```css
/* ===== 榴莲视频 - 全站样式表 ===== */
/* 版本：1.0.0 | 更新：2025 | 设计：榴莲视频UI团队 */

/* ---------- 1. CSS变量与主题系统 ---------- */
:root {
  /* 主色调 - 榴莲金/琥珀色系 */
  --durian-50: #fffbeb;
  --durian-100: #fef3c7;
  --durian-200: #fde68a;
  --durian-300: #fcd34d;
  --durian-400: #fbbf24;
  --durian-500: #f59e0b;
  --durian-600: #d97706;
  --durian-700: #b45309;
  --durian-800: #92400e;
  --durian-900: #78350f;

  /* 中性色 - 高对比度设计 */
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;

  /* 语义化变量（亮色模式默认值） */
  --bg-primary: #ffffff;
  --bg-secondary: var(--gray-50);
  --bg-tertiary: var(--durian-50);
  --text-primary: var(--gray-800);
  --text-secondary: var(--gray-600);
  --text-heading: var(--gray-900);
  --text-accent: var(--durian-700);
  --text-on-accent: #ffffff;
  --border-color: var(--gray-200);
  --border-color-light: var(--gray-100);
  --card-bg: #ffffff;
  --nav-bg: rgba(255, 255, 255, 0.85);
  --footer-bg: var(--gray-900);
  --footer-text: var(--gray-300);
  --footer-heading: #ffffff;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --btn-primary-bg: var(--durian-600);
  --btn-primary-text: #ffffff;
  --btn-primary-hover: var(--durian-700);
  --badge-bg: var(--durian-100);
  --badge-text: var(--durian-800);
  --hero-gradient-start: var(--durian-50);
  --hero-gradient-end: #ffffff;
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.3);
  --faq-border: var(--gray-200);
  --table-header-bg: var(--gray-50);
  --table-row-hover: var(--durian-50);
  --code-bg: var(--gray-100);
  --scrollbar-track: var(--gray-100);
  --scrollbar-thumb: var(--durian-300);
  --scrollbar-thumb-hover: var(--durian-400);
}

/* 暗色模式变量覆盖 */
body.dark-mode {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #1a2332;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-heading: #f8fafc;
  --text-accent: var(--durian-400);
  --text-on-accent: #0f172a;
  --border-color: #334155;
  --border-color-light: #1e293b;
  --card-bg: #1e293b;
  --nav-bg: rgba(15, 23, 42, 0.9);
  --footer-bg: #0b1120;
  --footer-text: #94a3b8;
  --footer-heading: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
  --btn-primary-bg: var(--durian-500);
  --btn-primary-text: #0f172a;
  --btn-primary-hover: var(--durian-400);
  --badge-bg: var(--durian-900);
  --badge-text: var(--durian-200);
  --hero-gradient-start: #1e293b;
  --hero-gradient-end: #0f172a;
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(148, 163, 184, 0.2);
  --faq-border: #334155;
  --table-header-bg: #1e293b;
  --table-row-hover: #1a2332;
  --code-bg: #1e293b;
  --scrollbar-track: #1e293b;
  --scrollbar-thumb: #475569;
  --scrollbar-thumb-hover: #64748b;
}

/* ---------- 2. 基础样式与重置 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 80px;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 16px;
  font-weight: 400;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

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

a {
  color: var(--text-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--durian-500);
}

ul,
ol {
  list-style-position: inside;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

::selection {
  background-color: var(--durian-200);
  color: var(--durian-900);
}

/* 滚动条美化 */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 10px;
  transition: background 0.2s;
}

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

/* ---------- 3. 布局工具类 ---------- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

.section {
  padding: 80px 0;
}

.section-sm {
  padding: 48px 0;
}

.section-lg {
  padding: 120px 0;
}

/* 网格布局 */
.grid {
  display: grid;
  gap: 24px;
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

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

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.flex {
  display: flex;
}

.flex-wrap {
  flex-wrap: wrap;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-center {
  justify-content: center;
}

.gap-8 {
  gap: 8px;
}

.gap-16 {
  gap: 16px;
}

.gap-24 {
  gap: 24px;
}

.gap-32 {
  gap: 32px;
}

/* 文本工具 */
.text-center {
  text-align: center;
}

.text-accent {
  color: var(--text-accent);
}

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

.text-sm {
  font-size: 0.875rem;
}

.text-lg {
  font-size: 1.125rem;
}

.text-xl {
  font-size: 1.25rem;
}

.text-2xl {
  font-size: 1.5rem;
}

.text-3xl {
  font-size: 1.875rem;
}

.text-4xl {
  font-size: 2.25rem;
}

.font-bold {
  font-weight: 700;
