/* =====================================================
   17C视频网 - 主样式文件
   极简高端风格 | 百度SEO优化版
   ===================================================== */

/* ---- CSS变量 ---- */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8f8f6;
  --color-bg-dark: #0d1117;
  --color-primary: #1a1a2e;
  --color-accent: #e63946;
  --color-accent2: #457b9d;
  --color-text: #1c1c1e;
  --color-text-muted: #6b7280;
  --color-border: #e5e7eb;
  --color-white: #ffffff;
  --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', monospace;
  --radius: 8px;
  --radius-lg: 16px;
  --shadow: 0 4px 24px rgba(0,0,0,0.08);
  --shadow-hover: 0 12px 40px rgba(0,0,0,0.15);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1200px;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ---- 容器 ---- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.section { padding: 80px 0; }
.section-sm { padding: 60px 0; }
.section-lg { padding: 120px 0; }

/* ---- 标题系统 ---- */
.section-label {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}
.section-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-primary);
  margin-bottom: 20px;
}
.section-desc {
  font-size: 17px;
  color: var(--color-text-muted);
  max-width: 560px;
  line-height: 1.8;
}
.text-center { text-align: center; }
.text-center .section-desc { margin: 0 auto; }

/* ---- 按钮 ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
}
.btn-primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 4px 16px rgba(230,57,70,0.3);
}
.btn-primary:hover {
  background: #c1121f;
  box-shadow: 0 8px 24px rgba(230,57,70,0.4);
  transform: translateY(-2px);
}
.btn-outline {
  border: 1.5px solid var(--color-primary);
  color: var(--color-primary);
}
.btn-outline:hover {
  background: var(--color-primary);
  color: #fff;
}
.btn-ghost {
  color: var(--color-accent);
  padding: 0;
  font-size: 14px;
}
.btn-ghost:hover { text-decoration: underline; }

/* =====================================================
   顶部导航
   ===================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: var(--transition);
}
.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 24px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 800;
  color: var(--color-primary);
  flex-shrink: 0;
}
.logo-mark {
  width: 36px;
  height: 36px;
  background: var(--color-accent);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: -0.5px;
}
.logo-text span { color: var(--color-accent); }

.site-nav { display: flex; align-items: center; gap: 4px; }
.site-nav a {
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.site-nav a:hover, .site-nav a.active {
  color: var(--color-primary);
  background: var(--color-bg-alt);
}

/* 搜索框 */
.header-search {
  position: relative;
  flex: 1;
  max-width: 280px;
}
.header-search input {
  width: 100%;
  height: 38px;
  padding: 0 16px 0 38px;
  border: 1.5px solid var(--color-border);
  border-radius: 20px;
  font-size: 14px;
  color: var(--color-text);
  background: var(--color-bg-alt);
  transition: var(--transition);
  outline: none;
}
.header-search input:focus {
  border-color: var(--color-accent);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(230,57,70,0.1);
}
.header-search .search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
}
.search-tips {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 12px 0;
  display: none;
  z-index: 100;
}
.search-tips.show { display: block; }
.search-tip-item {
  padding: 8px 16px;
  font-size: 13px;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition);
}
.search-tip-item:hover { background: var(--color-bg-alt); color: var(--color-text); }

.header-actions { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  cursor: pointer;
}
.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

