/* ===== T41AV 全站样式表 ===== */
/* 暗色模式变量 */
:root {
  --bg-dark: #0a0f1a;
  --bg-card-dark: #121a2b;
  --text-primary-dark: #e2e8f0;
  --text-secondary-dark: #b0c4de;
  --text-heading-dark: #ffffff;
  --accent-dark: #3b82f6;
  --border-dark: #2d3a55;
  --bg-light: #f8fafc;
  --bg-card-light: #ffffff;
  --text-primary-light: #1f2937;
  --text-secondary-light: #334155;
  --text-heading-light: #0f172a;
  --accent-light: #1d4ed8;
  --border-light: #cbd5e1;
  --footer-bg-dark: #0d1422;
  --footer-text-dark: #cbd5e1;
  --footer-bg-light: #e2e8f0;
  --footer-text-light: #1e293b;
  --btn-text: #ffffff;
  --btn-bg: #2563eb;
  --btn-bg-hover: #1d4ed8;
  --nav-bg-dark: rgba(10, 15, 26, 0.9);
  --nav-bg-light: rgba(255, 255, 255, 0.9);
  --shadow-dark: 0 4px 20px rgba(0, 0, 0, 0.5);
  --shadow-light: 0 4px 20px rgba(0, 0, 0, 0.1);
  --gradient-main: linear-gradient(135deg, #0f172a, #1e3a5f, #0f172a);
  --gradient-accent: linear-gradient(135deg, #2563eb, #8b5cf6);
  --gradient-hero: linear-gradient(145deg, #1e1b4b, #312e81, #1e1b4b);
  --gradient-card: linear-gradient(145deg, rgba(255,255,255,0.08), rgba(255,255,255,0.02));
  --glass-bg: rgba(255, 255, 255, 0.06);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-display: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}

/* ===== 基础重置 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-display);
  line-height: 1.7;
  font-size: 16px;
  background-color: var(--bg-light);
  color: var(--text-primary-light);
  transition: background-color 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
  min-height: 100vh;
}

body.dark-mode {
  background-color: var(--bg-dark);
  color: var(--text-primary-dark);
  background-image: var(--gradient-main);
  background-attachment: fixed;
}

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

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

::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, var(--accent-light), #8b5cf6);
  border-radius: 10px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(135deg, #1d4ed8, #7c3aed);
  border: 2px solid transparent;
  background-clip: padding-box;
}

/* ===== 排版 ===== */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-heading-light);
  letter-spacing: -0.02em;
  transition: color 0.3s ease;
}

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, 4vw, 3rem);
  margin-bottom: 1rem;
  font-weight: 800;
  line-height: 1.2;
  background: linear-gradient(135deg, #60a5fa, #a78bfa, #60a5fa);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  background-size: 200% 200%;
  animation: gradientShift 6s ease infinite;
}

body.dark-mode h1 {
  background: linear-gradient(135deg, #93c5fd, #c4b5fd, #93c5fd);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  background-size: 200% 200%;
  animation: gradientShift 6s ease infinite;
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  margin: 2.5rem 0 1.25rem;
  padding-bottom: 0.75rem;
  position: relative;
  font-weight: 700;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--gradient-accent);
  border-radius: 3px;
}

h3 {
  font-size: 1.35rem;
  margin: 1.5rem 0 0.75rem;
  font-weight: 600;
}

h4 {
  font-size: 1.1rem;
  margin: 1rem 0 0.5rem;
  font-weight: 600;
}

p {
  margin-bottom: 1.2rem;
  color: var(--text-primary-light);
  transition: color 0.3s ease;
  font-size: 1rem;
}

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

a {
  color: var(--accent-light);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease, opacity 0.3s ease;
  position: relative;
}

