:root{--ink:#1a1a1a;--muted:#6b6b6b;--rule:#d9d4c7;--paper:#fffdf8;--accent:#8b2d1c;--code:#f3efe6;--ok:#2e6b3a;--bad:#a12a2a;--w:44rem}
@media (prefers-color-scheme:dark){:root{--ink:#e8e4da;--muted:#9a958a;--rule:#3a372f;--paper:#161513;--accent:#e2735b;--code:#22201c;--ok:#7fc48f;--bad:#e07a7a}}
*{box-sizing:border-box}html{font-size:17px}
body{margin:0;background:var(--paper);color:var(--ink);font-family:Georgia,"Iowan Old Style",serif;line-height:1.55}
main{max-width:var(--w);margin:0 auto;padding:3rem 1rem 6rem}
h1{font-weight:400;font-size:2.2rem;line-height:1.15;margin:0 0 .25rem}
h2{font-weight:400;font-size:1.45rem;margin:2.6rem 0 .6rem;border-bottom:1px solid var(--rule);padding-bottom:.2rem}
h3{font-weight:600;font-size:1.05rem;margin:1.6rem 0 .4rem}
.sub{color:var(--muted);font-style:italic;margin:0 0 2rem}
p{margin:.7rem 0}
a{color:var(--accent);text-decoration:none;border-bottom:1px solid var(--rule)}a:hover{border-color:var(--accent)}
code,pre{font-family:"SF Mono",Menlo,Consolas,monospace;font-size:.86em}
code{background:var(--code);padding:.05em .3em;border-radius:3px}
pre{background:var(--code);padding:.9rem 1rem;overflow-x:auto;border-left:3px solid var(--rule);line-height:1.45}
pre code{background:none;padding:0}
.aside{color:var(--muted);font-size:.92rem;border-left:2px solid var(--rule);padding-left:.8rem;margin:1rem 0}
.why{background:var(--code);border-left:3px solid var(--accent);padding:.7rem 1rem;margin:1rem 0}
.why b{color:var(--accent)}
table{border-collapse:collapse;width:100%;margin:1rem 0;font-size:.93rem}
th,td{text-align:left;padding:.4rem .5rem;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-weight:600;color:var(--muted);font-size:.85rem;text-transform:uppercase;letter-spacing:.04em}
.flow{display:grid;gap:.4rem;margin:1rem 0}
.flow .step{display:grid;grid-template-columns:2.2rem 1fr;gap:.6rem;align-items:start}
.flow .n{color:var(--accent);font-variant-numeric:tabular-nums;text-align:right}
.flow .file{color:var(--muted);font-size:.85rem;font-family:"SF Mono",Menlo,monospace}
nav.crumbs{font-size:.85rem;color:var(--muted);margin-bottom:2rem}
nav.crumbs a{margin-right:.8rem}
.quiz{border:1px solid var(--rule);border-radius:6px;padding:1rem 1.2rem;margin:1.2rem 0}
.quiz .q{font-weight:600;margin-bottom:.6rem}
.quiz button{display:block;width:100%;text-align:left;background:var(--paper);color:var(--ink);border:1px solid var(--rule);border-radius:4px;padding:.5rem .7rem;margin:.3rem 0;font:inherit;font-size:.95rem;cursor:pointer}
.quiz button:hover{border-color:var(--accent)}
.quiz button.ok{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 12%,var(--paper))}
.quiz button.bad{border-color:var(--bad);background:color-mix(in srgb,var(--bad) 12%,var(--paper))}
.quiz .fb{margin-top:.6rem;font-size:.92rem;color:var(--muted);min-height:1.2em}
.score{margin:1.5rem 0;font-weight:600}
.next{margin-top:3rem;padding-top:1rem;border-top:1px solid var(--rule);color:var(--muted);font-size:.92rem}
@media print{body{background:#fff;color:#000}main{max-width:none;padding:0}.quiz button{border:1px solid #999}.quiz .fb{display:none}}