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

:root {
  --primary: #e8380d;
  --primary-dark: #c42f0a;
  --accent: #1a6fd4;
  --text: #333;
  --text-light: #666;
  --bg: #fff;
  --bg-gray: #f5f7fa;
  --border: #e8e8e8;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --radius: 8px;
}

html {
  scroll-behavior: smooth;
}

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

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

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

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

.logo img {
  width: 36px;
  height: 36px;
}

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

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

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

.btn-download {
  display: inline-block;
  background: var(--primary);
  color: #fff !important;
  padding: 10px 28px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 15px;
  transition: background 0.2s, transform 0.2s;
}

.btn-download:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  color: #fff !important;
}

.hero {
  background: linear-gradient(135deg, #fff5f2 0%, #fff 50%, #f0f6ff 100%);
  padding: 80px 0 60px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  background: #fff0eb;
  color: var(--primary);
  font-size: 14px;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 20px;
  font-weight: 500;
}

.hero h1 {
  font-size: 42px;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 20px;
  line-height: 1.3;
}

.hero p {
  font-size: 18px;
  color: var(--text-light);
  max-width: 720px;
  margin: 0 auto 12px;
}

.hero .hero-sub {
  font-size: 15px;
  color: #888;
  margin-bottom: 36px;
}

.hero .btn-download {
  padding: 14px 48px;
  font-size: 17px;
}

.section {
  padding: 70px 0;
}

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

.section-title {
  text-align: center;
  margin-bottom: 50px;
}

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

.section-title p {
  color: var(--text-light);
  font-size: 16px;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  max-width: 960px;
  margin: 0 auto;
}

.step-card {
  text-align: center;
  padding: 30px 20px;
}

.step-num {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
  margin: 0 auto 16px;
}

.step-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}

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

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 28px 22px;
  box-shadow: var(--shadow);
  transition: transform 0.3s;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-icon {
  width: 56px;
  height: 56px;
  background: #fff5f2;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-size: 26px;
}

.feature-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

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

.feature-tag {
  display: inline-block;
  margin-top: 10px;
  font-size: 12px;
  color: var(--accent);
  font-weight: 500;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 30px;
  text-align: center;
}

.stat-item h3 {
  font-size: 40px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 8px;
}

.stat-item p {
  color: var(--text-light);
  font-size: 15px;
}

.trust-list {
  max-width: 800px;
  margin: 0 auto;
  list-style: none;
}

.trust-list li {
  padding: 12px 0;
  font-size: 16px;
  color: var(--text-light);
  border-bottom: 1px solid var(--border);
}

.trust-list li::before {
  content: "✓ ";
  color: var(--primary);
  font-weight: 700;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.testimonial-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 30px;
  box-shadow: var(--shadow);
}

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

.testimonial-card cite {
  font-style: normal;
  font-weight: 600;
  font-size: 14px;
  color: var(--text);
}

.testimonial-label {
  display: block;
  font-size: 12px;
  color: #999;
  margin-top: 4px;
  font-weight: 400;
}

.why-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.why-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow);
}

.why-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
  color: var(--primary);
}

.why-card p {
  color: var(--text-light);
  font-size: 15px;
}

.quote-block {
  max-width: 800px;
  margin: 40px auto 0;
  padding: 24px 32px;
  background: #fff5f2;
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-size: 15px;
  color: var(--text-light);
  font-style: italic;
}

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

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

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 20px 0;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text);
}

.faq-question::after {
  content: "+";
  font-size: 22px;
  color: var(--primary);
  transition: transform 0.3s;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

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

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.article-card {
  background: var(--bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.3s;
}

.article-card:hover {
  transform: translateY(-4px);
}

.article-card-body {
  padding: 24px;
}

.article-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
  line-height: 1.4;
}

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

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

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

.article-meta {
  font-size: 13px;
  color: #999;
}

.article-page {
  padding: 50px 0 80px;
}

.article-page h1 {
  font-size: 32px;
  margin-bottom: 16px;
  line-height: 1.4;
}

.article-page .article-meta {
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

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

.article-content h2 {
  font-size: 24px;
  margin: 36px 0 16px;
}

.article-content h3 {
  font-size: 20px;
  margin: 28px 0 12px;
}

.article-content p {
  margin-bottom: 16px;
  color: var(--text-light);
  font-size: 16px;
}

.article-content ul, .article-content ol {
  margin: 16px 0 16px 24px;
  color: var(--text-light);
}

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

.download-hero {
  background: linear-gradient(135deg, #fff5f2, #f0f6ff);
  padding: 60px 0;
  text-align: center;
}

.download-hero h1 {
  font-size: 36px;
  margin-bottom: 16px;
}

.download-badges {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 20px;
  font-size: 14px;
  color: var(--text-light);
}

.download-badges span {
  background: #e8f5e9;
  color: #2e7d32;
  padding: 4px 12px;
  border-radius: 12px;
  font-weight: 500;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.download-card {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 36px 28px;
  box-shadow: var(--shadow);
  border: 2px solid transparent;
  transition: border-color 0.3s;
}

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

.download-card .platform-icon {
  font-size: 44px;
  margin-bottom: 14px;
}

.download-card h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.download-card .card-desc {
  color: var(--text-light);
  font-size: 14px;
  margin-bottom: 16px;
  line-height: 1.7;
}

.download-meta {
  font-size: 13px;
  color: #888;
  margin-bottom: 20px;
  line-height: 1.8;
}

.changelog {
  font-size: 13px;
  color: var(--text-light);
  background: var(--bg-gray);
  padding: 12px 16px;
  border-radius: var(--radius);
  margin-top: 16px;
  line-height: 1.7;
}

.sitemap-list {
  max-width: 700px;
  margin: 40px auto;
}

.sitemap-list h2 {
  font-size: 22px;
  margin: 30px 0 16px;
  color: var(--primary);
}

.sitemap-list ul {
  list-style: none;
}

.sitemap-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.sitemap-list li a {
  font-size: 16px;
}

.site-footer {
  background: #2c2c2c;
  color: #aaa;
  padding: 50px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 30px;
}

.footer-col h4 {
  color: #fff;
  font-size: 16px;
  margin-bottom: 16px;
}

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

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  color: #aaa;
  font-size: 14px;
}

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

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #444;
  font-size: 13px;
}

.breadcrumb {
  padding: 16px 0;
  font-size: 14px;
  color: var(--text-light);
}

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

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

.update-badge {
  display: inline-block;
  background: #e8f5e9;
  color: #2e7d32;
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 12px;
  margin-left: 8px;
}

.security-box {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow);
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.security-box h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.security-box p {
  color: var(--text-light);
  font-size: 15px;
  line-height: 1.8;
}

@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
  }

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

  .features-grid,
  .stats-grid,
  .testimonials-grid,
  .articles-grid,
  .download-grid,
  .footer-grid,
  .steps-grid,
  .why-grid {
    grid-template-columns: 1fr;
  }

  .section-title h2 {
    font-size: 24px;
  }
}