@import url('https://fonts.googleapis.com/css2?family=Fredoka:wght@400;500;600;700&family=Nunito:wght@300;400;500;600;700&display=swap');

/* ===== 基础重置与 CSS 变量 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-base: #000000;
  --bg-surface: #121212;
  --bg-elevated: #1a1a2e;
  --bg-card: #0d0d1a;
  --accent-blue: #4f8ef7;
  --accent-neon: #00e5ff;
  --accent-gold: #ffd700;
  --accent-purple: #b47eff;
  --accent-pink: #ff6eb4;
  --text-primary: #ffffff;
  --text-secondary: #b0b8cc;
  --text-muted: #6b7a99;
  --text-link: #4f8ef7;
  --border-subtle: rgba(79,142,247,0.15);
  --glow-blue: 0 0 10px rgba(79,142,247,0.4);
  --glow-neon: 0 0 10px rgba(0,229,255,0.3);
  --radius-card: 10px;
  --radius-sm: 6px;
  --font-heading: 'Fredoka', 'Nunito', -apple-system, sans-serif;
  --font-body: 'Nunito', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --nav-h: 64px;
  --max-w: 1100px;
  --content-w: 780px;
  color-scheme: dark;
}

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

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ===== 导航 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(0,0,0,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.25rem;
  height: var(--nav-h);
  gap: 1rem;
}

.nav-left,
.nav-right {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex: 1;
}

.nav-right {
  justify-content: flex-end;
}

.nav-brand {
  flex-shrink: 0;
}

.brand-link {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.brand-text {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  text-shadow: var(--glow-blue);
  white-space: nowrap;
  letter-spacing: 0.02em;
}

.brand-logo {
  height: 36px;
  width: auto;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.6rem;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color 0.2s, background 0.2s;
  white-space: nowrap;
  min-height: 40px;
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-neon);
  background: rgba(0,229,255,0.07);
  text-shadow: var(--glow-neon);
}

.nav-search {
  display: flex;
  align-items: center;
  margin-left: 0.5rem;
}

.search-input {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.82rem;
  padding: 0.35rem 0.75rem;
  width: 120px;
  outline: none;
  transition: border-color 0.2s, width 0.3s;
  min-height: 36px;
}

.search-input:focus {
  border-color: var(--accent-blue);
  width: 160px;
  box-shadow: var(--glow-blue);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.35rem 0.4rem;
  font-size: 0.9rem;
  min-height: 40px;
  min-width: 40px;
  border-radius: var(--radius-sm);
  transition: color 0.2s;
}

.search-btn:hover {
  color: var(--accent-neon);
}

/* ===== 页面包装器 ===== */
.page-wrapper {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.25rem 2rem;
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 1rem 0 0.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.breadcrumb a:hover {
  color: var(--accent-blue);
}

/* ===== Hero（首页）===== */
.hero-section {
  min-height: 45vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #000000 0%, #0a0a1f 50%, #0d1a2e 100%);
  padding: 3rem 1.25rem;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 70% 50%, rgba(79,142,247,0.08) 0%, transparent 60%);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
}

.hero-badges {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  justify-content: flex-end;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-heading);
}

.badge-neon {
  background: rgba(0,229,255,0.1);
  color: var(--accent-neon);
  border: 1px solid rgba(0,229,255,0.3);
  text-shadow: var(--glow-neon);
}

.badge-blue {
  background: rgba(79,142,247,0.1);
  color: var(--accent-blue);
  border: 1px solid rgba(79,142,247,0.3);
}

.hero-content {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 2rem;
}

.hero-illustration {
  flex-shrink: 0;
}

.dance-icon-group {
  position: relative;
  width: 120px;
  height: 120px;
}

.dance-icon {
  position: absolute;
  font-size: 2.5rem;
  animation: float-icon 3s ease-in-out infinite;
}

.di-1 { top: 0; left: 50%; transform: translateX(-50%); animation-delay: 0s; }
.di-2 { top: 20px; right: 0; font-size: 1.4rem; animation-delay: 0.5s; }
.di-3 { bottom: 10px; left: 0; font-size: 1.6rem; animation-delay: 1s; }
.di-4 { bottom: 0; right: 10px; font-size: 1.2rem; animation-delay: 1.5s; }

