/* ═════════════════════════════════════════════
   Chrome 安全下载站 - 全局样式表
   纯原生 CSS，无框架依赖
   ═════════════════════════════════════════════ */

/* ── CSS 变量 ── */
:root {
  --color-blue: #4285f4;
  --color-green: #34a853;
  --color-red: #ea4335;
  --color-yellow: #fbbc04;
  --color-dark: #202124;
  --color-gray-900: #3c4043;
  --color-gray-700: #5f6368;
  --color-gray-500: #80868b;
  --color-gray-300: #dadce0;
  --color-gray-100: #f8f9fa;
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --shadow-sm: 0 1px 2px rgba(60, 64, 67, 0.08);
  --shadow-md: 0 4px 12px rgba(60, 64, 67, 0.12);
  --shadow-lg: 0 8px 24px rgba(60, 64, 67, 0.16);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --max-width: 1200px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
}

/* ── 全局重置 ── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  color: var(--color-dark);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
  color: #1a73e8;
  text-decoration: underline;
}

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

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

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

.section-padding {
  padding: 80px 0;
}

.text-center {
  text-align: center;
}

/* ── spin 动画（下载按钮 loading 用） ── */
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

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

/* ── 导航栏 ── */
.main-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-gray-300);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 600;
  color: var(--color-dark);
  text-decoration: none;
}

.nav-logo:hover {
  text-decoration: none;
}

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

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-menu a {
  display: block;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-gray-700);
  text-decoration: none;
  transition: var(--transition);
}

.nav-menu a:hover {
  background: var(--color-gray-100);
  color: var(--color-dark);
  text-decoration: none;
}

.nav-menu a.active {
  background: var(--color-blue);
  color: #fff;
}

.nav-menu a.active:hover {
  background: #1a73e8;
}

/* ── 页脚 ── */
.site-footer {
  background: var(--color-gray-100);
  border-top: 1px solid var(--color-gray-300);
  padding: 40px 0 32px;
}

.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 14px;
  color: var(--color-gray-700);
}

.footer-links a:hover {
  color: var(--color-blue);
}

.footer-divider {
  border: none;
  height: 1px;
  background: var(--color-gray-300);
  margin: 20px 0;
}

.footer-text {
  text-align: center;
  font-size: 13px;
  color: var(--color-gray-500);
  line-height: 1.8;
}

.footer-text p {
  margin-bottom: 6px;
}

/* ═════════════════════════════════════════════
   首页专属样式
   ═════════════════════════════════════════════ */

/* Hero 区域 */
.hero-section {
  position: relative;
  padding: 100px 0 80px;
  background: linear-gradient(135deg, #f8f9fa 0%, #e8f0fe 50%, #f8f9fa 100%);
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -80px;
  right: -80px;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(66, 133, 244, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-section::after {
  content: '';
  position: absolute;
  bottom: -60px;
  left: -60px;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(52, 168, 83, 0.06) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: #e8f0fe;
  color: var(--color-blue);
  font-size: 13px;
  font-weight: 600;
  border-radius: 100px;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 52px;
  font-weight: 700;
  line-height: 1.15;
  color: var(--color-dark);
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--color-gray-700);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 480px;
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: var(--color-blue);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-xl);
  box-shadow: 0 4px 12px rgba(66, 133, 244, 0.3);
  transition: var(--transition);
}

.btn-primary:hover {
  background: #1a73e8;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(66, 133, 244, 0.4);
  text-decoration: none;
  color: #fff;
}

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

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  background: #fff;
  color: var(--color-blue);
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-xl);
  border: 2px solid var(--color-gray-300);
  transition: var(--transition);
}

.btn-secondary:hover {
  border-color: var(--color-blue);
  background: #f8f9fa;
  transform: translateY(-2px);
  text-decoration: none;
  color: var(--color-blue);
}

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

.hero-visual svg {
  width: 320px;
  height: 320px;
  animation: float 5s ease-in-out infinite;
}

/* 区块标题通用 */
.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 60px;
}

.section-label {
  display: inline-block;
  padding: 4px 12px;
  background: #e6f4ea;
  color: var(--color-green);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: 100px;
  margin-bottom: 16px;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 16px;
  letter-spacing: -0.3px;
}

