```css
/* ===== 全局重置与变量 ===== */
:root {
  --bg-light: #f8fafc;
  --bg-soft: #f1f5f9;
  --bg-card: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-heading: #0f172a;
  --text-link: #0891b2;
  --border-light: #e2e8f0;
  --brand-main: #0e7490;
  --brand-deep: #155e75;
  --brand-glow: rgba(14, 116, 144, 0.15);
  --button-text: #ffffff;
  --dark-bg: #0b1120;
  --dark-card: #1e293b;
  --dark-text: #e2e8f0;
  --dark-heading: #f8fafc;
  --dark-secondary: #94a3b8;
  --dark-border: #334155;
  --gradient-hero: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 40%, #a5f3fc 100%);
  --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.9), rgba(255,255,255,0.5));
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.08);
  --shadow-brand: 0 8px 30px rgba(14, 116, 144, 0.12);
  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 28px;
  --radius-full: 9999px;
  --transition-fast: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  background-color: var(--bg-light);
  color: var(--text-primary);
  transition: background-color 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 暗色模式 */
body.dark-mode {
  background-color: var(--dark-bg);
  color: var(--dark-text);
}

body.dark-mode .card,
body.dark-mode .article-card,
body.dark-mode .faq-item,
body.dark-mode .footer-content,
body.dark-mode .table-simple,
body.dark-mode .howto-box {
  background-color: var(--dark-card);
  color: var(--dark-text);
  border-color: var(--dark-border);
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4,
body.dark-mode h5,
body.dark-mode h6 {
  color: var(--dark-heading);
}

body.dark-mode p,
body.dark-mode li,
body.dark-mode blockquote {
  color: var(--dark-text);
}

body.dark-mode .site-footer {
  background-color: #0f172a;
  border-top: 1px solid var(--dark-border);
}

body.dark-mode .hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

body.dark-mode .hero h1 {
  color: var(--dark-heading);
  text-shadow: 0 2px 20px rgba(14, 116, 144, 0.3);
}

body.dark-mode .hero .lead {
  color: var(--dark-secondary);
}

body.dark-mode .navbar {
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--dark-border);
}

body.dark-mode .logo {
  color: var(--dark-heading);
}

body.dark-mode .nav-links a {
  color: var(--dark-text);
}

body.dark-mode .search-box {
  background: var(--dark-card);
  border-color: var(--dark-border);
}

body.dark-mode .search-box input {
  color: var(--dark-text);
}

body.dark-mode .search-box input::placeholder {
  color: var(--dark-secondary);
}

body.dark-mode .search-box button {
  background: var(--brand-main);
}

body.dark-mode .dark-toggle {
  border-color: var(--dark-border);
  color: var(--dark-text);
}

body.dark-mode .dark-toggle:hover {
  background: var(--dark-card);
}

body.dark-mode .card h3,
body.dark-mode .card h4 {
  color: var(--dark-heading);
}

body.dark-mode .article-card .meta {
  color: var(--dark-secondary);
}

body.dark-mode details summary {
  color: var(--dark-heading);
}

body.dark-mode .footer-grid a {
  color: var(--dark-secondary);
}

body.dark-mode .footer-grid a:hover {
  color: var(--dark-heading);
}

body.dark-mode .copyright {
  color: var(--dark-secondary);
  border-top-color: var(--dark-border);
}

body.dark-mode .svg-placeholder {
  background: var(--dark-card);
  color: var(--dark-text);
  border: 1px solid var(--dark-border);
}

body.dark-mode .table-simple th,
body.dark-mode .table-simple td {
  border-color: var(--dark-border);
}

body.dark-mode blockquote {
  background: var(--dark-card);
  border-left: 4px solid var(--brand-main);
}

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

/* ===== 标题层级 ===== */
h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  color: var(--text-heading);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0.5em 0;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--text-heading);
  border-left: 6px solid var(--brand-main);
  padding-left: 16px;
  margin: 2em 0 0.75em;
  line-height: 1.3;
  letter-spacing: -0.01em;
  position: relative;
}

h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--brand-main);
  border-radius: var(--radius-full);
  margin-top: 8px;
  opacity: 0.3;
}

h3 {
  font-size: clamp(1.25rem, 2vw, 1.5rem);
  font-weight: 600;
  color: var(--text-heading);
