot {
  width: 6px; height: 6px; background: var(--success); border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; } 50% { opacity: 0.4; }
}

.hero-title {
  font-size: clamp(40px, 6vw, 64px); font-weight: 800; line-height: 1.1;
  letter-spacing: -0.02em; margin-bottom: 20px;
}
.gradient-text {
  background: linear-gradient(135deg, var(--primary-light), var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc { font-size: 17px; color: var(--text2); margin-bottom: 32px; line-height: 1.7; }
.hero-actions { display: flex; gap: 16px; margin-bottom: 48px; flex-wrap: wrap; }

.hero-stats {
  display: flex; align-items: center; gap: 24px; flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-num {
  display: block; font-size: 32px; font-weight: 800;
  background: linear-gradient(135deg, var(--text), var(--primary-light));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-label { font-size: 13px; color: var(--text2); }
.stat-divider { width: 1px; height: 36px; background: rgba(255,255,255,0.1); }

/* Hero Visual */
.hero-visual {
  position: absolute; right: -40px; top: 50%; transform: translateY(-50%);
  z-index: 1; width: 480px;
}
.mockup {
  background: var(--bg2); border-radius: var(--radius-lg);
  border: 1px solid rgba(255,255,255,0.08); overflow: hidden;
  box-shadow: 0 20px 80px rgba(0,0,0,0.5), 0 0 0 1px rgba(255,255,255,0.05);
  animation: mockup-float 6s ease-in-out infinite;
}
@keyframes mockup-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
.mockup-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 12px 16px; background: rgba(0,0,0,0.3);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.dot { width: 10px; height: 10px; border-radius: 50%; }
.dot.red { background: #ff5f57; }
.dot.yellow { background: #febc2e; }
.dot.green { background: #28c840; }
.mockup-url { margin-left: 12px; font-size: 12px; color: var(--text2); }
.mockup-body { padding: 20px; }

.mock-header {
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 16px; padding-bottom: 16px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.mock-avatar { font-size: 36px; }
.mock-name { font-weight: 700; font-size: 16px; }
.mock-sub { font-size: 12px; color: var(--text2); }
.mock-xp {
  margin-left: auto; font-weight: 800; font-size: 18px;
  color: var(--warning);
}

.mock-stats-row { display: flex; gap: 10px; margin-bottom: 16px; }
.mock-stat-card {
  flex: 1; background: rgba(255,255,255,0.04); border-radius: 10px;
  padding: 12px; text-align: center;
  border: 1px solid rgba(255,255,255,0.06);
}
.mock-stat-card.accent {
  background: rgba(99,102,241,0.1);
  border-color: rgba(99,102,241,0.2);
}
.msc-num { font-size: 22px; font-weight: 800; }
.msc-label { font-size: 11px; color: var(--text2); margin-top: 2px; }

.mock-subjects { display: flex; flex-direction: column; gap: 8px; }
.mock-subj {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600;
}
.ms-icon { font-size: 16px; }
.ms-bar {
  flex: 1; height: 6px; background: rgba(255,255,255,0.06);
  border-radius: 3px; overflow: hidden; margin-left: 4px;
}
.ms-fill {
  height: 100%; border-radius: 3px;
  background: linear-gradient(90deg, var(--c), color-mix(in srgb, var(--c), white 30%));
  transition: width 1.5s ease;
}

/* ====== Sections ====== */
.section { padding: 100px 0; position: relative; }
.section-dark { background: var(--bg2); }

.section-header { text-align: center; margin-bottom: 64px; }
.section-tag {
  display: inline-block; font-size: 13px; font-weight: 600;
  color: var(--primary-light); background: rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.2); border-radius: 100px;
  padding: 4px 14px; margin-bottom: 16px;
}
.section-header h2 {
  font-size: clamp(28px, 4vw, 42px); font-weight: 800;
  line-height: 1.2; margin-bottom: 12px;
}
.section-header p { font-size: 17px; color: var(--text2); max-width: 600px; margin: 0 auto; }