.section-desc {
  font-size: 17px;
  color: var(--color-gray-700);
  line-height: 1.7;
}

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

.feature-card {
  background: #fff;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 14px;
  color: var(--color-gray-700);
  line-height: 1.7;
}

/* 下载入口区域 */
.download-entry-section {
  background: linear-gradient(180deg, #fff 0%, #f8f9fa 100%);
}

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

.platform-card {
  background: #fff;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
  transition: var(--transition);
}

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

.platform-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  background: var(--color-gray-100);
}

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

.platform-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.platform-card p {
  font-size: 13px;
  color: var(--color-gray-500);
  margin-bottom: 16px;
}

.platform-card .btn-small {
  padding: 10px 24px;
  font-size: 14px;
}

.btn-small {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  background: var(--color-blue);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-xl);
  transition: var(--transition);
}

.btn-small:hover {
  background: #1a73e8;
  transform: translateY(-1px);
  text-decoration: none;
  color: #fff;
}

/* 功能详情区 */
.detail-section {
  background: #fff;
}

.detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

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

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

.detail-content h3 {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 16px;
}

.detail-content p {
  font-size: 16px;
  color: var(--color-gray-700);
  line-height: 1.8;
  margin-bottom: 16px;
}

.detail-list {
  list-style: none;
  padding: 0;
}

.detail-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  color: var(--color-gray-900);
  margin-bottom: 12px;
}

.detail-list li svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  margin-top: 2px;
}

.detail-visual {
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  padding: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 300px;
}

.detail-visual svg {
  width: 200px;
  height: 200px;
}

/* 用户评价 */
.reviews-section {
  background: linear-gradient(180deg, #f8f9fa 0%, #fff 100%);
}

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

.review-card {
  background: #fff;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: var(--transition);
}

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

.review-stars {
  display: flex;
  gap: 2px;
  margin-bottom: 12px;
}

.review-stars svg {
  width: 18px;
  height: 18px;
}

.review-text {
  font-size: 15px;
  color: var(--color-gray-900);
  line-height: 1.7;
  margin-bottom: 16px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 10px;
}

.review-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-blue), var(--color-green));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 15px;
  font-weight: 600;
}

.review-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-dark);
}

.review-role {
  font-size: 12px;
  color: var(--color-gray-500);
}

/* 数据统计 */
.stats-section {
  background: var(--color-dark);
  color: #fff;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  text-align: center;
}

.stat-item h4 {
  font-size: 42px;
  font-weight: 700;
  background: linear-gradient(90deg, var(--color-blue), var(--color-green));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.stat-item p {
  font-size: 15px;
  color: #bdc1c6;
}

/* 对比表格 */
.compare-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-gray-300);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

.compare-table th,
.compare-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid var(--color-gray-300);
}

.compare-table th {
  background: var(--color-gray-100);
  font-weight: 600;
  color: var(--color-dark);
  font-size: 14px;
  white-space: nowrap;
}

.compare-table td {
  color: var(--color-gray-900);
}

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

.compare-table td:first-child {
  font-weight: 600;
  color: var(--color-dark);
}

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

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

.compare-mid {
  color: var(--color-yellow);
  font-weight: 500;
}

/* FAQ */
.faq-section {
  background: #fff;
}

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

.faq-item {
  border-bottom: 1px solid var(--color-gray-300);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0;
  background: none;
  font-size: 17px;
  font-weight: 600;
  color: var(--color-dark);
  text-align: left;
  cursor: pointer;
}

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

.faq-question svg {
  width: 22px;
  height: 22px;
  transition: var(--transition);
  flex-shrink: 0;
  margin-left: 12px;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease-out, padding 0.35s ease-out;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding-bottom: 24px;
}

.faq-answer p {
  font-size: 15px;
  color: var(--color-gray-700);
  line-height: 1.8;
}

/* ═════════════════════════════════════════════
   下载页专属样式
   ═════════════════════════════════════════════ */