@keyframes float-icon {
  0%, 100% { transform: translateY(0) translateX(var(--tx, 0)); }
  50% { transform: translateY(-8px) translateX(var(--tx, 0)); }
}

.di-1 { --tx: -50%; }

.hero-text {
  text-align: right;
  max-width: 600px;
}

.hero-h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
  text-shadow: var(--glow-blue);
  margin-bottom: 0.75rem;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  padding: 0.7rem 1.75rem;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-neon));
  color: #000;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  border-radius: 25px;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 0 20px rgba(79,142,247,0.4);
  min-height: 44px;
}

.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(0,229,255,0.5);
}

/* ===== 通用区块标题 ===== */
.section-title {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
  letter-spacing: 0.01em;
}

.section-divider {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin-bottom: 1.5rem;
  box-shadow: 0 1px 0 rgba(79,142,247,0.1);
}

/* ===== 首页主题卡片 ===== */
.topics-section {
  padding: 2.5rem 0;
}

.topic-grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 1.25rem;
}

.topic-card-wrap {
  list-style: none;
}

.topic-card {
  background: var(--bg-card);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  height: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: transform 0.25s, box-shadow 0.25s;
  position: relative;
  overflow: hidden;
}

.topic-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-neon));
  opacity: 0.6;
}

.topic-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(79,142,247,0.15);
}

.topic-card-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
}

.topic-number {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 700;
  color: rgba(79,142,247,0.25);
  line-height: 1;
  flex-shrink: 0;
}

.topic-card-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
}

.topic-card-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color 0.2s;
}

.topic-card-title a:hover {
  color: var(--accent-neon);
  text-shadow: var(--glow-neon);
}

.topic-card-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
}

.topic-card-links {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.topic-sub-link {
  font-size: 0.78rem;
  color: var(--text-muted);
  text-decoration: none;
  padding: 0.2rem 0;
  border-left: 2px solid var(--border-subtle);
  padding-left: 0.5rem;
  transition: color 0.2s, border-color 0.2s;
}

.topic-sub-link:hover {
  color: var(--accent-blue);
  border-color: var(--accent-blue);
}

.topic-card-more {
  font-size: 0.82rem;
  color: var(--accent-blue);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s;
}

.topic-card-more:hover {
  color: var(--accent-neon);
}

/* ===== 首页内容区 ===== */
.home-content-section {
  padding: 2rem 0;
}

.home-main {
  /* 包装器 */
}

/* ===== 专题页头部 ===== */
.topic-page-header {
  padding: 2rem 0 1rem;
}

.topic-eyebrow {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.eyebrow-tag {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  background: rgba(79,142,247,0.12);
  color: var(--accent-blue);
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-heading);
  border: 1px solid rgba(79,142,247,0.25);
}

.eyebrow-link {
  text-decoration: none;
  transition: background 0.2s, color 0.2s;
}

.eyebrow-link:hover {
  background: rgba(79,142,247,0.2);
  color: var(--accent-neon);
}

.topic-date,
.card-date,
.article-date {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.topic-page-h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.topic-page-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 680px;
}

/* ===== 专题子页列表 ===== */
.topic-children {
  padding: 2rem 0;
}

.article-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.article-list-item {
  list-style: none;
}

.article-card {
  background: var(--bg-card);
  border-radius: var(--radius-card);
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.article-card:hover {
  transform: translateX(4px);
  box-shadow: -3px 0 0 var(--accent-blue), 0 4px 20px rgba(79,142,247,0.1);
}

.article-card-num {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: rgba(79,142,247,0.2);
  flex-shrink: 0;
  min-width: 2.5rem;
}

.article-card-body {
  flex: 1;
  min-width: 0;
}

.article-card-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.25rem;
}

.article-card-title a {
  color: var(--text-primary);
  text-decoration: none;
  transition: color 0.2s;
}

.article-card-title a:hover {
  color: var(--accent-neon);
}

.article-card-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.article-card-arrow {
  color: var(--text-muted);
  font-size: 1rem;
  flex-shrink: 0;
  transition: color 0.2s, transform 0.2s;
}

.article-card:hover .article-card-arrow {
  color: var(--accent-blue);
  transform: translateX(3px);
}

/* ===== 相关专题 ===== */
.related-topics {
  padding: 1.5rem 0;
}

.related-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.related-item {
  list-style: none;
}

