```css
/* ===== 糖心vlog 全站样式 ===== */
:root {
  --bg-light: #FFFFFF;
  --bg-dark: #0F172A;
  --text-primary-light: #1F2937;
  --text-secondary-light: #243447;
  --text-heading-light: #111827;
  --text-link-light: #1D4ED8;
  --text-footer-light: #E5E7EB;
  --border-light: #D1D5DB;
  --card-bg-light: #F8FAFC;
  --nav-bg-light: rgba(255,255,255,0.92);
  --btn-primary-bg: #1E3A8A;
  --btn-primary-text: #FFFFFF;
  
  --bg-dark-main: #0B1220;
  --text-primary-dark: #E2E8F0;
  --text-secondary-dark: #CBD5E1;
  --text-heading-dark: #FFFFFF;
  --text-link-dark: #93C5FD;
  --border-dark: #334155;
  --card-bg-dark: #1E293B;
  --nav-bg-dark: rgba(15,23,42,0.95);
  --btn-primary-bg-dark: #2563EB;
  --btn-primary-text-dark: #FFFFFF;
  
  --gradient-main: linear-gradient(145deg, #eff6ff, #dbeafe);
  --gradient-accent: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.08);
  --shadow-xl: 0 20px 40px rgba(0,0,0,0.12);
  --radius-md: 16px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg-light);
  color: var(--text-primary-light);
  line-height: 1.7;
  font-size: 16px;
  transition: background 0.3s, color 0.3s;
  overflow-x: hidden;
}

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

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

body.dark-mode .site-footer,
body.dark-mode .footer-bottom {
  background-color: #0f172a;
  color: var(--text-footer-light);
}

body.dark-mode .card,
body.dark-mode .article-card,
body.dark-mode .faq-item,
body.dark-mode .howto-box {
  background-color: var(--card-bg-dark);
  border-color: var(--border-dark);
  color: var(--text-primary-dark);
}

body.dark-mode .nav-menu {
  background-color: var(--nav-bg-dark);
}

body.dark-mode .section-title,
body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4 {
  color: var(--text-heading-dark);
}

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

h1, h2, h3, h4 {
  color: var(--text-heading-light);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 0.5rem;
  transition: color 0.3s;
}

p {
  color: var(--text-primary-light);
  transition: color 0.3s;
}

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

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

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

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 导航栏 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--nav-bg-light);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  transition: background 0.3s, border-color 0.3s;
}

body.dark-mode .site-header {
  background-color: var(--nav-bg-dark);
  border-bottom-color: #1e293b;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
  gap: 20px;
}

.logo a {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--text-heading-light);
  transition: color 0.3s;
  text-decoration: none;
}

.logo a:hover {
  text-decoration: none;
}

body.dark-mode .logo a {
  color: #fff;
}

nav {
  position: relative;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  transition: all 0.3s;
}

.nav-links a {
  color: var(--text-primary-light);
  font-weight: 500;
  padding: 0.25rem 0;
  position: relative;
  transition: color 0.2s;
}

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

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

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

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

body.dark-mode .nav-links a::after {
  background: var(--btn-primary-bg-dark);
}

.nav-actions {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.search-box input {
  padding: 8px 16px;
  border-radius: 30px;
  border: 1px solid var(--border-light);
  background: transparent;
  color: var(--text-primary-light);
  font-size: 0.9rem;
  transition: all 0.3s;
  width: 140px;
}

.search-box input:focus {
  outline: none;
  border-color: var(--btn-primary-bg);
  box-shadow: 0 0 0 3px rgba(30, 58, 138, 0.1);
  width: 180px;
}

body.dark-mode .search-box input {
  color: #fff;
  border-color: #334155;
}

body.dark-mode .search-box input:focus {
  border-color: var(--btn-primary-bg-dark);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.dark-toggle,
.menu-toggle {
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
  color: var(--text-primary-light);
  transition: transform 0.3s, color 0.3s;
  padding: 4px;
}

.dark-toggle:hover,
.menu-toggle:hover {
  transform: scale(1.1);
}

body.dark-mode .dark-toggle,
body.dark-mode .menu-toggle {
  color: #fff;
}

.mobile-menu {
  display: none;
  font-size: 1.8rem;
  cursor: pointer;
  padding: 4px;
  user-select: none;
  transition: transform 0.3s;
}

.mobile-menu:hover {
  transform: scale(1.1);
}

/* ===== Hero 首屏 ===== */
.hero {
  background: var(--gradient-main);
  padding: 4rem 0;
  margin-bottom: 2.5rem;
  border-radius: 0 0 40px 40px;
  position: relative;
  overflow: hidden;
  transition: background 0.3s;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255,255,255,0.3) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

body.dark-mode .hero {
  background: #1e293b;
}

body.dark-mode .hero::before {
  background: radial-gradient(circle, rgba(147, 197, 253, 0.1) 0%, transparent 70%);
}

.hero-content {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2rem;
  position: relative;
  z-index: 1;
}

.hero-text {
  flex: 1 1 300px;
}

.hero-text h1 {
  font-size: 3rem;
  color: var(--text-heading-light);
  margin-bottom: 1rem;
  line-height: 1.2;
  transition: color 0.3s;
}

body.dark-mode .hero-text h1 {
  color: #fff;
}

.hero-text p {
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  color: var(--text-secondary-light);
}

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

.btn-primary {
  background-color: var(--btn-primary-bg);
  color: var(--btn-primary-text);
  padding: 12px 30px;
  border-radius: 40px;
  font-weight: 600;
  display: inline-block;
  border: none;
  cursor: pointer;
  transition: all 0.3s;
  text-decoration: none;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background-color: #1a2f6f;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}

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

body.dark-mode .btn-primary:hover {
  background-color: #1d4ed8;
}

.hero-image svg {
  width: 280px;
  height: auto;
  border-radius: 24px;
  transition: transform 0.5s;
  box-shadow: var(--shadow-lg);
}

.hero-image svg:hover {
  transform: scale(1.02) rotate(-1deg);
}

/* ===== 通用区块 ===== */
.section {
  margin: 3.5rem 0;
}

.section-title {
  font-size: 2rem;
  margin-bottom: 1.8rem;
  border-left: 6px solid #1E3A8A;
  padding-left: 1rem;
  transition: border-color 0.3s;
}

body.dark-mode .section-title {
  border-left-color: #3b82f6;
}

.grid-3,
.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 2rem;
}

.card {
  background-color: var(--card-bg-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.8rem 1.5rem;
  transition: transform 0.3s, box-shadow 0.3s, background 0.3s, border-color 0.3s;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s;
}

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

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

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

.card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.8rem;
}

.card p {
  margin-top: 0.6rem;
  font-size: 0.95rem;
}

/* ===== 文章卡片 ===== */
.article-card {
  background: var(--card-bg-light);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  transition: transform 0.3s, box-shadow 0.3s, background 0.3s, border-color 0.3s;
  position: relative;
}

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

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

.article-meta {
  font-size: 0.85rem;
  color: var(--text-secondary-light);
  margin-bottom: 0.8rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.article-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

.article-card p {
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.article-card a {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--btn-primary-bg);
}

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

/* ===== FAQ ===== */
.faq-item {
  background: var(--card-bg-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1rem;
  transition: all 0.3s;
}

.faq-item:hover {
  border-color: var(--btn-primary-bg);
  box-shadow: var(--shadow-md);
}

body.dark-mode .faq-item:hover {
  border-color: var(--btn-primary-bg-dark);
}

.faq-question {
  font-weight: 600;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-heading-light);
  transition: color 0.3s;
  user-select: none;
}

.faq-question span {
  font-size: 1.5rem;
  transition: transform 0.3s;
  color: var(--btn-primary-bg);
}

.faq-item.active .faq-question span {
  transform: rotate(45deg);
}

body.dark-mode .faq-question {
  color: #fff;
}

body.dark-mode .faq-question span {
  color: var(--btn-primary-bg-dark);
}

.faq-answer {
  margin-top: 0.8rem;
  color: var(--text-primary-light);
  line-height: 1.7;
  animation: fadeIn 0.3s;
}

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

/* ===== HowTo ===== */
.howto-box {
  background: var(--card-bg-light);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid var(--border-light);
  transition: background 0.3s, border-color 0.3s;
}

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

.step-list {
  list-style: none;
}

.step-list li {
  margin-bottom: 0.8rem;
  padding-left: 1.5rem;
  position: relative;
  line-height: 1.8;
}

.step-list li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--btn-primary-bg);
  font-weight: bold;
}

body.dark-mode .step-list li::before {
  color: var(--btn-primary-bg-dark);
