:root {
  --brand-primary: #2b5a7a;
  --brand-secondary: #4c8b9e;
  --brand-accent: #e8b84b;
  --brand-bg: #f9fbfc;
  --brand-surface: #ffffff;
  --brand-text: #1e2b32;
  --brand-text-secondary: #4a5c66;
  --brand-border: #dce5ea;
  --brand-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  --brand-radius: 10px;
  --brand-radius-sm: 6px;
  --brand-transition: 0.25s ease;
  --brand-max-width: 1200px;
  --brand-header-height: 64px;
  --brand-gradient: linear-gradient(135deg, #2b5a7a 0%, #4c8b9e 50%, #6bb3c4 100%);
  --brand-gradient-soft: linear-gradient(135deg, rgba(43, 90, 122, 0.08) 0%, rgba(76, 139, 158, 0.08) 50%, rgba(232, 184, 75, 0.06) 100%);
  --brand-glass: rgba(255, 255, 255, 0.72);
  --brand-glass-border: rgba(255, 255, 255, 0.4);
  --brand-glass-blur: 16px;
}

[data-theme="dark"] {
  --brand-primary: #3d7a9e;
  --brand-secondary: #5fa3b8;
  --brand-accent: #f0c85a;
  --brand-bg: #121a1f;
  --brand-surface: #1c262d;
  --brand-text: #e4ecf0;
  --brand-text-secondary: #a0b4bf;
  --brand-border: #2e3d46;
  --brand-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
  --brand-gradient: linear-gradient(135deg, #1a2e3d 0%, #2b5a7a 50%, #3d7a9e 100%);
  --brand-gradient-soft: linear-gradient(135deg, rgba(61, 122, 158, 0.12) 0%, rgba(95, 163, 184, 0.1) 50%, rgba(240, 200, 90, 0.06) 100%);
  --brand-glass: rgba(28, 38, 45, 0.72);
  --brand-glass-border: rgba(255, 255, 255, 0.08);
  --brand-glass-blur: 16px;
}

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

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

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

a {
  color: var(--brand-primary);
  text-decoration: none;
  transition: color var(--brand-transition);
}

a:hover {
  color: var(--brand-secondary);
}

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

.container {
  max-width: var(--brand-max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--brand-primary);
  color: #fff;
  padding: 10px 20px;
  border-radius: var(--brand-radius-sm);
  z-index: 10000;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 10px;
}

/* ===== 头部导航 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border-bottom: 1px solid var(--brand-glass-border);
  box-shadow: var(--brand-shadow);
  transition: background var(--brand-transition), border-color var(--brand-transition), box-shadow var(--brand-transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--brand-header-height);
  gap: 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--brand-text);
  flex-shrink: 0;
}

.logo svg {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  transition: transform var(--brand-transition);
}

.logo:hover svg {
  transform: rotate(-6deg) scale(1.05);
}

.logo span {
  color: var(--brand-primary);
}

.logo em {
  font-style: normal;
  color: var(--brand-secondary);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.main-nav a {
  padding: 8px 14px;
  border-radius: var(--brand-radius-sm);
  font-size: 0.92rem;
  color: var(--brand-text-secondary);
  white-space: nowrap;
  transition: background var(--brand-transition), color var(--brand-transition), transform var(--brand-transition);
}

.main-nav a:hover {
  background: var(--brand-gradient-soft);
  color: var(--brand-primary);
  transform: translateY(-1px);
}

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

.search-box {
  display: flex;
  align-items: center;
  background: var(--brand-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--brand-border);
  border-radius: 20px;
  padding: 4px 6px 4px 14px;
  transition: border-color var(--brand-transition), background var(--brand-transition), box-shadow var(--brand-transition);
}

.search-box:focus-within {
  border-color: var(--brand-primary);
  box-shadow: 0 0 0 3px rgba(43, 90, 122, 0.12);
}

.search-box input {
  border: none;
  outline: none;
  background: transparent;
  color: var(--brand-text);
  font-size: 0.88rem;
  width: 130px;
  padding: 4px 0;
}

