:root{--ink:#111827;--muted:#4b5563;--line:#e5e7eb;--accent:#0f766e;--bg:#ffffff}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.65}
header{border-bottom:1px solid var(--line)}
.wrap{max-width:760px;margin:0 auto;padding:0 20px}
header .wrap{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{font-weight:700;text-decoration:none;color:var(--ink);letter-spacing:.2px}
nav a{color:var(--muted);text-decoration:none;margin-left:18px;font-size:14px}
nav a:hover{color:var(--accent)}
main{padding:40px 0 64px}
h1{font-size:32px;margin:0 0 6px}
.meta{color:var(--muted);font-size:14px;margin-bottom:28px}
h2{font-size:20px;margin:32px 0 8px}
p,li{color:#1f2937}
ul{padding-left:22px}
a{color:var(--accent)}
footer{border-top:1px solid var(--line);padding:20px 0;color:var(--muted);font-size:13px}
@media (max-width:480px){h1{font-size:26px}nav a{margin-left:12px}}