/* ============================================
   91 - 动物写真与视频社区 | 3dtooLing.cn
   原创CSS样式 v1.0
   ============================================ */

/* === 基础重置与变量 === */
:root {
  --c-primary: #1A5C3A;
  --c-primary-light: #2A7D52;
  --c-primary-dark: #0F3D26;
  --c-accent: #F5A623;
  --c-accent-light: #FFD06B;
  --c-danger: #E8433E;
  --c-bg: #F8F6F0;
  --c-bg-dark: #0D2818;
  --c-text: #2D2D2D;
  --c-text-light: #6B7B8D;
  --c-text-white: #F0F0F0;
  --c-border: #E2DDD5;
  --c-card: #FFFFFF;
  --c-shadow: rgba(26,92,58,0.12);
  --font-main: 'PingFang SC','Hiragino Sans GB','Microsoft YaHei','Helvetica Neue',Arial,sans-serif;
  --font-title: 'PingFang SC','STHeiti','SimHei',sans-serif;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --max-w: 1280px;
}

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

html { font-size:16px; scroll-behavior:smooth; -webkit-text-size-adjust:100%; }

body {
  font-family: var(--font-main);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.75;
  overflow-x: hidden;
}

a { color: var(--c-primary); text-decoration:none; transition: var(--transition); }
a:hover { color: var(--c-accent); }

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

h1,h2,h3,h4,h5,h6 {
  font-family: var(--font-title);
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-primary-dark);
}

h1 { font-size: 2.4rem; margin-bottom: 1rem; }
h2 { font-size: 1.9rem; margin-bottom: 0.85rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.7rem; }
h4 { font-size: 1.25rem; margin-bottom: 0.6rem; }
h5 { font-size: 1.1rem; margin-bottom: 0.5rem; }
h6 { font-size: 1rem; margin-bottom: 0.4rem; }

p { margin-bottom: 1rem; }

.container { max-width: var(--max-w); margin: 0 auto; padding: 0 20px; }

/* === 干扰标签隐藏 === */
.jrtag { position:absolute; width:0; height:0; overflow:hidden; opacity:0; pointer-events:none; z-index:-9999; }

/* === 顶部导航 === */
.site-header {
  background: var(--c-card);
  box-shadow: 0 2px 16px var(--c-shadow);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 3px solid var(--c-primary);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--c-primary);
}

.site-logo img { width: 44px; height: 44px; border-radius: 8px; }

.site-logo span { letter-spacing: 1px; }

/* 导航菜单 */
.main-nav { display: flex; align-items: center; gap: 0; }

.main-nav a {
  display: block;
  padding: 0 16px;
  height: 72px;
  line-height: 72px;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--c-text);
  position: relative;
  white-space: nowrap;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 3px;
  background: var(--c-accent);
  transition: var(--transition);
  border-radius: 3px 3px 0 0;
}

.main-nav a:hover { color: var(--c-primary); background: rgba(26,92,58,0.04); }
.main-nav a:hover::after { width: 60%; }
.main-nav a.active { color: var(--c-primary); }
.main-nav a.active::after { width: 60%; }

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 26px;
  height: 3px;
  background: var(--c-primary);
  margin: 5px 0;
  border-radius: 2px;
  transition: var(--transition);
}

/* === 搜索栏 === */
.search-bar {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
  padding: 14px 0;
}

.search-bar-inner {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  gap: 0;
}

.search-bar input {
  flex: 1;
  height: 46px;
  padding: 0 20px;
  border: none;
  border-radius: var(--radius) 0 0 var(--radius);
  font-size: 0.95rem;
  outline: none;
  background: var(--c-card);
  color: var(--c-text);
}

.search-bar input::placeholder { color: var(--c-text-light); }

.search-bar button {
  height: 46px;
  padding: 0 28px;
  background: var(--c-accent);
  color: #fff;
  border: none;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.search-bar button:hover { background: #E09515; }

/* === Banner区域 === */
.hero-banner {
  position: relative;
  width: 100%;
  min-height: 520px;
  overflow: hidden;
  display: flex;
  align-items: center;
}

.hero-banner .hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.55);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 80px 40px;
  color: #fff;
}