/* =====================================================
   搜索栏（导航下方）
   ===================================================== */
.search-bar-section {
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  padding: 12px 0;
}
.search-bar-inner {
  display: flex;
  align-items: center;
  gap: 12px;
}
.search-bar-wrap {
  position: relative;
  flex: 1;
  max-width: 600px;
}
.search-bar-wrap input {
  width: 100%;
  height: 44px;
  padding: 0 20px 0 48px;
  border: 1.5px solid var(--color-border);
  border-radius: 22px;
  font-size: 15px;
  background: #fff;
  outline: none;
  transition: var(--transition);
}
.search-bar-wrap input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(230,57,70,0.1);
}
.search-bar-wrap .sb-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
}
.search-bar-btn {
  height: 44px;
  padding: 0 24px;
  background: var(--color-accent);
  color: #fff;
  border-radius: 22px;
  font-size: 14px;
  font-weight: 600;
  transition: var(--transition);
}
.search-bar-btn:hover { background: #c1121f; }
.search-hot-tags {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.search-hot-tags .tag-label { font-size: 13px; color: var(--color-text-muted); white-space: nowrap; }
.hot-tag {
  display: inline-block;
  padding: 4px 12px;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  font-size: 12px;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition);
}
.hot-tag:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* =====================================================
   首屏 Banner
   ===================================================== */
.hero-section {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--color-bg-dark);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.35;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(13,17,23,0.9) 0%, rgba(13,17,23,0.5) 60%, rgba(69,123,157,0.2) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 700px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(230,57,70,0.15);
  border: 1px solid rgba(230,57,70,0.3);
  border-radius: 20px;
  padding: 6px 16px;
  font-size: 13px;
  color: #ff8fa3;
  margin-bottom: 28px;
}
.hero-badge .dot {
  width: 6px;
  height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.5); }
}
.hero-title {
  font-size: clamp(36px, 6vw, 72px);
  font-weight: 800;
  line-height: 1.1;
  color: #fff;
  margin-bottom: 24px;
  letter-spacing: -1px;
}
.hero-title .accent { color: var(--color-accent); }
.hero-subtitle {
  font-size: clamp(16px, 2vw, 20px);
  color: rgba(255,255,255,0.7);
  line-height: 1.7;
  margin-bottom: 40px;
  max-width: 540px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid rgba(255,255,255,0.1);
}
.hero-stat-item { text-align: left; }
.hero-stat-num {
  font-size: 32px;
  font-weight: 800;
  color: #fff;
  line-height: 1;
}
.hero-stat-num span { color: var(--color-accent); }
.hero-stat-label { font-size: 13px; color: rgba(255,255,255,0.5); margin-top: 4px; }

/* =====================================================
   视频卡片
   ===================================================== */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.video-card {
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}
.video-thumb {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
  background: #1a1a2e;
}
.video-thumb img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s 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(0,0,0,0.3);
  opacity: 0;
  transition: var(--transition);
}
.video-card:hover .video-play-btn { opacity: 1; }
.play-circle {
  width: 60px;
  height: 60px;
  background: rgba(255,255,255,0.95);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: scale(0.8);
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.video-card:hover .play-circle { transform: scale(1); }
.play-icon {
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent var(--color-accent);
  margin-left: 4px;
}
.video-duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-size: 12px;
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 500;
}
.video-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--color-accent);
  color: #fff;
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 4px;
  font-weight: 600;
}
.video-info { padding: 16px 20px 20px; }
.video-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.5;
  margin-bottom: 10px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--color-text-muted);
}
.video-meta-item { display: flex; align-items: center; gap: 4px; }
.video-author { display: flex; align-items: center; gap: 8px; margin-top: 12px; }
.video-author-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  object-fit: cover;
}
.video-author-name { font-size: 13px; color: var(--color-text-muted); }

/* =====================================================
   品牌介绍
   ===================================================== */
.about-section { background: var(--color-bg-alt); }
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}
.about-img-wrap {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.about-img-wrap img { width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.about-img-badge {
  position: absolute;
  bottom: 24px;
  left: 24px;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(8px);
  border-radius: var(--radius);
  padding: 16px 20px;
  box-shadow: var(--shadow);
}
.about-img-badge .num { font-size: 28px; font-weight: 800; color: var(--color-accent); }
.about-img-badge .label { font-size: 12px; color: var(--color-text-muted); }
.about-content .section-desc { margin-bottom: 32px; }
.about-features { display: flex; flex-direction: column; gap: 16px; }
.about-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}
.about-feature-icon {
  width: 40px;
  height: 40px;
  background: rgba(230,57,70,0.1);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--color-accent);
  font-size: 18px;
}
.about-feature-text h4 { font-size: 15px; font-weight: 600; margin-bottom: 4px; }
.about-feature-text p { font-size: 14px; color: var(--color-text-muted); }

