:root {
  color-scheme: light;
  --ink: #14202b;
  --muted: #5a6978;
  --line: #e2e9f0;
  --brand: #126fae;
  --brand-deep: #0e649e;
  --soft: #eef8ff;
  --surface: #ffffff;
  --page: #f7fafc;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--page);
  font-family: -apple-system, BlinkMacSystemFont, system-ui, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}
a { color: inherit; }
img { display: block; max-width: 100%; height: auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: 68px;
  padding: 0 max(20px, 5vw);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid rgba(226, 233, 240, .9);
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(12px);
}
.brand { color: var(--ink); font-size: 18px; font-weight: 850; text-decoration: none; }
.site-nav { display: flex; align-items: center; gap: 20px; color: #3a4a59; font-size: 14px; }
.site-nav a { text-decoration: none; }
.site-nav a:hover, .text-link:hover { color: var(--brand); text-decoration: underline; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--brand);
  border-radius: 10px;
  background: var(--brand);
  color: #fff;
  font-weight: 750;
  text-decoration: none;
}
.button:hover { background: var(--brand-deep); border-color: var(--brand-deep); }
.button.secondary { color: var(--brand-deep); background: #fff; border-color: #b8d8eb; }
.button.secondary:hover { background: var(--soft); }
.hero {
  padding: 56px max(20px, 6vw) 64px;
  display: grid;
  grid-template-columns: minmax(0, .92fr) minmax(390px, 1.08fr);
  align-items: center;
  gap: clamp(32px, 5vw, 72px);
  background: linear-gradient(145deg, #fff 0%, #f6fbff 62%, #eef8f6 100%);
}
.breadcrumbs { margin-bottom: 18px; color: #687887; font-size: 13px; }
.breadcrumbs a { color: var(--brand-deep); }
.eyebrow { color: var(--brand-deep); font-size: 13px; font-weight: 800; letter-spacing: .06em; }
h1 { margin: 8px 0 16px; font-size: clamp(34px, 4.4vw, 56px); line-height: 1.16; letter-spacing: -.04em; text-wrap: balance; }
.lead { margin: 0; max-width: 690px; color: var(--muted); font-size: clamp(16px, 1.7vw, 19px); line-height: 1.85; }
.actions { margin-top: 24px; display: flex; flex-wrap: wrap; gap: 12px; }
.hero-media { margin: 0; padding: 10px; border: 1px solid var(--line); border-radius: 18px; background: #fff; box-shadow: 0 24px 60px rgba(28, 59, 81, .13); }
.hero-media img { width: 100%; border-radius: 11px; }
.hero-media figcaption { padding: 9px 6px 2px; color: var(--muted); font-size: 12px; text-align: center; }
.section { padding: 68px max(20px, 6vw); background: #fff; }
.section.alt { background: var(--page); }
.section.narrow > * { max-width: 900px; margin-left: auto; margin-right: auto; }
.section-head { max-width: 780px; margin: 0 auto 34px; text-align: center; }
h2 { margin: 8px 0 12px; font-size: clamp(25px, 3vw, 38px); line-height: 1.3; letter-spacing: -.025em; text-wrap: balance; }
h3 { margin: 0 0 8px; font-size: 19px; line-height: 1.45; }
.section-head p, .muted { color: var(--muted); }
.grid-2, .grid-3, .grid-4 { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.card { padding: 24px; border: 1px solid var(--line); border-radius: 15px; background: var(--surface); }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.card .num { width: 38px; height: 38px; margin-bottom: 16px; display: grid; place-items: center; border-radius: 10px; color: var(--brand-deep); background: var(--soft); font-weight: 850; }
.checklist { padding: 0; list-style: none; display: grid; gap: 10px; }
.checklist li { position: relative; padding-left: 28px; }
.checklist li::before { content: "✓"; position: absolute; left: 0; color: #087d57; font-weight: 900; }
.comparison { width: 100%; border-collapse: collapse; border: 1px solid var(--line); background: #fff; }
.comparison th, .comparison td { padding: 14px 16px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.comparison th { background: #eef7fc; }
.image-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.image-card { margin: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 15px; background: #fff; }
.image-card img { width: 100%; aspect-ratio: 1 / 1; object-fit: cover; }
.image-card.portrait img { aspect-ratio: 3 / 4; }
.image-card figcaption { padding: 14px 16px; color: var(--muted); font-size: 13px; }
.image-card strong { display: block; margin-bottom: 3px; color: var(--ink); font-size: 14px; }
.faq { max-width: 880px; margin: 0 auto; display: grid; gap: 12px; }
.faq details { border: 1px solid var(--line); border-radius: 13px; background: #fff; overflow: hidden; }
.faq summary { position: relative; padding: 18px 52px 18px 20px; font-weight: 750; cursor: pointer; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 20px; top: 50%; transform: translateY(-50%); color: var(--brand); font-size: 22px; }
.faq details[open] summary::after { content: "−"; }
.faq p { margin: 0; padding: 0 20px 20px; color: var(--muted); }
.cta { padding: 48px max(20px, 6vw); display: flex; align-items: center; justify-content: space-between; gap: 28px; background: linear-gradient(135deg, #e8f5ff, #f6fbff 50%, #edf8f4); }
.cta h2 { margin: 0 0 8px; font-size: clamp(24px, 3vw, 34px); }
.cta p { margin: 0; color: var(--muted); }
.cta .actions { margin: 0; flex-shrink: 0; }
.site-footer { padding: 34px max(20px, 6vw); display: grid; grid-template-columns: minmax(220px, .8fr) minmax(400px, 1.2fr); gap: 28px; color: #d5dee8; background: #101923; }
.site-footer .brand { color: #f8fafc; }
.site-footer p { margin: 8px 0 0; color: #9eacba; font-size: 13px; }
.footer-links { display: flex; justify-content: flex-end; align-items: flex-start; gap: 12px 20px; flex-wrap: wrap; font-size: 13px; }
.footer-links a { text-decoration: none; }
.footer-links a:hover { color: #fff; text-decoration: underline; }
.legal { grid-column: 1 / -1; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.12); color: #9eacba; font-size: 12px; text-align: center; }
.legal a { color: inherit; }
.article-meta { color: var(--muted); font-size: 13px; }
.article-body { max-width: 840px; margin: 0 auto; }
.article-body h2 { margin-top: 48px; font-size: 30px; }
.article-body h3 { margin-top: 28px; }
.article-body p, .article-body li { color: #3f4f5e; }
.note { padding: 18px 20px; border-left: 4px solid var(--brand); border-radius: 0 10px 10px 0; background: var(--soft); }
@media (max-width: 900px) {
  .site-nav { display: none; }
  .hero { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .site-footer { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
  .cta { align-items: flex-start; flex-direction: column; }
  .cta .actions { margin-top: 8px; }
}
@media (max-width: 620px) {
  .site-header { padding: 0 16px; }
  .site-header > .button { min-height: 38px; padding: 0 12px; font-size: 13px; }
  .hero { padding: 38px 18px 48px; }
  .section { padding: 50px 18px; }
  .grid-2, .grid-3, .grid-4, .image-grid { grid-template-columns: 1fr; }
  .comparison { font-size: 13px; }
  .comparison th, .comparison td { padding: 10px; }
  .cta { padding: 40px 18px; }
  .cta .actions { width: 100%; flex-direction: column; }
  .site-footer { padding: 30px 18px; }
}