.related-link {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 1rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-decoration: none;
  transition: border-color 0.2s, color 0.2s, box-shadow 0.2s;
  min-height: 40px;
}

.related-link:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
  box-shadow: var(--glow-blue);
}

/* ===== 文章页 ===== */
.article-page-wrapper {
  max-width: var(--content-w);
}

.article-page-header {
  padding: 2rem 0 1rem;
}

.article-eyebrow {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.article-h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.article-dates {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.date-label {
  color: var(--text-muted);
}

.date-sep {
  color: var(--text-muted);
}

.article-lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.65;
  border-left: 3px solid var(--accent-blue);
  padding-left: 1rem;
  margin-top: 0.5rem;
}

.article-img-wrap {
  margin-bottom: 1.5rem;
  border-radius: var(--radius-card);
  overflow: hidden;
}

.article-hero-img {
  width: 100%;
  height: auto;
  display: block;
}

/* ===== 同专题阅读 ===== */
.sibling-articles {
  padding: 2rem 0;
}

.sibling-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}

.sibling-item {
  list-style: none;
}

.sibling-card {
  background: var(--bg-card);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
}

.sibling-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(79,142,247,0.12);
}

.sibling-card-link {
  display: block;
  padding: 1.25rem;
  text-decoration: none;
}

.sibling-card-title {
  font-family: var(--font-heading);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 0.4rem;
  transition: color 0.2s;
}

.sibling-card:hover .sibling-card-title {
  color: var(--accent-neon);
}

.sibling-card-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== 正文排版 ===== */
.content-article {
  /* 结构层 */
}

.content-body {
  /* 内容层 */
}

.prose-wrap {
  /* 排版层 */
}

.prose-wrap h2 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 2rem 0 0.35rem;
  line-height: 1.3;
}

.prose-wrap h2 + hr,
.prose-wrap h2 ~ hr:first-of-type {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin-bottom: 1rem;
}

.prose-wrap h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 1.5rem 0 0.5rem;
}

.prose-wrap p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 1rem;
}

.prose-wrap a {
  color: var(--accent-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s;
}

.prose-wrap a:hover {
  color: var(--accent-neon);
}

.prose-wrap ul,
.prose-wrap ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.prose-wrap li {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.35rem;
}

.prose-wrap table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}

.prose-wrap th,
.prose-wrap td {
  padding: 0.6rem 0.9rem;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.prose-wrap th {
  color: var(--text-primary);
  font-weight: 600;
  background: var(--bg-surface);
}

.prose-wrap blockquote {
  border-left: 3px solid var(--accent-purple);
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: var(--text-secondary);
  font-style: italic;
}

.prose-wrap strong {
  color: var(--text-primary);
  font-weight: 600;
}

.prose-wrap time {
  color: var(--accent-gold);
  font-style: normal;
}

/* ===== 关于页 ===== */
.about-page-wrapper {
  max-width: var(--content-w);
}

.about-header {
  padding: 2.5rem 0 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
}

.about-icon-wrap {
  flex-shrink: 0;
}

.about-icon {
  font-size: 3rem;
  animation: float-icon 4s ease-in-out infinite;
  display: block;
}

.about-headline {
  flex: 1;
}

.about-h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--text-primary);
  margin: 0.5rem 0;
  text-shadow: var(--glow-blue);
}

.about-lead {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.about-topics {
  padding: 2rem 0;
}

.about-topic-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.about-topic-item {
  list-style: none;
}

.about-topic-link {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.25rem;
  background: var(--bg-card);
  border-radius: var(--radius-card);
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
  border-left: 3px solid transparent;
}

.about-topic-link:hover {
  transform: translateX(4px);
  border-left-color: var(--accent-blue);
  box-shadow: 0 4px 15px rgba(79,142,247,0.1);
}

.about-topic-title {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.about-topic-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== 隐私政策页 ===== */
.privacy-page-wrapper {
  max-width: var(--content-w);
}

.privacy-header {
  padding: 2.5rem 0 1.5rem;
}

.privacy-h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 2.5vw, 1.8rem);
  font-weight: 700;
  color: var(--text-primary);
  margin: 0.5rem 0;
}

.privacy-updated {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.privacy-lead {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.privacy-nav-links {
  display: flex;
  gap: 1rem;
  padding: 1.5rem 0;
  flex-wrap: wrap;
}

