/* ============================================
   Neural Academy — AI 知识付费学习网站
   Awwwards 风格：深色 / 玻璃拟态 / 动效
   ============================================ */

:root {
  /* 主色：深空 + 青紫渐变 */
  --bg-deep: #0a0a0f;
  --bg-card: rgba(18, 18, 28, 0.6);
  --bg-glass: rgba(255, 255, 255, 0.04);
  --border-glass: rgba(255, 255, 255, 0.08);
  --accent-cyan: #00d4ff;
  --accent-purple: #a855f7;
  --accent-violet: #6366f1;
  --accent-mint: #22d3c7;
  --text-primary: #f4f4f6;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  --gradient-hero: linear-gradient(135deg, #00d4ff 0%, #a855f7 50%, #6366f1 100%);
  --gradient-subtle: linear-gradient(180deg, rgba(0, 212, 255, 0.08) 0%, transparent 50%, rgba(168, 85, 247, 0.06) 100%);
  --font-display: 'Syne', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --header-height: 72px;
  --transition-smooth: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --transition-bounce: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-display);
  background: var(--bg-deep);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* 背景噪点层 */
.noise {
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
}

/* 渐变光球 */
.gradient-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.5;
  pointer-events: none;
  z-index: 0;
  animation: orbFloat 20s ease-in-out infinite;
}
.gradient-orb--1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.35) 0%, transparent 70%);
  top: -200px;
  right: -100px;
  animation-delay: 0s;
}
.gradient-orb--2 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.3) 0%, transparent 70%);
  bottom: 20%;
  left: -150px;
  animation-delay: -7s;
}
.gradient-orb--3 {
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.25) 0%, transparent 70%);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -14s;
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -30px) scale(1.05); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

/* ========== 全局科技动效（所有页面） ========== */
.tech-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.tech-bg::before {
  content: '';
  position: absolute;
  inset: -30%;
  background: radial-gradient(ellipse 70% 50% at 30% 20%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
              radial-gradient(ellipse 60% 50% at 75% 80%, rgba(168, 85, 247, 0.1) 0%, transparent 50%);
  animation: heroGlowPulse 8s ease-in-out infinite;
}
.tech-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 0%, rgba(0, 212, 255, 0.015) 50%, transparent 100%);
  background-size: 100% 200%;
  animation: heroScan 6s linear infinite;
  opacity: 0.5;
}
.tech-bg .tech-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 15%, transparent 65%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 15%, transparent 65%);
  animation: gridShift 20s linear infinite;
}

/* 布局 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* ========== 导航 ========== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 100;
  transition: background var(--transition-smooth), backdrop-filter var(--transition-smooth);
}
.header.scrolled {
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-glass);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.25rem;
}
.logo-icon {
  color: var(--accent-cyan);
  font-size: 1.1em;
}
.logo-accent {
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 32px;
}
.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-smooth);
}
.nav-links a:hover {
  color: var(--accent-cyan);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: none;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  padding: 8px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition-smooth);
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-ghost {
  color: var(--text-secondary);
  background: transparent;
}
.btn-ghost:hover {
  color: var(--text-primary);
}
.btn-primary {
  color: var(--bg-deep);
  background: var(--gradient-hero);
  border-color: transparent;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 212, 255, 0.35);
}
.btn-outline {
  color: var(--accent-cyan);
  background: transparent;
  border-color: rgba(0, 212, 255, 0.4);
}
.btn-outline:hover {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--accent-cyan);
}
.btn-lg {
  padding: 14px 28px;
  font-size: 1rem;
}
.btn-arrow {
  transition: transform var(--transition-smooth);
}
.btn:hover .btn-arrow {
  transform: translateX(4px);
}

/* ========== Hero（首页首屏，动效由全局 .tech-bg 提供） ========== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: calc(var(--header-height) + 48px) 24px 80px;
  position: relative;
}
@keyframes heroGlowPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.05); }
}
@keyframes heroScan {
  0% { background-position: 0 0; }
  100% { background-position: 0 200%; }
}
@keyframes gridShift {
  0% { transform: translate(0, 0); }
  100% { transform: translate(60px, 30px); }
}