.download-hero {
  background: linear-gradient(135deg, #e8f0fe 0%, #f8f9fa 50%, #fce8e6 100%);
  padding: 80px 0 60px;
}

.download-hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.download-hero-content h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.3px;
}

.download-hero-content p {
  font-size: 17px;
  color: var(--color-gray-700);
  line-height: 1.7;
  margin-bottom: 28px;
}

.download-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 28px;
}

.download-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: #fff;
  border-radius: 100px;
  font-size: 13px;
  color: var(--color-gray-700);
  border: 1px solid var(--color-gray-300);
}

.download-meta svg {
  width: 14px;
  height: 14px;
}

.download-hero-visual {
  display: flex;
  justify-content: center;
}

.download-hero-visual svg {
  width: 280px;
  height: 280px;
}

/* 平台下载卡片（下载页） */
.platform-section {
  background: #fff;
}

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

.platform-detail-card {
  background: #fff;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  padding: 32px;
  transition: var(--transition);
}

.platform-detail-card:hover {
  border-color: var(--color-blue);
  box-shadow: var(--shadow-md);
}

.platform-detail-card .platform-icon {
  margin-bottom: 20px;
}

.platform-detail-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.platform-detail-card .version-info {
  font-size: 13px;
  color: var(--color-gray-500);
  margin-bottom: 16px;
}

.platform-detail-card .install-steps {
  list-style: none;
  padding: 0;
  margin-bottom: 20px;
}

.platform-detail-card .install-steps li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: var(--color-gray-700);
  margin-bottom: 10px;
  line-height: 1.6;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: var(--color-blue);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

/* 安装指南 */
.guide-section {
  background: var(--color-gray-100);
}

.guide-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}

.guide-block {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 36px;
  border: 1px solid var(--color-gray-300);
}

.guide-block h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.guide-block h3 svg {
  width: 26px;
  height: 26px;
}

.guide-steps {
  list-style: none;
  counter-reset: step;
}

.guide-steps li {
  position: relative;
  padding-left: 48px;
  padding-bottom: 24px;
  border-left: 2px solid var(--color-gray-300);
  margin-left: 15px;
}

.guide-steps li:last-child {
  border-left: 2px solid transparent;
  padding-bottom: 0;
}

.guide-steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: -15px;
  top: 0;
  width: 30px;
  height: 30px;
  background: var(--color-blue);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  border: 3px solid #fff;
  box-shadow: var(--shadow-sm);
}

.guide-steps h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.guide-steps p {
  font-size: 14px;
  color: var(--color-gray-700);
  line-height: 1.7;
}

/* 系统要求 */
.sysreq-section {
  background: #fff;
}

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

.sysreq-card {
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  padding: 24px;
}

.sysreq-card h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.sysreq-card h4 svg {
  width: 20px;
  height: 20px;
}

.sysreq-card ul {
  list-style: none;
  font-size: 14px;
  color: var(--color-gray-700);
  line-height: 2;
}

/* 更新日志 */
.changelog-section {
  background: var(--color-gray-100);
}

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

.changelog-item {
  background: #fff;
  border-radius: var(--radius-md);
  padding: 28px 32px;
  margin-bottom: 16px;
  border: 1px solid var(--color-gray-300);
}

.changelog-item:last-child {
  margin-bottom: 0;
}

.changelog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 8px;
}

.changelog-header h4 {
  font-size: 18px;
  font-weight: 600;
}

.changelog-date {
  font-size: 13px;
  color: var(--color-gray-500);
  background: var(--color-gray-100);
  padding: 4px 12px;
  border-radius: 100px;
}

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

.changelog-item li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 14px;
  color: var(--color-gray-700);
  margin-bottom: 8px;
  line-height: 1.6;
}

.changelog-item li svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  margin-top: 3px;
}

/* 安全下载 */
.security-section {
  background: linear-gradient(135deg, #e6f4ea 0%, #fce8e6 50%, #e8f0fe 100%);
}

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

.security-card {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.6);
}

.security-card svg {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
}

.security-card h4 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 10px;
}

.security-card p {
  font-size: 14px;
  color: var(--color-gray-700);
  line-height: 1.7;
}