/* ====== Features ====== */
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px;
}
.feature-card {
  background: var(--bg2); border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg); padding: 32px;
  transition: all var(--transition); position: relative; overflow: hidden;
}
.feature-card:hover {
  border-color: rgba(99,102,241,0.3);
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(99,102,241,0.1);
}
.feature-card.featured {
  grid-column: span 1; background: linear-gradient(135deg, rgba(99,102,241,0.1), rgba(167,139,250,0.05));
  border-color: rgba(99,102,241,0.2);
}
.fc-icon { font-size: 36px; margin-bottom: 16px; }
.feature-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.feature-card p { font-size: 14px; color: var(--text2); line-height: 1.7; }
.fc-tag {
  display: inline-block; margin-top: 16px; font-size: 12px; font-weight: 600;
  color: var(--primary-light); background: rgba(99,102,241,0.15);
  padding: 4px 10px; border-radius: 6px;
}

/* ====== Subjects ====== */
.subjects-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px;
}
.subjects-grid > :last-child {
  grid-column: span 2; max-width: calc(50% - 10px); margin: 0 auto;
}
.subject-card {
  background: var(--bg); border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg); padding: 28px;
  transition: all var(--transition);
}
.subject-card:hover {
  border-color: var(--accent, rgba(255,255,255,0.15));
  transform: translateY(-2px);
}
.sc-header { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.sc-icon { font-size: 36px; }
.sc-info h3 { font-size: 20px; font-weight: 700; }
.sc-count { font-size: 13px; color: var(--accent); }
.sc-score {
  margin-left: auto; font-size: 24px; font-weight: 800;
  color: var(--accent); opacity: 0.8;
}
.sc-topics {
  display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px;
}
.sc-topics span {
  font-size: 12px; padding: 4px 10px; border-radius: 6px;
  background: rgba(255,255,255,0.05); color: var(--text2);
  border: 1px solid rgba(255,255,255,0.06);
}
.sc-types { font-size: 12px; color: var(--text2); line-height: 1.8; }
.subjects-total {
  display: flex; align-items: center; justify-content: center; gap: 16px;
  margin-top: 40px; font-size: 16px; color: var(--text2);
}
.subjects-total strong { color: var(--text); font-weight: 700; }

/* ====== AI ====== */
.ai-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 40px; }
.ai-card {
  background: var(--bg2); border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg); padding: 28px;
  transition: all var(--transition);
}
.ai-card:hover { border-color: rgba(99,102,241,0.3); transform: translateY(-2px); }
.ai-step {
  font-size: 36px; font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text; margin-bottom: 16px;
}
.ai-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.ai-card p { font-size: 14px; color: var(--text2); line-height: 1.7; }

.ai-banner {
  background: linear-gradient(135deg, rgba(99,102,241,0.15), rgba(34,211,238,0.1));
  border: 1px solid rgba(99,102,241,0.2); border-radius: var(--radius-lg);
  padding: 36px 40px; display: flex; align-items: center; justify-content: space-between;
  gap: 24px;
}
.ai-banner h3 { font-size: 20px; font-weight: 700; margin-bottom: 6px; }
.ai-banner p { font-size: 14px; color: var(--text2); }

/* ====== Parent ====== */
.parent-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
.parent-card {
  background: var(--bg); border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius); padding: 24px;
  transition: all var(--transition);
}
.parent-card:hover { border-color: rgba(99,102,241,0.2); transform: translateY(-2px); }
.pc-icon { font-size: 28px; display: block; margin-bottom: 12px; }
.parent-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.parent-card p { font-size: 13px; color: var(--text2); line-height: 1.6; }
.parent-cta { text-align: center; margin-top: 40px; }

