/* Historical backbone */
.history-jump{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:.7rem;margin:1.5rem 0 0}.history-jump a{display:flex;flex-direction:column;min-height:104px;padding:.9rem;border:1px solid var(--line);border-radius:14px;background:var(--paper-card);color:inherit;text-decoration:none}.history-jump a:hover,.history-jump a:focus-visible{border-color:var(--accent);color:inherit;box-shadow:var(--shadow)}.history-jump strong{font-size:.85rem;color:var(--accent)}.history-jump span{margin-top:.25rem;font-weight:850;line-height:1.15}
.history-principle{margin-top:1.4rem;padding:1.1rem 1.2rem;border-left:4px solid var(--accent);border-radius:0 14px 14px 0;background:var(--paper-warm)}.history-principle p{margin:.35rem 0 0;color:var(--ink-soft)}
.era{scroll-margin-top:100px}.era-head{display:grid;grid-template-columns:150px minmax(0,1fr);gap:1.4rem;align-items:start;margin-bottom:1.4rem}.era-date{font-family:Georgia,"Times New Roman",serif;font-size:1.55rem;font-weight:800;color:var(--accent)}.era-head h2{margin:0}.era-head p{margin:.45rem 0 0;color:var(--ink-soft);max-width:72ch}
.era-grid{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(260px,.65fr);gap:1.2rem;align-items:start}.era-card{padding:1.25rem;border:1px solid var(--line);border-radius:16px;background:var(--paper-card)}.era-card h3{margin-top:0}.era-card p,.era-card li{color:var(--ink-soft)}.era-card ul{margin-bottom:0;padding-left:1.2rem}.capability{border-top:5px solid var(--accent)}.handoff{border-top:5px solid var(--blue)}
.node-chips{display:flex;flex-wrap:wrap;gap:.45rem;margin:.8rem 0}.node-chip{display:inline-flex;align-items:center;gap:.18rem;padding:.36rem .58rem;border-radius:999px;background:var(--blue-soft);color:var(--blue);font-size:.8rem;font-weight:850}.node-chip-link{text-decoration:none;cursor:pointer;transition:transform .15s ease,background .15s ease,color .15s ease,box-shadow .15s ease}.node-chip-link::after{content:' ›';font-weight:900}.node-chip-link:hover,.node-chip-link:focus-visible{background:var(--ink);color:#fff;transform:translateY(-1px);box-shadow:0 5px 14px rgba(13,47,70,.16)}
.source-stack{display:grid;gap:.55rem;margin-top:1rem}.history-source{display:block;padding:.75rem .8rem;border:1px solid var(--line);border-radius:10px;background:#fff;color:var(--ink-deep);text-decoration:none}.history-source:hover,.history-source:focus-visible{border-color:var(--accent);color:var(--accent)}.history-source small{display:block;color:var(--ink-soft);font-weight:500;margin-top:.15rem}
.history-arrow{display:grid;place-items:center;height:52px;font-size:1.7rem;color:var(--accent)}
.pattern-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1rem}.pattern-card{padding:1.15rem;border:1px solid var(--line);border-radius:15px;background:var(--paper-card)}.pattern-card strong{display:block;margin-bottom:.35rem}.pattern-card p{margin:0;color:var(--ink-soft)}
.history-boundary{padding:1.2rem;border:1px solid var(--line);border-radius:16px;background:var(--ink);color:#fff}.history-boundary p{color:#dbe5eb;margin-bottom:0}
@media(max-width:900px){.history-jump{grid-template-columns:repeat(2,minmax(0,1fr))}.history-jump a:last-child{grid-column:1/-1}.era-grid,.pattern-grid{grid-template-columns:1fr}.era-head{grid-template-columns:1fr;gap:.25rem}}
@media(max-width:620px){.history-jump{grid-template-columns:1fr}.history-jump a:last-child{grid-column:auto}.history-jump a{min-height:0}.era-date{font-size:1.3rem}.era-card{padding:1rem}}