:root {
  --bg: #0b1020;
  --bg-alt: #121a2f;
  --panel: #151d33;
  --text: #e8edf7;
  --muted: #9aa8c0;
  --primary: #4d6bfe;
  --primary-2: #6b8cff;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --radius: 12px;
  --container: 1000px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: radial-gradient(1200px 600px at 10% -10%, #1a2450 0%, var(--bg) 55%);
  color: var(--text);
  line-height: 1.65;
  font-size: 15px;
}
a { color: var(--primary-2); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(100% - 32px, var(--container)); margin: 0 auto; }

.header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(11, 16, 32, 0.85);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 64px; gap: 12px; }
.logo { display: inline-flex; align-items: center; gap: 10px; color: #fff; font-weight: 600; }
.logo:hover { text-decoration: none; }
.logo-mark {
  width: 32px; height: 32px; border-radius: 9px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--primary), #7c5cff);
  font-size: 11px; font-weight: 700;
}
.nav { display: flex; flex-wrap: wrap; gap: 14px; }
.nav a { color: var(--muted); }
.nav a.active, .nav a:hover { color: #fff; text-decoration: none; }
.nav-toggle { display: none; background: none; border: 0; width: 40px; height: 40px; flex-direction: column; justify-content: center; gap: 5px; cursor: pointer; }
.nav-toggle span { display: block; height: 2px; background: #fff; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 18px; border-radius: 999px; font-weight: 600; font-size: 0.92rem;
  border: 0; cursor: pointer; text-decoration: none !important;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: var(--shadow); }
.btn-primary:hover { background: var(--primary-2); }
.btn-outline { background: transparent; color: #fff; border: 1px solid rgba(255,255,255,0.25); }
.btn-outline:hover { border-color: #fff; }
.btn-lg { padding: 12px 22px; }
.btn-disabled, a.btn-disabled { opacity: 0.5; pointer-events: none; cursor: not-allowed; }

.hero { padding: 48px 0 36px; }
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 28px; align-items: center; }
.eyebrow { color: var(--primary-2); font-size: 0.85rem; margin-bottom: 10px; }
.hero-content h1 { font-size: clamp(1.7rem, 3.5vw, 2.4rem); line-height: 1.25; margin-bottom: 12px; font-weight: 700; }
.hero-desc { color: var(--muted); margin-bottom: 18px; max-width: 34em; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }

.chat-mock {
  background: var(--panel); border: 1px solid var(--border); border-radius: 16px;
  overflow: hidden; box-shadow: var(--shadow); max-width: 380px; margin-left: auto;
}
.chat-mock-bar { padding: 12px 14px; background: #1c2748; font-weight: 600; }
.chat-bubble { margin: 12px 14px; padding: 10px 12px; border-radius: 12px; font-size: 0.9rem; }
.chat-bubble.bot { background: #222c4d; }
.chat-bubble.user { background: rgba(77,107,254,0.25); margin-left: 40px; }

.stats { padding: 18px 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: rgba(255,255,255,0.02); }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; text-align: center; }
.stat-item strong { display: block; color: #fff; }
.stat-item span { color: var(--muted); font-size: 0.82rem; }

.section { padding: 40px 0; }
.section-head h2 { font-size: 1.35rem; margin-bottom: 16px; }
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.feature-card, .link-card {
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px;
  color: inherit; display: block;
}
.link-card:hover { border-color: rgba(77,107,254,0.5); text-decoration: none; }
.feature-card h3 { margin-bottom: 6px; }
.feature-card p { color: var(--muted); font-size: 0.92rem; }

.cta { padding: 40px 0; text-align: center; background: linear-gradient(180deg, transparent, rgba(77,107,254,0.12)); }
.cta-inner h2 { margin-bottom: 8px; }
.cta-inner p { color: var(--muted); margin-bottom: 14px; }