/* ====== Steps ====== */
.steps-row {
  display: flex; align-items: center; justify-content: center; gap: 24px;
}
.step-card {
  flex: 1; max-width: 300px; text-align: center;
  background: var(--bg2); border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg); padding: 36px 28px;
}
.step-num {
  width: 48px; height: 48px; border-radius: 50%; margin: 0 auto 16px;
  background: linear-gradient(135deg, var(--primary), var(--accent2));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 800; color: #fff;
}
.step-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.step-card p { font-size: 14px; color: var(--text2); }
.step-arrow { font-size: 28px; color: var(--primary); font-weight: 300; }

/* ====== FAQ ====== */
.faq-list { max-width: 720px; margin: 0 auto; }
.faq-item {
  border: 1px solid rgba(255,255,255,0.06); border-radius: var(--radius);
  margin-bottom: 12px; overflow: hidden;
  background: var(--bg);
}
.faq-item summary {
  padding: 18px 24px; font-weight: 600; font-size: 15px;
  cursor: pointer; list-style: none; display: flex; align-items: center;
  transition: background var(--transition);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+'; margin-left: auto; font-size: 20px; color: var(--text2);
  transition: transform var(--transition);
}
.faq-item[open] summary::after { content: '−'; color: var(--primary-light); }
.faq-item summary:hover { background: rgba(255,255,255,0.03); }
.faq-item p { padding: 0 24px 18px; font-size: 14px; color: var(--text2); line-height: 1.7; }

/* ====== CTA ====== */
.cta-section { padding: 60px 0 100px; }
.cta-box {
  text-align: center; padding: 64px 40px;
  background: linear-gradient(135deg, rgba(99,102,241,0.12), rgba(34,211,238,0.08), rgba(167,139,250,0.1));
  border: 1px solid rgba(99,102,241,0.2); border-radius: var(--radius-lg);
  position: relative; overflow: hidden;
}
.cta-box::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(99,102,241,0.15), transparent 60%);
}
.cta-box h2 { font-size: clamp(24px, 3.5vw, 36px); font-weight: 800; margin-bottom: 10px; position: relative; }
.cta-box p { font-size: 17px; color: var(--text2); margin-bottom: 28px; position: relative; }
.cta-actions { display: flex; justify-content: center; gap: 16px; position: relative; flex-wrap: wrap; }

/* ====== Footer ====== */
.footer { padding: 40px 0 24px; border-top: 1px solid rgba(255,255,255,0.06); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; margin-bottom: 24px; }
.footer-brand { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.footer-brand p { width: 100%; font-size: 13px; color: var(--text2); margin-top: 4px; }
.footer-links { display: flex; gap: 24px; }
.footer-links a { font-size: 14px; color: var(--text2); transition: color var(--transition); }
.footer-links a:hover { color: var(--text); }
.footer-bottom { text-align: center; padding-top: 24px; border-top: 1px solid rgba(255,255,255,0.04); }
.footer-bottom p { font-size: 13px; color: rgba(255,255,255,0.3); }

/* ====== Responsive ====== */
@media (max-width: 1024px) {
  .hero-visual { display: none; }
  .hero-content { max-width: 100%; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .ai-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute; top: 64px; left: 0; right: 0;
    background: var(--bg); padding: 20px 24px; gap: 16px;
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .hero { padding: 90px 20px 50px; min-height: auto; }
  .hero-title { font-size: 36px; }
  .hero-stats { gap: 16px; }
  .stat-num { font-size: 24px; }
  .features-grid { grid-template-columns: 1fr; }
  .subjects-grid { grid-template-columns: 1fr; }
  .subjects-grid > :last-child { grid-column: span 1; max-width: 100%; }
  .ai-grid { grid-template-columns: 1fr; }
  .parent-grid { grid-template-columns: 1fr; }
  .steps-row { flex-direction: column; }
  .step-arrow { transform: rotate(90deg); }
  .ai-banner { flex-direction: column; text-align: center; }
  .footer-inner { flex-direction: column; gap: 16px; text-align: center; }
  .btn-sm { display: none; }
  .nav-actions .btn-primary.btn-sm { display: inline-flex; }
}

/* ====== Animations ====== */
.reveal {
  opacity: 0; transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }