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

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --accent: #06b6d4;
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-light: #f8fafc;
  --text: #334155;
  --text-light: #94a3b8;
  --white: #ffffff;
  --gradient: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
  --shadow: 0 4px 24px rgba(37, 99, 235, 0.15);
  --radius: 12px;
}

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-light);
}

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

.container { max-width: 1140px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 12px rgba(0,0,0,0.3);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--white);
  font-size: 1.35rem;
  font-weight: 700;
}

.logo img { width: 32px; height: 32px; }

.nav { display: flex; gap: 28px; align-items: center; }

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

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

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--gradient);
  color: var(--white) !important;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-download:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow);
  color: var(--white) !important;
}

.mobile-toggle { display: none; background: none; border: none; color: var(--white); font-size: 1.5rem; cursor: pointer; }

/* Hero */
.hero {
  background: var(--bg);
  color: var(--white);
  padding: 80px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(37,99,235,0.2) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-content { position: relative; z-index: 1; max-width: 720px; }

.hero h1 {
  font-size: 2.8rem;
  line-height: 1.2;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub { font-size: 1.15rem; color: var(--text-light); margin-bottom: 32px; }

.hero-features { list-style: none; margin-bottom: 36px; }

.hero-features li {
  padding: 8px 0;
  padding-left: 28px;
  position: relative;
  color: #cbd5e1;
}

.hero-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--gradient);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow); color: var(--white); }

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 2px solid rgba(255,255,255,0.3);
  color: var(--white);
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 600;
  transition: border-color 0.2s, background 0.2s;
}

.btn-outline:hover { border-color: var(--white); background: rgba(255,255,255,0.05); color: var(--white); }

/* Sections */
.section { padding: 72px 0; }
.section-dark { background: var(--bg); color: var(--white); }
.section-title { text-align: center; margin-bottom: 48px; }
.section-title h2 { font-size: 2rem; margin-bottom: 12px; color: inherit; }
.section-title p { color: var(--text-light); max-width: 600px; margin: 0 auto; }
.section-dark .section-title p { color: #64748b; }

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

.feature-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  transition: transform 0.2s, box-shadow 0.2s;
}

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

.feature-icon {
  width: 52px;
  height: 52px;
  background: var(--gradient);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 18px;
}

.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; color: #1e293b; }
.feature-card p { color: var(--text); font-size: 0.95rem; }

/* Reviews */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
}

.review-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid rgba(255,255,255,0.06);
}

.review-card h4 { color: var(--white); margin-bottom: 4px; font-size: 1rem; }
.review-tag { color: var(--accent); font-size: 0.85rem; margin-bottom: 12px; }
.review-card p { color: #94a3b8; font-size: 0.92rem; margin-bottom: 12px; }
.stars { color: #fbbf24; letter-spacing: 2px; }

/* Pricing */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 960px;
  margin: 0 auto;
}

.pricing-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  position: relative;
}

.pricing-card.featured { border: 2px solid var(--primary); }

.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient);
  color: var(--white);
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

.pricing-card h3 { font-size: 1.2rem; margin-bottom: 16px; }
.pricing-price { font-size: 2.4rem; font-weight: 700; color: var(--primary); margin-bottom: 20px; }
.pricing-price span { font-size: 1rem; color: var(--text-light); font-weight: 400; }

/* Articles */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--white);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  transition: transform 0.2s, box-shadow 0.2s;
}

.article-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); }

.article-card-body { padding: 24px; }
.article-date { color: var(--text-light); font-size: 0.85rem; margin-bottom: 8px; }
.article-card h3 { font-size: 1.1rem; margin-bottom: 10px; line-height: 1.4; }
.article-card h3 a { color: #1e293b; }
.article-card h3 a:hover { color: var(--primary); }
.article-card p { font-size: 0.92rem; color: var(--text); margin-bottom: 14px; }
.read-more { font-weight: 600; font-size: 0.9rem; }

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

.faq-item {
  background: var(--white);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  box-shadow: 0 1px 6px rgba(0,0,0,0.04);
}

.faq-question {
  padding: 20px 24px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #1e293b;
  user-select: none;
}

.faq-question::after { content: "+"; font-size: 1.3rem; color: var(--primary); transition: transform 0.2s; }
.faq-item.open .faq-question::after { content: "−"; }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s;
  padding: 0 24px;
  color: var(--text);
  font-size: 0.95rem;
}

.faq-item.open .faq-answer { max-height: 300px; padding: 0 24px 20px; }

/* CTA */
.cta-section {
  background: var(--gradient);
  text-align: center;
  padding: 64px 20px;
  color: var(--white);
}

.cta-section h2 { font-size: 1.8rem; margin-bottom: 24px; }

/* Footer */
.site-footer {
  background: #0b1120;
  color: #64748b;
  padding: 48px 0 24px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}

.footer-brand p { margin-top: 12px; font-size: 0.9rem; line-height: 1.6; }
.footer-col h4 { color: var(--white); margin-bottom: 16px; font-size: 0.95rem; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a { color: #64748b; font-size: 0.9rem; }
.footer-col a:hover { color: var(--white); }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 20px;
  text-align: center;
  font-size: 0.85rem;
}

/* Download Page */
.download-hero {
  background: var(--bg);
  color: var(--white);
  padding: 60px 0;
  text-align: center;
}

.download-hero h1 { font-size: 2.2rem; margin-bottom: 12px; }
.download-hero p { color: var(--text-light); max-width: 560px; margin: 0 auto 32px; }

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  max-width: 900px;
  margin: 0 auto;
}

.platform-card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: border-color 0.2s;
}

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

.platform-icon { font-size: 2.5rem; margin-bottom: 12px; }
.platform-card h3 { color: var(--white); margin-bottom: 8px; }
.platform-card p { color: #64748b; font-size: 0.88rem; margin-bottom: 16px; }

.download-steps {
  max-width: 720px;
  margin: 0 auto;
}

.step-item {
  display: flex;
  gap: 20px;
  margin-bottom: 28px;
  align-items: flex-start;
}

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

.step-content h3 { margin-bottom: 6px; font-size: 1.05rem; }
.step-content p { color: var(--text); font-size: 0.95rem; }

/* Article Page */
.article-header {
  background: var(--bg);
  color: var(--white);
  padding: 48px 0;
}

.article-header h1 { font-size: 1.8rem; margin-bottom: 12px; line-height: 1.3; }
.article-meta { color: var(--text-light); font-size: 0.9rem; }

.article-content {
  max-width: 760px;
  margin: 0 auto;
  padding: 48px 20px;
}

.article-content h2 { font-size: 1.4rem; margin: 32px 0 14px; color: #1e293b; }
.article-content h3 { font-size: 1.15rem; margin: 24px 0 10px; color: #1e293b; }
.article-content p { margin-bottom: 16px; }
.article-content ul, .article-content ol { margin: 0 0 16px 24px; }
.article-content li { margin-bottom: 8px; }

.breadcrumb {
  padding: 16px 0;
  font-size: 0.88rem;
  color: var(--text-light);
}

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

/* Server Map Visual */
.server-map {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 48px;
  text-align: center;
  border: 1px solid rgba(255,255,255,0.06);
}

.server-dots {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
}

.server-dot {
  background: rgba(37,99,235,0.15);
  border: 1px solid rgba(37,99,235,0.3);
  color: #93c5fd;
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 0.85rem;
}

@media (max-width: 768px) {
  .mobile-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 20px;
    gap: 16px;
  }
  .nav.open { display: flex; }
  .hero h1 { font-size: 2rem; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 48px 0 64px; }
}