  margin: 1.2em 0 0.5em;
  line-height: 1.4;
}

h4 {
  font-size: clamp(1.1rem, 1.5vw, 1.25rem);
  font-weight: 600;
  color: var(--text-heading);
  margin-bottom: 0.4em;
  line-height: 1.4;
}

p {
  margin: 0.8em 0;
  line-height: 1.8;
}

a {
  color: var(--text-link);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--brand-main);
  text-decoration: underline;
}

ul,
ol {
  padding-left: 1.5rem;
  margin: 0.8em 0;
}

li {
  margin: 0.4em 0;
  line-height: 1.8;
}

/* ===== 按钮 ===== */
.btn {
  background: linear-gradient(135deg, var(--brand-main), var(--brand-deep));
  color: var(--button-text);
  padding: 0.7rem 2rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 1rem;
  display: inline-block;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(14, 116, 144, 0.3);
  transition: all 0.3s ease;
  text-decoration: none;
  letter-spacing: 0.02em;
}

.btn:hover {
  background: linear-gradient(135deg, var(--brand-deep), var(--brand-main));
  color: white;
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(14, 116, 144, 0.4);
}

.btn:active {
  transform: translateY(0);
  box-shadow: 0 2px 10px rgba(14, 116, 144, 0.2);
}

/* ===== 导航栏 ===== */
.navbar {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: all 0.3s ease;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 24px;
  max-width: 1280px;
  margin: 0 auto;
  gap: 1rem;
}

.logo {
  font-weight: 800;
  font-size: 1.4rem;
  color: var(--text-heading);
  white-space: nowrap;
  letter-spacing: -0.02em;
  transition: color 0.3s ease;
}

.logo span {
  color: var(--brand-main);
  font-size: 1.6em;
  vertical-align: middle;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  flex-wrap: nowrap;
}

.nav-links a {
  color: var(--text-primary);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0.2rem;
  position: relative;
  transition: color 0.2s ease;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand-main);
  transition: width 0.3s ease;
  border-radius: var(--radius-full);
}

.nav-links a:hover {
  color: var(--brand-main);
  text-decoration: none;
}

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

.search-box {
  display: flex;
  align-items: center;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  overflow: hidden;
  background: white;
  flex-shrink: 0;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.search-box:focus-within {
  border-color: var(--brand-main);
  box-shadow: 0 0 0 3px rgba(14, 116, 144, 0.1);
}

.search-box input {
  border: none;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  background: transparent;
  color: var(--text-primary);
  outline: none;
  width: 180px;
  transition: width 0.3s ease;
}

.search-box input:focus {
  width: 220px;
}

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

.search-box button {
  background: var(--brand-main);
  border: none;
  padding: 0.5rem 1.2rem;
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.search-box button:hover {
  background: var(--brand-deep);
}

.dark-toggle {
  background: none;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  padding: 0.4rem 1rem;
  cursor: pointer;
  font-weight: 500;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  white-space: nowrap;
  flex-shrink: 0;
}

.dark-toggle:hover {
  background: var(--bg-soft);
  border-color: var(--brand-main);
}

.mobile-menu {
  display: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: background 0.2s ease;
  color: var(--text-primary);
}

.mobile-menu:hover {
  background: var(--bg-soft);
}

/* ===== Hero ===== */
.hero {
  background: var(--gradient-hero);
  padding: 4rem 0 5rem;
  position: relative;
  overflow: hidden;
  transition: background 0.4s ease;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(14, 116, 144, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(8, 145, 178, 0.08) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  background: linear-gradient(135deg, #0f172a 0%, #155e75 50%, #0e7490 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.03em;
  margin-bottom: 0.3em;
  animation: fadeInUp 0.8s ease both;
}

body.dark-mode .hero h1 {
  background: linear-gradient(135deg, #f8fafc 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .lead {
  font-size: clamp(1.1rem, 2vw, 1.4rem);
  color: var(--text-secondary);
