/* =====================================================
   AI商业破局 - 设计系统
   风格：Luxury/Refined + 暗黑科技风
   主色：深黑 / 暗红 / 亮红 / 金色
   ===================================================== */

/* ---------- 字体引入 ---------- */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;700&family=Noto+Serif+SC:wght@400;600;700;900&family=Playfair+Display:ital,wght@0,400;0,700;1,400&display=swap');

/* ---------- 设计令牌 ---------- */
:root {
  /* 颜色 */
  --color-bg: #050505;
  --color-bg-elevated: #0a0a0a;
  --color-bg-card: #111111;
  --color-bg-card-hover: #1a1a1a;
  --color-red-deep: #4a0000;
  --color-red-dark: #8B0000;
  --color-red: #DC143C;
  --color-red-bright: #ff1a4d;
  --color-gold: #D4AF37;
  --color-gold-light: #f0d878;
  --color-text: #f5f5f5;
  --color-text-muted: #a0a0a0;
  --color-text-dim: #666666;
  --color-border: rgba(220, 20, 60, 0.2);
  --color-border-gold: rgba(212, 175, 55, 0.3);

  /* 字体 */
  --font-display: 'Noto Serif SC', 'Songti SC', serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-accent: 'Playfair Display', 'Noto Serif SC', serif;

  /* 间距 */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
  --space-3xl: 9rem;

  /* 过渡 */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.8s cubic-bezier(0.16, 1, 0.3, 1);

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
}

/* ---------- 重置与基础 ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

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

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

ul {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ---------- 工具类 ---------- */
.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  position: relative;
  padding: var(--space-3xl) 0;
  overflow: hidden;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
  position: relative;
}

.section-title .highlight {
  color: var(--color-red);
}

.section-title .gold {
  color: var(--color-gold);
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 700px;
  margin-bottom: var(--space-xl);
}

.label {
  display: inline-block;
  font-family: var(--font-accent);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: var(--space-sm);
}

/* ---------- 背景装饰 ---------- */
.bg-gradient-radial {
  position: absolute;
  width: 60vw;
  height: 60vw;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(220, 20, 60, 0.12) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.bg-gradient-radial--top-right {
  top: -20vw;
  right: -20vw;
}

.bg-gradient-radial--bottom-left {
  bottom: -20vw;
  left: -20vw;
}

.bg-grid {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(rgba(220, 20, 60, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(220, 20, 60, 0.03) 1px, transparent 1px);
  background-size: 80px 80px;
  pointer-events: none;
  z-index: 0;
}

/* ---------- 导航 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--space-sm) 0;
  transition: all var(--transition-normal);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(5, 5, 5, 0.92);
  backdrop-filter: blur(20px);
  border-bottom-color: var(--color-border);
  padding: 0.75rem 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo-mark {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--color-red-dark), var(--color-red));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-accent);
  font-weight: 700;
  font-size: 1.2rem;
  color: #fff;
  box-shadow: 0 0 20px rgba(220, 20, 60, 0.4);
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.logo-text span {
  color: var(--color-red);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-muted);
  position: relative;
  padding: 0.5rem 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-red);
  transition: width var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-cta {
  background: linear-gradient(135deg, var(--color-red-dark), var(--color-red));
  color: #fff !important;
  padding: 0.7rem 1.5rem !important;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: all var(--transition-fast);
}

.nav-cta::after {
  display: none !important;
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(220, 20, 60, 0.4);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
  z-index: 1001;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all var(--transition-fast);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-red-dark), var(--color-red));
  color: #fff;
  box-shadow: 0 4px 20px rgba(220, 20, 60, 0.3);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(220, 20, 60, 0.5);
}

.btn-outline {
  border: 1px solid var(--color-border);
  color: var(--color-text);
  background: transparent;
}

.btn-outline:hover {
  border-color: var(--color-red);
  color: var(--color-red-bright);
  background: rgba(220, 20, 60, 0.05);
}

.btn-gold {
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-light));
  color: var(--color-bg);
  font-weight: 700;
}

.btn-gold:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(212, 175, 55, 0.3);
}

/* ---------- Hero 区域 ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  padding-top: 100px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(5,5,5,0.95) 0%, rgba(5,5,5,0.7) 50%, rgba(74,0,0,0.4) 100%);
  z-index: 1;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.6;
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: var(--space-xl);
  align-items: center;
}