.hero-inner {
  position: relative;
  z-index: 1;
}

.hero-label {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 24px;
}
.pill {
  display: inline-block;
  padding: 6px 14px;
  background: var(--bg-glass);
  border: 1px solid var(--border-glass);
  border-radius: 100px;
  color: var(--accent-cyan);
  font-weight: 600;
  font-size: 0.85rem;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}
.hero-title .line {
  display: block;
}
.hero-title .gradient-text {
  background: linear-gradient(90deg, #00d4ff, #a855f7, #6366f1, #00d4ff);
  background-size: 200% 100%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShimmer 4s linear infinite;
}
@keyframes gradientShimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}
.gradient-text {
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  max-width: 520px;
  margin: 0 auto 40px;
  color: var(--text-secondary);
  font-size: 1.15rem;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-bottom: 64px;
}
.hero-cta .btn-primary:hover {
  box-shadow: 0 0 28px rgba(0, 212, 255, 0.5), 0 0 56px rgba(168, 85, 247, 0.25);
}
.hero-cta .btn-outline:hover {
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.35);
  border-color: var(--accent-cyan);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}
.stat {
  text-align: center;
}
.stat-value {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 20px rgba(0, 212, 255, 0.2);
  transition: text-shadow 0.4s ease;
}
.hero-stats .stat:hover .stat-value {
  text-shadow: 0 0 24px rgba(0, 212, 255, 0.4);
}
.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
}
.stat-divider {
  width: 1px;
  height: 32px;
  background: linear-gradient(to bottom, transparent, var(--accent-cyan), transparent);
  opacity: 0.5;
  animation: statDividerPulse 2.5s ease-in-out infinite;
}
@keyframes statDividerPulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.8; }
}

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.8rem;
  font-family: var(--font-mono);
}
.scroll-line {
  position: relative;
  width: 2px;
  height: 48px;
  background: linear-gradient(to bottom, var(--accent-cyan), rgba(0, 212, 255, 0.2), transparent);
  border-radius: 2px;
  box-shadow: 0 0 12px rgba(0, 212, 255, 0.4);
  overflow: hidden;
  animation: scrollLineFlow 2.5s ease-in-out infinite;
}
.scroll-line::after {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  width: 4px;
  height: 8px;
  margin-left: -2px;
  background: var(--accent-cyan);
  border-radius: 2px;
  box-shadow: 0 0 10px var(--accent-cyan);
  animation: scrollDot 2s ease-in-out infinite;
}
@keyframes scrollDot {
  0% { top: 0; opacity: 1; }
  90% { top: 100%; opacity: 0.3; }
  100% { top: 100%; opacity: 0; }
}
@keyframes scrollLineFlow {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}

/* ========== 通用区块 ========== */
.section {
  padding: 100px 0;
  position: relative;
  z-index: 1;
}
.section-label {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
}
.section-desc {
  text-align: center;
  color: var(--text-secondary);
  max-width: 560px;
  margin: -32px auto 48px;
  line-height: 1.6;
}