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

.search-box button {
  background: var(--brand-gradient);
  border: none;
  color: #fff;
  border-radius: 16px;
  padding: 4px 12px;
  font-size: 0.82rem;
  cursor: pointer;
  transition: opacity var(--brand-transition), transform var(--brand-transition);
  white-space: nowrap;
}

.search-box button:hover {
  opacity: 0.9;
  transform: scale(1.03);
}

.theme-toggle {
  background: var(--brand-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--brand-border);
  border-radius: 50%;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--brand-text-secondary);
  transition: background var(--brand-transition), border-color var(--brand-transition), color var(--brand-transition), transform var(--brand-transition);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--brand-primary);
  color: #fff;
  border-color: var(--brand-primary);
  transform: rotate(20deg);
}

.mobile-menu-btn {
  display: none;
  background: var(--brand-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--brand-border);
  border-radius: var(--brand-radius-sm);
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--brand-text);
  flex-shrink: 0;
  transition: background var(--brand-transition);
}

.mobile-menu-btn:hover {
  background: var(--brand-gradient-soft);
}

.mobile-nav {
  display: none;
  position: fixed;
  top: var(--brand-header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--brand-glass);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  z-index: 999;
  padding: 20px;
  flex-direction: column;
  gap: 4px;
  overflow-y: auto;
  border-top: 1px solid var(--brand-border);
}

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

.mobile-nav a {
  padding: 14px 16px;
  border-radius: var(--brand-radius-sm);
  font-size: 1rem;
  color: var(--brand-text);
  border-bottom: 1px solid var(--brand-border);
  transition: background var(--brand-transition), padding-left var(--brand-transition);
}

.mobile-nav a:hover {
  background: var(--brand-gradient-soft);
  padding-left: 22px;
}

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 16px 0 8px;
  font-size: 0.85rem;
  color: var(--brand-text-secondary);
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb li + li::before {
  content: "›";
  color: var(--brand-border);
  font-size: 1.1rem;
  margin-right: 2px;
}

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

.breadcrumb a:hover {
  color: var(--brand-primary);
}

.breadcrumb [aria-current="page"] {
  color: var(--brand-text);
  font-weight: 500;
}

/* ===== Hero ===== */
.hero {
  padding: 40px 0 48px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(76, 139, 158, 0.12) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatGlow 12s ease-in-out infinite;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(232, 184, 75, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatGlow 10s ease-in-out infinite reverse;
}

@keyframes floatGlow {
  0%, 100% {
    transform: translate(0, 0) scale(1);
  }
  50% {
    transform: translate(30px, -20px) scale(1.1);
  }
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  position: relative;
  z-index: 2;
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--brand-gradient-soft);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--brand-primary);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 600;
  margin-bottom: 18px;
  border: 1px solid rgba(43, 90, 122, 0.15);
  transition: transform var(--brand-transition), box-shadow var(--brand-transition);
}

.hero-badge:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(43, 90, 122, 0.15);
}

[data-theme="dark"] .hero-badge {
  background: rgba(61, 122, 158, 0.15);
  border-color: rgba(61, 122, 158, 0.25);
}

.hero h1 {
  font-size: 2.2rem;
  line-height: 1.3;
  font-weight: 800;
  margin-bottom: 18px;
  color: var(--brand-text);
  letter-spacing: -0.5px;
}

.hero h1 em {
  font-style: normal;
  color: var(--brand-primary);
  position: relative;
}

.hero h1 em::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 0;
  right: 0;
  height: 8px;
  background: var(--brand-accent);
  opacity: 0.35;
  border-radius: 4px;
  z-index: -1;
}

.hero p {
  font-size: 1.05rem;
  color: var(--brand-text-secondary);
  margin-bottom: 28px;
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: 28px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--brand-transition);
  border: 2px solid transparent;
  text-align: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.25);
  transform: translate(-50%, -50%);
  transition: width 0.5s ease, height 0.5s ease;
}