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

a:hover {
  color: var(--btn-bg-hover);
  text-decoration: none;
}

body.dark-mode a:hover {
  color: #93c5fd;
}

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

li {
  margin-bottom: 0.5rem;
}

strong {
  font-weight: 700;
}

/* ===== 布局容器 ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

/* ===== 导航栏 ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  background-color: var(--nav-bg-light);
  box-shadow: var(--shadow-light);
  transition: background-color 0.4s ease, box-shadow 0.4s ease;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

body.dark-mode .navbar {
  background-color: var(--nav-bg-dark);
  box-shadow: var(--shadow-dark);
  border-bottom-color: rgba(255, 255, 255, 0.05);
}

.nav-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.9rem 24px;
  max-width: 1280px;
  margin: 0 auto;
  gap: 1rem;
}

.logo {
  font-size: 1.9rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: -0.5px;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
  transition: transform 0.3s ease;
}

.logo:hover {
  transform: scale(1.05);
}

.nav-links {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  list-style: none;
  flex-wrap: wrap;
}

.nav-links a {
  color: var(--text-primary-light);
  font-weight: 500;
  padding: 0.4rem 0.9rem;
  border-radius: 50px;
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

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

.nav-links a:hover {
  color: var(--accent-light);
  background: rgba(59, 130, 246, 0.1);
}

body.dark-mode .nav-links a:hover {
  color: var(--accent-dark);
  background: rgba(59, 130, 246, 0.2);
}

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-card-light);
  border-radius: 50px;
  padding: 0.35rem 0.35rem 0.35rem 1rem;
  border: 1px solid var(--border-light);
  transition: all 0.3s ease;
  margin-left: 0.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

body.dark-mode .search-box {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.search-box:focus-within {
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

body.dark-mode .search-box:focus-within {
  border-color: var(--accent-dark);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
}

.search-box input {
  border: none;
  background: transparent;
  padding: 0.5rem 0;
  font-size: 0.9rem;
  color: var(--text-primary-light);
  outline: none;
  width: 120px;
  transition: width 0.3s ease;
}

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

.search-box input:focus {
  width: 160px;
}

.search-box button {
  background: var(--gradient-accent);
  border: none;
  cursor: pointer;
  color: white;
  font-size: 1rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.search-box button:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.theme-toggle {
  background: none;
  border: 2px solid var(--border-light);
  border-radius: 50px;
  padding: 0.4rem 0.9rem;
  cursor: pointer;
  font-weight: 600;
  color: var(--text-primary-light);
  background-color: var(--bg-card-light);
  transition: all 0.3s ease;
  font-size: 1.1rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
}

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

.theme-toggle:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 1.25rem 0;
  color: var(--text-secondary-light);
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

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

.breadcrumb span {
  transition: color 0.3s ease;
}

.breadcrumb span:not(:last-child) {
  cursor: pointer;
  color: var(--accent-light);
}

body.dark-mode .breadcrumb span:not(:last-child) {
  color: var(--accent-dark);
}

/* ===== Hero 区域 ===== */
.hero {
  padding: 4rem 0;
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
  min-height: 60vh;
  display: flex;
  align-items: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 50%;
  height: 150%;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 70%);
  animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(30px, -20px); }
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 4rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.hero-text {
  flex: 1 1 400px;
  animation: fadeInUp 0.8s ease;
}

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

.hero-text p {
  color: rgba(255, 255, 255, 0.8);
  font-size: 1.1rem;
  max-width: 600px;
}

.hero-image {
  flex: 1 1 300px;
  text-align: center;
  animation: fadeInRight 0.8s ease 0.2s both;
}

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

.hero-image svg {
  max-width: 100%;
  height: auto;
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
  transition: transform 0.5s ease, box-shadow 0.5s ease;
  backdrop-filter: blur(8px);
}

.hero-image svg:hover {
  transform: scale(1.02);
  box-shadow: 0 25px 70px rgba(0, 0, 0, 0.5);
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  background: var(--gradient-accent);
  color: var(--btn-text);
  padding: 0.9rem 2.2rem;
  border-radius: 50px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 1rem;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s ease;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
  color: white;
}

