/* ============================================================
   17C 智能科技官网 - 主样式文件
   深空黑 + 霓虹蓝紫渐变配色
   ============================================================ */

:root {
  --bg-primary: #050a14;
  --bg-secondary: #0a1628;
  --bg-card: rgba(10, 22, 40, 0.85);
  --neon-blue: #00c8ff;
  --neon-purple: #8b5cf6;
  --neon-cyan: #06b6d4;
  --gradient-main: linear-gradient(135deg, #00c8ff 0%, #8b5cf6 100%);
  --gradient-dark: linear-gradient(135deg, #0a1628 0%, #1a0a2e 100%);
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-accent: #00c8ff;
  --border-glow: rgba(0, 200, 255, 0.3);
  --shadow-neon: 0 0 20px rgba(0, 200, 255, 0.3), 0 0 40px rgba(139, 92, 246, 0.2);
  --font-main: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
}

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

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

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ---- 滚动条 ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--neon-blue); border-radius: 3px; }

/* ---- 通用容器 ---- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---- 通用按钮 ---- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: var(--gradient-main);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.btn-primary::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.1);
  opacity: 0;
  transition: opacity 0.3s;
}
.btn-primary:hover::before { opacity: 1; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-neon); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 30px;
  background: transparent;
  color: var(--neon-blue);
  font-size: 15px;
  font-weight: 600;
  border: 1.5px solid var(--neon-blue);
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.3s ease;
}
.btn-outline:hover {
  background: rgba(0, 200, 255, 0.1);
  box-shadow: 0 0 20px rgba(0, 200, 255, 0.3);
  transform: translateY(-2px);
}

/* ---- 章节标题 ---- */
.section-header {
  text-align: center;
  margin-bottom: 60px;
}
.section-tag {
  display: inline-block;
  padding: 6px 18px;
  background: rgba(0, 200, 255, 0.1);
  border: 1px solid rgba(0, 200, 255, 0.3);
  border-radius: 20px;
  color: var(--neon-blue);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 16px;
}
.section-title span {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ---- 卡片通用 ---- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  padding: 32px;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}
.card:hover {
  border-color: var(--neon-blue);
  box-shadow: var(--shadow-neon);
  transform: translateY(-4px);
}

/* ============================================================
   头部导航
   ============================================================ */
#header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(5, 10, 20, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 200, 255, 0.1);
  transition: all 0.3s ease;
}
#header.scrolled {
  background: rgba(5, 10, 20, 0.98);
  border-bottom-color: rgba(0, 200, 255, 0.2);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.logo-mark {
  width: 42px;
  height: 42px;
  background: var(--gradient-main);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 900;
  color: #fff;
  letter-spacing: -1px;
  box-shadow: 0 0 15px rgba(0, 200, 255, 0.4);
}
.logo-text {
  font-size: 20px;
  font-weight: 700;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}
.nav-menu a {
  display: block;
  padding: 8px 16px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  border-radius: 8px;
  transition: all 0.2s;
}
.nav-menu a:hover, .nav-menu a.active {
  color: var(--neon-blue);
  background: rgba(0, 200, 255, 0.08);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ---- 搜索框 ---- */
.search-bar-wrap {
  background: rgba(10, 22, 40, 0.95);
  border-bottom: 1px solid rgba(0, 200, 255, 0.15);
  padding: 12px 0;
  display: none;
}
.search-bar-wrap.active { display: block; }
.search-bar-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: 700px;
  margin: 0 auto;
  padding: 0 24px;
}
.search-input {
  flex: 1;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(0, 200, 255, 0.3);
  border-radius: 8px;
  padding: 10px 16px;
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}
.search-input:focus { border-color: var(--neon-blue); }
.search-input::placeholder { color: var(--text-secondary); }
.search-btn {
  padding: 10px 24px;
  background: var(--gradient-main);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-size: 14px;
  cursor: pointer;
  transition: opacity 0.2s;
}
.search-btn:hover { opacity: 0.85; }
.search-close {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 20px;
  cursor: pointer;
  padding: 4px 8px;
}

