/* ============================================================
   Chrome 安全下载站 - 全局样式
   ============================================================ */

/* ---- CSS 变量 ---- */
:root {
  --primary-blue: #1a73e8;
  --primary-blue-dark: #1557b0;
  --chrome-green: #34a853;
  --chrome-yellow: #fbbc04;
  --chrome-red: #ea4335;
  --text-primary: #202124;
  --text-secondary: #5f6368;
  --text-light: #80868b;
  --bg-white: #ffffff;
  --bg-gray: #f8f9fa;
  --bg-gray-light: #f1f3f4;
  --border-light: #dadce0;
  --shadow-sm: 0 1px 2px rgba(60, 64, 67, 0.08), 0 1px 3px rgba(60, 64, 67, 0.04);
  --shadow-md: 0 4px 12px rgba(60, 64, 67, 0.12), 0 2px 4px rgba(60, 64, 67, 0.08);
  --shadow-lg: 0 8px 24px rgba(60, 64, 67, 0.16), 0 2px 8px rgba(60, 64, 67, 0.08);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --max-width: 1200px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---- 重置与基础 ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text-primary);
  background: var(--bg-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
  color: var(--primary-blue-dark);
}

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

/* ---- 工具类 ---- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 1.125rem;
  text-align: center;
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto 48px;
}

/* ---- 导航栏 ---- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 64px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: var(--transition);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.125rem;
  color: var(--text-primary);
}

.nav-logo svg {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  border-radius: 100px;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.nav-links a:hover {
  background: var(--bg-gray-light);
  color: var(--text-primary);
}

.nav-links a.active {
  background: var(--primary-blue);
  color: #fff;
  box-shadow: 0 2px 8px rgba(26, 115, 232, 0.3);
}

.nav-links a.active:hover {
  background: var(--primary-blue-dark);
  color: #fff;
}

.nav-links svg {
  width: 18px;
  height: 18px;
}

/* ---- 按钮 ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 100px;
  font-size: 1rem;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--primary-blue);
  color: #fff;
  box-shadow: 0 4px 12px rgba(26, 115, 232, 0.3);
}

.btn-primary:hover {
  background: var(--primary-blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(26, 115, 232, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-gray-light);
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}

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

.btn-lg {
  padding: 18px 48px;
  font-size: 1.125rem;
}

.btn-sm {
  padding: 10px 24px;
  font-size: 0.875rem;
}

/* ---- 下载按钮特殊样式 ---- */
.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  background: var(--chrome-green);
  color: #fff;
  border-radius: 100px;
  font-size: 1.0625rem;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(52, 168, 83, 0.35);
  transition: var(--transition);
}

.download-btn:hover {
  background: #2d9147;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(52, 168, 83, 0.45);
  color: #fff;
}

.download-btn svg {
  width: 20px;
  height: 20px;
}

/* ---- 卡片 ---- */
.card {
  background: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: transparent;
}

/* ---- Hero 区域 ---- */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(180deg, #e8f0fe 0%, var(--bg-white) 100%);
  position: relative;
  overflow: hidden;
}

.hero-decoration {
  position: absolute;
  top: -100px;
  right: -100px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(26, 115, 232, 0.08) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-decoration-2 {
  position: absolute;
  bottom: -80px;
  left: -80px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(52, 168, 83, 0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(26, 115, 232, 0.1);
  color: var(--primary-blue);
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-badge svg {
  width: 16px;
  height: 16px;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
  color: var(--text-primary);
  letter-spacing: -1px;
}

.hero-title span {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--chrome-green) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.hero-meta {
  display: flex;
  gap: 24px;
  font-size: 0.875rem;
  color: var(--text-light);
}

.hero-meta span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hero-meta svg {
  width: 16px;
  height: 16px;
}

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

.hero-browser-mockup {
  width: 100%;
  max-width: 520px;
  background: var(--bg-white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
}

.mockup-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  background: var(--bg-gray-light);
  border-bottom: 1px solid var(--border-light);
}

.mockup-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.mockup-dot.red { background: var(--chrome-red); }
.mockup-dot.yellow { background: var(--chrome-yellow); }
.mockup-dot.green { background: var(--chrome-green); }

.mockup-address {
  flex: 1;
  height: 28px;
  background: var(--bg-white);
  border-radius: 100px;
  margin-left: 8px;
  display: flex;
  align-items: center;
  padding: 0 14px;
  font-size: 0.8125rem;
  color: var(--text-light);
  border: 1px solid var(--border-light);
}