/* =====================================================
   服务/功能模块
   ===================================================== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.service-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-accent);
  transform: scaleX(0);
  transition: var(--transition);
}
.service-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); }
.service-card:hover::before { transform: scaleX(1); }
.service-icon {
  width: 52px;
  height: 52px;
  background: rgba(230,57,70,0.08);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 20px;
}
.service-title { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.service-desc { font-size: 14px; color: var(--color-text-muted); line-height: 1.7; }

/* =====================================================
   数据/优势
   ===================================================== */
.stats-section {
  background: var(--color-primary);
  color: #fff;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  text-align: center;
}
.stat-item {}
.stat-num {
  font-size: 48px;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 8px;
}
.stat-num .unit { font-size: 24px; color: var(--color-accent); }
.stat-label { font-size: 14px; color: rgba(255,255,255,0.6); }
.stat-desc { font-size: 13px; color: rgba(255,255,255,0.4); margin-top: 4px; }

/* =====================================================
   用户评价
   ===================================================== */
.reviews-section { background: var(--color-bg-alt); }
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}
.review-card {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.review-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.review-header { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}
.review-avatar-placeholder {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-user-name { font-size: 15px; font-weight: 600; }
.review-user-tag { font-size: 12px; color: var(--color-text-muted); margin-top: 2px; }
.review-stars { display: flex; gap: 2px; margin-bottom: 12px; }
.star { color: #fbbf24; font-size: 16px; }
.review-text { font-size: 14px; color: var(--color-text-muted); line-height: 1.8; }
.review-date { font-size: 12px; color: #d1d5db; margin-top: 12px; }

/* =====================================================
   FAQ
   ===================================================== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border-bottom: 1px solid var(--color-border);
}
.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 0;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  transition: var(--transition);
  gap: 16px;
}
.faq-question:hover { color: var(--color-accent); }
.faq-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 1.5px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: var(--transition);
  font-size: 14px;
  color: var(--color-text-muted);
}
.faq-item.open .faq-icon {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
  transform: rotate(45deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}
.faq-answer-inner {
  padding-bottom: 20px;
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.8;
}
.faq-item.open .faq-answer { max-height: 300px; }

/* =====================================================
   联系我们
   ===================================================== */
.contact-section {}
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 60px;
  align-items: start;
}
.contact-info-list { display: flex; flex-direction: column; gap: 24px; margin-top: 32px; }
.contact-info-item { display: flex; align-items: flex-start; gap: 16px; }
.contact-info-icon {
  width: 44px;
  height: 44px;
  background: rgba(230,57,70,0.08);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}
.contact-info-text h4 { font-size: 14px; font-weight: 600; margin-bottom: 4px; }
.contact-info-text p { font-size: 14px; color: var(--color-text-muted); }
.contact-social { display: flex; gap: 12px; margin-top: 32px; }
.social-link {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--color-bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: var(--transition);
  color: var(--color-text-muted);
}
.social-link:hover { background: var(--color-accent); color: #fff; transform: translateY(-2px); }

/* 联系表单 */
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-label { font-size: 13px; font-weight: 600; color: var(--color-text); }
.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--color-text);
  background: #fff;
  transition: var(--transition);
  outline: none;
}
.form-input:focus, .form-textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(230,57,70,0.1);
}
.form-textarea { resize: vertical; min-height: 120px; }

