:/* 全局样式与颜色规范 - 高可读性优先 */
:root {
  --bg-light: #F8FAFC;
  --bg-dark: #0F172A;
  --text-primary-light: #1F2937;
  --text-secondary-light: #334155;
  --text-heading-light: #111827;
  --text-link-light: #1D4ED8;
  --bg-card-light: #FFFFFF;
  --border-light: #E2E8F0;
  --bg-footer-light: #1E293B;
  --text-footer-light: #E2E8F0;
  
  --text-primary-dark: #E2E8F0;
  --text-secondary-dark: #CBD5E1;
  --text-heading-dark: #FFFFFF;
  --text-link-dark: #93C5FD;
  --bg-card-dark: #1E293B;
  --border-dark: #334155;
  --bg-footer-dark: #0B1120;
  --text-footer-dark: #CBD5E1;
  
  --accent-light: #2563EB;
  --accent-dark: #3B82F6;
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-banner: linear-gradient(135deg, #1E293B 0%, #334155 50%, #475569 100%);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
  --shadow-hover: 0 20px 40px rgba(0,0,0,0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition-fast: 0.2s ease;
  --transition-slow: 0.3s ease;
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(255, 255, 255, 0.3);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --glass-blur: blur(10px);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji';
  background-color: var(--bg-light);
  color: var(--text-primary-light);
  line-height: 1.7;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

body.dark-mode {
  background-color: var(--bg-dark);
  color: var(--text-primary-dark);
}

body.dark-mode {
  background-image: radial-gradient(ellipse at 20% 50%, rgba(59, 130, 246, 0.05), transparent 50%);
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
  flex: 1;
}

/* 标题颜色与层级 */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading-light);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.5em;
  letter-spacing: -0.02em;
}

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(--text-heading-dark);
}

h1 {
  font-size: clamp(2rem, 5vw, 2.5rem);
  font-weight: 800;
}

h2 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  border-bottom: 2px solid var(--border-light);
  padding-bottom: 0.5em;
  margin-bottom: 1em;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 60px;
  height: 2px;
  background: var(--gradient-primary);
}

body.dark-mode h2 {
  border-bottom-color: var(--border-dark);
}

h3 {
  font-size: clamp(1.2rem, 3vw, 1.5rem);
}

h4 {
  font-size: clamp(1rem, 2vw, 1.2rem);
}

p {
  color: var(--text-primary-light);
  margin-bottom: 1rem;
}

body.dark-mode p {
  color: var(--text-primary-dark);
}

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

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

a:hover {
  text-decoration: underline;
  color: var(--accent-light);
}

body.dark-mode a:hover {
  color: var(--accent-dark);
}

/* 卡片样式 - 毛玻璃效果 */
.card {
  background-color: var(--bg-card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: background-color 0.3s ease, border-color 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
}

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

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

/* 按钮样式 */
.btn {
  display: inline-block;
  background: var(--gradient-primary);
  color: #FFFFFF;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.35);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  transform: translate(-50%, -50%);
  transition: width 0.6s ease, height 0.6s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.45);
  background: linear-gradient(135deg, #5a67d8, #6b46c1);
}

.btn:active {
  transform: translateY(0);
}

.btn:hover::before {
  width: 300px;
  height: 300px;
}

body.dark-mode .btn {
  color: #FFFFFF;
}

/* 导航栏 */
.navbar {
  background-color: var(--glass-bg);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 50;
  transition: background-color 0.3s ease, border-color 0.3s ease;
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

body.dark-mode .navbar {
  background-color: rgba(30, 41, 59, 0.8);
  border-bottom-color: var(--border-dark);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  max-width: 1280px;
  margin: 0 auto;
  position: relative;
}

.logo {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-heading-light);
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

body.dark-mode .logo {
  color: var(--text-heading-dark);
  -webkit-text-fill-color: currentColor;
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary-light);
  font-weight: 500;
  position: relative;
  transition: color 0.2s ease;
}