}

.font-semibold {
  font-weight: 600;
}

.font-medium {
  font-weight: 500;
}

/* 显示控制 */
.hidden {
  display: none !important;
}

/* ---------- 4. 导航栏 ---------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border-color-light);
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
  background: var(--nav-bg);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 16px;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-heading);
  display: flex;
  align-items: center;
  gap: 10px;
  letter-spacing: -0.5px;
  flex-shrink: 0;
}

.logo svg {
  width: 36px;
  height: 36px;
  color: var(--durian-600);
  transition: transform 0.3s ease;
}

.logo:hover svg {
  transform: rotate(15deg) scale(1.05);
}

.nav-links {
  display: flex;
  gap: 8px;
  font-weight: 500;
  margin: 0 auto;
}

.nav-links a {
  color: var(--text-primary);
  text-decoration: none;
  padding: 8px 16px;
  border-radius: 40px;
  border: 1px solid transparent;
  transition: all 0.25s ease;
  font-size: 0.95rem;
  position: relative;
}

.nav-links a:hover {
  color: var(--text-accent);
  background: var(--durian-50);
  border-color: var(--durian-200);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--durian-500);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 40%;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

/* 搜索框 */
.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border-radius: 40px;
  padding: 4px 8px 4px 16px;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  width: 200px;
}

.search-box:focus-within {
  border-color: var(--durian-400);
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.1);
  background: var(--bg-primary);
}

.search-box input {
  border: none;
  background: transparent;
  color: var(--text-primary);
  padding: 8px 0;
  width: 100%;
  outline: none;
  font-size: 0.9rem;
}

.search-box input::placeholder {
  color: var(--text-secondary);
  opacity: 0.7;
}

.search-box svg {
  width: 18px;
  height: 18px;
  color: var(--text-secondary);
  flex-shrink: 0;
  margin-left: 8px;
}

/* 主题切换按钮 */
.theme-toggle,
.menu-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--text-primary);
  font-size: 1.2rem;
  transition: background 0.2s ease, transform 0.2s ease;
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.theme-toggle:hover,
.menu-btn:hover {
  background: var(--durian-50);
  transform: scale(1.05);
}

/* 移动端菜单 */
.mobile-menu {
  display: none;
  flex-direction: column;
  background: var(--card-bg);
  padding: 16px 24px;
  gap: 4px;
  border-top: 1px solid var(--border-color-light);
  box-shadow: var(--shadow-lg);
}

.mobile-menu a {
  color: var(--text-primary);
  padding: 12px 16px;
  border-radius: 12px;
  font-weight: 500;
  transition: background 0.2s ease;
}

.mobile-menu a:hover {
  background: var(--durian-50);
  color: var(--text-accent);
}

.mobile-menu.open {
  display: flex;
}

/* ---------- 5. 英雄区（Hero） ---------- */
.hero {
  background: linear-gradient(145deg, var(--hero-gradient-start), var(--hero-gradient-end));
  padding: 80px 0;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--durian-200) 0%, transparent 70%);
  opacity: 0.3;
  border-radius: 50%;
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, var(--durian-300) 0%, transparent 70%);
  opacity: 0.2;
  border-radius: 50%;
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 60px;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.hero-text {
  flex: 1 1 450px;
}

.hero-text h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1.15;
  color: var(--text-heading);
  margin: 0 0 24px;
  font-weight: 800;
  letter-spacing: -1px;
  background: linear-gradient(135deg, var(--text-heading), var(--durian-700));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

body.dark-mode .hero-text h1 {
  background: linear-gradient(135deg, #f8fafc, var(--durian-400));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.8;
  max-width: 560px;
}

.hero-visual {
  flex: 1 1 350px;
  text-align: center;
  position: relative;
}

.hero-visual svg {
  max-width: 100%;
  height: auto;
  filter: drop-shadow(0 20px 30px rgba(180, 83, 9, 0.15));
  animation: heroFloat 6s ease-in-out infinite;
}

@keyframes heroFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  font-weight: 600;
  padding: 14px 32px;
  border-radius: 60px;
  text-decoration: none;
  transition: all 0.3s ease;
  border: 2px solid transparent;
  font-size: 1rem;
