:root { color-scheme: light dark; --bg:#f5f5f7; --paper:#fff; --text:#1d1d1f; --muted:#626268; --line:#dedee3; --note:#f1f1f4; }
* { box-sizing:border-box; }
html { scroll-padding-top:28px; }
body { margin:0; background:var(--bg); color:var(--text); font:17px/1.85 -apple-system,BlinkMacSystemFont,"Helvetica Neue",sans-serif; -webkit-text-size-adjust:100%; overflow-wrap:anywhere; }
a { color:inherit; text-underline-offset:4px; }
a:hover { text-decoration-thickness:2px; }
a:focus-visible { outline:3px solid currentColor; outline-offset:4px; border-radius:3px; }
header,main,footer { width:min(100% - 48px,860px); margin-inline:auto; }
header { display:flex; align-items:center; justify-content:space-between; flex-wrap:wrap; gap:12px; padding-block:26px; font-size:14px; }
.brand { text-decoration:none; font-weight:650; letter-spacing:.02em; }
header nav { display:flex; flex-wrap:wrap; gap:20px; }
header nav a { display:inline-flex; align-items:center; min-height:44px; }
header [aria-current=page] { font-weight:650; text-decoration:none; }
main { padding:42px 54px 52px; background:var(--paper); border:1px solid var(--line); border-radius:24px; }
.eyebrow { margin:0 0 12px; font-size:12px; font-weight:650; letter-spacing:.12em; color:var(--muted); }
h1 { font-size:clamp(27px,4.6vw,40px); line-height:1.3; letter-spacing:-.03em; font-weight:650; margin:0 0 30px; }
h2 { font-size:23px; line-height:1.45; margin:44px 0 14px; font-weight:650; letter-spacing:-.02em; }
h3 { font-size:18px; line-height:1.6; margin:28px 0 10px; }
p { margin:12px 0 18px; }
ul,ol { padding-left:1.4em; margin:14px 0 22px; }
li { margin:9px 0; padding-left:3px; }
.notice { background:var(--note); border-radius:14px; padding:18px 22px; font-size:15px; line-height:1.8; margin:0 0 24px; }
.notice p { margin:0; }
.toc { border-block:1px solid var(--line); padding-block:20px; margin-top:30px; font-size:15px; }
.toc strong { font-size:13px; color:var(--muted); }
.toc ul { list-style:none; padding:0; margin:10px 0 0; display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:6px 24px; }
.toc li { padding:0; margin:0; }
.toc a { display:block; padding-block:7px; }
footer { padding-block:26px 40px; font-size:13px; color:var(--muted); }
@media (max-width:600px) { header,main,footer { width:calc(100% - 32px); } main { padding:28px 22px 36px; border-radius:20px; } header { padding-block:16px; } h2 { font-size:21px; } .toc ul { grid-template-columns:1fr; } .notice { padding:16px; } }
@media (prefers-color-scheme:dark) { :root { --bg:#101012; --paper:#1b1b1e; --text:#f5f5f7; --muted:#b2b2b8; --line:#3a3a40; --note:#29292e; } }
@media (prefers-reduced-motion:reduce) { html { scroll-behavior:auto; } }
@media print { :root { color-scheme:light; } body { background:white; } header,footer,.toc { display:none; } main { border:0; width:100%; padding:0; } a { text-decoration:none; } }

/* Phase 14: same typography, surface, borders and colors as phase 13. */
header nav { gap:16px; }
.skip { position:absolute; left:16px; top:-120px; z-index:10; padding:10px 16px; background:var(--paper); border:1px solid var(--line); }
.skip:focus { top:8px; }
footer p { margin-block:0 12px; }