  max-width: 800px;
  font-weight: 400;
  margin: 0.5em 0 1em;
  animation: fadeInUp 0.8s ease 0.2s both;
}

.hero p {
  max-width: 700px;
  color: var(--text-secondary);
  font-size: 1.05rem;
  animation: fadeInUp 0.8s ease 0.3s both;
}

.hero .btn {
  margin-top: 1.5rem;
  animation: fadeInUp 0.8s ease 0.4s both;
  font-size: 1.05rem;
  padding: 0.85rem 2.5rem;
}

/* ===== 卡片网格 ===== */
.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.8rem;
  margin: 2.5rem 0;
}

.card {
  background: var(--gradient-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: var(--radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  transition: all 0.4s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--brand-main), var(--brand-deep));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(14, 116, 144, 0.3);
}

.card:hover::before {
  transform: scaleX(1);
}

.card h3 {
  margin-top: 0;
  font-size: 1.35rem;
}

.card h4 {
  font-size: 1.1rem;
}

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

body.dark-mode .card p {
  color: var(--dark-secondary);
}

/* ===== 文章列表 ===== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.article-card {
  background: white;
  border-radius: var(--radius-md);
  padding: 1.5rem 2rem;
  border: 1px solid var(--border-light);
  transition: all 0.35s ease;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.article-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--brand-main), var(--brand-deep));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.article-card:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
  border-color: rgba(14, 116, 144, 0.2);
}

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

.article-card h4 {
  margin-bottom: 0.3rem;
  font-size: 1.15rem;
  transition: color 0.3s ease;
}

.article-card:hover h4 {
  color: var(--brand-main);
}

.article-card .meta {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin: 0.3rem 0 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.article-card .meta::before {
  content: '📅';
  font-size: 0.9rem;
}

.article-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin: 0.5rem 0;
  line-height: 1.7;
}

.article-card a {
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap 0.3s ease;
}

.article-card a:hover {
  gap: 0.6rem;
}

body.dark-mode .article-card p {
  color: var(--dark-secondary);
}

/* ===== FAQ ===== */
.faq-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 0.8rem 1.5rem;
  margin-bottom: 0.8rem;
  background: white;
  transition: all 0.3s ease;
  box-shadow: var(--shadow-sm);
}

.faq-item:hover {
  border-color: rgba(14, 116, 144, 0.3);
  box-shadow: var(--shadow-md);
}

details summary {
  font-weight: 600;
  cursor: pointer;
  color: var(--text-heading);
  padding: 0.8rem 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  transition: color 0.3s ease;
  font-size: 1.05rem;
}

details summary::-webkit-details-marker {
  display: none;
}

details summary::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--brand-main);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

details[open] summary::after {
  content: '−';
  transform: rotate(180deg);
}

details summary:hover {
  color: var(--brand-main);
}

details p {
  padding: 0.5rem 0 1rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  border-top: 1px solid var(--border-light);
  margin-top: 0.5rem;
}

body.dark-mode details p {
  border-top-color: var(--dark-border);
  color: var(--dark-secondary);
}

/* ===== 表格 ===== */
.table-simple {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.table-simple th {
  background: var(--brand-main);
  color: white;
  font-weight: 600;
  text-align: left;
  padding: 0.8rem 1rem;
}

.table-simple td {
  border: 1px solid var(--border-light);
  padding: 0.8rem 1rem;
  text-align: left;
  background: white;
}

.table-simple tr:nth-child(even) td {
  background: var(--bg-soft);
}

body.dark-mode .table-simple td {
  background: var(--dark-card);
}

body.dark-mode .table-simple tr:nth-child(even) td {
  background: #172033;
}

/* ===== Footer ===== */
.site-footer {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: var(--dark-secondary);
  padding: 3rem 0 2rem;
  margin-top: 5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

.footer-grid div {