  gap: 8px;
  box-shadow: 0 4px 15px rgba(180, 83, 9, 0.2);
}

.btn:hover {
  background: var(--btn-primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(180, 83, 9, 0.3);
  color: var(--btn-primary-text);
}

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

.btn-outline {
  background: transparent;
  border-color: var(--durian-600);
  color: var(--durian-700);
  box-shadow: none;
}

.btn-outline:hover {
  background: var(--durian-50);
  border-color: var(--durian-500);
  color: var(--durian-800);
}

.btn-lg {
  padding: 16px 40px;
  font-size: 1.1rem;
}

.btn-sm {
  padding: 8px 20px;
  font-size: 0.875rem;
}

/* ---------- 6. 区块标题 ---------- */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  color: var(--text-heading);
  margin: 0 0 16px;
  font-weight: 800;
  letter-spacing: -0.5px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--durian-500), var(--durian-300));
  border-radius: 4px;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

/* 左侧对齐的标题变体 */
.section-title-left {
  text-align: left;
  display: block;
}

.section-title-left::after {
  left: 0;
  transform: none;
}

/* ---------- 7. 卡片组件 ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 32px;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--durian-500), var(--durian-300));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: var(--durian-200);
}

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

.card h3,
.card h4 {
  color: var(--text-heading);
  font-size: 1.4rem;
  margin: 0 0 16px;
  font-weight: 700;
  line-height: 1.3;
}

.card p {
  color: var(--text-primary);
  margin-bottom: 16px;
  line-height: 1.7;
}

.card .meta {
  color: var(--text-secondary);
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: var(--durian-50);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--durian-600);
  transition: all 0.3s ease;
}

.card:hover .card-icon {
  background: var(--durian-600);
  color: white;
  transform: scale(1.05);
}

/* 玻璃拟态卡片 */
.card-glass {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
}

/* ---------- 8. 文章卡片 ---------- */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.article-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 28px;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.article-card:hover {
  box-shadow: var(--shadow-xl);
  transform: translateY(-4px);
  border-color: var(--durian-200);
}

.article-card .badge {
  align-self: flex-start;
  margin-bottom: 16px;
}

.article-card h4 {
  color: var(--text-heading);
  font-size: 1.25rem;
  margin: 8px 0 12px;
  line-height: 1.4;
  font-weight: 700;
}

.article-card .date {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-card p {
  color: var(--text-primary);
  margin-bottom: 20px;
  flex-grow: 1;
  line-height: 1.6;
}

.article-card a {
  color: var(--text-accent);
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.3s ease;
}

.article-card a:hover {
  gap: 12px;
  color: var(--durian-500);
}

/* 标签 */
.badge {
  display: inline-flex;
  align-items: center;
  background: var(--badge-bg);
  color: var(--badge-text);
  padding: 4px 14px;
  border-radius: 40px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.badge-durian {
  background: var(--durian-100);
  color: var(--durian-800);
}

.badge-green {
  background: #d1fae5;
  color: #065f46;
}

.badge-blue {
  background: #dbeafe;
  color: #1e40af;
}

/* ---------- 9. FAQ 手风琴 ---------- */
.faq-item {
  border-bottom: 1px solid var(--faq-border);
  padding: 8px 0;
  transition: background 0.3s ease;
}

.faq-item:first-child {
  border-top: 1px solid var(--faq-border);
}

.faq-question {
  font-weight: 600;
  color: var(--text-heading);
  font-size: 1.1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  padding: 20px 16px;
  transition: color 0.2s ease;
  gap: 16px;
}

.faq-question:hover {
  color: var(--text-accent);
}

.faq-question .icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--durian-50);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  transition: all 0.3s ease;
  color: var(--durian-600);
}

.faq-item.active .faq-question .icon {
  background: var(--durian-600);
  color: white;
  transform: rotate(45deg);
}

.faq-answer {
  color: var(--text-primary);
  padding: 0 16px 20px;
  line-height: 1.7;
  font-size: 0.95rem;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 10. HowTo 教程 ---------- */
.howto-steps {
  background: var(--bg-secondary);
