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

:root {
  --primary: #4d6bff;
  --primary-dark: #3a56e0;
  --accent: #00c2a8;
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #1a1f36;
  --text-muted: #5c6378;
  --border: #e4e8f0;
  --shadow: 0 4px 24px rgba(26, 31, 54, 0.08);
  --radius: 12px;
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
}

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

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: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 14px;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

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

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff !important;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 14px rgba(77, 107, 255, 0.35);
}

.btn-download:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(77, 107, 255, 0.45);
  color: #fff !important;
}

/* Hero */
.hero {
  background: linear-gradient(160deg, #eef1ff 0%, #f5f7fb 50%, #e8faf7 100%);
  padding: 72px 0 80px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  background: rgba(77, 107, 255, 0.1);
  color: var(--primary);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 18px;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 32px;
}

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

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 2px solid var(--border);
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.2s, color 0.2s;
}

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

/* Sections */
.section {
  padding: 64px 0;
}

.section-title {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.section-desc {
  text-align: center;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto 40px;
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s;
}

.feature-card:hover {
  transform: translateY(-3px);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, rgba(77, 107, 255, 0.12), rgba(0, 194, 168, 0.12));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
}

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

.download-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.download-card .platform-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.download-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.download-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

/* Article List */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.article-item {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 24px 28px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  display: flex;
  gap: 20px;
  align-items: flex-start;
  transition: transform 0.2s;
}

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

.article-date {
  flex-shrink: 0;
  background: rgba(77, 107, 255, 0.08);
  color: var(--primary);
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  text-align: center;
  min-width: 80px;
}

.article-date .day {
  display: block;
  font-size: 1.3rem;
  font-weight: 800;
  line-height: 1.2;
}

.article-content h3 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}

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

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

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

.article-tag {
  display: inline-block;
  background: rgba(0, 194, 168, 0.1);
  color: var(--accent);
  padding: 2px 10px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 600;
  margin-top: 8px;
}

/* Daily Update Section */
.daily-update {
  background: linear-gradient(135deg, #eef1ff, #e8faf7);
  border-radius: var(--radius);
  padding: 32px;
  margin-top: 32px;
  border: 1px solid var(--border);
}

.daily-update-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.daily-update-header h3 {
  font-size: 1.15rem;
}

.daily-badge {
  background: var(--accent);
  color: #fff;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 600;
}

#daily-articles-container .article-item {
  box-shadow: none;
  border: 1px dashed var(--border);
}

/* Article Page */
.article-page {
  padding: 48px 0 64px;
}

.article-page .breadcrumb {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

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

.article-page h1 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 32px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.article-body {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 36px 40px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.article-body h2 {
  font-size: 1.3rem;
  margin: 28px 0 12px;
}

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

.article-body p {
  margin-bottom: 16px;
  color: var(--text);
}

.article-body ul, .article-body ol {
  margin: 12px 0 16px 24px;
  color: var(--text);
}

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

.article-body blockquote {
  border-left: 4px solid var(--primary);
  padding: 12px 20px;
  background: rgba(77, 107, 255, 0.05);
  margin: 20px 0;
  color: var(--text-muted);
  border-radius: 0 8px 8px 0;
}

/* Steps */
.steps {
  counter-reset: step;
  list-style: none;
  margin: 20px 0;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 16px 16px 16px 56px;
  background: var(--bg);
  border-radius: 8px;
  margin-bottom: 12px;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 16px;
  width: 28px;
  height: 28px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
}

/* FAQ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 20px 24px;
  border: 1px solid var(--border);
}

.faq-item h3 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.faq-item p {
  color: var(--text-muted);
  font-size: 0.92rem;
}

/* Footer */
.site-footer {
  background: var(--text);
  color: rgba(255, 255, 255, 0.7);
  padding: 48px 0 24px;
  margin-top: 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}

.footer-col h4 {
  color: #fff;
  font-size: 0.95rem;
  margin-bottom: 14px;
}

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

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

.footer-col a {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.88rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* Page Header */
.page-header {
  background: linear-gradient(160deg, #eef1ff, #f5f7fb);
  padding: 48px 0;
  text-align: center;
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.page-header p {
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto;
}

/* Sitemap Page */
.sitemap-list {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.sitemap-list h2 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.sitemap-list ul {
  list-style: none;
  margin-bottom: 24px;
}

.sitemap-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

.sitemap-list li:last-child {
  border-bottom: none;
}

.sitemap-list a {
  font-weight: 500;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .article-page h1 {
    font-size: 1.5rem;
  }

  .article-body {
    padding: 24px 20px;
  }

  .article-item {
    flex-direction: column;
  }
}