:root {
  --bg: #f5f8fb;
  --surface: #ffffff;
  --text: #111827;
  --muted: #5f6f86;
  --line: #dce6ef;
  --teal: #14b8a6;
  --teal-dark: #087f73;
  --teal-light: #e8f9f7;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* NAV */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(245,248,251,0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1080px; margin: 0 auto; padding: 0 32px;
  height: 60px; display: flex; align-items: center; justify-content: space-between;
}
.nav-logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.nav-logo svg { width: 42px; height: 42px; flex-shrink: 0; }
.nav-logo-text { font-size: 22px; font-weight: 800; color: var(--text); letter-spacing: -0.01em; }
.nav-logo-text span { color: var(--teal); }
.nav-back {
  font-size: 14px; font-weight: 600; color: var(--muted);
  text-decoration: none; padding: 7px 14px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--surface);
  transition: color 0.15s, background 0.15s;
}
.nav-back:hover { color: var(--text); background: var(--bg); }

/* PAGE */
.page-wrap {
  max-width: 760px; margin: 0 auto; padding: 64px 32px 96px;
}
.page-eyebrow {
  font-size: 12px; font-weight: 800; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--teal-dark); margin-bottom: 12px;
}
.page-title {
  font-size: clamp(28px, 4vw, 40px); font-weight: 800;
  line-height: 1.15; letter-spacing: -0.02em; margin-bottom: 10px;
}
.page-meta { font-size: 13px; color: var(--muted); margin-bottom: 48px; }

/* PROSE */
.prose h2 {
  font-size: 18px; font-weight: 700; color: var(--text);
  margin: 40px 0 12px; padding-top: 40px;
  border-top: 1px solid var(--line);
}
.prose h2:first-child { border-top: none; margin-top: 0; padding-top: 0; }
.prose p { font-size: 15px; color: var(--muted); line-height: 1.8; margin-bottom: 14px; }
.prose ul { padding-left: 20px; margin-bottom: 14px; }
.prose ul li { font-size: 15px; color: var(--muted); line-height: 1.8; margin-bottom: 6px; }
.prose strong { color: var(--text); font-weight: 700; }
.prose a { color: var(--teal-dark); font-weight: 600; }

/* HIGHLIGHT BOX */
.info-box {
  background: var(--teal-light); border: 1px solid rgba(24,184,165,0.22);
  border-radius: 12px; padding: 18px 20px; margin: 20px 0;
}
.info-box p { margin: 0; color: var(--teal-dark) !important; font-size: 14px !important; }

/* FOOTER */
footer {
  background: var(--surface); border-top: 1px solid var(--line);
}
.footer-top {
  max-width: 1080px; margin: 0 auto; padding: 48px 32px 40px;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px; align-items: start;
}
.footer-brand-logo {
  display: flex; align-items: center; gap: 10px;
  text-decoration: none; margin-bottom: 12px;
}
.footer-brand-logo svg { width: 28px; height: 28px; }
.footer-brand-name { font-size: 15px; font-weight: 800; color: var(--text); letter-spacing: -0.01em; }
.footer-brand-name span { color: var(--teal); }
.footer-tagline { font-size: 13px; color: var(--muted); line-height: 1.7; max-width: 22em; }
.footer-col h4 {
  font-size: 11px; font-weight: 800; text-transform: uppercase;
  letter-spacing: 0.09em; color: #9aaabb; margin-bottom: 14px;
}
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 9px; }
.footer-col ul li a {
  font-size: 13px; color: var(--muted); text-decoration: none;
  font-weight: 500; transition: color 0.15s;
}
.footer-col ul li a:hover { color: var(--text); }
.footer-bottom {
  border-top: 1px solid var(--line); max-width: 1080px;
  margin: 0 auto; padding: 16px 32px;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 8px;
}
.footer-copy { font-size: 12px; color: #b0bec8; }
.footer-domain { font-size: 12px; color: #b0bec8; font-weight: 600; }

@media (max-width: 900px) { .footer-top { grid-template-columns: 1fr 1fr; gap: 28px; } }
@media (max-width: 640px) {
  .page-wrap { padding: 48px 20px 72px; }
  .footer-top { grid-template-columns: 1fr; padding: 36px 20px 28px; }
  .footer-bottom { padding: 14px 20px; }
}