/* ============================================================
   Hero Banner
   ============================================================ */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 70px;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--bg-primary);
}
.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(5,10,20,0.85) 0%, rgba(5,10,20,0.5) 50%, rgba(5,10,20,0.85) 100%);
}
.hero-particles {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 750px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(0, 200, 255, 0.1);
  border: 1px solid rgba(0, 200, 255, 0.3);
  border-radius: 30px;
  color: var(--neon-blue);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 28px;
  animation: fadeInDown 0.8s ease;
}
.hero-badge::before {
  content: '';
  width: 8px;
  height: 8px;
  background: var(--neon-blue);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--neon-blue);
  animation: pulse 2s infinite;
}
.hero-title {
  font-size: clamp(36px, 5.5vw, 68px);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 24px;
  animation: fadeInUp 0.8s ease 0.2s both;
}
.hero-title .brand { color: var(--neon-blue); }
.hero-title .gradient-text {
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 580px;
  animation: fadeInUp 0.8s ease 0.4s both;
}
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease 0.6s both;
}
.hero-stats {
  display: flex;
  gap: 48px;
  margin-top: 64px;
  animation: fadeInUp 0.8s ease 0.8s both;
}
.stat-item { text-align: left; }
.stat-num {
  font-size: 36px;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}
.stat-label {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ============================================================
   产品矩阵
   ============================================================ */
#products {
  padding: 100px 0;
  position: relative;
}
.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  padding: 36px 28px;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-main);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}
.product-card:hover::before { transform: scaleX(1); }
.product-card:hover {
  border-color: var(--neon-blue);
  box-shadow: var(--shadow-neon);
  transform: translateY(-6px);
}
.product-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 24px;
}
.product-icon {
  width: 56px;
  height: 56px;
  background: rgba(0, 200, 255, 0.1);
  border: 1px solid rgba(0, 200, 255, 0.2);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}
.product-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
}
.product-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}
.product-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.product-tag {
  padding: 4px 12px;
  background: rgba(0, 200, 255, 0.08);
  border: 1px solid rgba(0, 200, 255, 0.2);
  border-radius: 20px;
  font-size: 12px;
  color: var(--neon-blue);
}
.product-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--neon-blue);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  margin-top: 20px;
  transition: gap 0.2s;
}
.product-link:hover { gap: 10px; }

/* ============================================================
   核心技术引擎
   ============================================================ */
#tech {
  padding: 100px 0;
  background: var(--gradient-dark);
  position: relative;
  overflow: hidden;
}
.tech-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.tech-visual {
  position: relative;
}
.tech-visual img {
  width: 100%;
  border-radius: 20px;
  border: 1px solid var(--border-glow);
  box-shadow: var(--shadow-neon);
}
.tech-features {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.tech-feature {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}
.tech-feature-icon {
  width: 48px;
  height: 48px;
  min-width: 48px;
  background: rgba(0, 200, 255, 0.1);
  border: 1px solid rgba(0, 200, 255, 0.2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}
.tech-feature-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.tech-feature-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ============================================================
   行业解决方案
   ============================================================ */
#solutions {
  padding: 100px 0;
}
.solutions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}
.solution-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}
.solution-card:hover {
  border-color: var(--neon-purple);
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.3);
  transform: translateY(-4px);
}
.solution-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}
.solution-body {
  padding: 28px;
}
.solution-industry {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(139, 92, 246, 0.1);
  border: 1px solid rgba(139, 92, 246, 0.3);
  border-radius: 20px;
  font-size: 12px;
  color: var(--neon-purple);
  margin-bottom: 12px;
}
.solution-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}
.solution-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}
.solution-benefits {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.solution-benefits li {
  font-size: 13px;
  color: var(--neon-cyan);
  display: flex;
  align-items: center;
  gap: 8px;
}
.solution-benefits li::before {
  content: '✓';
  font-weight: 700;
}