  border-radius: 20px;
  padding: 40px;
  border: 1px solid var(--border-color);
  position: relative;
  overflow: hidden;
}

.howto-steps::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--durian-500), var(--durian-300), var(--durian-500));
  background-size: 200% 100%;
  animation: gradientMove 3s linear infinite;
}

@keyframes gradientMove {
  0% { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

.howto-steps h3 {
  color: var(--text-heading);
  font-size: 1.3rem;
  margin-bottom: 12px;
}

.howto-steps h4 {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 20px;
  font-weight: 500;
}

.howto-steps ol {
  padding-left: 24px;
  margin-bottom: 24px;
}

.howto-steps li {
  margin-bottom: 16px;
  color: var(--text-primary);
  line-height: 1.7;
  position: relative;
}

.howto-steps li::marker {
  color: var(--durian-600);
  font-weight: 700;
}

.howto-steps p {
  color: var(--text-primary);
  margin-bottom: 12px;
}

.howto-steps strong {
  color: var(--text-heading);
  font-weight: 600;
}

/* ---------- 11. 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  background: var(--card-bg);
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}

th,
td {
  padding: 14px 20px;
  border-bottom: 1px solid var(--border-color);
  text-align: left;
  font-size: 0.95rem;
}

th {
  color: var(--text-heading);
  font-weight: 600;
  background: var(--table-header-bg);
  white-space: nowrap;
}

td {
  color: var(--text-primary);
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: var(--table-row-hover);
}

/* ---------- 12. 联系方式区块 ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  background: var(--bg-secondary);
  padding: 40px;
  border-radius: 24px;
  border: 1px solid var(--border-color);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--durian-50);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--durian-600);
  flex-shrink: 0;
}

.contact-item p {
  color: var(--text-primary);
  line-height: 1.6;
}

.contact-item strong {
  color: var(--text-heading);
  display: block;
  margin-bottom: 4px;
}

/* ---------- 13. 页脚 ---------- */
footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 80px 0 32px;
  margin-top: 80px;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 48px;
  margin-bottom: 48px;
}

.footer-grid h4 {
  color: var(--footer-heading);
  margin-bottom: 20px;
  font-size: 1.1rem;
  font-weight: 700;
  position: relative;
  padding-bottom: 12px;
}

.footer-grid h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 3px;
  background: var(--durian-500);
  border-radius: 3px;
}

.footer-grid a {
  color: var(--footer-text);
  text-decoration: none;
  display: block;
  margin: 10px 0;
  transition: all 0.2s ease;
  font-size: 0.95rem;
  padding: 4px 0;
}

.footer-grid a:hover {
  color: var(--durian-400);
  padding-left: 8px;
}

.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: 48px;
  padding-top: 32px;
  text-align: center;
  color: var(--footer-text);
  font-size: 0.9rem;
  opacity: 0.8;
}

/* ---------- 14. 返回顶部按钮 ---------- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  background: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  cursor: pointer;
  font-weight: bold;
  font-size: 1.2rem;
  box-shadow: var(--shadow-lg);
  z-index: 99;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.back-to-top:hover {
  background: var(--btn-primary-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.back-to-top.show {
  display: flex;
}

/* ---------- 15. 滚动动画 ---------- */
.scroll-animate {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.scroll-animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 延迟动画 */
.delay-1 {
  transition-delay: 0.1s;
}

.delay-2 {
  transition-delay: 0.2s;
}

.delay-3 {
  transition-delay: 0.3s;
}

.delay-4 {
  transition-delay: 0.4s;
}

.delay-5 {
  transition-delay: 0.5s;
}

/* ---------- 16. 数字动画 ---------- */
.num {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--durian-600);
  line-height: 1.2;
}

/* ---------- 17. 响应式设计 ---------- */
@media (max-width: 1024px) {
  .container {
    padding: 0 20px;
  }

  .section {
    padding: 64px 0;
  }

  .hero-content {
    gap: 40px;
  }

  .hero-text h1 {
    font-size: 2.5rem;
  }

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

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }

  .section {
    padding: 48px 0;
  }

  .nav-inner {
    height: 64px;
  }

