:root {
  --bg: #ffffff;
  --panel: #f8fafc;
  --text: #1f2937;
  --muted: #6b7280;
  --brand: #3b82f6;
  --brand-strong: #1d4ed8;
  --border: #e5e7eb;
  --ok: #10b981;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

.site-header { position: sticky; top: 0; z-index: 10; background: rgba(255,255,255,0.9); backdrop-filter: saturate(120%) blur(10px); border-bottom: 1px solid var(--border); }
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 700; letter-spacing: 0.5px; }
.nav nav { display: flex; align-items: center; gap: 16px; }
.nav nav a { color: var(--muted); text-decoration: none; padding: 8px 10px; border-radius: 8px; }
.nav nav a:hover { color: var(--text); background: #f3f4f6; }

.btn { display: inline-block; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--border); color: var(--text); text-decoration: none; background: #f8fafc; transition: 0.2s ease; }
.btn:hover { background: #f1f5f9; }
.btn.primary { background: linear-gradient(135deg, var(--brand), var(--brand-strong)); border-color: transparent; color: #fff; box-shadow: 0 6px 18px rgba(58,169,255,0.25); }
.btn.primary:hover { filter: brightness(1.05); transform: translateY(-1px); }
.btn.full { width: 100%; text-align: center; }

.hero { text-align: center; padding: 88px 0 56px; }
.hero h1 { font-size: 40px; margin: 0 0 12px; letter-spacing: 0.5px; }
.subtitle { color: var(--muted); margin: 0 0 8px; }
.meta { color: #9cd2ff; margin-bottom: 18px; }
.cta { display: inline-flex; gap: 12px; margin-top: 8px; }

.section { padding: 56px 0; }
.section h2 { font-size: 28px; margin: 0 0 20px; }

.grid { display: grid; gap: 16px; }
.cards { grid-template-columns: repeat(4, 1fr); }
.pricing { grid-template-columns: repeat(3, 1fr); }

.card, .price-card { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 18px; }
.card h3, .price-card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }

.price-card .price { margin: 6px 0 10px; color: var(--text); }
.price-card .price span { color: var(--muted); margin-right: 6px; }
.price-card ul { margin: 10px 0 0; padding-left: 18px; color: var(--muted); }

.steps { counter-reset: step; list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.steps li { background: var(--panel); border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px; position: relative; }
.steps li::before { counter-increment: step; content: counter(step); position: absolute; left: -10px; top: -10px; width: 28px; height: 28px; border-radius: 50%; background: var(--brand); color: #fff; display: grid; place-items: center; font-weight: 700; box-shadow: 0 6px 14px rgba(58,169,255,0.35); }

.contact { display: grid; grid-template-columns: 1.2fr 1fr; gap: 20px; }
.contact-info p { margin: 4px 0; color: var(--muted); }
.contact-form { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 16px; display: grid; gap: 10px; }
.contact-form label { display: grid; gap: 6px; color: var(--text); }
.contact-form input, .contact-form textarea { width: 100%; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--border); background: #ffffff; color: var(--text); }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px rgba(58,169,255,0.15); }
.form-hint { color: var(--muted); font-size: 12px; margin: 0; }

.site-footer { border-top: 1px solid var(--border); padding: 28px 0; color: var(--muted); text-align: center; }
.icp { margin: 6px 0 0; font-size: 12px; }

@media (max-width: 980px) {
  .cards { grid-template-columns: 1fr 1fr; }
  .pricing { grid-template-columns: 1fr; }
  .contact { grid-template-columns: 1fr; }
}

/* FAQ 手风琴样式 */
.faq-item {
  transition: all 0.3s ease;
}

.faq-question {
  cursor: pointer;
  user-select: none;
}

.faq-answer {
  overflow: hidden;
  transition: max-height 0.3s ease, padding-top 0.3s ease, padding-bottom 0.3s ease;
}

.faq-answer.hidden {
  max-height: 0 !important;
  padding-top: 0 !important;
  padding-bottom: 0 !important;
}

.faq-icon {
  transition: transform 0.3s ease;
}

@media (max-width: 560px) {
  .nav nav { display: none; }
  .hero { padding-top: 60px; }
  .hero h1 { font-size: 28px; }
}