/* ============================================================
   价值交付流程
   ============================================================ */
#process {
  padding: 100px 0;
  background: var(--gradient-dark);
}
.process-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0;
  position: relative;
}
.process-steps::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 10%;
  right: 10%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--neon-blue), var(--neon-purple), transparent);
}
.process-step {
  text-align: center;
  padding: 0 20px;
  position: relative;
}
.step-num {
  width: 80px;
  height: 80px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  font-weight: 900;
  color: #fff;
  margin: 0 auto 24px;
  box-shadow: var(--shadow-neon);
  position: relative;
  z-index: 1;
}
.step-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}
.step-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ============================================================
   视频专区
   ============================================================ */
#videos {
  padding: 100px 0;
}
.videos-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.video-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
}
.video-card:hover {
  border-color: var(--neon-blue);
  box-shadow: var(--shadow-neon);
  transform: translateY(-4px);
}
.video-thumb {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  overflow: hidden;
}
.video-thumb img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.05); }
.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(5, 10, 20, 0.4);
  opacity: 0;
  transition: opacity 0.3s ease;
}
.video-card:hover .video-play-btn { opacity: 1; }
.play-icon {
  width: 64px;
  height: 64px;
  background: rgba(0, 200, 255, 0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 30px rgba(0, 200, 255, 0.6);
  transition: transform 0.2s;
}
.video-card:hover .play-icon { transform: scale(1.1); }
.play-icon::after {
  content: '';
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 12px 0 12px 22px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}
.video-meta {
  padding: 20px;
}
.video-category {
  display: inline-block;
  padding: 3px 10px;
  background: rgba(0, 200, 255, 0.1);
  border-radius: 20px;
  font-size: 11px;
  color: var(--neon-blue);
  margin-bottom: 8px;
}
.video-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.5;
}
.video-stats {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--text-secondary);
}
.video-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0,0,0,0.9);
  align-items: center;
  justify-content: center;
}
.video-modal.active { display: flex; }
.video-modal-inner {
  position: relative;
  width: 90%;
  max-width: 900px;
  background: var(--bg-secondary);
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border-glow);
}
.video-modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  z-index: 1;
  width: 36px;
  height: 36px;
  background: rgba(0,0,0,0.6);
  border: none;
  border-radius: 50%;
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.video-modal video {
  width: 100%;
  display: block;
  background: #000;
}
.video-modal-info {
  padding: 20px 24px;
}
.video-modal-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

/* ============================================================
   标杆案例
   ============================================================ */
#cases {
  padding: 100px 0;
  background: var(--gradient-dark);
}
.cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.case-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  padding: 32px;
  transition: all 0.3s ease;
}
.case-card:hover {
  border-color: var(--neon-cyan);
  box-shadow: 0 0 20px rgba(6, 182, 212, 0.3);
  transform: translateY(-4px);
}
.case-industry {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: 20px;
  font-size: 12px;
  color: var(--neon-cyan);
  margin-bottom: 16px;
}
.case-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.4;
}
.case-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}
.case-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--neon-cyan);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  transition: gap 0.2s;
}
.case-link:hover { gap: 10px; }

/* ============================================================
   科技动态
   ============================================================ */
#news {
  padding: 100px 0;
}
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}
.news-card:hover {
  border-color: var(--neon-blue);
  box-shadow: var(--shadow-neon);
  transform: translateY(-4px);
}
.news-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 0.4s;
}
.news-card:hover .news-img { transform: scale(1.03); }
.news-img-wrap { overflow: hidden; }
.news-body { padding: 24px; }
.news-date {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 10px;
}
.news-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.5;
}
.news-excerpt {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}
.news-link {
  color: var(--neon-blue);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.2s;
}
.news-link:hover { gap: 8px; }

/* ============================================================
   用户评价
   ============================================================ */
#reviews {
  padding: 100px 0;
  background: var(--gradient-dark);
}
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 16px;
  padding: 28px;
  transition: all 0.3s ease;
}
.review-card:hover {
  border-color: var(--neon-purple);
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.2);
}
.review-stars {
  color: #fbbf24;
  font-size: 16px;
  margin-bottom: 16px;
  letter-spacing: 2px;
}
.review-text {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 20px;
  font-style: italic;
}
.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}
.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.review-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
}
.review-role {
  font-size: 12px;
  color: var(--text-secondary);
}

