.subject-nav{display:flex;gap:8px;padding:24px 0;border-bottom:1px solid var(--line);flex-wrap:wrap}.subject-nav a{font-size:13px;text-decoration:none;padding:12px 18px;border:1px solid var(--line);border-radius:6px}.subject-nav [aria-current=page]{background:var(--ink);color:white;border-color:var(--ink)}.history-page{--ink:#523b3e;--muted:#786a66;--gold:#a26937}.history-hero{padding:45px 0 0;max-width:850px}.history-hero h1{font-size:clamp(38px,5vw,64px)}.history-hero .intro{max-width:660px}.phase-map{display:grid;grid-template-columns:repeat(5,1fr);gap:12px}.phase-box{border:1px solid var(--line);border-top:4px solid var(--gold);background:#fffcf6;border-radius:6px;padding:18px;color:inherit;text-decoration:none}.phase-box h3{font-size:20px;margin:9px 0}.phase-box small{font-size:11px;color:var(--muted)}.phase-box p{font-size:12px;line-height:1.7}.phase-box b{font-size:12px;color:var(--gold);line-height:1.8}.ruler{border:1px solid var(--line);background:#fffcf6;border-radius:8px;margin:12px 0;overflow:hidden}.ruler>summary{display:flex;align-items:center;gap:20px;color:var(--ink);list-style:none;padding:22px;cursor:pointer}.ruler>summary::-webkit-details-marker{display:none}.ruler-no{font-size:13px;color:var(--gold);border:1px solid var(--line);border-radius:50%;width:38px;height:38px;display:flex;align-items:center;justify-content:center;flex-shrink:0}.ruler-title{font:500 24px 'Playfair Display',Georgia,serif;flex:1}.ruler-title small{display:block;font:12px 'DM Sans',sans-serif;color:var(--muted);margin-top:6px}.ruler>summary>span:last-child{font-size:22px;color:var(--gold)}.ruler[open]>summary{border-bottom:1px solid var(--line);background:#f0e7df}.ruler-body{padding:24px}.ruler-intro{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-bottom:20px}.ruler-intro p{font-size:14px;line-height:1.8;margin:0}.ruler-body>.code{margin-bottom:22px;background:#f1e6d6}.events{display:grid;grid-template-columns:1fr 1fr;gap:16px}.event{border-left:3px solid #baa189;padding:16px;background:var(--bg);border-radius:0 6px 6px 0}.event .event-date{display:flex;flex-wrap:wrap;gap:10px;align-items:center;color:var(--gold);font-weight:700;font-size:14px}.event-date small{font-weight:400;color:var(--muted);font-size:10px;border:1px solid var(--line);border-radius:3px;padding:3px 6px}.event h4{font-size:17px;margin:12px 0;font-family:'Playfair Display',Georgia,serif}.event dl{font-size:13px;line-height:1.7;margin:0}.event dt{font-size:10px;letter-spacing:1px;color:var(--muted);font-weight:700;margin-top:12px}.event dd{margin:2px 0 0}.event-code{font-size:12px;font-weight:600;color:var(--gold);border-top:1px solid var(--line);padding-top:12px;margin-top:14px}.ruler-note{font-size:12px;line-height:1.8;padding:16px;background:#eeeede;border-radius:5px;margin-top:20px}.source-link{display:inline-block;font-size:11px;color:var(--muted);margin-top:18px}.period-heading{padding:25px 0 10px;scroll-margin-top:20px}.period-heading h3{font-size:27px;margin:0}.period-heading p{font-size:12px;color:var(--muted)}.reading-tools{display:flex;gap:8px;flex-wrap:wrap}.history-page .compare-grid{row-gap:25px}.history-page .learn.done{color:#173d36}.history-page .answers button{color:#523b3e}@media(max-width:950px){.phase-map{grid-template-columns:repeat(3,1fr)}}@media(max-width:600px){.phase-map{grid-template-columns:1fr 1fr}.events{grid-template-columns:1fr}.ruler>summary{gap:12px;padding:16px}.ruler-title{font-size:20px}.ruler-body{padding:16px}.ruler-intro{align-items:start;flex-direction:column}.subject-nav a{flex:1;text-align:center;padding:10px;font-size:11px}.phase-box{padding:12px}.phase-box h3{font-size:18px}}