/* ========== AI 工具 logo 轮播 ========== */
.tools-section {
  padding-bottom: 64px;
}
.tools-carousel-wrap {
  overflow: hidden;
  margin: 0 -24px;
  padding: 24px 0;
}
.tools-carousel-track {
  display: flex;
  width: max-content;
  animation: toolsCarousel 40s linear infinite;
}
.tools-carousel-track:hover {
  animation-play-state: paused;
}
.tools-carousel-row {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-shrink: 0;
  padding: 0 24px;
}
.tool-logo {
  flex-shrink: 0;
  width: 88px;
  height: 88px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: border-color var(--transition-smooth), transform var(--transition-smooth), box-shadow var(--transition-smooth);
  color: inherit;
  text-decoration: none;
  cursor: pointer;
}
.tool-logo:hover {
  border-color: rgba(0, 212, 255, 0.4);
  transform: scale(1.06);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.25);
}
.tool-logo svg {
  width: 32px;
  height: 32px;
  color: var(--accent-cyan);
}
.tool-logo:nth-child(2) svg { color: #d97706; }
.tool-logo:nth-child(3) svg { color: var(--accent-purple); }
.tool-logo:nth-child(4) svg { color: #0ea5e9; }
.tool-logo:nth-child(5) svg { color: #ec4899; }
.tool-logo:nth-child(6) svg { color: var(--accent-mint); }
.tool-logo:nth-child(7) svg { color: #f43f5e; }
.tool-logo:nth-child(8) svg { color: #8b5cf6; }
.tool-logo:nth-child(9) svg { color: #06b6d4; }
.tool-logo:nth-child(10) svg { color: #eab308; }
.tool-logo span {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-secondary);
  max-width: 76px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
@keyframes toolsCarousel {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

.section-cta {
  text-align: center;
  margin-top: 48px;
}

/* 玻璃拟态卡片 */
.glass {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  transition: all var(--transition-smooth);
}
.glass:hover {
  border-color: rgba(255, 255, 255, 0.12);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.3);
}

/* ========== Features 五大模块（一行五列，紧凑） ========== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}
.feature-card {
  padding: 20px 16px;
  transition: transform var(--transition-smooth);
}
.feature-card:hover {
  transform: translateY(-4px);
}
.feature-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.15), rgba(168, 85, 247, 0.1));
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}
.icon-symbol {
  color: var(--accent-cyan);
  font-size: 1rem;
}
.feature-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
  line-height: 1.3;
}
.feature-card p {
  color: var(--text-secondary);
  font-size: 0.82rem;
  line-height: 1.5;
}

/* ========== AI 最新资讯 ========== */
.news-section {
  padding-top: 80px;
  padding-bottom: 80px;
}
.news-list-wrap {
  max-width: 720px;
  margin: 0 auto 24px;
  max-height: 380px;
  overflow-y: auto;
  overflow-x: hidden;
  scroll-behavior: smooth;
  border-radius: var(--radius-md);
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.news-list-wrap::-webkit-scrollbar {
  display: none;
}
.news-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.news-item {
  padding: 20px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  transition: border-color var(--transition-smooth), box-shadow var(--transition-smooth), transform var(--transition-smooth);
}
.news-item:hover {
  border-color: rgba(255, 255, 255, 0.12);
  transform: translateX(4px);
}
.news-date {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-cyan);
  margin-bottom: 8px;
}
.news-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.4;
}
.news-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color var(--transition-smooth);
}
.news-title a:hover {
  color: var(--accent-cyan);
}
.news-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.55;
  margin: 0;
}
.news-more {
  text-align: center;
  margin: 0;
}
.link-muted {
  color: var(--text-muted);
  font-size: 0.9rem;
  text-decoration: none;
  transition: color var(--transition-smooth);
}
.link-muted:hover {
  color: var(--accent-cyan);
}

/* ========== 课程卡片 ========== */
.courses-search-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.search-input {
  flex: 1;
  min-width: 200px;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
}
.search-input:focus {
  outline: none;
  border-color: var(--accent-cyan);
}
.search-input::placeholder {
  color: var(--text-muted);
}