.hero-content h1 {
  font-size: 3rem;
  color: #fff;
  text-shadow: 0 3px 20px rgba(0,0,0,0.4);
  margin-bottom: 16px;
}

.hero-content p {
  font-size: 1.15rem;
  max-width: 640px;
  line-height: 1.85;
  color: rgba(255,255,255,0.92);
  text-shadow: 0 1px 8px rgba(0,0,0,0.3);
}

.hero-btns {
  margin-top: 28px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--c-accent);
  color: #fff;
  box-shadow: 0 4px 16px rgba(245,166,35,0.35);
}

.btn-primary:hover { background: #E09515; color: #fff; transform: translateY(-2px); }

.btn-outline {
  background: transparent;
  color: #fff;
  border: 2px solid rgba(255,255,255,0.7);
}

.btn-outline:hover { background: rgba(255,255,255,0.15); color: #fff; }

/* === 面包屑 === */
.breadcrumb {
  padding: 14px 0;
  font-size: 0.88rem;
  color: var(--c-text-light);
}

.breadcrumb a { color: var(--c-primary); }
.breadcrumb a:hover { color: var(--c-accent); }
.breadcrumb span { margin: 0 6px; color: var(--c-border); }

/* === 通用区块 === */
.section {
  padding: 64px 0;
}

.section-alt {
  background: var(--c-card);
}

.section-dark {
  background: var(--c-bg-dark);
  color: var(--c-text-white);
}

.section-dark h2, .section-dark h3, .section-dark h4 { color: #fff; }

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 { position: relative; display: inline-block; }

.section-header h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--c-accent);
  margin: 12px auto 0;
  border-radius: 2px;
}

.section-header p {
  color: var(--c-text-light);
  max-width: 640px;
  margin: 16px auto 0;
  font-size: 1.02rem;
}

/* === 视频卡片 === */
.video-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.video-card {
  background: var(--c-card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 20px var(--c-shadow);
  transition: var(--transition);
  cursor: pointer;
}

.video-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 36px rgba(26,92,58,0.18);
}

.video-card .thumb {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
}

.video-card .thumb img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.video-card:hover .thumb img { transform: scale(1.06); }

.video-card .play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.8);
  width: 56px;
  height: 56px;
  background: rgba(245,166,35,0.92);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.video-card:hover .play-btn { opacity: 1; transform: translate(-50%, -50%) scale(1); }

.play-btn::after {
  content: '';
  display: block;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 3px;
}

.video-card .duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 500;
}

.video-card .card-body { padding: 16px; }

.video-card .card-body h4 {
  font-size: 1rem;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  color: var(--c-text);
}

.video-card .meta {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.82rem;
  color: var(--c-text-light);
}

.video-card .meta-item { display: flex; align-items: center; gap: 4px; }

/* === 内容卡片网格 === */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.content-card {
  background: var(--c-card);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 20px var(--c-shadow);
  transition: var(--transition);
}

.content-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 32px rgba(26,92,58,0.16);
}

.content-card .card-img {
  position: relative;
  padding-top: 60%;
  overflow: hidden;
}

.content-card .card-img img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.content-card:hover .card-img img { transform: scale(1.05); }

.content-card .card-content { padding: 22px; }

.content-card .card-content h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.content-card .card-content p {
  color: var(--c-text-light);
  font-size: 0.92rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.content-card .card-tag {
  display: inline-block;
  padding: 3px 12px;
  background: rgba(26,92,58,0.08);
  color: var(--c-primary);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  margin-bottom: 10px;
}

/* === 专家展示 === */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.expert-card {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  box-shadow: 0 4px 20px var(--c-shadow);
  transition: var(--transition);
}

.expert-card:hover { transform: translateY(-4px); }

.expert-card .avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  margin: 0 auto 16px;
  overflow: hidden;
  border: 3px solid var(--c-accent);
}

.expert-card .avatar img { width: 100%; height: 100%; object-fit: cover; }

.expert-card h4 { color: var(--c-primary-dark); margin-bottom: 4px; }

.expert-card .role {
  color: var(--c-accent);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.expert-card p {
  font-size: 0.9rem;
  color: var(--c-text-light);
  margin-bottom: 16px;
}