.btn:active::after {
  width: 300px;
  height: 300px;
}

.btn-primary {
  background: var(--brand-gradient);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(43, 90, 122, 0.25);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(43, 90, 122, 0.35);
}

.btn-outline {
  background: var(--brand-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--brand-primary);
  border-color: var(--brand-primary);
}

.btn-outline:hover {
  background: var(--brand-primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(43, 90, 122, 0.25);
}

.hero-stats {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--brand-primary);
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--brand-text-secondary);
  margin-top: 2px;
}

.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-visual svg {
  width: 100%;
  max-width: 480px;
  height: auto;
  filter: drop-shadow(0 12px 32px rgba(43, 90, 122, 0.15));
  animation: heroFloat 6s ease-in-out infinite;
}

@keyframes heroFloat {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* ===== Banner 轮播 ===== */
.banner-carousel {
  position: relative;
  border-radius: var(--brand-radius);
  overflow: hidden;
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  box-shadow: var(--brand-shadow);
  margin-top: 8px;
}

.carousel-track {
  display: flex;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-slide {
  min-width: 100%;
  padding: 32px 36px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--brand-gradient-soft);
}

.carousel-slide h3 {
  font-size: 1.15rem;
  color: var(--brand-text);
  display: flex;
  align-items: center;
  gap: 8px;
}

.carousel-slide h3::before {
  content: "";
  width: 4px;
  height: 18px;
  background: var(--brand-gradient);
  border-radius: 2px;
  flex-shrink: 0;
}

.carousel-slide p {
  font-size: 0.9rem;
  color: var(--brand-text-secondary);
  line-height: 1.6;
}

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  padding: 12px 0 16px;
  background: var(--brand-glass);
}

.carousel-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand-border);
  cursor: pointer;
  border: none;
  padding: 0;
  transition: background var(--brand-transition), transform var(--brand-transition), width var(--brand-transition);
}

.carousel-dot.active {
  background: var(--brand-gradient);
  transform: scale(1.3);
  width: 20px;
  border-radius: 4px;
}

/* ===== 通用区块 ===== */
.section {
  padding: 56px 0;
}

.section-alt {
  background: var(--brand-surface);
  position: relative;
}

.section-alt::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--brand-border), transparent);
}

.section-header {
  text-align: center;
  margin-bottom: 40px;
}

.section-header h2 {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--brand-text);
  margin-bottom: 10px;
  position: relative;
  display: inline-block;
}

.section-header h2::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 3px;
  background: var(--brand-gradient);
  border-radius: 2px;
}

.section-header p {
  color: var(--brand-text-secondary);
  font-size: 0.95rem;
  max-width: 620px;
  margin: 0 auto;
  margin-top: 14px;
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.card {
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  border-radius: var(--brand-radius);
  padding: 28px 24px;
  transition: transform var(--brand-transition), box-shadow var(--brand-transition), border-color var(--brand-transition);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--brand-gradient);
  opacity: 0;
  transition: opacity var(--brand-transition);
}

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

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
  border-color: var(--brand-primary);
}

[data-theme="dark"] .card:hover {
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.5);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--brand-gradient-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--brand-primary);
  transition: transform var(--brand-transition), background var(--brand-transition);
}

.card:hover .card-icon {
  transform: scale(1.1) rotate(-4deg);
  background: var(--brand-gradient);
  color: #fff;
}

[data-theme="dark"] .card-icon {
  background: rgba(61, 122, 158, 0.15);
}

.card h3 {
  font-size: 1.08rem;
  margin-bottom: 10px;
  color: var(--brand-text);
}

.card p {
  font-size: 0.9rem;
  color: var(--brand-text-secondary);
  line-height: 1.65;
}

/* ===== 文章列表 ===== */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  border-radius: var(--brand-radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: transform var(--brand-transition), box-shadow var(--brand-transition), border-color var(--brand-transition);
  position: relative;
  overflow: hidden;
}

