:root{--bg:#fbfaf7;--fg:#1d2b2a;--muted:#5b6b69;--accent:#0f6b63;--rule:#dfe5e2;--card:#ffffff}
@media (prefers-color-scheme:dark){:root{--bg:#111a19;--fg:#e6efed;--muted:#9bb0ac;--accent:#5fd0c4;--rule:#243533;--card:#162321}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
main{max-width:42rem;margin:0 auto;padding:2.5rem 1rem 4rem}
header.site{max-width:42rem;margin:0 auto;padding:1.25rem 1rem 0;display:flex;gap:1.25rem;align-items:baseline;flex-wrap:wrap}
header.site a.brand{font-weight:700;font-size:1.2rem;color:var(--fg);text-decoration:none}
header.site a.brand span{color:var(--accent)}
nav a{color:var(--muted);text-decoration:none;margin-right:1rem}
nav a:hover,nav a:focus{color:var(--accent);text-decoration:underline}
h1{font-size:2rem;line-height:1.2;margin:.2rem 0 .5rem}
h2{font-size:1.15rem;margin:2rem 0 .4rem}
p,li{margin:.4rem 0}
a{color:var(--accent)}
.lede{color:var(--muted);font-size:1.1rem}
.card{background:var(--card);border:1px solid var(--rule);border-radius:12px;padding:1rem 1.25rem;margin:1.25rem 0}
.keyval{display:grid;grid-template-columns:max-content 1fr;gap:.35rem 1rem;margin:0}
.keyval dt{color:var(--muted)}
.keyval dd{margin:0}
.flow{padding-left:1.25rem}
code,.sms{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.95em}
.sms{background:var(--card);border:1px solid var(--rule);border-radius:8px;padding:.1rem .45rem}
footer{max-width:42rem;margin:0 auto;padding:1.5rem 1rem 3rem;color:var(--muted);font-size:.9rem;border-top:1px solid var(--rule)}
footer a{color:var(--muted)}
@media (max-width:480px){.keyval{grid-template-columns:1fr}.keyval dt{margin-top:.5rem}}