/* ============================================================
   FAQ
   ============================================================ */
#faq {
  padding: 100px 0;
}
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s;
}
.faq-item.active { border-color: var(--neon-blue); }
.faq-question {
  width: 100%;
  background: none;
  border: none;
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  cursor: pointer;
  text-align: left;
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 600;
  transition: color 0.2s;
}
.faq-item.active .faq-question { color: var(--neon-blue); }
.faq-icon {
  width: 24px;
  height: 24px;
  min-width: 24px;
  border: 1.5px solid currentColor;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: transform 0.3s;
}
.faq-item.active .faq-icon { transform: rotate(45deg); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s;
}
.faq-item.active .faq-answer { max-height: 300px; }
.faq-answer-inner {
  padding: 0 24px 20px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ============================================================
   联系我们
   ============================================================ */
#contact {
  padding: 100px 0;
  background: var(--gradient-dark);
}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}
.contact-info { display: flex; flex-direction: column; gap: 24px; }
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.contact-icon {
  width: 48px;
  height: 48px;
  min-width: 48px;
  background: rgba(0, 200, 255, 0.1);
  border: 1px solid rgba(0, 200, 255, 0.2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}
.contact-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}
.contact-value {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}
.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-glow);
  border-radius: 20px;
  padding: 40px;
}
.form-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 28px;
}
.form-group { margin-bottom: 20px; }
.form-label {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  font-weight: 500;
}
.form-input, .form-textarea {
  width: 100%;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(0, 200, 255, 0.2);
  border-radius: 8px;
  padding: 12px 16px;
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font-main);
  outline: none;
  transition: border-color 0.2s;
}
.form-input:focus, .form-textarea:focus { border-color: var(--neon-blue); }
.form-textarea { height: 120px; resize: vertical; }
.form-submit {
  width: 100%;
  padding: 14px;
  background: var(--gradient-main);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.2s;
}
.form-submit:hover { opacity: 0.9; transform: translateY(-1px); }

/* ============================================================
   页脚
   ============================================================ */
#footer {
  background: rgba(3, 7, 14, 0.98);
  border-top: 1px solid rgba(0, 200, 255, 0.1);
  padding: 60px 0 30px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand .logo { margin-bottom: 16px; }
.footer-brand-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 20px;
}
.footer-col-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  letter-spacing: 1px;
}
.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-links a {
  font-size: 13px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-links a:hover { color: var(--neon-blue); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-copyright {
  font-size: 13px;
  color: var(--text-secondary);
}
.footer-copyright a { color: var(--neon-blue); text-decoration: none; }
.footer-update {
  font-size: 12px;
  color: var(--text-secondary);
}

/* ============================================================
   内页通用
   ============================================================ */
.page-hero {
  padding: 140px 0 80px;
  background: var(--gradient-dark);
  text-align: center;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(0,200,255,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.page-hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 900;
  margin-bottom: 16px;
}
.page-hero p {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 20px;
  justify-content: center;
}
.breadcrumb a { color: var(--neon-blue); text-decoration: none; }
.breadcrumb span { color: var(--text-secondary); }

/* ============================================================
   动画
   ============================================================ */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.8); }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
@keyframes glow {
  0%, 100% { box-shadow: 0 0 20px rgba(0,200,255,0.3); }
  50% { box-shadow: 0 0 40px rgba(0,200,255,0.6); }
}
.float-anim { animation: float 4s ease-in-out infinite; }
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1024px) {
  .tech-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-menu { display: none; position: fixed; top: 70px; left: 0; right: 0; background: rgba(5,10,20,0.98); flex-direction: column; padding: 20px; border-bottom: 1px solid var(--border-glow); }
  .nav-menu.open { display: flex; }
  .nav-toggle { display: flex; }
  .hero-stats { gap: 24px; flex-wrap: wrap; }
  .process-steps::before { display: none; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .header-actions .btn-primary { display: none; }
}
@media (max-width: 480px) {
  .hero-actions { flex-direction: column; }
  .hero-actions .btn-primary, .hero-actions .btn-outline { width: 100%; justify-content: center; }
  .section-header { margin-bottom: 40px; }
}