.article-card::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--brand-gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--brand-transition);
}

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

.article-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
  border-color: var(--brand-primary);
}

[data-theme="dark"] .article-card:hover {
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.4);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--brand-text-secondary);
  margin-bottom: 12px;
}

.article-meta time {
  display: flex;
  align-items: center;
  gap: 4px;
}

.article-card h3 {
  font-size: 1rem;
  margin-bottom: 10px;
  color: var(--brand-text);
  line-height: 1.45;
  transition: color var(--brand-transition);
}

.article-card:hover h3 {
  color: var(--brand-primary);
}

.article-card p {
  font-size: 0.86rem;
  color: var(--brand-text-secondary);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 16px;
}

.article-card .read-more {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--brand-primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--brand-transition), color var(--brand-transition);
}

.article-card .read-more:hover {
  gap: 8px;
  color: var(--brand-secondary);
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.faq-item {
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  border-radius: var(--brand-radius-sm);
  overflow: hidden;
  transition: border-color var(--brand-transition), box-shadow var(--brand-transition);
}

.faq-item[open] {
  border-color: var(--brand-primary);
  box-shadow: 0 4px 16px rgba(43, 90, 122, 0.1);
}

.faq-item summary {
  padding: 16px 20px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--brand-text);
  transition: background var(--brand-transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 1.3rem;
  color: var(--brand-primary);
  font-weight: 400;
  transition: transform var(--brand-transition);
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  content: "−";
  transform: rotate(180deg);
}

.faq-item summary:hover {
  background: var(--brand-gradient-soft);
}

.faq-answer {
  padding: 0 20px 18px;
  font-size: 0.9rem;
  color: var(--brand-text-secondary);
  line-height: 1.7;
  border-top: 1px solid var(--brand-border);
  padding-top: 14px;
  animation: fadeSlideIn 0.3s ease;
}

@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== HowTo ===== */
.howto-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
  counter-reset: step;
}

.howto-step {
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  border-radius: var(--brand-radius);
  padding: 24px;
  position: relative;
  counter-increment: step;
  transition: transform var(--brand-transition), box-shadow var(--brand-transition), border-color var(--brand-transition);
}

.howto-step:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.08);
  border-color: var(--brand-primary);
}

.howto-step::before {
  content: counter(step);
  position: absolute;
  top: -14px;
  left: 20px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--brand-gradient);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(43, 90, 122, 0.3);
}

.howto-step h4 {
  font-size: 0.98rem;
  margin-bottom: 10px;
  margin-top: 6px;
  color: var(--brand-text);
}

.howto-step p {
  font-size: 0.86rem;
  color: var(--brand-text-secondary);
  line-height: 1.65;
}

/* ===== 联系信息 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.contact-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  background: var(--brand-glass);
  backdrop-filter: blur(var(--brand-glass-blur));
  -webkit-backdrop-filter: blur(var(--brand-glass-blur));
  border: 1px solid var(--brand-glass-border);
  border-radius: var(--brand-radius);
  padding: 20px;
  transition: transform var(--brand-transition), box-shadow var(--brand-transition), border-color var(--brand-transition);
}

.contact-item:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  border-color: var(--brand-primary);
}

.contact-item svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  color: var(--brand-primary);
  margin-top: 2px;
  transition: transform var(--brand-transition);
}

.contact-item:hover svg {
  transform: scale(1.15);
}

.contact-item h4 {
  font-size: 0.92rem;
  margin-bottom: 4px;
  color: var(--brand-text);
}

.contact-item p {
  font-size: 0.84rem;
  color: var(--brand-text-secondary);
  line-height: 1.5;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--brand-surface);
  border-top: 1px solid var(--brand-border);
  padding: 48px 0 24px;
  margin-top: 20px;
  position: relative;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 36px;
  margin-bottom: 36px;
}

.footer-brand p {
  font-size: 0.86rem;
  color: var(--brand-text-secondary);
  margin-top: 12px;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.92rem;
  margin-bottom: 14px;
  color: var(--brand-text);
  position: relative;
  padding-bottom: 8px;
}