.btn:hover::before {
  left: 100%;
}

.btn:active {
  transform: translateY(-1px);
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.card {
  background: var(--bg-card-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-light);
  border: 1px solid var(--border-light);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
  animation: cardFadeIn 0.6s ease both;
}

body.dark-mode .card {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-dark);
  background-image: var(--gradient-card);
  backdrop-filter: blur(8px);
}

.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 ease;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

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

@keyframes cardFadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card h3 {
  margin-top: 0;
  font-size: 1.2rem;
}

.card svg {
  width: 100%;
  height: 160px;
  border-radius: var(--radius-md);
  background: linear-gradient(145deg, #1e293b, #334155);
  margin-bottom: 1rem;
  transition: transform 0.3s ease;
}

.card:hover svg {
  transform: scale(1.02);
}

.card .text-secondary {
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

.card a {
  display: inline-block;
  margin-top: 0.5rem;
  font-weight: 600;
  font-size: 0.9rem;
}

.card a::after {
  content: ' →';
  transition: transform 0.3s ease;
  display: inline-block;
}

.card a:hover::after {
  transform: translateX(4px);
}

/* ===== 文章卡片 ===== */
.article-card {
  background: var(--bg-card-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  border: 1px solid var(--border-light);
  margin-bottom: 1.5rem;
  transition: all 0.3s ease;
  animation: cardFadeIn 0.6s ease both;
}

body.dark-mode .article-card {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  background-image: var(--gradient-card);
  backdrop-filter: blur(8px);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.article-card h3 {
  margin-bottom: 0.75rem;
}

/* ===== FAQ ===== */
.faq-item {
  background: var(--bg-card-light);
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  border: 1px solid var(--border-light);
  overflow: hidden;
  transition: all 0.3s ease;
  animation: cardFadeIn 0.6s ease both;
}

body.dark-mode .faq-item {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  background-image: var(--gradient-card);
  backdrop-filter: blur(8px);
}

.faq-item:hover {
  border-color: var(--accent-light);
  box-shadow: 0 8px 20px rgba(59, 130, 246, 0.1);
}

.faq-question {
  padding: 1.2rem 1.5rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-primary-light);
  transition: all 0.3s ease;
  font-size: 1.05rem;
}

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

.faq-question::after {
  content: '＋';
  font-size: 1.2rem;
  transition: transform 0.4s ease;
  color: var(--accent-light);
  flex-shrink: 0;
  margin-left: 1rem;
}

body.dark-mode .faq-question::after {
  color: var(--accent-dark);
}

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

.faq-answer {
  padding: 0 1.5rem 1.5rem;
  color: var(--text-primary-light);
  display: none;
  border-top: 1px solid var(--border-light);
  padding-top: 1rem;
}

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

.faq-answer p {
  margin-bottom: 0.5rem;
}

/* ===== HowTo 教程 ===== */
.howto-section {
  background: var(--bg-card-light);
  padding: 2rem;
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-light);
  transition: all 0.3s ease;
}

body.dark-mode .howto-section {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-dark);
  background-image: var(--gradient-card);
  backdrop-filter: blur(8px);
}

.howto-section ol {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

.howto-section ol li {
  counter-increment: step;
  position: relative;
  padding-left: 3rem;
  margin-bottom: 1rem;
  font-size: 1rem;
}

.howto-section ol li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 2.2rem;
  height: 2.2rem;
  background: var(--gradient-accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
}

.howto-tip {
  background: rgba(59, 130, 246, 0.1);
  border-left: 4px solid var(--accent-light);
  padding: 1rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
}

body.dark-mode .howto-tip {
  background: rgba(59, 130, 246, 0.15);
  border-left-color: var(--accent-dark);
}

