:root{--ink:#16233a;--muted:#56627a;--line:#d9dee7;--bg:#f4f6f9;--accent:#1f6f8b;--card:#ffffff}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:"Segoe UI",Roboto,Helvetica,Arial,sans-serif;line-height:1.65;font-size:17px}
header{background:var(--ink);color:#fff;padding:28px 20px}
header .wrap{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px}
.brand{font-size:1.5rem;font-weight:700;letter-spacing:.02em;color:#fff;text-decoration:none}
nav a{color:#cfe3ea;text-decoration:none;margin-left:18px;font-size:.95rem}
nav a:hover,nav a:focus{color:#fff;text-decoration:underline}
.wrap{max-width:760px;margin:0 auto}
main{padding:48px 20px}
h1{font-size:2.1rem;line-height:1.2;margin:0 0 16px}
h2{font-size:1.25rem;margin:36px 0 8px;color:var(--accent)}
p,li{color:var(--ink)}
.lead{font-size:1.15rem;color:var(--muted)}
.box{background:var(--card);border-left:4px solid var(--accent);padding:18px 22px;margin:28px 0}
a{color:var(--accent)}
a:focus{outline:2px solid var(--accent);outline-offset:2px}
footer{border-top:1px solid var(--line);padding:24px 20px;color:var(--muted);font-size:.9rem}