  font-size: 0.95rem;
}

.footer-grid strong {
  display: block;
  color: var(--dark-heading);
  margin-bottom: 0.8rem;
  font-size: 1rem;
}

.footer-grid a {
  color: var(--dark-secondary);
  display: block;
  margin: 0.4rem 0;
  transition: all 0.2s ease;
  text-decoration: none;
}

.footer-grid a:hover {
  color: white;
  transform: translateX(4px);
  text-decoration: none;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 1.5rem;
  margin-top: 2rem;
  text-align: center;
  color: var(--dark-secondary);
  font-size: 0.85rem;
}

/* ===== 联系信息 ===== */
.contact-info p {
  margin: 0.4rem 0;
  display: flex;
  align-items: flex-start;
  gap: 0.8rem;
}

.contact-info p strong {
  min-width: 80px;
  color: var(--text-heading);
}

body.dark-mode .contact-info p strong {
  color: var(--dark-heading);
}

/* ===== 区块引用 ===== */
blockquote {
  background: var(--bg-soft);
  padding: 1.5rem 2rem;
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
  border-left: 4px solid var(--brand-main);
  font-style: italic;
  box-shadow: var(--shadow-sm);
  position: relative;
}

blockquote::before {
  content: '"';
  font-size: 4rem;
  color: var(--brand-main);
  opacity: 0.2;
  position: absolute;
  top: -10px;
  left: 10px;
  font-family: Georgia, serif;
}

/* ===== SVG 占位 ===== */
.svg-placeholder {
  background: var(--bg-soft);
  border-radius: var(--radius-md);
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
  font-weight: 500;
  border: 2px dashed var(--border-light);
  transition: all 0.3s ease;
}

.svg-placeholder:hover {
  border-color: var(--brand-main);
  background: var(--bg-light);
}

/* ===== 滚动动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
}

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

/* ===== 返回顶部 ===== */
#backTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: linear-gradient(135deg, var(--brand-main), var(--brand-deep));
  color: white;
  border: none;
  padding: 12px 16px;
  border-radius: 50%;
  font-size: 1.2rem;
  cursor: pointer;
  display: none;
  z-index: 999;
  box-shadow: 0 4px 15px rgba(14, 116, 144, 0.3);
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

#backTop:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(14, 116, 144, 0.4);
}

#backTop:active {
  transform: translateY(0);
}

/* ===== 网格布局辅助 ===== */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

/* ===== 暗色模式下的额外调整 ===== */
body.dark-mode .gradient-border {
  background: var(--dark-card);
  border-color: var(--dark-border);
}

body.dark-mode .text-muted {
  color: var(--dark-secondary);
}

/* ===== HowTo 样式 ===== */
.howto-box {
  background: var(--bg-soft);
  padding: 2rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  transition: box-shadow 0.3s ease;
}

.howto-box:hover {
  box-shadow: var(--shadow-md);
}

.howto-box ol {
  padding-left: 1.5rem;
}

.howto-box li {
  margin: 0.6rem 0;
}

.howto-box li::marker {
  color: var(--brand-main);
  font-weight: 700;
}

/* ===== 动画关键帧 ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .nav-links {
    gap: 1rem;
  }
  
  .search-box input {
    width: 140px;
  }
  
  .search-box input:focus {
    width: 160px;
  }
  
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 800px) {
  .container {
    padding: 0 16px;
  }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow-md);
    border-bottom: 1px solid var(--border-light);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    gap: 0.5rem;
  }
  
  body.dark-mode .nav-links {
    background: var(--dark-card);
    border-bottom-color: var(--dark-border);
  }
  
  .nav-links.open {
    display: flex;
  }
  
  .nav-links a {
    padding: 0.6rem 1rem;
    width: 100%;
    text-align: center;
    border-radius: var(--radius-sm);
  }
  
  .nav-links a:hover {
    background: var(--bg-soft);
  }
  
  body.dark-mode .nav-links a:hover {
    background: var(--dark-bg);
  }
  
  .mobile-menu {
    display: block;
  }
  
  .search-box {
    order: 3;
  }
  
  .search-box input {
    width: 120px;
  }
  
  .search-box input:focus {
    width: 150px;
  }
  
  .dark-toggle {
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
  }
  
  .hero {
    padding: 3rem 0 3.5rem;
  }
  
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .grid-2 {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .grid-3 {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }
  