/* ===== Footer ===== */
.footer {
  background-color: var(--footer-bg-light);
  color: var(--footer-text-light);
  padding: 3rem 0 0;
  margin-top: 5rem;
  border-top: 1px solid var(--border-light);
  position: relative;
  overflow: hidden;
}

body.dark-mode .footer {
  background-color: var(--footer-bg-dark);
  color: var(--footer-text-dark);
  border-top-color: var(--border-dark);
  background-image: linear-gradient(135deg, #0d1422, #1a1f35);
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2.5rem;
  padding-bottom: 2.5rem;
}

.footer h4 {
  color: var(--text-heading-light);
  margin-bottom: 1rem;
  font-size: 1.05rem;
  position: relative;
  padding-bottom: 0.75rem;
}

body.dark-mode .footer h4 {
  color: var(--text-heading-dark);
}

.footer h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 30px;
  height: 2px;
  background: var(--gradient-accent);
  border-radius: 2px;
}

.footer ul {
  list-style: none;
  padding: 0;
}

.footer ul li {
  margin-bottom: 0.6rem;
}

.footer a {
  color: var(--footer-text-light);
  opacity: 0.8;
  transition: all 0.3s ease;
}

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

.footer a:hover {
  color: var(--accent-light);
  opacity: 1;
  padding-left: 4px;
}

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

.footer p {
  color: inherit;
}

.footer-bottom {
  border-top: 1px solid rgba(100, 116, 139, 0.2);
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.9rem;
}

body.dark-mode .footer-bottom {
  border-top-color: rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
  margin-bottom: 0.5rem;
  color: inherit;
}

/* ===== 通用工具类 ===== */
.text-secondary {
  color: var(--text-secondary-light);
  font-size: 0.9rem;
}

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

.badge {
  background: var(--gradient-accent);
  color: white;
  padding: 0.25rem 1rem;
  border-radius: 50px;
  font-size: 0.8rem;
  display: inline-block;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.2);
}

.back-to-top {
  position: fixed;
  bottom: 2.5rem;
  right: 2.5rem;
  background: var(--gradient-accent);
  color: white;
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 1.5rem;
  cursor: pointer;
  z-index: 100;
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.3);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(37, 99, 235, 0.4);
}

.back-to-top:active {
  transform: translateY(-2px);
}

/* ===== 移动端菜单按钮 ===== */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  cursor: pointer;
  color: var(--text-primary-light);
  padding: 0.25rem;
  line-height: 1;
  transition: color 0.3s ease;
}

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

.menu-toggle:hover {
  color: var(--accent-light);
}

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

/* ===== 联系信息区块 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 2rem 0;
}

.contact-card {
  background: var(--bg-card-light);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid var(--border-light);
  transition: all 0.3s ease;
}

body.dark-mode .contact-card {
  background: var(--bg-card-dark);
  border-color: var(--border-dark);
  background-image: var(--gradient-card);
  backdrop-filter: blur(8px);
}

.contact-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.contact-card p {
  margin-bottom: 0.75rem;
}

.contact-card strong {
  display: block;
  margin-bottom: 0.25rem;
}

/* ===== 友情链接 ===== */
.friendly-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0;
}

.friendly-links a {
  padding: 0.5rem 1.2rem;
  background: var(--bg-card-light);
  border: 1px solid var(--border-light);
  border-radius: 50px;
  font-size: 0.9rem;
  transition: all 0.3s ease;
}

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

.friendly-links a:hover {
  background: var(--gradient-accent);
  color: white;
  border-color: transparent;
  transform: translateY(-2px);
}

/* ===== 响应式布局 ===== */
@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }

  .nav-content {
    padding: 0.75rem 16px;
  }

  .logo {
    font-size: 1.5rem;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 60px;
    right: 16px;
    background: var(--bg-card-light);
    width: 220px;
    padding: 1.25rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-light);
    gap: 0.25rem;
    backdrop-filter: blur(20px);
  }

  body.dark-mode .nav-links {
    background: var(--bg-card-dark);
    box-shadow: var(--shadow-dark);
    border-color: var(--border-dark);
    background-image: var(--gradient-card);
  }

