/* ===== 全局重置与变量 ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #0d1b2a;
  --secondary: #1b2838;
  --accent: #f0c040;
  --accent2: #d4a017;
  --accent-gradient: linear-gradient(135deg, #f0c040, #d4a017);
  --text: #e0e0e0;
  --text2: #a0a0a0;
  --bg: #0f1923;
  --card-bg: rgba(255, 255, 255, 0.05);
  --glass: rgba(255, 255, 255, 0.08);
  --glass-strong: rgba(255, 255, 255, 0.12);
  --shadow: rgba(0, 0, 0, 0.3);
  --shadow-glow: rgba(240, 192, 64, 0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition-fast: 0.2s ease;
  --transition: 0.3s ease;
  --transition-slow: 0.5s ease;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --header-height: 72px;
}

.light-mode {
  --primary: #ffffff;
  --secondary: #f5f5f5;
  --accent: #1a73e8;
  --accent2: #1557b0;
  --accent-gradient: linear-gradient(135deg, #1a73e8, #1557b0);
  --text: #1a1a1a;
  --text2: #555555;
  --bg: #fafafa;
  --card-bg: rgba(0, 0, 0, 0.03);
  --glass: rgba(0, 0, 0, 0.05);
  --glass-strong: rgba(0, 0, 0, 0.08);
  --shadow: rgba(0, 0, 0, 0.1);
  --shadow-glow: rgba(26, 115, 232, 0.3);
}

/* ===== 基础样式 ===== */
html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background var(--transition), color var(--transition);
  overflow-x: hidden;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent2);
}

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

ul, ol {
  list-style: none;
}

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

input, textarea {
  font-family: inherit;
  outline: none;
}

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

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

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

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

::-webkit-scrollbar-thumb {
  background: var(--text2);
  border-radius: 4px;
}

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

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 16px;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0);
  transition: background var(--transition);
}

.btn:hover::after {
  background: rgba(255, 255, 255, 0.1);
}

.btn-primary {
  background: var(--accent-gradient);
  color: #0d1b2a;
  box-shadow: 0 8px 24px var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 32px var(--shadow-glow);
}

.btn-secondary {
  background: var(--glass);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: var(--glass-strong);
  transform: translateY(-2px);
}

/* ===== Header ===== */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(13, 27, 42, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  transition: background var(--transition), box-shadow var(--transition), border-color var(--transition);
  height: var(--header-height);
}

.light-mode header {
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

header.scrolled {
  box-shadow: 0 4px 30px var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  gap: 20px;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 24px;
  font-weight: 800;
  color: var(--accent);
  flex-shrink: 0;
}

.logo svg {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
}

.logo span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== 导航 ===== */
nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

nav a {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  transition: background var(--transition-fast), color var(--transition-fast);
  position: relative;
}

nav a:hover,
nav a.active {
  background: var(--glass);
  color: var(--accent);
}

nav a.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

/* ===== 导航操作区 ===== */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.theme-toggle {
  background: var(--glass);
  border: none;
  color: var(--text);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--glass-strong);
  transform: scale(1.05);
}

.search-btn {
  background: var(--glass);
  border: none;
  color: var(--text);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  transition: background var(--transition-fast);
}

.search-btn:hover {
  background: var(--glass-strong);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 28px;
  cursor: pointer;
  padding: 4px;
  transition: transform var(--transition-fast);
}

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

/* ===== 响应式导航 ===== */
@media (max-width: 768px) {
  nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--primary);
    padding: 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    gap: 4px;
    max-height: 60vh;
    overflow-y: auto;
  }

  nav.open {
    display: flex;
    animation: navSlideIn 0.3s ease;
  }

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

  nav a {
    padding: 12px 16px;
    width: 100%;
    border-radius: var(--radius-sm);
  }

  .mobile-menu-btn {
    display: block;
  }

  .header-inner {
    flex-wrap: nowrap;
  }

  .search-btn span {
    display: none;
  }

  .search-btn {
    padding: 8px;
    font-size: 18px;
  }
}

/* ===== Hero Banner ===== */
.hero {
  padding-top: var(--header-height);
  position: relative;
  overflow: hidden;
  min-height: 600px;
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(240, 192, 64, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 50%, rgba(13, 27, 42, 0.9) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}

.light-mode .hero-bg {
  background:
    radial-gradient(ellipse at 20% 50%, rgba(26, 115, 232, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 50%, rgba(245, 245, 245, 0.8) 0%, transparent 70%);
}