.privacy-nav-links a {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1.2rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-decoration: none;
  transition: border-color 0.2s, color 0.2s;
  min-height: 40px;
}

.privacy-nav-links a:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* ===== 专题介绍（内容区域）===== */
.topic-intro {
  padding: 1.5rem 0;
}

.topic-article {
  max-width: var(--content-w);
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  margin-top: 3rem;
}

.footer-cta-block {
  background: linear-gradient(135deg, #0a0a1f, #0d1a2e);
  padding: 2.5rem 1.25rem;
  text-align: center;
  border-bottom: 1px solid var(--border-subtle);
}

.footer-cta-text {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  font-family: var(--font-heading);
}

.footer-cta-btn {
  display: inline-flex;
  align-items: center;
  padding: 0.7rem 2rem;
  background: linear-gradient(135deg, var(--accent-blue), #1a6fe0);
  color: #fff;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  border-radius: 25px;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: var(--glow-blue);
  min-height: 44px;
}

.footer-cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 25px rgba(79,142,247,0.5);
}

.footer-cols {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2rem 1.25rem;
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.footer-dl {
  flex: 1;
  min-width: 150px;
}

.footer-dl dt {
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-subtle);
}

.footer-dl dd {
  margin: 0 0 0.4rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.footer-dl dd a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
  display: inline-block;
  min-height: 28px;
  padding: 0.1rem 0;
}

.footer-dl dd a:hover {
  color: var(--accent-blue);
}

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding: 1rem 1.25rem;
  text-align: center;
  max-width: var(--max-w);
  margin: 0 auto;
}

.footer-bottom p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ===== 动效：Scroll Reveal ===== */
.reveal-section {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.reveal-section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.stagger-item {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease calc(var(--stagger-i, 0) * 0.07s),
              transform 0.4s ease calc(var(--stagger-i, 0) * 0.07s);
}

.stagger-item.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal-section,
  .stagger-item {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .dance-icon {
    animation: none;
  }
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  :root {
    --nav-h: 56px;
  }

  .main-nav {
    flex-wrap: wrap;
    height: auto;
    padding: 0.5rem 1rem;
    gap: 0.5rem;
    position: relative;
  }

  .nav-left,
  .nav-right {
    flex-wrap: wrap;
    gap: 0.15rem;
  }

  .nav-link {
    font-size: 0.75rem;
    padding: 0.4rem 0.45rem;
  }

  .nav-brand {
    order: -1;
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 0.3rem 0;
    border-bottom: 1px solid var(--border-subtle);
  }

  .search-input {
    width: 90px;
    font-size: 0.75rem;
  }

  .search-input:focus {
    width: 120px;
  }

  .hero-section {
    min-height: auto;
    padding: 2rem 1rem;
  }

  .hero-content {
    flex-direction: column-reverse;
    align-items: flex-end;
  }

  .hero-text {
    width: 100%;
  }

  .dance-icon-group {
    width: 80px;
    height: 80px;
  }

  .dance-icon { font-size: 1.8rem; }
  .di-2, .di-3, .di-4 { font-size: 1.1rem; }

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

  .article-card {
    padding: 1rem;
    gap: 0.75rem;
  }

  .article-card-num {
    font-size: 1.1rem;
    min-width: 2rem;
  }

  .about-header {
    flex-direction: column;
    gap: 0.75rem;
  }

  .footer-cols {
    flex-direction: column;
    gap: 1.25rem;
  }

  .sibling-list {
    grid-template-columns: 1fr;
  }

  .page-wrapper {
    padding: 0 1rem 1.5rem;
  }
}

@media (max-width: 480px) {
  .hero-badges {
    justify-content: flex-start;
  }

  .hero-text {
    text-align: left;
  }

  .hero-cta {
    width: 100%;
    justify-content: center;
  }

  .nav-left,
  .nav-right {
    display: none;
  }

  .main-nav::after {
    content: '☰ 菜单';
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 0.85rem;
    pointer-events: none;
  }
}

/* ===== 焦点可见性 ===== */
:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-base);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-elevated);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-blue);
}

/* ===== 选中文字 ===== */
::selection {
  background: rgba(79,142,247,0.3);
  color: var(--text-primary);
}