.page-content { padding: 28px 0 48px; }
.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: 16px;
  padding: 24px 28px 32px; box-shadow: var(--shadow);
}
.breadcrumb { color: var(--muted); font-size: 0.85rem; margin-bottom: 14px; }
.article-body h1 { font-size: 1.55rem; margin-bottom: 12px; }
.article-body h2 { font-size: 1.15rem; margin: 1.35em 0 0.55em; }
.article-body h3 { font-size: 1.02rem; margin: 1.1em 0 0.45em; }
.article-body p, .article-body li { margin-bottom: 0.7em; color: #c9d3e7; }
.related-posts {
  margin-top: 1.4rem; padding: 14px 16px; border-radius: 12px;
  border: 1px solid var(--border); background: rgba(255,255,255,0.03);
}
.related-posts h2 { font-size: 1.05rem; margin-bottom: 8px; }
.related-posts ul { padding-left: 1.1em; margin: 0; }
.related-posts li { margin-bottom: 6px; }
.article-body ul, .article-body ol { padding-left: 1.25em; margin-bottom: 1em; }
.article-meta { color: var(--muted) !important; font-size: 0.85rem; }
.article-cta {
  margin-top: 1.5rem; padding: 16px; border-radius: 12px;
  background: rgba(77,107,254,0.12); border: 1px solid rgba(77,107,254,0.3);
}
.article-cta .btn { margin: 4px 8px 4px 0; }
.back-link { margin-top: 18px; font-size: 0.9rem; }

.download-smart {
  text-align: center; padding: 18px; border-radius: 12px; margin-bottom: 18px;
  background: linear-gradient(120deg, rgba(77,107,254,0.35), rgba(124,92,255,0.25));
}
.download-smart-label { margin-bottom: 10px; font-weight: 600; }
.download-smart-hint { margin-top: 10px; font-size: 0.85rem; color: #d7def0; }
.download-hero h1 { font-size: 1.45rem; margin-bottom: 8px; }
.download-lead { color: var(--muted); margin-bottom: 16px; }
.download-section-title { margin: 8px 0 12px; font-size: 1.1rem; }
.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.download-grid-main { grid-template-columns: repeat(2, 1fr); }
.download-card {
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: 12px;
  padding: 16px; text-align: center; color: inherit;
}
.download-card:hover { border-color: rgba(77,107,254,0.5); text-decoration: none; }
.download-card h3 { margin: 8px 0 4px; }
.download-card p { color: var(--muted); font-size: 0.85rem; }
.platform-icon {
  display: inline-grid; place-items: center; min-width: 42px; height: 42px; padding: 0 8px;
  border-radius: 10px; background: rgba(77,107,254,0.2); font-weight: 700; font-size: 0.75rem;
}
.download-btn-label { display: inline-block; margin-top: 10px; color: var(--primary-2); font-weight: 600; font-size: 0.88rem; }
.download-help { margin-top: 24px; padding-top: 16px; border-top: 1px solid var(--border); }
.download-help-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 14px; margin-top: 10px; }

.blog-list { list-style: none; }
.blog-item { padding: 14px 0; border-bottom: 1px solid var(--border); }
.blog-date { display: block; color: var(--muted); font-size: 0.8rem; margin: 4px 0; }
.blog-index-cta { margin-top: 18px; }
.faq-item { background: var(--bg-alt); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; margin-bottom: 8px; }
.faq-item summary { cursor: pointer; font-weight: 600; }
.faq-item p { margin-top: 8px; color: var(--muted); }

.footer { margin-top: 20px; padding: 36px 0 20px; background: #070b16; border-top: 1px solid var(--border); color: var(--muted); font-size: 0.9rem; }
.footer a { color: #b8c4ff; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 18px; margin-bottom: 20px; }
.footer-col { display: flex; flex-direction: column; gap: 6px; }
.footer-col strong { color: #fff; margin-bottom: 4px; }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 12px; font-size: 0.82rem; }
.error-page { min-height: 50vh; display: grid; place-content: center; text-align: center; gap: 12px; }

@media (max-width: 800px) {
  .nav-toggle { display: flex; }
  .nav, .header-actions { display: none; }
  .header-inner.nav-open .nav {
    display: flex; flex-direction: column; position: absolute; left: 0; right: 0; top: 64px;
    background: #121a2f; padding: 12px 16px; gap: 10px; border-bottom: 1px solid var(--border);
  }
  .hero-grid, .feature-grid, .download-grid, .download-grid-main, .download-help-grid, .stats-grid, .footer-grid { grid-template-columns: 1fr; }
  .chat-mock { margin: 0 auto; }
  .panel { padding: 18px 16px 24px; }
}