/* 小蓝视频 - 完整样式表 */
:root {
  --bg: #f0f4f8;
  --surface: rgba(255, 255, 255, 0.85);
  --surface-solid: #ffffff;
  --primary: #1a73e8;
  --primary-light: #4d9fff;
  --primary-dark: #0b2545;
  --accent: #00c6ff;
  --accent2: #7b2ff7;
  --text-strong: #0f172a;
  --text-body: #1e293b;
  --text-muted: #475569;
  --heading: #0b2545;
  --border: rgba(148, 163, 184, 0.25);
  --nav-bg: rgba(11, 37, 69, 0.92);
  --footer-bg: #0b2545;
  --footer-text: #cbd5e1;
  --card-bg: rgba(255, 255, 255, 0.82);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow: 0 12px 32px -8px rgba(0, 0, 0, 0.08), 0 6px 12px -6px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 24px 48px -12px rgba(0, 0, 0, 0.15);
  --banner-overlay: linear-gradient(120deg, rgba(2, 24, 56, 0.92) 0%, rgba(26, 115, 232, 0.75) 45%, rgba(0, 198, 255, 0.35) 100%);
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(255, 255, 255, 0.5);
  --radius-sm: 12px;
  --radius: 20px;
  --radius-lg: 28px;
  --radius-xl: 36px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --blur: blur(16px);
}

[data-theme="dark"] {
  --bg: #0a0f1e;
  --surface: rgba(30, 41, 59, 0.85);
  --surface-solid: #1e293b;
  --primary: #3b82f6;
  --primary-light: #60a5fa;
  --primary-dark: #93c5fd;
  --accent: #22d3ee;
  --accent2: #a78bfa;
  --text-strong: #f8fafc;
  --text-body: #e2e8f0;
  --text-muted: #94a3b8;
  --heading: #ffffff;
  --border: rgba(148, 163, 184, 0.2);
  --nav-bg: rgba(10, 15, 30, 0.92);
  --footer-bg: #070b14;
  --footer-text: #94a3b8;
  --card-bg: rgba(30, 41, 59, 0.85);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow: 0 12px 32px -8px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 24px 48px -12px rgba(0, 0, 0, 0.6);
  --banner-overlay: linear-gradient(120deg, rgba(0, 0, 0, 0.9) 0%, rgba(15, 23, 42, 0.8) 50%, rgba(30, 41, 59, 0.6) 100%);
  --glass-bg: rgba(30, 41, 59, 0.6);
  --glass-border: rgba(148, 163, 184, 0.25);
}

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

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

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--bg);
  background-image: 
    radial-gradient(ellipse 80% 50% at 20% -20%, rgba(26, 115, 232, 0.08) 0%, transparent 100%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(0, 198, 255, 0.06) 0%, transparent 100%);
  background-attachment: fixed;
  color: var(--text-body);
  line-height: 1.7;
  transition: background 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--heading);
  font-weight: 700;
  line-height: 1.25;
  transition: color 0.3s;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2.4rem, 5vw, 4rem);
  letter-spacing: -0.03em;
}

h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  margin-bottom: 1.5rem;
  position: relative;
}

h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
  margin-top: 8px;
}

h3 {
  font-size: 1.35rem;
  margin-top: 1.2rem;
}

h4 {
  font-size: 1.1rem;
  font-weight: 600;
}

p {
  color: var(--text-body);
}

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

a:hover {
  color: var(--primary-light);
  text-decoration: none;
}

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

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 32px);
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  z-index: 1000;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: all 0.3s ease;
}

.navbar.scrolled {
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.2);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1.5rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.brand svg {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(26, 115, 232, 0.3);
}

.brand span {
  color: white;
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: 0.5px;
  background: linear-gradient(135deg, #ffffff 0%, #a0c4ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.nav-links a {
  color: #cbd5e1;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 40px;
  transition: all 0.25s ease;
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: white;
  background: rgba(255, 255, 255, 0.12);
  text-decoration: none;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 20px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: transform 0.3s ease;
}

.nav-links a:hover::after {
  transform: translateX(-50%) scaleX(1);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-box {
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 40px;
  padding: 0.3rem 1rem;
  transition: all 0.3s ease;
}

.search-box:focus-within {
  background: rgba(255, 255, 255, 0.18);
  border-color: rgba(255, 255, 255, 0.3);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.2);
}