}

.step-list li strong {
  color: var(--text-heading-light);
}

body.dark-mode .step-list li strong {
  color: var(--text-heading-dark);
}

/* ===== 表格 ===== */
.info-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.info-table th,
.info-table td {
  border: 1px solid var(--border-light);
  padding: 12px 15px;
  color: var(--text-primary-light);
  text-align: left;
  transition: color 0.3s, border-color 0.3s;
}

body.dark-mode .info-table th,
body.dark-mode .info-table td {
  color: var(--text-primary-dark);
  border-color: #334155;
}

.info-table th {
  background-color: #eef2ff;
  font-weight: 600;
}

body.dark-mode .info-table th {
  background-color: #1e293b;
}

.info-table tr:hover td {
  background-color: rgba(30, 58, 138, 0.03);
}

body.dark-mode .info-table tr:hover td {
  background-color: rgba(37, 99, 235, 0.05);
}

/* ===== 友情链接/页脚 ===== */
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  justify-content: center;
  padding: 1rem 0;
}

.footer-links a {
  position: relative;
  transition: color 0.2s;
}

.footer-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: #93C5FD;
  transition: width 0.3s;
}

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

.site-footer {
  background-color: #1e293b;
  color: #e5e7eb;
  padding: 2.5rem 0 1rem;
  margin-top: 4rem;
  transition: background 0.3s;
}

.site-footer a {
  color: #93C5FD;
  text-decoration: none;
}

.site-footer a:hover {
  color: #fff;
}

.footer-bottom {
  text-align: center;
  border-top: 1px solid #334155;
  padding-top: 1.5rem;
  margin-top: 2rem;
  font-size: 0.9rem;
  color: #cbd5e1;
}

/* ===== 返回顶部 ===== */
.go-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--btn-primary-bg);
  color: white;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s, transform 0.3s, background 0.3s;
  z-index: 999;
  border: none;
  box-shadow: var(--shadow-lg);
}

.go-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.go-top:hover {
  transform: translateY(-4px);
  background: var(--btn-primary-bg-dark);
}

body.dark-mode .go-top {
  background: var(--btn-primary-bg-dark);
}

/* ===== 滚动动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.5s;
}

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

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

.mt-2 {
  margin-top: 1rem;
}

.mt-4 {
  margin-top: 2rem;
}

.mb-2 {
  margin-bottom: 1rem;
}

.mb-4 {
  margin-bottom: 2rem;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .nav-links {
    gap: 1.5rem;
  }
  
  .search-box input {
    width: 120px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--bg-light);
    padding: 1rem 2rem;
    box-shadow: var(--shadow-lg);
    border-radius: 0 0 16px 16px;
    gap: 1rem;
  }
  
  .nav-links.open {
    display: flex;
  }
  
  .nav-links a::after {
    display: none;
  }
  
  .mobile-menu {
    display: block;
  }
  
  body.dark-mode .nav-links.open {
    background: var(--bg-dark-main);
  }
  
  .hero-text h1 {
    font-size: 2.2rem;
  }
  
  .hero-image svg {
    width: 200px;
  }
  
  .section-title {
    font-size: 1.6rem;
  }
  
  .card {
    padding: 1.4rem 1.2rem;
  }
  
  .grid-3,
  .grid-4 {
    gap: 1.2rem;
  }
  
  .search-box {
    display: none;
  }
  
  .nav-wrapper {
    gap: 10px;
  }
  
  .go-top {
    bottom: 1.5rem;
    right: 1.5rem;
    width: 42px;
    height: 42px;
    font-size: 1.5rem;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }
  
  .container {
    padding: 0 16px;
  }
  
  .hero {
    padding: 2.5rem 0;
    border-radius: 0 0 24px 24px;
  }
  
  .hero-text h1 {
    font-size: 1.8rem;
  }
  
  .hero-text p {
    font-size: 1rem;
  }
  
  .btn-primary {
    padding: 10px 24px;
    font-size: 0.95rem;
  }
  
  .section {
    margin: 2.5rem 0;
  }
  
  .section-title {
    font-size: 1.4rem;
  }
  
  .logo a {
    font-size: 1.4rem;
  }
  
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .card {
    padding: 1.2rem 1rem;
  }
  
  .footer-links {
    gap: 0.8rem;
    font-size: 0.9rem;
  }
  
  .faq-question {
    font-size: 1rem;
  }
  
  .howto-box {
    padding: 1.5rem;
  }
}

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

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== 暗色模式额外优化 ===== */
body.dark-mode .hero-image svg {
  filter: brightness(0.9);
}

body.dark-mode .article-card a:hover {
  color: #dbeafe;
}

/* ===== 无障碍支持 ===== */
:focus {
  outline: 2px solid var(--btn-primary-bg);
  outline-offset: 2px;
}

body.dark-mode :focus {
  outline-color: var(--btn-primary-bg-dark);
}

@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;
  }
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

body.dark-mode ::-webkit-scrollbar-thumb {
  background: #475569;
}

body.dark-mode ::-webkit-scrollbar-thumb:hover {
  background: #64748b;
}
```