.mockup-body {
  padding: 28px;
  min-height: 280px;
}

.mockup-search {
  max-width: 400px;
  margin: 0 auto 32px;
  height: 48px;
  background: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: 100px;
  display: flex;
  align-items: center;
  padding: 0 20px;
  gap: 10px;
  box-shadow: var(--shadow-sm);
}

.mockup-search svg {
  width: 20px;
  height: 20px;
  color: var(--text-light);
}

.mockup-search span {
  color: var(--text-light);
  font-size: 0.9375rem;
}

.mockup-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.mockup-card {
  height: 80px;
  background: var(--bg-gray);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
}

/* ---- 功能特性 ---- */
.features {
  padding: 100px 0;
  background: var(--bg-white);
}

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

.feature-card {
  background: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  transition: var(--transition);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-6px);
  border-color: transparent;
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-icon.blue { background: rgba(26, 115, 232, 0.1); color: var(--primary-blue); }
.feature-icon.green { background: rgba(52, 168, 83, 0.1); color: var(--chrome-green); }
.feature-icon.yellow { background: rgba(251, 188, 4, 0.1); color: #c29b00; }
.feature-icon.red { background: rgba(234, 67, 53, 0.1); color: var(--chrome-red); }
.feature-icon.purple { background: rgba(138, 43, 226, 0.1); color: #6b21a8; }
.feature-icon.teal { background: rgba(0, 150, 136, 0.1); color: #00796b; }

.feature-icon svg {
  width: 28px;
  height: 28px;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ---- 平台下载区 ---- */
.platforms {
  padding: 100px 0;
  background: var(--bg-gray);
}

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

.platform-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.platform-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: transparent;
}

.platform-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--bg-gray-light);
}

.platform-icon svg {
  width: 36px;
  height: 36px;
}

.platform-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.platform-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

/* ---- 功能详情 ---- */
.details {
  padding: 100px 0;
  background: var(--bg-white);
}

.detail-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 80px;
}

.detail-row:last-child {
  margin-bottom: 0;
}

.detail-row.reverse {
  direction: rtl;
}

.detail-row.reverse > * {
  direction: ltr;
}

.detail-visual {
  background: var(--bg-gray);
  border-radius: var(--radius-lg);
  padding: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  border: 1px solid var(--border-light);
}

.detail-visual svg {
  width: 100%;
  max-width: 360px;
  height: auto;
}

.detail-content h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.detail-content p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.detail-list {
  list-style: none;
  margin-top: 20px;
}

.detail-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.detail-list svg {
  width: 20px;
  height: 20px;
  color: var(--chrome-green);
  flex-shrink: 0;
  margin-top: 2px;
}

/* ---- 评价区 ---- */
.reviews {
  padding: 100px 0;
  background: linear-gradient(180deg, var(--bg-gray) 0%, var(--bg-white) 100%);
}

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

.review-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 32px;
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.review-card:hover {
  box-shadow: var(--shadow-md);
  border-color: transparent;
}

.review-stars {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}

.review-stars svg {
  width: 18px;
  height: 18px;
  color: var(--chrome-yellow);
}

.review-text {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 20px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--chrome-green) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
}

.review-name {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--text-primary);
}

.review-role {
  font-size: 0.8125rem;
  color: var(--text-light);
}

/* ---- 数据统计 ---- */
.stats {
  padding: 80px 0;
  background: var(--text-primary);
  color: #fff;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
  text-align: center;
}

.stat-item h4 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 8px;
  background: linear-gradient(135deg, #fff 0%, #aecbfa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-item p {
  font-size: 1rem;
  color: #9aa0a6;
}

/* ---- 对比表格 ---- */
.comparison {
  padding: 100px 0;
  background: var(--bg-white);
}

.compare-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.compare-table th {
  background: var(--bg-gray-light);
  padding: 18px 24px;
  text-align: left;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: 2px solid var(--border-light);
  white-space: nowrap;
}

.compare-table th:first-child {
  width: 30%;
}

.compare-table td {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-secondary);
}

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

.compare-table tr:hover td {
  background: var(--bg-gray);
}

.compare-check {
  color: var(--chrome-green);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 600;
}

.compare-check svg {
  width: 18px;
  height: 18px;
}

.compare-cross {
  color: var(--chrome-red);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.compare-cross svg {
  width: 18px;
  height: 18px;
}

.compare-partial {
  color: var(--chrome-yellow);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.compare-partial svg {
  width: 18px;
  height: 18px;
}

/* ---- FAQ ---- */
.faq {
  padding: 100px 0;
  background: var(--bg-gray);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  border: 1px solid var(--border-light);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  box-shadow: var(--shadow-sm);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 28px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1.0625rem;
  color: var(--text-primary);
  transition: var(--transition);
}