.hero-slider {
  position: relative;
  z-index: 1;
  width: 100%;
}

.hero-slide {
  display: none;
  animation: fadeSlide 0.6s ease;
}

.hero-slide.active {
  display: block;
}

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

.hero-content {
  display: flex;
  align-items: center;
  gap: 60px;
  padding: 60px 0;
}

.hero-text {
  flex: 1;
}

.hero-text h1 {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.light-mode .hero-text h1 {
  background: linear-gradient(135deg, #1a1a1a, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-text p {
  font-size: 18px;
  color: var(--text2);
  margin-bottom: 32px;
  max-width: 560px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-visual {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-visual svg {
  width: 100%;
  max-width: 500px;
  height: auto;
  filter: drop-shadow(0 20px 40px rgba(240, 192, 64, 0.15));
  transition: transform var(--transition);
}

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

.slider-dots {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 32px;
}

.slider-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--text2);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
}

.slider-dot::after {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid transparent;
  transition: border-color var(--transition);
}

.slider-dot.active {
  background: var(--accent);
  transform: scale(1.3);
}

.slider-dot.active::after {
  border-color: var(--accent);
}

/* ===== Hero 响应式 ===== */
@media (max-width: 768px) {
  .hero {
    min-height: auto;
    padding-top: calc(var(--header-height) + 20px);
  }

  .hero-content {
    flex-direction: column;
    text-align: center;
    padding: 40px 0;
    gap: 40px;
  }

  .hero-text h1 {
    font-size: 32px;
  }

  .hero-text p {
    margin: 0 auto 32px;
    font-size: 16px;
  }

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

  .hero-visual svg {
    max-width: 300px;
  }
}

/* ===== Sections ===== */
section {
  padding: 80px 0;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 16px;
  text-align: center;
  position: relative;
  display: inline-block;
  width: 100%;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--accent-gradient);
  margin: 12px auto 0;
  border-radius: 2px;
}

.section-subtitle {
  text-align: center;
  color: var(--text2);
  max-width: 700px;
  margin: 0 auto 48px;
  font-size: 16px;
  line-height: 1.7;
}

/* ===== Grid 系统 ===== */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

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

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid-3 {
    grid-template-columns: 1fr 1fr;
  }
  .grid-4 {
    grid-template-columns: 1fr 1fr;
  }
}

/* ===== 卡片 ===== */
.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 32px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px var(--shadow);
  border-color: rgba(240, 192, 64, 0.15);
}

.light-mode .card:hover {
  border-color: rgba(26, 115, 232, 0.15);
}

.card-icon {
  width: 60px;
  height: 60px;
  margin-bottom: 16px;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.card h3 {
  font-size: 20px;
  margin-bottom: 12px;
  font-weight: 700;
}

.card p {
  color: var(--text2);
  font-size: 14px;
  line-height: 1.7;
}

/* ===== 时间线 ===== */
.timeline {
  position: relative;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 32px;
  padding-left: 32px;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -24px;
  top: 8px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 4px rgba(240, 192, 64, 0.2);
  transition: transform var(--transition), box-shadow var(--transition);
}

.timeline-item:hover::before {
  transform: scale(1.2);
  box-shadow: 0 0 0 6px rgba(240, 192, 64, 0.3);
}

.timeline-item h4 {
  font-size: 18px;
  color: var(--accent);
  margin-bottom: 4px;
}

.timeline-item p {
  color: var(--text2);
  line-height: 1.6;
}

/* ===== FAQ ===== */
.faq-item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding: 16px 0;
  transition: border-color var(--transition);
}

.faq-item:first-child {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  font-size: 16px;
  padding: 8px 0;
  user-select: none;
  gap: 16px;
}

.faq-question span {
  transition: transform var(--transition);
  font-size: 20px;
  flex-shrink: 0;
  color: var(--accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease, opacity 0.3s ease;
  color: var(--text2);
  padding: 0;
  opacity: 0;
  line-height: 1.7;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding: 12px 0;
  opacity: 1;
}

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

/* ===== Footer ===== */
footer {
  background: var(--primary);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding: 60px 0 20px;
}

.light-mode footer {
  background: var(--primary);
  border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

.footer-col h4 {
  font-size: 18px;
  margin-bottom: 16px;
  color: var(--accent);
  font-weight: 700;
}

.footer-col p,
.footer-col a {
  font-size: 14px;
  color: var(--text2);
  display: block;
  margin-bottom: 8px;
  line-height: 1.7;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 20px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--text2);
}

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

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Back to Top ===== */
.back-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #0d1b2a;
  border: none;
  cursor: pointer;
  font-size: 20px;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px var(--shadow-glow);
  z-index: 999;
  transition: all var(--transition);
}