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

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

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

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width 0.3s ease;
}

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

/* 移动菜单按钮 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--text-heading-light);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease;
}

.menu-toggle:hover {
  background-color: rgba(0, 0, 0, 0.05);
}

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

body.dark-mode .menu-toggle:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

/* Banner 样式 - 渐变 */
.banner {
  background: var(--gradient-banner);
  color: #F8FAFC;
  padding: clamp(48px, 8vw, 64px) 24px;
  border-radius: var(--radius-lg);
  margin: 32px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

.banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(255, 255, 255, 0.1), transparent 50%);
  animation: bannerGlow 8s ease-in-out infinite;
}

@keyframes bannerGlow {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(10%, -10%); }
}

.banner h2 {
  color: #FFFFFF;
  border-bottom: none;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  margin-bottom: 0.5em;
  position: relative;
  z-index: 1;
}

.banner p {
  color: #E2E8F0;
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  max-width: 700px;
  margin: 16px auto;
  position: relative;
  z-index: 1;
}

.banner .btn {
  background-color: #F59E0B;
  color: #1F2937;
  background: linear-gradient(135deg, #F59E0B, #F97316);
  box-shadow: 0 4px 15px rgba(245, 158, 11, 0.4);
  position: relative;
  z-index: 1;
}

.banner .btn:hover {
  background-color: #D97706;
  background: linear-gradient(135deg, #D97706, #EA580C);
  box-shadow: 0 8px 25px rgba(245, 158, 11, 0.5);
}

/* 网格布局 */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 768px) {
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    background: var(--bg-card-light);
    padding: 16px;
    position: absolute;
    top: 60px;
    left: 0;
    box-shadow: var(--shadow-md);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    gap: 12px;
  }
  
  body.dark-mode .nav-links {
    background: var(--bg-card-dark);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .menu-toggle {
    display: block;
  }
  
  .search-box {
    width: 100%;
  }
  
  .search-box input {
    flex: 1;
  }
}

/* 表格样式 */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  box-shadow: var(--shadow-sm);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

th, td {
  border: 1px solid var(--border-light);
  padding: 12px;
  text-align: left;
  color: var(--text-primary-light);
  transition: background-color 0.2s ease;
}

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

th {
  background-color: var(--bg-card-light);
  font-weight: 600;
  position: relative;
}

th::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--gradient-primary);
}

body.dark-mode th {
  background-color: var(--bg-card-dark);
}

tr:hover td {
  background-color: rgba(37, 99, 235, 0.05);
}

body.dark-mode tr:hover td {
  background-color: rgba(59, 130, 246, 0.1);
}

/* FAQ 样式 */
.faq-item {
  margin-bottom: 16px;
}

.faq-question {
  background: none;
  border: none;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-heading-light);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  text-align: left;
  padding: 16px 20px;
  background-color: var(--bg-card-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.faq-question::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.faq-question:hover {
  border-color: var(--accent-light);
  box-shadow: var(--shadow-md);
}

.faq-question:hover::before {
  opacity: 1;
}

body.dark-mode .faq-question {
  color: var(--text-heading-dark);
  background-color: var(--bg-card-dark);
  border-color: var(--border-dark);
}

.faq-question span {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--accent-light);
}

.faq-answer {
  padding: 16px 20px;
  border-left: 4px solid;
  border-image: var(--gradient-primary) 1;
  background-color: var(--bg-card-light);
  margin-top: 4px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-primary-light);
  animation: fadeIn 0.3s ease;
  box-shadow: var(--shadow-sm);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

body.dark-mode .faq-answer {
  background-color: var(--bg-card-dark);
  color: var(--text-primary-dark);
}

/* Footer 样式 */
.footer {
  background-color: var(--bg-footer-light);
  color: var(--text-footer-light);
  padding: 40px 0;
  margin-top: 48px;
  position: relative;
  overflow: hidden;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-primary);
}

body.dark-mode .footer {
  background-color: var(--bg-footer-dark);
  color: var(--text-footer-dark);
}