  .nav-links.open {
    display: flex;
    animation: slideDown 0.3s ease;
  }

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

  .nav-links a {
    padding: 0.6rem 1rem;
    border-radius: var(--radius-sm);
    width: 100%;
    text-align: left;
  }

  .nav-links a:hover {
    background: rgba(59, 130, 246, 0.1);
  }

  .menu-toggle {
    display: block;
    order: 2;
  }

  .search-box {
    display: none;
    width: 100%;
    margin-top: 0.5rem;
    margin-left: 0;
  }

  .search-box input {
    width: 100%;
  }

  .search-box input:focus {
    width: 100%;
  }

  .theme-toggle {
    order: 1;
    margin-left: auto;
  }

  .hero {
    padding: 3rem 0;
    min-height: auto;
  }

  .hero-content {
    gap: 2rem;
    text-align: center;
  }

  .hero-text {
    flex: 1 1 100%;
  }

  .hero-text p {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-image {
    flex: 1 1 100%;
  }

  .hero-image svg {
    width: 100%;
    max-width: 350px;
  }

  h1 {
    font-size: 1.8rem;
  }

  h2 {
    font-size: 1.4rem;
    margin: 2rem 0 1rem;
  }

  h3 {
    font-size: 1.15rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .back-to-top {
    bottom: 1.5rem;
    right: 1.5rem;
    width: 44px;
    height: 44px;
    font-size: 1.25rem;
  }

  .howto-section {
    padding: 1.5rem;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }

  .footer-bottom {
    padding: 1.25rem 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 12px;
  }

  .nav-content {
    padding: 0.6rem 12px;
  }

  .logo {
    font-size: 1.3rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    text-align: left;
  }

  .btn {
    padding: 0.75rem 1.75rem;
    font-size: 0.95rem;
  }

  .card {
    padding: 1.25rem;
  }

  .faq-question {
    padding: 1rem 1.25rem;
    font-size: 0.95rem;
  }

  .faq-answer {
    padding: 0 1.25rem 1.25rem;
  }
}

/* ===== 暗色模式微调 ===== */
body.dark-mode .card,
body.dark-mode .article-card,
body.dark-mode .faq-item,
body.dark-mode .contact-card,
body.dark-mode .howto-section {
  background-image: var(--gradient-card);
}

body.dark-mode .hero {
  background: linear-gradient(145deg, #0f172a, #1e1b4b, #0f172a);
}

body.dark-mode .btn {
  background: var(--gradient-accent);
}

/* ===== 滚动动画 ===== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===== 渐变文字 ===== */
.gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ===== 毛玻璃效果 ===== */
.glass-effect {
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);
}

/* ===== 分隔线 ===== */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-light), transparent);
  border: none;
  margin: 2.5rem 0;
}

body.dark-mode .divider {
  background: linear-gradient(90deg, transparent, var(--border-dark), transparent);
}

/* ===== 标签 ===== */
.tag {
  display: inline-block;
  padding: 0.2rem 0.8rem;
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent-light);
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 500;
  margin: 0.2rem;
  transition: all 0.3s ease;
}

body.dark-mode .tag {
  background: rgba(59, 130, 246, 0.2);
  color: var(--accent-dark);
}

.tag:hover {
  background: var(--gradient-accent);
  color: white;
  transform: translateY(-2px);
}

/* ===== 统计数字 ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.stat-item {
  text-align: center;
  padding: 1.5rem;
  background: var(--bg-card-light);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  transition: all 0.3s ease;
}

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

.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.stat-number {
  font-size: 2rem;
  font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary-light);
  margin-top: 0.25rem;
}

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

/* ===== 播放列表 ===== */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.video-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  transition: all 0.3s ease;
  background: var(--bg-card-light);
  border: 1px solid var(--border-light);
}