.footer-col h4::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 24px;
  height: 2px;
  background: var(--brand-gradient);
  border-radius: 1px;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col a {
  font-size: 0.84rem;
  color: var(--brand-text-secondary);
  transition: color var(--brand-transition), padding-left var(--brand-transition);
}

.footer-col a:hover {
  color: var(--brand-primary);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid var(--brand-border);
  padding-top: 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 0.8rem;
  color: var(--brand-text-secondary);
}

.footer-bottom-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-bottom-links a {
  font-size: 0.8rem;
  color: var(--brand-text-secondary);
  transition: color var(--brand-transition);
}

.footer-bottom-links a:hover {
  color: var(--brand-primary);
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--brand-gradient);
  color: #fff;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--brand-transition), visibility var(--brand-transition), transform var(--brand-transition), box-shadow var(--brand-transition);
  z-index: 900;
  box-shadow: 0 4px 16px rgba(43, 90, 122, 0.35);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 8px 24px rgba(43, 90, 122, 0.45);
}

/* ===== 滚动动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ===== 搜索高亮 ===== */
.search-highlight {
  background: var(--brand-accent);
  color: var(--brand-text);
  padding: 0 2px;
  border-radius: 2px;
  animation: highlightPulse 0.6s ease;
}

@keyframes highlightPulse {
  0% {
    background: var(--brand-accent);
  }
  50% {
    background: rgba(232, 184, 75, 0.5);
  }
  100% {
    background: var(--brand-accent);
  }
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .hero h1 {
    font-size: 1.9rem;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .hero-visual {
    order: -1;
  }
  .hero-visual svg {
    max-width: 360px;
  }
}

@media (max-width: 768px) {
  .main-nav {
    display: none;
  }
  .mobile-menu-btn {
    display: flex;
  }
  .search-box {
    display: none;
  }
  .hero h1 {
    font-size: 1.6rem;
  }
  .hero-stats {
    gap: 24px;
  }
  .stat-number {
    font-size: 1.4rem;
  }
  .section {
    padding: 36px 0;
  }
  .section-header h2 {
    font-size: 1.35rem;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .footer-brand p {
    max-width: 100%;
  }
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
  .card-grid {
    grid-template-columns: 1fr;
  }
  .article-list {
    grid-template-columns: 1fr;
  }
  .howto-steps {
    grid-template-columns: 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.35rem;
  }
  .hero p {
    font-size: 0.92rem;
  }
  .hero-actions {
    flex-direction: column;
  }
  .btn {
    width: 100%;
  }
  .carousel-slide {
    padding: 24px 20px;
  }
  .hero-stats {
    gap: 16px;
  }
  .stat-number {
    font-size: 1.2rem;
  }
  .section-header h2 {
    font-size: 1.2rem;
  }
}

/* ===== 打印 ===== */
@media print {
  .site-header,
  .back-to-top,
  .mobile-nav,
  .theme-toggle,
  .mobile-menu-btn,
  .search-box {
    display: none !important;
  }
  body {
    background: #fff;
    color: #000;
  }
  .card,
  .article-card,
  .faq-item,
  .howto-step,
  .contact-item {
    background: #fff;
    border: 1px solid #ddd;
    box-shadow: none;
  }
}

/* ===== 减少动画 ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
  .hero-visual svg {
    animation: none;
  }
  .hero::before,
  .hero::after {
    animation: none;
  }
}

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

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

::-webkit-scrollbar-thumb {
  background: var(--brand-border);
  border-radius: 4px;
}

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

/* ===== 选中文字 ===== */
::selection {
  background: var(--brand-primary);
  color: #fff;
}

::-moz-selection {
  background: var(--brand-primary);
  color: #fff;
}

/* ===== 焦点可见 ===== */
:focus-visible {
  outline: 2px solid var(--brand-primary);
  outline-offset: 2px;
  border-radius: 4px;
}