.expert-card .expert-btns { display: flex; gap: 10px; justify-content: center; }

.expert-card .expert-btns a {
  padding: 6px 18px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 500;
}

.btn-sm-primary {
  background: var(--c-primary);
  color: #fff !important;
}

.btn-sm-primary:hover { background: var(--c-primary-light); color: #fff !important; }

.btn-sm-outline {
  border: 1.5px solid var(--c-primary);
  color: var(--c-primary) !important;
}

.btn-sm-outline:hover { background: var(--c-primary); color: #fff !important; }

/* === FAQ区域 === */
.faq-list { max-width: 800px; margin: 0 auto; }

.faq-item {
  background: var(--c-card);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  box-shadow: 0 2px 10px var(--c-shadow);
  overflow: hidden;
}

.faq-question {
  padding: 18px 24px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
  color: var(--c-primary-dark);
}

.faq-question:hover { background: rgba(26,92,58,0.03); }

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 300;
  color: var(--c-accent);
  transition: var(--transition);
}

.faq-item.active .faq-question::after { content: '-'; }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}

.faq-item.active .faq-answer { max-height: 300px; }

.faq-answer-inner {
  padding: 0 24px 18px;
  color: var(--c-text-light);
  font-size: 0.94rem;
  line-height: 1.8;
}

/* === 用户评论 === */
.review-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 4px 16px var(--c-shadow);
  position: relative;
}

.review-card::before {
  content: '\201C';
  position: absolute;
  top: 12px;
  left: 20px;
  font-size: 4rem;
  color: rgba(26,92,58,0.08);
  font-family: Georgia, serif;
  line-height: 1;
}

.review-card .stars {
  color: var(--c-accent);
  font-size: 1rem;
  margin-bottom: 10px;
  letter-spacing: 2px;
}

.review-card .review-text {
  font-size: 0.94rem;
  color: var(--c-text);
  line-height: 1.8;
  margin-bottom: 14px;
  font-style: italic;
}

.review-card .reviewer {
  display: flex;
  align-items: center;
  gap: 10px;
}

.review-card .reviewer-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--c-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.review-card .reviewer-info { font-size: 0.85rem; }
.review-card .reviewer-info strong { color: var(--c-primary-dark); }
.review-card .reviewer-info span { color: var(--c-text-light); display: block; }

/* === 合作品牌墙 === */
.partner-wall {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 40px;
  padding: 20px 0;
}

.partner-wall .partner-item {
  width: 140px;
  height: 60px;
  background: var(--c-card);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px var(--c-shadow);
  font-weight: 700;
  color: var(--c-text-light);
  font-size: 0.9rem;
  transition: var(--transition);
}

.partner-wall .partner-item:hover {
  box-shadow: 0 6px 20px var(--c-shadow);
  transform: translateY(-2px);
  color: var(--c-primary);
}

/* === 社交分享 === */
.share-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 0;
}

.share-bar span { font-size: 0.9rem; color: var(--c-text-light); font-weight: 500; }

.share-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  transition: var(--transition);
}

.share-btn:hover { transform: scale(1.12); color: #fff; }

.share-wechat { background: #07C160; }
.share-weibo { background: #E6162D; }
.share-douyin { background: var(--c-primary); }
.share-bilibili { background: #00A1D6; }

/* === 页脚 === */
.site-footer {
  background: var(--c-bg-dark);
  color: var(--c-text-white);
  padding: 56px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
}

.footer-col h5 {
  color: var(--c-accent);
  font-size: 1.05rem;
  margin-bottom: 18px;
  font-weight: 700;
}

.footer-col p, .footer-col a {
  color: rgba(240,240,240,0.72);
  font-size: 0.9rem;
  line-height: 2;
}

.footer-col a:hover { color: var(--c-accent); }

.footer-col ul { list-style: none; }
.footer-col ul li a { display: block; padding: 2px 0; }

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.footer-logo img { width: 40px; height: 40px; border-radius: 8px; }
.footer-logo span { font-size: 1.3rem; font-weight: 800; color: #fff; }