.faq-question:hover {
  background: var(--bg-gray-light);
}

.faq-question svg {
  width: 22px;
  height: 22px;
  color: var(--text-light);
  transition: transform 0.3s ease;
  flex-shrink: 0;
  margin-left: 12px;
}

.faq-item.open .faq-question svg {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 28px 24px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.8;
  display: none;
}

.faq-item.open .faq-answer {
  display: block;
}

/* ---- CTA 区域 ---- */
.cta-section {
  padding: 100px 0;
  background: linear-gradient(135deg, #e8f0fe 0%, #d2e3fc 100%);
  text-align: center;
}

.cta-section h2 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.cta-section p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 36px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* ---- 页脚 ---- */
.footer {
  padding: 60px 0 40px;
  background: var(--text-primary);
  color: #9aa0a6;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.125rem;
  color: #fff;
  margin-bottom: 16px;
}

.footer-brand svg {
  width: 28px;
  height: 28px;
}

.footer-about {
  font-size: 0.875rem;
  line-height: 1.8;
  color: #9aa0a6;
  max-width: 320px;
}

.footer-column h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: 20px;
}

.footer-column ul {
  list-style: none;
}

.footer-column li {
  margin-bottom: 12px;
}

.footer-column a {
  color: #9aa0a6;
  font-size: 0.875rem;
  transition: var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid #3c4043;
  padding-top: 24px;
  text-align: center;
  font-size: 0.8125rem;
  color: #5f6368;
}

.footer-safety {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  color: var(--chrome-green);
  font-weight: 500;
}

.footer-safety svg {
  width: 18px;
  height: 18px;
}

/* ============================================================
   下载页专用样式
   ============================================================ */

.download-hero {
  padding: 140px 0 60px;
  background: linear-gradient(180deg, #e8f0fe 0%, var(--bg-white) 100%);
}

.download-main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.download-main .hero-title {
  font-size: 2.75rem;
}

.download-info {
  display: flex;
  gap: 24px;
  margin: 28px 0;
  flex-wrap: wrap;
}

.download-info-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.download-info-item .label {
  font-size: 0.8125rem;
  color: var(--text-light);
}

.download-info-item .value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.version-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  background: rgba(52, 168, 83, 0.1);
  color: var(--chrome-green);
  border-radius: 100px;
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.version-badge svg {
  width: 18px;
  height: 18px;
}

.download-cards {
  padding: 80px 0;
  background: var(--bg-white);
}

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

.dl-card {
  background: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: var(--transition);
}

.dl-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: transparent;
}

.dl-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.dl-card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--bg-gray-light);
  display: flex;
  align-items: center;
  justify-content: center;
}

.dl-card-icon svg {
  width: 32px;
  height: 32px;
}

.dl-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.dl-card-subtitle {
  font-size: 0.875rem;
  color: var(--text-light);
}

.dl-card-info {
  margin-bottom: 24px;
}

.dl-card-info-item {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 0.875rem;
}

.dl-card-info-item:last-child {
  border-bottom: none;
}

.dl-card-info-item .info-label {
  color: var(--text-light);
}

.dl-card-info-item .info-value {
  color: var(--text-primary);
  font-weight: 500;
}

.dl-card-steps {
  margin-bottom: 24px;
}

.dl-card-steps h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.dl-card-steps ol {
  padding-left: 18px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.dl-card-actions {
  display: flex;
  gap: 12px;
}

.dl-card-actions .btn {
  flex: 1;
  justify-content: center;
}

/* ---- 安装指南 ---- */
.guide-section {
  padding: 80px 0;
}

.guide-section.alt-bg {
  background: var(--bg-gray);
}

.guide-steps {
  max-width: 800px;
  margin: 0 auto;
}

.guide-step {
  display: flex;
  gap: 28px;
  margin-bottom: 40px;
  position: relative;
}

.guide-step:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 24px;
  top: 56px;
  width: 2px;
  height: calc(100% - 16px);
  background: var(--border-light);
}

.step-number {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--primary-blue);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.125rem;
  flex-shrink: 0;
  z-index: 1;
}

.step-content h4 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
  margin-top: 10px;
}

.step-content p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.step-content .step-tip {
  margin-top: 12px;
  padding: 14px 18px;
  background: #e8f5e9;
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--chrome-green);
  font-size: 0.875rem;
  color: #2e7d32;
}

/* ---- 系统要求 ---- */
.sysreq {
  padding: 80px 0;
  background: var(--bg-gray);
}