.search-box input {
  background: transparent;
  border: none;
  color: white;
  padding: 0.4rem;
  outline: none;
  font-size: 0.9rem;
  width: 130px;
  transition: width 0.3s ease;
}

.search-box input:focus {
  width: 180px;
}

.search-box input::placeholder {
  color: #94a3b8;
}

.theme-toggle {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  border-radius: 40px;
  padding: 0.4rem 1.2rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  transition: all 0.3s ease;
  backdrop-filter: blur(8px);
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-1px);
}

.mobile-menu {
  display: none;
}

.mobile-menu-btn {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  font-size: 1.4rem;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.mobile-menu-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* ===== Hero 区域 ===== */
.hero {
  background: var(--banner-overlay), 
    radial-gradient(ellipse 60% 50% at 70% 20%, rgba(0, 198, 255, 0.3) 0%, transparent 100%),
    radial-gradient(ellipse 40% 30% at 20% 80%, rgba(123, 47, 247, 0.2) 0%, transparent 100%),
    url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 500" width="1200" height="500"><rect width="1200" height="500" fill="%230b2545"/><circle cx="150" cy="120" r="90" fill="%231a73e8" opacity="0.4"/><circle cx="1050" cy="350" r="140" fill="%2300c6ff" opacity="0.2"/><circle cx="600" cy="400" r="80" fill="%237b2ff7" opacity="0.15"/><polygon points="420,60 600,180 300,200" fill="%23facc15" opacity="0.1"/><polygon points="900,80 1050,160 850,190" fill="%23ff6b6b" opacity="0.1"/></svg>');
  background-size: cover;
  background-position: center;
  padding: clamp(8rem, 15vw, 12rem) 0 clamp(4rem, 8vw, 6rem);
  color: white;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(2deg); }
}

.hero-content {
  max-width: 720px;
  position: relative;
  z-index: 2;
}

.hero h1 {
  color: white;
  font-size: clamp(2.5rem, 6vw, 4.2rem);
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  line-height: 1.15;
  margin-bottom: 1.5rem;
  animation: fadeInUp 1s ease 0.2s both;
}

.hero p {
  color: rgba(255, 255, 255, 0.9);
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  margin-bottom: 2rem;
  animation: fadeInUp 1s ease 0.4s both;
}

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

.btn-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease 0.6s both;
}

.btn {
  background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
  color: var(--primary-dark);
  padding: 0.9rem 2.4rem;
  border-radius: 60px;
  font-weight: 700;
  font-size: 1rem;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-block;
  border: none;
  cursor: pointer;
}

.btn:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 16px 32px rgba(26, 115, 232, 0.25);
  color: var(--primary);
  text-decoration: none;
}

.btn-outline {
  background: rgba(255, 255, 255, 0.15);
  border: 2px solid rgba(255, 255, 255, 0.6);
  color: white;
  padding: 0.8rem 2.2rem;
  border-radius: 60px;
  font-weight: 600;
  backdrop-filter: blur(8px);
  transition: all 0.3s ease;
  display: inline-block;
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: white;
  color: white;
  transform: translateY(-2px);
  text-decoration: none;
}

/* ===== 区块通用 ===== */
.section {
  padding: clamp(3rem, 8vw, 6rem) 0;
  position: relative;
}

.section.bg-muted {
  background: var(--surface-solid);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: clamp(1.2rem, 3vw, 2rem);
}

/* ===== 卡片 ===== */
.card {
  background: var(--card-bg);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border-radius: var(--radius-lg);
  padding: clamp(1.5rem, 3vw, 2.2rem);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent2));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(26, 115, 232, 0.2);
}

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

.card h3 {
  margin-bottom: 0.8rem;
  margin-top: 0;
}

.card p {
  color: var(--text-body);
  font-size: 0.95rem;
}

.card .icon-badge {
  background: linear-gradient(135deg, rgba(26, 115, 232, 0.1) 0%, rgba(0, 198, 255, 0.1) 100%);
  width: 56px;
  height: 56px;
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.2rem;
  font-size: 1.6rem;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05);
}

.card[style*="grid-column: span 2"] {
  grid-column: span 2;
}

@media (max-width: 768px) {
  .card[style*="grid-column: span 2"] {
    grid-column: span 1;
  }
}

/* ===== 文章列表 ===== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.article-item {
  display: flex;
  gap: 1.5rem;
  background: var(--card-bg);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  padding: 1.5rem 2rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: all 0.35s ease;
  cursor: pointer;
}