.footer-qr {
  display: flex;
  gap: 20px;
  margin-top: 16px;
}

.footer-qr .qr-item { text-align: center; }
.footer-qr .qr-item img { width: 100px; height: 100px; border-radius: 6px; background: #fff; padding: 4px; }
.footer-qr .qr-item span { display: block; font-size: 0.78rem; color: rgba(240,240,240,0.6); margin-top: 6px; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  margin-top: 40px;
  padding: 20px 0;
  text-align: center;
  font-size: 0.84rem;
  color: rgba(240,240,240,0.5);
}

.footer-bottom a { color: rgba(240,240,240,0.5); }
.footer-bottom a:hover { color: var(--c-accent); }

/* === How-To指南 === */
.howto-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  counter-reset: step;
}

.howto-step {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 28px 22px;
  text-align: center;
  box-shadow: 0 4px 16px var(--c-shadow);
  position: relative;
  counter-increment: step;
}

.howto-step::before {
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--c-primary);
  color: #fff;
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0 auto 16px;
}

.howto-step h4 { font-size: 1.05rem; margin-bottom: 8px; }
.howto-step p { font-size: 0.88rem; color: var(--c-text-light); }

/* === AI赋能区 === */
.ai-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.ai-feature-card {
  background: linear-gradient(145deg, var(--c-card) 0%, rgba(26,92,58,0.03) 100%);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  box-shadow: 0 4px 20px var(--c-shadow);
  border: 1px solid rgba(26,92,58,0.06);
  transition: var(--transition);
}

.ai-feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--c-accent);
}

.ai-feature-card .icon {
  width: 64px;
  height: 64px;
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-light) 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 18px;
  font-size: 1.8rem;
}

.ai-feature-card h4 { margin-bottom: 10px; }
.ai-feature-card p { font-size: 0.9rem; color: var(--c-text-light); }

/* === 统计数据 === */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item .stat-num {
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--c-accent);
  line-height: 1.2;
}

.stat-item .stat-label {
  font-size: 0.92rem;
  color: rgba(240,240,240,0.7);
  margin-top: 6px;
}

/* === 标签 === */
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }

.tag {
  display: inline-block;
  padding: 4px 14px;
  background: rgba(26,92,58,0.06);
  color: var(--c-primary);
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  transition: var(--transition);
}

.tag:hover { background: var(--c-primary); color: #fff; }

/* === 内页Hero === */
.page-hero {
  position: relative;
  min-height: 320px;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.page-hero .hero-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.45);
}

.page-hero .hero-content {
  position: relative;
  z-index: 2;
  padding: 60px 40px;
}

.page-hero h1 { font-size: 2.4rem; color: #fff; }
.page-hero p { color: rgba(255,255,255,0.85); max-width: 580px; }

/* === 联系信息 === */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.contact-card {
  background: var(--c-card);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 4px 16px var(--c-shadow);
}

.contact-card h4 {
  color: var(--c-primary);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--c-border);
}

.contact-card .info-row {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 0.92rem;
}

.contact-card .info-label {
  font-weight: 600;
  color: var(--c-primary-dark);
  min-width: 80px;
}

/* === 响应式 === */
@media (max-width: 1024px) {
  .video-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .howto-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .menu-toggle { display: block; }

  .main-nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--c-card);
    flex-direction: column;
    box-shadow: 0 8px 24px var(--c-shadow);
    z-index: 999;
  }

  .main-nav.open { display: flex; }

  .main-nav a {
    height: auto;
    line-height: 1.5;
    padding: 14px 24px;
    border-bottom: 1px solid var(--c-border);
  }

  .main-nav a::after { display: none; }

  .hero-banner { min-height: 380px; }
  .hero-content h1 { font-size: 2rem; }
  .hero-content { padding: 40px 20px; }

  .video-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .card-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .ai-features { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .howto-steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }

  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.5rem; }

  .section { padding: 40px 0; }
}

@media (max-width: 480px) {
  .video-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; }
  .hero-btns .btn { width: 100%; text-align: center; }
  .stats-row { grid-template-columns: 1fr; }
}

/* === 懒加载 === */
img[loading="lazy"] {
  opacity: 0;
  transition: opacity 0.5s ease;
}

img[loading="lazy"].loaded, img[loading="lazy"][src] {
  opacity: 1;
}

/* === 动画 === */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fadeInUp 0.6s ease forwards;
}