.back-top.show {
  display: flex;
  animation: backTopIn 0.3s ease;
}

@keyframes backTopIn {
  from { opacity: 0; transform: translateY(20px) scale(0.8); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.back-top:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 24px var(--shadow-glow);
}

/* ===== Search Overlay ===== */
.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  animation: overlayIn 0.3s ease;
}

@keyframes overlayIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.search-overlay.open {
  display: flex;
}

.search-box {
  background: var(--primary);
  padding: 40px;
  border-radius: var(--radius-lg);
  width: 90%;
  max-width: 600px;
  box-shadow: 0 20px 60px var(--shadow);
  animation: boxIn 0.3s ease;
}

@keyframes boxIn {
  from { opacity: 0; transform: scale(0.95) translateY(20px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.search-box input {
  width: 100%;
  padding: 16px;
  border-radius: var(--radius-md);
  border: 2px solid var(--accent);
  background: var(--secondary);
  color: var(--text);
  font-size: 18px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  border-color: var(--accent2);
  box-shadow: 0 0 0 4px rgba(240, 192, 64, 0.15);
}

.search-box .close-search {
  margin-top: 16px;
  display: flex;
  justify-content: flex-end;
}

/* ===== Article Cards ===== */
.article-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 24px;
  border: 1px solid rgba(255, 255, 255, 0.05);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px var(--shadow);
  border-color: rgba(240, 192, 64, 0.1);
}

.article-card h4 {
  font-size: 18px;
  margin-bottom: 8px;
  font-weight: 700;
  line-height: 1.4;
}

.article-card .date {
  font-size: 13px;
  color: var(--text2);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-card .date::before {
  content: '📅';
  font-size: 12px;
}

.article-card p {
  color: var(--text2);
  font-size: 14px;
  margin-bottom: 12px;
  line-height: 1.7;
}

.article-card .read-more {
  color: var(--accent);
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap var(--transition-fast);
}

.article-card .read-more:hover {
  gap: 8px;
}

/* ===== Partners ===== */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}

.partner-item {
  padding: 12px 24px;
  background: var(--card-bg);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.05);
  font-weight: 600;
  color: var(--text2);
  transition: all var(--transition);
  font-size: 14px;
}

.partner-item:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 16px var(--shadow);
}

/* ===== Counter Grid ===== */
.counter-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

@media (max-width: 768px) {
  .counter-grid {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }
}

.counter-item .number {
  font-size: 48px;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.counter-item .label {
  color: var(--text2);
  font-size: 16px;
  margin-top: 8px;
  font-weight: 500;
}

/* ===== HowTo Steps ===== */
.howto-steps {
  counter-reset: step;
}

.howto-step {
  display: flex;
  gap: 20px;
  padding: 20px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  align-items: flex-start;
}

.howto-step:last-child {
  border-bottom: none;
}

.howto-step::before {
  counter-increment: step;
  content: counter(step);
  width: 40px;
  height: 40px;
  background: var(--accent-gradient);
  color: #0d1b2a;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
  font-size: 16px;
  box-shadow: 0 4px 12px var(--shadow-glow);
}

.howto-step div {
  flex: 1;
}

.howto-step strong {
  color: var(--accent);
  display: block;
  margin-bottom: 4px;
}

/* ===== Map Placeholder ===== */
.map-placeholder {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
  overflow: hidden;
  transition: border-color var(--transition);
}

.map-placeholder:hover {
  border-color: rgba(240, 192, 64, 0.2);
}

/* ===== Badge ===== */
.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  background: rgba(240, 192, 64, 0.15);
  color: var(--accent);
  font-size: 12px;
  font-weight: 600;
}

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

.mt-20 {
  margin-top: 20px;
}

.mb-20 {
  margin-bottom: 20px;
}

.gap-16 {
  gap: 16px;
}

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

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ===== 打印样式 ===== */
@media print {
  header,
  .back-top,
  .search-overlay,
  .mobile-menu-btn {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

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

/* ===== 性能优化：减少重排 ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ===== 暗色模式下的微调 ===== */
.light-mode .card {
  border-color: rgba(0, 0, 0, 0.05);
}

.light-mode .faq-item {
  border-color: rgba(0, 0, 0, 0.05);
}

.light-mode .timeline-item::before {
  border-color: #fafafa;
}

.light-mode .howto-step {
  border-color: rgba(0, 0, 0, 0.05);
}

.light-mode .footer-bottom {
  border-color: rgba(0, 0, 0, 0.05);
}

/* ===== 高分辨率屏幕优化 ===== */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .card,
  .article-card {
    border-width: 0.5px;
  }
}