.article-item:hover {
  transform: translateX(8px);
  border-color: rgba(26, 115, 232, 0.3);
  box-shadow: var(--shadow);
}

.article-meta {
  min-width: 110px;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding-top: 0.3rem;
  flex-shrink: 0;
}

.article-summary h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 1.2rem;
  transition: color 0.2s;
}

.article-item:hover .article-summary h3 {
  color: var(--primary);
}

.article-summary p {
  color: var(--text-body);
  font-size: 0.95rem;
  margin-bottom: 0.8rem;
}

.read-more {
  color: var(--primary);
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.3s ease;
}

.read-more::after {
  content: '→';
  transition: transform 0.3s ease;
}

.article-item:hover .read-more::after {
  transform: translateX(4px);
}

@media (max-width: 640px) {
  .article-item {
    flex-direction: column;
    gap: 0.5rem;
    padding: 1.2rem;
  }
  
  .article-meta {
    min-width: auto;
  }
}

/* ===== 表格 ===== */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

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

th, td {
  padding: 1rem 1.2rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  background: linear-gradient(135deg, rgba(26, 115, 232, 0.08) 0%, rgba(0, 198, 255, 0.08) 100%);
  color: var(--heading);
  font-weight: 700;
}

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

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

tr:hover td {
  background: rgba(26, 115, 232, 0.03);
}

/* ===== FAQ ===== */
.faq-item {
  background: var(--card-bg);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.8rem;
  padding: 0 1.5rem;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: rgba(26, 115, 232, 0.3);
}

.faq-item.active {
  border-color: var(--primary);
  box-shadow: 0 8px 24px rgba(26, 115, 232, 0.1);
}

.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: 600;
  padding: 1.2rem 0;
  color: var(--heading);
  font-size: 1.05rem;
  user-select: none;
  transition: color 0.2s;
}

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

.faq-question span {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

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

.faq-answer {
  color: var(--text-body);
  padding-bottom: 1.2rem;
  font-size: 0.95rem;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== HowTo 步骤 ===== */
.howto-step {
  background: var(--card-bg);
  backdrop-filter: var(--blur);
  -webkit-backdrop-filter: var(--blur);
  border-left: 5px solid var(--primary);
  padding: 1.2rem 1.5rem;
  margin-bottom: 0.8rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s ease;
  border-left-color: var(--primary);
  background: linear-gradient(90deg, var(--card-bg) 0%, var(--card-bg) 100%);
}

.howto-step:hover {
  border-left-width: 8px;
  transform: translateX(4px);
  box-shadow: var(--shadow);
}

.howto-step strong {
  color: var(--heading);
}

/* ===== Banner ===== */
.banner {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  padding: 2.5rem;
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  animation: float 10s ease-in-out infinite;
}

.banner h2, .banner p {
  color: white;
}

.banner h2::after {
  background: rgba(255, 255, 255, 0.5);
}

.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: clamp(3rem, 6vw, 4rem) 0 2rem;
  margin-top: 3rem;
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent2), var(--primary));
  background-size: 300% 100%;
  animation: gradientMove 8s ease infinite;
}

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

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  padding-bottom: 2.5rem;
}

.footer h4 {
  color: #ffffff;
  margin-bottom: 1rem;
  font-size: 1.1rem;
}

.footer a {
  color: #cbd5e1;
  transition: color 0.2s ease;
}

.footer a:hover {
  color: white;
  text-decoration: underline;
}

.footer p {
  color: var(--footer-text);
  font-size: 0.9rem;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.9rem;
}

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  box-shadow: 0 8px 24px rgba(26, 115, 232, 0.3);
  cursor: pointer;
  border: none;
  z-index: 999;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

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

.back-to-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 12px 32px rgba(26, 115, 232, 0.4);
}

.back-to-top:active {
  transform: scale(0.95);
}

/* ===== 滚动动画 ===== */
.scroll-animation {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.scroll-animation.visible {
  opacity: 1;
  transform: none;
}

/* ===== 可读性 ===== */
.text-muted {
  color: var(--text-muted) !important;
}

.bg-muted {
  background: var(--surface-solid);
}

.footer p, .footer li {
  color: var(--footer-text);
}

.footer h4 {
  color: #ffffff;
}

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

.search-box input {
  color: white;
}

.search-box input::placeholder {
  color: #94a3b8;
  opacity: 0.7;
}

.btn-outline {
  border-color: rgba(255, 255, 255, 0.6);
  color: white;
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: white;
  color: white;
}