.category-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}
.category-tab {
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-glass);
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}
.category-tab:hover {
  border-color: rgba(0, 212, 255, 0.4);
  color: var(--text-primary);
}
.category-tab.active {
  border-color: var(--accent-cyan);
  background: rgba(0, 212, 255, 0.1);
  color: var(--accent-cyan);
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
}
.course-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-smooth);
}
.course-card:hover {
  transform: translateY(-6px);
}
.course-image {
  position: relative;
  aspect-ratio: 16/10;
  overflow: hidden;
}
.course-image-placeholder {
  width: 100%;
  height: 100%;
  background-size: cover;
  background-position: center;
  transition: transform var(--transition-smooth);
}
.course-card:hover .course-image-placeholder {
  transform: scale(1.05);
}
.course-bg-1 {
  background: linear-gradient(135deg, #0ea5e9 0%, #6366f1 50%, #a855f7 100%);
}
.course-bg-2 {
  background: linear-gradient(135deg, #22d3c7 0%, #06b6d4 50%, #0ea5e9 100%);
}
.course-bg-3 {
  background: linear-gradient(135deg, #a855f7 0%, #ec4899 50%, #f43f5e 100%);
}
.course-badge {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 6px 12px;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-cyan);
}
.course-content {
  padding: 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
}
.course-category {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-purple);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}
.course-content h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 10px;
  line-height: 1.4;
}
.course-content p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 16px;
  flex: 1;
}
.course-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.course-price {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 1.1rem;
}
.course-link {
  color: var(--accent-cyan);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: gap var(--transition-smooth);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.course-link:hover {
  gap: 8px;
}

/* ========== CTA 区块 ========== */
.cta-section {
  padding: 80px 0;
}
.cta-box {
  padding: 64px 48px;
  text-align: center;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.06) 0%, rgba(168, 85, 247, 0.04) 100%);
  border: 1px solid rgba(0, 212, 255, 0.15);
}
.cta-title {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 12px;
}
.cta-desc {
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-size: 1.05rem;
}

/* ========== Footer ========== */
.footer {
  padding: 48px 0 32px;
  border-top: 1px solid var(--border-glass);
  position: relative;
  z-index: 1;
}
.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
  margin-bottom: 32px;
}
.footer-links {
  display: flex;
  list-style: none;
  gap: 24px;
}
.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color var(--transition-smooth);
}
.footer-links a:hover {
  color: var(--accent-cyan);
}
.footer-bottom p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ========== 滚动揭示动画 ========== */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.8s var(--transition-smooth), transform 0.8s var(--transition-smooth);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}
.reveal.revealed .line {
  animation: lineReveal 0.6s var(--transition-bounce) forwards;
}
.hero-title .line {
  opacity: 0;
  transform: translateY(20px);
}
.hero-title.revealed .line:nth-child(1) { animation-delay: 0.1s; }
.hero-title.revealed .line:nth-child(2) { animation-delay: 0.2s; }
.hero-title.revealed .line:nth-child(3) { animation-delay: 0.3s; }
@keyframes lineReveal {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.98);
    backdrop-filter: blur(20px);
    padding: 24px;
    flex-direction: column;
    gap: 16px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.3s, visibility 0.3s, transform 0.3s;
    pointer-events: none;
  }
  .nav-links.open {
    display: flex;
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
    pointer-events: auto;
  }
  .nav-actions {
    display: none;
  }
  .nav-actions.open {
    display: flex;
    position: fixed;
    top: calc(var(--header-height) + 200px);
    left: 24px;
    right: 24px;
    flex-direction: column;
    gap: 12px;
  }
  .nav-toggle {
    display: flex;
    flex-direction: column;
    gap: 6px;
  }
  .nav-toggle span {
    width: 22px;
    height: 2px;
    background: currentColor;
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
  }
  .nav-toggle.open span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }
  .nav-toggle.open span:nth-child(2) {
    opacity: 0;
  }
  .nav-toggle.open span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }
  .hero-stats {
    gap: 24px;
  }
  .stat-divider {
    display: none;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .feature-card {
    padding: 24px 20px;
  }
  .feature-card h3 {
    font-size: 1.1rem;
  }
  .feature-card p {
    font-size: 0.9rem;
  }
  .courses-grid {
    grid-template-columns: 1fr;
  }
  .cta-box {
    padding: 40px 24px;
  }
  .footer-top {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
  }
  .hero-cta .btn {
    width: 100%;
  }
}