:root {
  color-scheme: dark;
  --ink: #eaf2f3;
  --muted: #91a5aa;
  --line: rgba(180, 211, 215, .16);
  --accent: #83e1ca;
  --deep: #071116;
  --panel: rgba(14, 31, 37, .72);
}

* { box-sizing: border-box; }
html { min-width: 320px; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--deep);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
body::before {
  position: fixed; inset: 0; z-index: -1; content: "";
  background: radial-gradient(circle at 82% 12%, rgba(36, 104, 104, .22), transparent 32rem), linear-gradient(135deg, #071116 0%, #0a1920 52%, #071116 100%);
}
.site-shell { width: min(100% - 48px, 1080px); margin: auto; }
.site-header { display: flex; justify-content: space-between; align-items: center; padding: 30px 0; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--ink); text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; border: 1px solid var(--accent); border-radius: 50%; color: var(--accent); font: 700 1.15rem/1 Georgia, serif; }
.brand strong, .brand small { display: block; line-height: 1.2; }
.brand strong { letter-spacing: .18em; font-size: .96rem; }
.brand small { margin-top: 4px; color: var(--muted); font-size: .76rem; }
.site-status { color: var(--muted); font-size: .78rem; letter-spacing: .08em; }
.site-status i { display: inline-block; width: 6px; height: 6px; margin-right: 8px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(131,225,202,.1); }
.intro { padding: clamp(76px, 12vw, 142px) 0 100px; max-width: 760px; }
.eyebrow { margin: 0 0 24px; color: var(--accent); font-size: .78rem; font-weight: 700; letter-spacing: .2em; }
.eyebrow span { padding: 0 5px; color: var(--muted); }
h1 { margin: 0; font: 500 clamp(3.5rem, 8vw, 6.8rem)/1.04 Georgia, "Songti SC", serif; letter-spacing: -.05em; }
h1 em { color: var(--accent); font-style: normal; }
.intro-copy { max-width: 510px; margin: 34px 0 0; color: var(--muted); font-size: 1.05rem; }
.scope-card { padding: 32px 36px 38px; border: 1px solid var(--line); border-radius: 3px; background: var(--panel); }
.section-heading { display: flex; align-items: baseline; gap: 14px; margin-bottom: 28px; }
.section-index { color: var(--accent); font: 700 .72rem/1 monospace; letter-spacing: .08em; }
h2 { margin: 0; font-size: 1.05rem; font-weight: 500; letter-spacing: .08em; }
.scope-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 64px; }
.scope-grid > p { margin: 0; max-width: 520px; font-size: 1.12rem; }
dl { margin: 0; }
dl div { display: flex; justify-content: space-between; gap: 24px; padding: 10px 0; border-bottom: 1px solid var(--line); font-size: .86rem; }
dt { color: var(--muted); } dd { margin: 0; color: var(--ink); }
.notes { padding: 70px 0 100px; }
.note-list { display: flex; flex-wrap: wrap; gap: 10px; }
.note-list span { padding: 8px 15px; border: 1px solid var(--line); color: var(--muted); font-size: .88rem; }
.site-footer { display: flex; justify-content: space-between; gap: 20px; padding: 22px 0 28px; border-top: 1px solid var(--line); color: var(--muted); font-size: .76rem; }
.site-footer p { margin: 0; }
.site-footer a { color: var(--muted); text-underline-offset: 3px; }
.site-footer a:hover, .site-footer a:focus { color: var(--accent); }
@media (max-width: 640px) {
  .site-shell { width: min(100% - 32px, 1080px); }
  .site-header { padding: 22px 0; }
  .site-status { display: none; }
  .intro { padding: 70px 0 74px; }
  h1 { font-size: clamp(3.25rem, 17vw, 5rem); }
  .intro-copy { font-size: 1rem; }
  .scope-card { padding: 25px 22px 28px; }
  .scope-grid { display: block; }
  .scope-grid dl { margin-top: 30px; }
  .notes { padding: 58px 0 70px; }
  .site-footer { display: block; }
  .site-footer a { display: inline-block; margin-top: 8px; }
}