:root{--a:#e87321;--ink:#21262f;--mut:#6b7380}
body{font:16px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;color:var(--ink);max-width:780px;margin:0 auto;padding:32px 20px 64px}
h1{font-size:30px;margin:.2em 0}h2{margin-top:2em;border-bottom:2px solid var(--a);padding-bottom:4px}h3{margin-top:1.4em}
a{color:var(--a)}nav a{margin-right:16px}.muted{color:var(--mut);font-size:14px}
.todo{background:#fff4cc;border-left:4px solid #e0a800;padding:8px 12px}
details{border:1px solid #ddd;border-radius:8px;padding:10px 14px;margin:8px 0}summary{font-weight:600;cursor:pointer}