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

.sysreq-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 28px;
  border: 1px solid var(--border-light);
}

.sysreq-card h4 {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.0625rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.sysreq-card h4 svg {
  width: 22px;
  height: 22px;
}

.sysreq-card ul {
  list-style: none;
}

.sysreq-card li {
  display: flex;
  justify-content: space-between;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 0.875rem;
}

.sysreq-card li:last-child {
  border-bottom: none;
}

.sysreq-card .req-label {
  color: var(--text-light);
}

.sysreq-card .req-value {
  color: var(--text-primary);
  font-weight: 500;
}

/* ---- 更新日志 ---- */
.changelog {
  padding: 80px 0;
  background: var(--bg-white);
}

.changelog-list {
  max-width: 800px;
  margin: 0 auto;
}

.changelog-item {
  display: flex;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--border-light);
}

.changelog-item:last-child {
  border-bottom: none;
}

.changelog-version {
  flex-shrink: 0;
  width: 100px;
}

.changelog-version .ver-num {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--primary-blue);
}

.changelog-version .ver-date {
  font-size: 0.8125rem;
  color: var(--text-light);
  margin-top: 4px;
}

.changelog-content h4 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.changelog-content ul {
  padding-left: 18px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ---- 安全保障 ---- */
.safety-section {
  padding: 80px 0;
  background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
}

.safety-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.safety-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.safety-card svg {
  width: 48px;
  height: 48px;
  color: var(--chrome-green);
  margin-bottom: 16px;
}

.safety-card h4 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.safety-card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================================
   SEO 页 (zh-cn.html) 专用样式
   ============================================================ */

.seo-hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, #e8f0fe 0%, #f3e8fd 100%);
  text-align: center;
}

.seo-hero .hero-title {
  font-size: 2.75rem;
}

.seo-content {
  padding: 80px 0;
}

.seo-content .container {
  max-width: 840px;
}

.seo-content h2 {
  font-size: 1.875rem;
  font-weight: 700;
  margin: 48px 0 20px;
  color: var(--text-primary);
}

.seo-content h3 {
  font-size: 1.375rem;
  font-weight: 700;
  margin: 32px 0 14px;
  color: var(--text-primary);
}

.seo-content p {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 18px;
}

.seo-content ul, .seo-content ol {
  padding-left: 24px;
  margin-bottom: 20px;
}

.seo-content li {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 10px;
}

.seo-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.seo-highlight {
  background: #e8f0fe;
  border-radius: var(--radius-md);
  padding: 28px 32px;
  margin: 28px 0;
  border-left: 4px solid var(--primary-blue);
}

.seo-highlight p {
  margin-bottom: 0;
  font-size: 1rem;
}

.seo-cta-box {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-dark) 100%);
  border-radius: var(--radius-lg);
  padding: 48px 36px;
  text-align: center;
  margin: 48px 0;
  color: #fff;
}

.seo-cta-box h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #fff;
}

.seo-cta-box p {
  font-size: 1.0625rem;
  margin-bottom: 28px;
  opacity: 0.9;
  color: #fff;
}

.seo-cta-box .btn {
  background: #fff;
  color: var(--primary-blue);
  font-weight: 700;
}

.seo-cta-box .btn:hover {
  background: var(--bg-gray-light);
  color: var(--primary-blue-dark);
}

/* ============================================================
   动画与响应式
   ============================================================ */

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

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

.animate-in {
  animation: fadeInUp 0.6s ease forwards;
}

/* ---- 响应式 ---- */
@media (max-width: 1024px) {
  .hero .container,
  .download-main,
  .detail-row,
  .detail-row.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .detail-row.reverse > * {
    direction: ltr;
  }

  .features-grid,
  .reviews-grid,
  .dl-card-grid,
  .safety-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .platforms-grid,
  .stats-grid,
  .sysreq-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
  }

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

@media (max-width: 640px) {
  .features-grid,
  .platforms-grid,
  .reviews-grid,
  .stats-grid,
  .dl-card-grid,
  .sysreq-grid,
  .safety-grid,
  .footer-content {
    grid-template-columns: 1fr;
  }

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

  .hero {
    padding: 120px 0 60px;
  }

  .section-title {
    font-size: 1.75rem;
  }

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

  .nav-links a {
    padding: 8px 12px;
  }

  .btn-lg {
    padding: 16px 32px;
    font-size: 1rem;
  }

  .mockup-cards {
    grid-template-columns: 1fr;
  }

  .guide-step {
    flex-direction: column;
    gap: 16px;
  }

  .guide-step:not(:last-child)::after {
    display: none;
  }

  .step-number {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }
}