/* =====================================================
   页脚
   ===================================================== */
.site-footer {
  background: var(--color-primary);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-brand .site-logo { color: #fff; margin-bottom: 16px; }
.footer-brand p { font-size: 14px; line-height: 1.8; max-width: 280px; }
.footer-col h4 {
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 20px;
  letter-spacing: 0.05em;
}
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links a {
  font-size: 14px;
  color: rgba(255,255,255,0.55);
  transition: var(--transition);
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  font-size: 13px;
  color: rgba(255,255,255,0.4);
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom a { color: rgba(255,255,255,0.4); transition: var(--transition); }
.footer-bottom a:hover { color: rgba(255,255,255,0.8); }
.footer-bottom-links { display: flex; gap: 20px; }

/* =====================================================
   面包屑
   ===================================================== */
.breadcrumb {
  padding: 16px 0;
  font-size: 13px;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--color-text-muted); transition: var(--transition); }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb .sep { color: #d1d5db; }
.breadcrumb .current { color: var(--color-text); }

/* =====================================================
   内页通用
   ===================================================== */
.page-hero {
  background: var(--color-primary);
  color: #fff;
  padding: 80px 0 60px;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(230,57,70,0.15) 0%, transparent 70%);
  pointer-events: none;
}
.page-hero-title { font-size: clamp(28px, 4vw, 48px); font-weight: 800; margin-bottom: 12px; }
.page-hero-desc { font-size: 16px; color: rgba(255,255,255,0.65); max-width: 500px; }

/* 文章内容 */
.article-content {
  font-size: 16px;
  line-height: 1.9;
  color: var(--color-text);
}
.article-content h2 { font-size: 24px; font-weight: 700; margin: 40px 0 16px; }
.article-content h3 { font-size: 20px; font-weight: 600; margin: 32px 0 12px; }
.article-content p { margin-bottom: 20px; }
.article-content ul, .article-content ol { padding-left: 24px; margin-bottom: 20px; }
.article-content li { margin-bottom: 8px; }

/* =====================================================
   分类标签
   ===================================================== */
.category-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
.category-tab {
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  border: 1.5px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition);
  background: #fff;
}
.category-tab:hover, .category-tab.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

/* =====================================================
   加载更多
   ===================================================== */
.load-more-wrap { text-align: center; margin-top: 48px; }

/* =====================================================
   Toast提示
   ===================================================== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--color-primary);
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 14px;
  z-index: 9999;
  transition: transform 0.3s ease;
  box-shadow: var(--shadow-hover);
}
.toast.show { transform: translateX(-50%) translateY(0); }

/* =====================================================
   响应式
   ===================================================== */
@media (max-width: 1024px) {
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
  .section-lg { padding: 80px 0; }
  .site-nav { display: none; }
  .header-search { display: none; }
  .mobile-menu-btn { display: flex; }
  .hero-stats { gap: 24px; flex-wrap: wrap; }
  .contact-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .services-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .video-grid { grid-template-columns: 1fr; }
  .reviews-grid { grid-template-columns: 1fr; }
  .search-bar-inner { flex-direction: column; align-items: stretch; }
  .search-hot-tags { display: none; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .hero-title { font-size: 32px; }
  .hero-actions { flex-direction: column; }
  .btn { width: 100%; justify-content: center; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .stat-num { font-size: 36px; }
}

/* =====================================================
   动画
   ===================================================== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
.animate-fade-up { animation: fadeInUp 0.6s ease forwards; }
.animate-fade { animation: fadeIn 0.5s ease forwards; }

/* 滚动动画 */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* =====================================================
   移动端菜单
   ===================================================== */
.mobile-nav {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 999;
}
.mobile-nav.open { display: block; }
.mobile-nav-panel {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 280px;
  background: #fff;
  padding: 24px;
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.3s ease;
}
.mobile-nav.open .mobile-nav-panel { transform: translateX(0); }
.mobile-nav-close {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 24px;
}
.mobile-nav-links { display: flex; flex-direction: column; gap: 4px; }
.mobile-nav-links a {
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  transition: var(--transition);
}
.mobile-nav-links a:hover { background: var(--color-bg-alt); color: var(--color-accent); }