.hero-content {
  max-width: 680px;
}

.hero-label {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-accent);
  font-size: 0.85rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: var(--space-md);
}

.hero-label::before {
  content: '';
  width: 40px;
  height: 1px;
  background: var(--color-gold);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 900;
  line-height: 1.1;
  margin-bottom: var(--space-md);
  letter-spacing: 0.02em;
}

.hero-title .red {
  color: var(--color-red);
}

.hero-title .gold {
  color: var(--color-gold);
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  max-width: 560px;
}

.hero-stats {
  display: flex;
  gap: var(--space-xl);
  margin: var(--space-xl) 0;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
}

.stat-item {
  text-align: left;
}

.stat-number {
  font-family: var(--font-accent);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-gold);
  line-height: 1;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 0.5rem;
}

.hero-actions {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-frame {
  position: relative;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.8);
}

.hero-image-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid var(--color-gold);
  border-radius: var(--radius-lg);
  transform: translate(12px, 12px);
  z-index: -1;
  opacity: 0.3;
}

.hero-image-frame img {
  width: 100%;
  max-width: 520px;
  opacity: 0.9;
}

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  z-index: 2;
}

.scroll-indicator::after {
  content: '';
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--color-red), transparent);
  animation: scrollPulse 2s infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.5); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* ---------- 卡片 ---------- */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-red), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.card:hover {
  transform: translateY(-8px);
  border-color: rgba(220, 20, 60, 0.4);
  background: var(--color-bg-card-hover);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

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

.card-icon {
  width: 56px;
  height: 56px;
  background: rgba(220, 20, 60, 0.1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
  color: var(--color-red);
  font-size: 1.4rem;
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.card-text {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ---------- 价值展示 ---------- */
.value-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.value-card {
  background: linear-gradient(145deg, rgba(17,17,17,0.9), rgba(10,10,10,0.95));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  position: relative;
  overflow: hidden;
  transition: all var(--transition-normal);
}

.value-card:hover {
  border-color: var(--color-red);
  transform: translateY(-5px);
}

.value-number {
  font-family: var(--font-accent);
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-gold);
  line-height: 1;
  margin-bottom: var(--space-md);
  opacity: 0.9;
}

.value-card h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: var(--space-xs);
}

.value-card p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* ---------- 课程体系 ---------- */
.course-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.course-image {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.course-image img {
  width: 100%;
  transition: transform var(--transition-slow);
}

.course-image:hover img {
  transform: scale(1.03);
}

.course-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.course-item {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.course-item:hover {
  border-color: var(--color-red);
  background: var(--color-bg-card-hover);
}

.course-item-number {
  font-family: var(--font-accent);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-red);
  line-height: 1;
  min-width: 40px;
}

.course-item-content h4 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin-bottom: 0.25rem;
}

.course-item-content p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* ---------- 困境与解决方案 ---------- */
.pain-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.pain-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(220, 20, 60, 0.05);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.pain-item i {
  color: var(--color-red);
  font-size: 1.2rem;
  margin-top: 0.2rem;
}

.pain-item h4 {
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.pain-item p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* ---------- 架构图区域 ---------- */
.architecture-section {
  background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-elevated) 50%, var(--color-bg) 100%);
}

.architecture-image {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.6);
}

.architecture-image img {
  width: 100%;
}

.architecture-caption {
  text-align: center;
  margin-top: var(--space-lg);
  font-family: var(--font-display);
  font-size: 1.3rem;
  color: var(--color-gold);
}

/* ---------- CTA 区域 ---------- */
.cta-section {
  position: relative;
  padding: var(--space-3xl) 0;
  text-align: center;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(220, 20, 60, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.cta-content {
  position: relative;
  z-index: 1;
}

.cta-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.cta-price {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  margin: var(--space-lg) 0;
  flex-wrap: wrap;
}

.price-original {
  font-size: 1.5rem;
  color: var(--color-text-dim);
  text-decoration: line-through;
}

.price-current {
  font-family: var(--font-accent);
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--color-gold);
}

.price-unit {
  font-size: 1.2rem;
  color: var(--color-text-muted);
}

/* ---------- 关于我们 ---------- */
.about-hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  padding-top: 120px;
  position: relative;
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

.about-content h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: var(--space-md);
  line-height: 1.3;
}

.about-content .lead {
  font-size: 1.2rem;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.about-content p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-top: var(--space-xl);
}