  .article-card {
    padding: 1.2rem 1.5rem;
  }
  
  .faq-item {
    padding: 0.6rem 1.2rem;
  }
  
  #backTop {
    bottom: 20px;
    right: 20px;
    padding: 10px 14px;
    font-size: 1rem;
  }
  
  h2 {
    font-size: 1.6rem;
  }
  
  h3 {
    font-size: 1.3rem;
  }
  
  .nav-container {
    padding: 0.6rem 16px;
    flex-wrap: wrap;
  }
  
  .logo {
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 12px;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .hero .lead {
    font-size: 1rem;
  }
  
  .btn {
    padding: 0.6rem 1.6rem;
    font-size: 0.9rem;
  }
  
  .grid-cards {
    grid-template-columns: 1fr;
  }
  
  .card {
    padding: 1.5rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.2rem;
  }
  
  .search-box input {
    width: 90px;
  }
  
  .search-box input:focus {
    width: 120px;
  }
  
  .dark-toggle {
    display: none;
  }
  
  .article-card {
    padding: 1rem 1.2rem;
  }
  
  .article-card h4 {
    font-size: 1rem;
  }
  
  blockquote {
    padding: 1rem 1.2rem;
  }
  
  details summary {
    font-size: 0.95rem;
  }
}

/* ===== 打印样式 ===== */
@media print {
  .navbar,
  .hero .btn,
  #backTop,
  .dark-toggle,
  .mobile-menu,
  .search-box {
    display: none !important;
  }
  
  body {
    background: white;
    color: black;
  }
  
  .card,
  .article-card,
  .faq-item {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ccc;
  }
}

/* ===== 滚动条样式 ===== */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--brand-main), var(--brand-deep));
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-soft);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--brand-deep);
}

/* ===== 选中文本样式 ===== */
::selection {
  background: rgba(14, 116, 144, 0.2);
  color: var(--text-heading);
}

body.dark-mode ::selection {
  background: rgba(14, 116, 144, 0.4);
  color: white;
}

/* ===== 焦点可见性 ===== */
:focus-visible {
  outline: 3px solid rgba(14, 116, 144, 0.5);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ===== 工具类 ===== */
.text-center {
  text-align: center;
}

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

.mt-1 {
  margin-top: 1rem;
}

.mt-2 {
  margin-top: 2rem;
}

.mt-3 {
  margin-top: 3rem;
}

.mb-1 {
  margin-bottom: 1rem;
}

.mb-2 {
  margin-bottom: 2rem;
}

.mb-3 {
  margin-bottom: 3rem;
}

/* ===== 渐变边框卡片 ===== */
.gradient-border {
  position: relative;
  background: white;
  border-radius: var(--radius-md);
  padding: 1px;
}

.gradient-border::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  padding: 2px;
  background: linear-gradient(135deg, var(--brand-main), var(--brand-deep), var(--brand-main));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* ===== 品牌色渐变文字 ===== */
.gradient-text {
  background: linear-gradient(135deg, var(--brand-main), var(--brand-deep));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== 卡片悬停动效增强 ===== */
.card:hover,
.article-card:hover,
.faq-item:hover {
  animation: cardHover 0.3s ease;
}

@keyframes cardHover {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.02);
  }
  100% {
    transform: scale(1);
  }
}

/* ===== 导航栏滚动状态 ===== */
.navbar.scrolled {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

/* ===== 列表样式优化 ===== */
ul li::marker {
  color: var(--brand-main);
}

ol li::marker {
  color: var(--brand-main);
  font-weight: 600;
}

/* ===== 链接下划线动画 ===== */
.article-card a,
.card a {
  position: relative;
}

.article-card a::after,
.card a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand-main);
  transition: width 0.3s ease;
  border-radius: var(--radius-full);
}

.article-card a:hover::after,
.card a:hover::after {
  width: 100%;
}

/* ===== 响应式字体调整 ===== */
@media (max-width: 600px) {
  body {
    font-size: 15px;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1.4rem;
  }
  
  h3 {
    font-size: 1.2rem;
  }
}

/* ===== 暗色模式下的渐变卡片支持 ===== */
body.dark-mode .card {
  background: linear-gradient(145deg, #1e293b, #263449);
  border-color: var(--dark-border);
}

/* ===== 暗色模式下的按钮微调 ===== */
body.dark-mode .btn {
  box-shadow: 0 4px 15px rgba(14, 116, 144, 0.4);
}

/* ===== 加载动画（占位） ===== */
.loading {
  animation: pulse 1.5s ease infinite;
}

/* ===== 结束 ===== */
```