/* ═════════════════════════════════════════════
   SEO 引导页专属样式
   ═════════════════════════════════════════════ */

.seo-hero {
  background: linear-gradient(135deg, #e8f0fe 0%, #fce8e6 100%);
  padding: 80px 0 60px;
}

.seo-hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  text-align: center;
}

.seo-hero h1 {
  font-size: 42px;
  font-weight: 700;
  margin-bottom: 20px;
  letter-spacing: -0.3px;
}

.seo-hero-inner > p {
  font-size: 18px;
  color: var(--color-gray-700);
  line-height: 1.7;
  max-width: 700px;
  margin: 0 auto 32px;
}

/* 软文内容区 */
.article-section {
  background: #fff;
}

.article-content {
  max-width: 800px;
  margin: 0 auto;
}

.article-content h2 {
  font-size: 28px;
  font-weight: 700;
  margin: 48px 0 20px;
  color: var(--color-dark);
}

.article-content h2:first-child {
  margin-top: 0;
}

.article-content h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 32px 0 14px;
  color: var(--color-gray-900);
}

.article-content p {
  font-size: 16px;
  color: var(--color-gray-700);
  line-height: 1.9;
  margin-bottom: 16px;
}

.article-content ul {
  margin: 16px 0;
  padding-left: 24px;
  color: var(--color-gray-700);
}

.article-content ul li {
  margin-bottom: 10px;
  line-height: 1.7;
}

.article-content strong {
  color: var(--color-dark);
  font-weight: 600;
}

/* 技巧网格 */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.tip-card {
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  padding: 24px;
  border-left: 4px solid var(--color-blue);
}

.tip-card h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.tip-card p {
  font-size: 14px;
  color: var(--color-gray-700);
  line-height: 1.7;
  margin-bottom: 0;
}

/* CTA 区块 */
.cta-section {
  background: linear-gradient(135deg, var(--color-blue) 0%, #1a73e8 100%);
  color: #fff;
  text-align: center;
  padding: 60px 0;
}

.cta-section h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 12px;
}

.cta-section p {
  font-size: 17px;
  opacity: 0.9;
  margin-bottom: 28px;
}

.cta-section .btn-primary {
  background: #fff;
  color: var(--color-blue);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.cta-section .btn-primary:hover {
  background: var(--color-gray-100);
  color: #1a73e8;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

/* ═════════════════════════════════════════════
   响应式设计
   ═════════════════════════════════════════════ */
@media (max-width: 1024px) {
  .hero-inner,
  .download-hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-subtitle {
    margin-left: auto;
    margin-right: auto;
  }

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

  .detail-grid,
  .guide-grid {
    grid-template-columns: 1fr;
  }

  .detail-grid.reverse {
    direction: ltr;
  }
}

@media (max-width: 768px) {
  .section-padding {
    padding: 56px 0;
  }

  .hero-title {
    font-size: 36px;
  }

  .section-title {
    font-size: 28px;
  }

  .features-grid,
  .platform-grid,
  .reviews-grid,
  .stats-grid,
  .sysreq-grid,
  .security-grid,
  .platform-cards,
  .tips-grid {
    grid-template-columns: 1fr;
  }

  .hero-visual svg,
  .download-hero-visual svg {
    width: 220px;
    height: 220px;
  }

  .nav-container {
    padding: 0 16px;
  }

  .nav-menu a {
    padding: 6px 12px;
    font-size: 14px;
  }

  .container,
  .footer-container {
    padding: 0 16px;
  }

  .hero-section {
    padding: 60px 0 48px;
  }

  .btn-primary,
  .btn-secondary {
    padding: 12px 24px;
    font-size: 15px;
  }

  .compare-table th,
  .compare-table td {
    padding: 12px 14px;
    font-size: 13px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 28px;
  }

  .section-title {
    font-size: 24px;
  }

  .download-hero-content h1 {
    font-size: 28px;
  }

  .seo-hero h1 {
    font-size: 28px;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .stat-item h4 {
    font-size: 32px;
  }
}