.footer a {
  color: #93C5FD;
  transition: color 0.2s ease;
}

.footer a:hover {
  color: #FFFFFF;
  text-decoration: none;
}

.footer p {
  color: var(--text-footer-light);
}

body.dark-mode .footer p {
  color: var(--text-footer-dark);
}

.footer .copyright {
  border-top: 1px solid #334155;
  padding-top: 24px;
  margin-top: 24px;
  font-size: 0.9rem;
}

/* 搜索框 */
.search-box {
  display: flex;
  gap: 8px;
  align-items: center;
}

.search-box input {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  background-color: var(--bg-card-light);
  color: var(--text-primary-light);
  transition: all 0.2s ease;
  min-width: 0;
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

/* 文章卡片 */
.article-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
}

.article-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

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

.article-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.article-card a {
  display: inline-block;
  margin-top: 8px;
  font-weight: 600;
}

/* 滚动动画 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* SVG 文字颜色 */
.svg-text {
  fill: #1F2937;
  transition: fill 0.3s ease;
}

body.dark-mode .svg-text {
  fill: #E2E8F0;
}

/* 引用块 */
blockquote {
  position: relative;
  padding: 16px 24px;
  margin: 16px 0;
  background: var(--bg-card-light);
  border-radius: var(--radius-sm);
  border-left: 4px solid;
  border-image: var(--gradient-primary) 1;
  box-shadow: var(--shadow-sm);
}

body.dark-mode blockquote {
  background: var(--bg-card-dark);
}

blockquote p {
  margin-bottom: 8px;
  font-style: italic;
}

blockquote footer {
  font-size: 0.9rem;
  color: var(--text-secondary-light);
}

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

/* 返回顶部按钮 */
#backTop {
  position: fixed;
  bottom: 40px;
  right: 30px;
  display: none;
  background: var(--gradient-primary);
  color: white;
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  font-size: 24px;
  cursor: pointer;
  z-index: 99;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
  transition: all 0.3s ease;
}

#backTop:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
}

/* 列表样式 */
ol, ul {
  padding-left: 1.5em;
  margin-bottom: 1rem;
}

li {
  margin-bottom: 0.5rem;
}

/* 分割线 */
hr {
  border: none;
  height: 1px;
  background: var(--border-light);
  margin: 24px 0;
}

body.dark-mode hr {
  background: var(--border-dark);
}

/* 辅助类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* 响应式字体 */
@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }
  
  .card {
    padding: 16px;
  }
  
  .banner {
    padding: 32px 16px;
    margin: 16px 0;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  h3 {
    font-size: 1.2rem;
  }
  
  .footer {
    padding: 24px 0;
  }
  
  #backTop {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    font-size: 20px;
  }
}

/* 暗色模式滚动条 */
body.dark-mode::-webkit-scrollbar {
  width: 10px;
}

body.dark-mode::-webkit-scrollbar-track {
  background: var(--bg-dark);
}

body.dark-mode::-webkit-scrollbar-thumb {
  background: var(--border-dark);
  border-radius: 5px;
}

body.dark-mode::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary-dark);
}

/* 自定义滚动条 (亮色模式) */
::-webkit-scrollbar {
  width: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--border-light);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary-light);
}

/* 打印样式 */
@media print {
  .navbar, .footer, #backTop, .btn, .search-box {
    display: none !important;
  }
  
  .container {
    max-width: 100%;
    padding: 0;
  }
  
  body {
    font-size: 12pt;
  }
}

/* 无障碍焦点样式 */
a:focus, button:focus, input:focus {
  outline: 2px solid var(--accent-light);
  outline-offset: 2px;
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* 高对比度模式 */
@media (prefers-contrast: high) {
  :root {
    --text-link-light: #1D4ED8;
    --text-link-dark: #93C5FD;
  }
}