:root{color-scheme:light;--ink:#182838;--muted:#4d6070;--line:#d7e2e7;--accent:#165d70}*{box-sizing:border-box}body{margin:0;background:#f5f8fa;color:var(--ink);font:17px/1.65 system-ui,sans-serif}header,main,footer{max-width:900px;margin:auto;padding:24px}header{display:flex;gap:24px;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line)}nav{display:flex;gap:18px;flex-wrap:wrap}a{color:var(--accent);text-underline-offset:3px}.brand{font-weight:700;text-decoration:none;color:var(--ink)}main{padding-top:56px;padding-bottom:56px}h1{font-size:clamp(30px,5vw,48px);line-height:1.15;letter-spacing:-.025em;margin:0 0 28px}h2{font-size:23px;margin-top:36px}p,li{max-width:760px}.intro{font-size:21px;color:var(--muted)}.note{padding:20px 24px;background:#e9f0f4;border-left:4px solid var(--accent)}footer{border-top:1px solid var(--line);font-size:14px;color:var(--muted)}@media(max-width:650px){header{align-items:flex-start;flex-direction:column}main{padding-top:32px}}