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

.video-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.video-thumb {
  width: 100%;
  aspect-ratio: 16/9;
  background: linear-gradient(145deg, #1e293b, #334155);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.video-thumb .play-icon {
  width: 50px;
  height: 50px;
  background: rgba(255, 255, 255, 0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--accent-light);
  transition: all 0.3s ease;
  opacity: 0;
  transform: scale(0.8);
}

.video-card:hover .play-icon {
  opacity: 1;
  transform: scale(1);
}

.video-info {
  padding: 1rem;
}

.video-title {
  font-weight: 600;
  margin-bottom: 0.25rem;
  font-size: 0.95rem;
}

.video-meta {
  font-size: 0.8rem;
  color: var(--text-secondary-light);
}

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

/* ===== 加载动画 ===== */
.loading-spinner {
  display: inline-block;
  width: 30px;
  height: 30px;
  border: 3px solid rgba(59, 130, 246, 0.2);
  border-top-color: var(--accent-light);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

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

  body {
    background: white;
    color: black;
  }

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

/* ===== 无障碍 ===== */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===== 焦点可见性 ===== */
a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent-light);
  outline-offset: 2px;
  border-radius: 4px;
}

body.dark-mode a:focus-visible,
body.dark-mode button:focus-visible,
body.dark-mode input:focus-visible {
  outline-color: var(--accent-dark);
}

/* ===== 内容区块 ===== */
.section-spacing {
  padding: 3rem 0;
}

.section-intro {
  max-width: 800px;
  margin-bottom: 2rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

/* ===== 高亮框 ===== */
.highlight-box {
  background: rgba(59, 130, 246, 0.05);
  border: 1px solid rgba(59, 130, 246, 0.2);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

body.dark-mode .highlight-box {
  background: rgba(59, 130, 246, 0.1);
  border-color: rgba(59, 130, 246, 0.3);
}

/* ===== 表格 ===== */
.table-responsive {
  overflow-x: auto;
  margin: 1.5rem 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card-light);
  border-radius: var(--radius-md);
  overflow: hidden;
}

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

th, td {
  padding: 0.75rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-light);
}

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

th {
  font-weight: 600;
  background: rgba(59, 130, 246, 0.08);
}

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

/* ===== 代码块 ===== */
code {
  background: rgba(59, 130, 246, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: 'Fira Code', monospace;
}

pre {
  background: var(--bg-dark);
  color: var(--text-primary-dark);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: 1.5rem 0;
  border: 1px solid var(--border-dark);
}

pre code {
  background: none;
  padding: 0;
}

/* ===== 引用 ===== */
blockquote {
  border-left: 4px solid var(--accent-light);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  background: rgba(59, 130, 246, 0.05);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
}

body.dark-mode blockquote {
  border-left-color: var(--accent-dark);
  background: rgba(59, 130, 246, 0.1);
}

/* ===== 图片 ===== */
img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
}

/* ===== 表单 ===== */
.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  font-size: 1rem;
  background: var(--bg-card-light);
  color: var(--text-primary-light);
  transition: all 0.3s ease;
}

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

.form-control:focus {
  outline: none;
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

/* ===== 最终修复 ===== */
* {
  -webkit-tap-highlight-color: transparent;
}

body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

button {
  font-family: inherit;
}

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

/* 暗色模式下的图片和卡片 */
body.dark-mode .card svg,
body.dark-mode .hero-image svg {
  filter: brightness(0.9) contrast(1.1);
}

body.dark-mode img {
  filter: brightness(0.9);
}

/* 响应式字体大小 */
@media (max-width: 480px) {
  html {
    font-size: 14px;
  }
}

@media (min-width: 481px) and (max-width: 768px) {
  html {
    font-size: 15px;
  }
}

@media (min-width: 769px) {
  html {
    font-size: 16px;
  }
}