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

@media (max-width: 800px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    backdrop-filter: var(--blur);
    -webkit-backdrop-filter: var(--blur);
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem 1.5rem;
    gap: 0.5rem;
    border-radius: 0 0 var(--radius) var(--radius);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
  }

  .nav-links.show {
    display: flex;
    animation: fadeInDown 0.3s ease;
  }

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

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

  .nav-links a:hover {
    background: rgba(255, 255, 255, 0.1);
  }

  .nav-links a::after {
    display: none;
  }

  .nav-actions .search-box {
    display: none;
  }

  .mobile-menu {
    display: block;
  }

  .nav-inner {
    padding: 0.6rem 1rem;
  }

  .search-box input:focus {
    width: 130px;
  }

  .hero {
    padding-top: 7rem;
  }

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

  .hero p {
    font-size: 1.1rem;
  }

  .footer-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 640px) {
  .hero {
    padding-top: 6rem;
    padding-bottom: 3rem;
  }

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

  .hero p {
    font-size: 1rem;
  }

  .btn, .btn-outline {
    padding: 0.7rem 1.6rem;
    font-size: 0.9rem;
    width: 100%;
    text-align: center;
  }

  .btn-group {
    flex-direction: column;
    width: 100%;
  }

  .back-to-top {
    bottom: 1.2rem;
    right: 1.2rem;
    width: 44px;
    height: 44px;
    font-size: 1.2rem;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
    gap: 0.5rem;
  }

  .article-item {
    padding: 1rem;
  }

  .card {
    padding: 1.2rem;
  }

  h2 {
    font-size: 1.6rem;
  }

  h3 {
    font-size: 1.2rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .brand span {
    font-size: 1.3rem;
  }

  .brand svg {
    width: 32px;
    height: 32px;
  }

  .card .icon-badge {
    width: 48px;
    height: 48px;
    font-size: 1.4rem;
  }

  .howto-step {
    padding: 1rem;
  }
}

/* ===== 暗色模式适配 ===== */
[data-theme="dark"] .card {
  background: var(--card-bg);
}

[data-theme="dark"] .article-item {
  background: var(--card-bg);
}

[data-theme="dark"] .faq-item {
  background: var(--card-bg);
}

[data-theme="dark"] .howto-step {
  background: var(--card-bg);
}

[data-theme="dark"] .navbar {
  background: var(--nav-bg);
}

[data-theme="dark"] .hero {
  background: var(--banner-overlay),
    radial-gradient(ellipse 60% 50% at 70% 20%, rgba(0, 198, 255, 0.15) 0%, transparent 100%),
    radial-gradient(ellipse 40% 30% at 20% 80%, rgba(123, 47, 247, 0.1) 0%, transparent 100%),
    url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 500" width="1200" height="500"><rect width="1200" height="500" fill="%230a0f1e"/><circle cx="150" cy="120" r="90" fill="%233b82f6" opacity="0.2"/><circle cx="1050" cy="350" r="140" fill="%2322d3ee" opacity="0.1"/><circle cx="600" cy="400" r="80" fill="%23a78bfa" opacity="0.08"/></svg>');
}

[data-theme="dark"] .btn {
  background: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%);
  color: white;
}

[data-theme="dark"] .btn:hover {
  color: white;
  box-shadow: 0 16px 32px rgba(59, 130, 246, 0.4);
}

[data-theme="dark"] .btn-outline {
  border-color: rgba(255, 255, 255, 0.4);
}

[data-theme="dark"] .card::before {
  background: linear-gradient(90deg, #3b82f6, #22d3ee, #a78bfa);
}

[data-theme="dark"] .brand span {
  background: linear-gradient(135deg, #ffffff 0%, #93c5fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="dark"] .theme-toggle {
  background: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .theme-toggle:hover {
  background: rgba(255, 255, 255, 0.15);
}

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

  body {
    background: white;
    color: black;
  }

  .card, .article-item, .faq-item, .howto-step {
    background: white;
    border: 1px solid #ccc;
    box-shadow: none;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
}

/* ===== 无障碍 ===== */
@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;
  }
}

:focus-visible {
  outline: 3px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}

::selection {
  background: rgba(26, 115, 232, 0.2);
  color: var(--text-strong);
}

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

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

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--primary), var(--primary-dark));
  border-radius: 10px;
  border: 2px solid var(--bg);
}

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

[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #3b82f6, #1e40af);
}