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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --accent: #06b6d4;
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-light: #f8fafc;
  --text: #1e293b;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --white: #ffffff;
  --border: #e2e8f0;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 48px rgba(15, 23, 42, 0.12);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.25s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  font-size: 16px;
}

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

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

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

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: var(--primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 800;
  font-size: 18px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-menu a {
  color: var(--text);
  font-weight: 500;
  font-size: 15px;
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--primary);
}

.nav-cta {
  background: var(--primary);
  color: var(--white) !important;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
}

.nav-cta:hover {
  background: var(--primary-dark);
  color: var(--white) !important;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: var(--transition);
}

/* Hero */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(160deg, #eff6ff 0%, #f0fdfa 50%, #ffffff 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 800;
  line-height: 1.25;
  color: var(--bg);
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 18px;
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
}

.btn-primary {
  background: var(--primary);
  color: var(--white);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35);
}

.btn-outline {
  background: var(--white);
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 720px;
  margin: 0 auto;
}

.stat-item {
  text-align: center;
  padding: 24px 16px;
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.stat-num {
  font-size: 36px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 14px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* Section */
.section {
  padding: 80px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  color: var(--bg);
  margin-bottom: 12px;
}

.section-header p {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
}

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

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
  border: 1px solid var(--border);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, #eff6ff, #dbeafe);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--bg);
}

.feature-card p {
  color: var(--text-muted);
  font-size: 15px;
  margin-bottom: 12px;
}

.feature-tag {
  display: inline-block;
  background: #eff6ff;
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
}

/* Download platforms */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.platform-card {
  background: var(--white);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
  transition: all var(--transition);
  cursor: pointer;
}

.platform-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.platform-card.recommended {
  border-color: var(--primary);
  position: relative;
}

.platform-card.recommended::after {
  content: "推荐";
  position: absolute;
  top: -10px;
  right: 16px;
  background: var(--primary);
  color: var(--white);
  font-size: 12px;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 10px;
}

.platform-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.platform-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.platform-card p {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

/* Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.review-stars {
  color: #f59e0b;
  font-size: 18px;
  margin-bottom: 12px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 15px;
  color: var(--text);
  font-style: italic;
  margin-bottom: 16px;
  line-height: 1.8;
}

.review-author {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 500;
}

/* FAQ */
.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  padding: 20px 24px;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--bg);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question::after {
  content: "+";
  font-size: 22px;
  color: var(--primary);
  transition: transform var(--transition);
}

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

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

.faq-item.open .faq-answer {
  max-height: 300px;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.8;
}

/* Articles */
.article-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.article-card-body {
  padding: 28px;
}

.article-card-meta {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 10px;
}

.article-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--bg);
}

.article-card h3 a {
  color: inherit;
}

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

.article-card p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.read-more {
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
}

/* Article page */
.article-page {
  padding: 120px 0 80px;
}

.article-header {
  max-width: 780px;
  margin: 0 auto 40px;
  text-align: center;
}

.article-header h1 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  color: var(--bg);
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-meta {
  font-size: 14px;
  color: var(--text-light);
}

.article-content {
  max-width: 780px;
  margin: 0 auto;
}

.article-content h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--bg);
  margin: 36px 0 16px;
}

.article-content h3 {
  font-size: 20px;
  font-weight: 600;
  color: var(--bg);
  margin: 28px 0 12px;
}

.article-content p {
  margin-bottom: 18px;
  color: var(--text);
  line-height: 1.85;
}

.article-content ul,
.article-content ol {
  margin: 0 0 18px 24px;
  color: var(--text);
}

.article-content li {
  margin-bottom: 8px;
}

.article-content blockquote {
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  background: #eff6ff;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 24px 0;
  color: var(--text-muted);
}

.article-update-notice {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: var(--radius);
  padding: 12px 18px;
  font-size: 14px;
  color: #166534;
  margin-bottom: 28px;
  text-align: center;
}

/* Download page */
.download-hero {
  padding: 120px 0 60px;
  background: linear-gradient(160deg, #eff6ff 0%, #ffffff 100%);
  text-align: center;
}

.download-hero h1 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  color: var(--bg);
  margin-bottom: 16px;
}

.download-hero p {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

.download-section {
  padding: 60px 0 80px;
}

.download-card {
  background: var(--white);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  text-align: center;
  transition: all var(--transition);
}

.download-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.download-card .platform-icon {
  font-size: 56px;
  margin-bottom: 20px;
}

.download-card h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

.download-card .version {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 12px;
}

.download-card p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.download-steps {
  max-width: 680px;
  margin: 48px auto 0;
}

.download-steps h2 {
  text-align: center;
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 32px;
}

.step-item {
  display: flex;
  gap: 20px;
  margin-bottom: 24px;
  align-items: flex-start;
}

.step-num {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
}

.step-content h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 6px;
}

.step-content p {
  font-size: 15px;
  color: var(--text-muted);
}

/* Footer */
.site-footer {
  background: var(--bg);
  color: var(--text-light);
  padding: 56px 0 28px;
}

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

.footer-brand .logo {
  color: var(--white);
  margin-bottom: 16px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-light);
}

.footer-col h4 {
  color: var(--white);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

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

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--text-light);
  font-size: 14px;
}

.footer-col a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid #334155;
  padding-top: 24px;
  text-align: center;
  font-size: 13px;
  color: #64748b;
}

/* Breadcrumb */
.breadcrumb {
  padding: 100px 0 0;
  font-size: 14px;
  color: var(--text-light);
}

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

.breadcrumb span {
  margin: 0 8px;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
  }

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

  .menu-toggle {
    display: block;
  }

  .stats-row {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 28px;
  }

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

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }
}