  .nav-links {
    display: none;
  }

  .search-box {
    width: 140px;
  }

  .search-box input {
    width: 80px;
  }

  .hero {
    padding: 48px 0;
  }

  .hero-content {
    flex-direction: column;
    text-align: center;
  }

  .hero-text h1 {
    font-size: 2rem;
  }

  .hero-text p {
    font-size: 1rem;
    margin-bottom: 24px;
    margin-left: auto;
    margin-right: auto;
  }

  .hero-visual {
    order: -1;
  }

  .hero-visual svg {
    width: 200px;
    height: auto;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

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

  .section-title {
    font-size: 1.8rem;
  }

  .howto-steps {
    padding: 24px;
  }

  .contact-grid {
    padding: 24px;
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 480px) {
  .nav-right {
    gap: 4px;
  }

  .search-box {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .hero-text h1 {
    font-size: 1.75rem;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.95rem;
  }

  .card {
    padding: 24px;
  }

  .article-card {
    padding: 20px;
  }
}

/* ---------- 18. 暗色模式微调 ---------- */
body.dark-mode .card {
  background: var(--card-bg);
  border-color: var(--border-color);
}

body.dark-mode .card:hover {
  border-color: var(--durian-700);
}

body.dark-mode .card-icon {
  background: var(--durian-900);
  color: var(--durian-300);
}

body.dark-mode .card:hover .card-icon {
  background: var(--durian-600);
  color: white;
}

body.dark-mode .badge {
  background: var(--durian-900);
  color: var(--durian-200);
}

body.dark-mode .faq-question .icon {
  background: var(--durian-900);
  color: var(--durian-300);
}

body.dark-mode .faq-item.active .faq-question .icon {
  background: var(--durian-500);
  color: #0f172a;
}

body.dark-mode .contact-icon {
  background: var(--durian-900);
  color: var(--durian-300);
}

body.dark-mode .back-to-top {
  background: var(--durian-500);
  color: #0f172a;
}

body.dark-mode .back-to-top:hover {
  background: var(--durian-400);
}

/* ---------- 19. 辅助工具类 ---------- */
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mt-48 { margin-top: 48px; }
.mt-64 { margin-top: 64px; }

.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.mb-32 { margin-bottom: 32px; }
.mb-48 { margin-bottom: 48px; }
.mb-64 { margin-bottom: 64px; }

.py-16 { padding-top: 16px; padding-bottom: 16px; }
.py-24 { padding-top: 24px; padding-bottom: 24px; }
.py-32 { padding-top: 32px; padding-bottom: 32px; }
.py-48 { padding-top: 48px; padding-bottom: 48px; }
.py-64 { padding-top: 64px; padding-bottom: 64px; }

.px-16 { padding-left: 16px; padding-right: 16px; }
.px-24 { padding-left: 24px; padding-right: 24px; }
.px-32 { padding-left: 32px; padding-right: 32px; }

/* 渐变边框 */
.gradient-border {
  border: 2px solid transparent;
  background-image: linear-gradient(var(--card-bg), var(--card-bg)), 
                    linear-gradient(135deg, var(--durian-500), var(--durian-300));
  background-origin: border-box;
  background-clip: padding-box, border-box;
}

/* 阴影工具 */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* 圆角工具 */
.rounded-sm { border-radius: 8px; }
.rounded-md { border-radius: 12px; }
.rounded-lg { border-radius: 16px; }
.rounded-xl { border-radius: 24px; }
.rounded-full { border-radius: 9999px; }

/* 动画工具 */
.animate-float {
  animation: float 6s ease-in-out infinite;
}

.animate-pulse {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

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

/* 打印样式 */
@media print {
  .navbar,
  .footer,
  .back-to-top,
  .theme-toggle,
  .menu-btn,
  .search-box {
    display: none !important;
  }

  body {
    background: white;
    color: black;
    font-size: 12pt;
  }

  .container {
    max-width: 100%;
    padding: 0;
  }

  .card,
  .article-card {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
}

/* ---------- 20. 性能优化 ---------- */
@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;
  }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
  :root {
    --text-primary: #000000;
    --text-secondary: #1a1a1a;
    --text-heading: #000000;
    --border-color: #000000;
  }

  body.dark-mode {
    --text-primary: #ffffff;
    --text-secondary: #e0e0e0;
    --text-heading: #ffffff;
    --border-color: #ffffff;
  }
}

/* 焦点可见性 */
:focus-visible {
  outline: 3px solid var(--durian-500);
  outline-offset: 2px;
  border-radius: 4px;
}

/* 最终输出结束 */
```