.team-card {
  text-align: center;
  padding: var(--space-lg);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.team-card:hover {
  border-color: var(--color-gold);
  transform: translateY(-5px);
}

.team-avatar {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--color-red-dark), var(--color-red));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: #fff;
}

.team-card h4 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin-bottom: 0.25rem;
}

.team-card p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* ---------- 产品服务 ---------- */
.services-hero {
  min-height: 60vh;
  display: flex;
  align-items: center;
  padding-top: 120px;
  text-align: center;
}

.services-hero .section-title {
  margin: 0 auto var(--space-md);
}

.services-hero .section-subtitle {
  margin: 0 auto var(--space-lg);
}

.service-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.service-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  transition: all var(--transition-normal);
  position: relative;
}

.service-card.featured {
  border-color: var(--color-gold);
  background: linear-gradient(145deg, rgba(17,17,17,0.95), rgba(74,0,0,0.3));
}

.service-card.featured::after {
  content: '推荐';
  position: absolute;
  top: 0;
  right: var(--space-md);
  background: var(--color-gold);
  color: var(--color-bg);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
}

.service-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-red);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

.service-price {
  font-family: var(--font-accent);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-gold);
  margin: var(--space-md) 0;
}

.service-price span {
  font-size: 1rem;
  color: var(--color-text-muted);
}

.service-features {
  margin: var(--space-md) 0;
}

.service-features li {
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.service-features li:last-child {
  border-bottom: none;
}

.service-features li i {
  color: var(--color-red);
  margin-right: 0.5rem;
}

/* ---------- 联系我们 ---------- */
.contact-hero {
  min-height: 60vh;
  display: flex;
  align-items: center;
  padding-top: 120px;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--space-2xl);
  align-items: start;
}

.contact-info-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.contact-info-item {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md) 0;
  border-bottom: 1px solid rgba(255,255,255,0.05);
}

.contact-info-item:last-child {
  border-bottom: none;
}

.contact-info-item i {
  width: 48px;
  height: 48px;
  background: rgba(220, 20, 60, 0.1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-red);
  font-size: 1.1rem;
  flex-shrink: 0;
}

.contact-info-item h4 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.contact-info-item p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.contact-form {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.form-group {
  margin-bottom: var(--space-md);
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.9rem 1rem;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-family: inherit;
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-red);
  background: rgba(220, 20, 60, 0.05);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

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

/* ---------- 页脚 ---------- */
.footer {
  background: var(--color-bg-elevated);
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) 0 var(--space-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand .logo-text {
  margin-bottom: var(--space-md);
}

.footer-brand p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  max-width: 300px;
}

.footer-column h4 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.footer-column li {
  margin-bottom: 0.75rem;
}

.footer-column a {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  transition: color var(--transition-fast);
}

.footer-column a:hover {
  color: var(--color-red);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.05);
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--color-text-dim);
  font-size: 0.85rem;
}

.footer-social {
  display: flex;
  gap: var(--space-sm);
}

.footer-social a {
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--color-red);
  border-color: var(--color-red);
  color: #fff;
}

/* ---------- 动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-slow);
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }
.stagger-6 { transition-delay: 0.6s; }

/* ---------- 页面内页通用标题 ---------- */
.page-header {
  min-height: 55vh;
  display: flex;
  align-items: center;
  padding-top: 120px;
  position: relative;
  text-align: center;
}

.page-header .container {
  position: relative;
  z-index: 2;
}

.page-header-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  margin-bottom: var(--space-md);
}

.page-header-subtitle {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  max-width: 700px;
  margin: 0 auto;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-grid,
  .about-grid,
  .contact-grid,
  .course-showcase {
    grid-template-columns: 1fr;
  }

  .value-grid,
  .service-cards {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    max-width: 320px;
    height: 100vh;
    background: rgba(5, 5, 5, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: var(--space-xl);
    gap: var(--space-lg);
    transition: right var(--transition-normal);
    border-left: 1px solid var(--color-border);
  }

  .nav-links.active {
    right: 0;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero-stats {
    flex-direction: column;
    gap: var(--space-md);
  }

  .value-grid,
  .service-cards,
  .pain-grid,
  .team-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .section {
    padding: var(--space-2xl) 0;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }

  .container {
    padding: 0 var(--space-md);
  }

  .hero-title {
    font-size: 2.5rem;
  }
}