:root{color-scheme:light dark;font-family:Inter,Segoe UI,system-ui,-apple-system,sans-serif;line-height:1.55;--arche-max: 1120px;--arche-gap: 16px;--arche-gap-lg: 32px}*,*:before,*:after{box-sizing:border-box}html,body{margin:0;min-height:100%;background:var(--ran-color-bg, #fff);color:var(--ran-color-text, #111)}a{color:var(--ran-color-link, #2563eb);text-decoration:none}a:hover{text-decoration:underline}#app{min-height:100vh}.shell{max-width:var(--arche-max);margin:0 auto;padding:16px 16px 48px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:8px 0 16px;border-bottom:1px solid var(--ran-color-border, #e5e5e5);margin-bottom:var(--arche-gap-lg)}.brand{display:flex;flex-direction:column;gap:2px;min-width:0}.brand a{color:inherit;text-decoration:none;font-size:22px;font-weight:650;letter-spacing:-.02em}.brand span{color:var(--ran-color-text-secondary, #666);font-size:13px}.topbar-actions{display:flex;align-items:center;gap:8px;flex-shrink:0}.layout{display:grid;grid-template-columns:220px minmax(0,1fr);gap:var(--arche-gap-lg)}@media(max-width:800px){.layout{grid-template-columns:1fr}}.nav{display:flex;flex-direction:column;gap:4px;position:sticky;top:12px;align-self:start}.nav-link{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:0;background:transparent;color:var(--ran-color-text-secondary, #666);text-align:left;padding:8px 10px;border-radius:8px;cursor:pointer;font:inherit}.nav-link:hover{background:var(--ran-color-bg-muted, #f5f5f5);color:var(--ran-color-text, #111)}.nav-link[aria-current=page]{background:var(--ran-color-bg-muted, #f5f5f5);color:var(--ran-color-text, #111);font-weight:600}.nav-ep{font-variant-numeric:tabular-nums;opacity:.7;margin-right:6px}.article h1{margin:0 0 8px;font-size:28px;letter-spacing:-.03em;line-height:1.2}.lede{margin:0 0 20px;color:var(--ran-color-text-secondary, #666);font-size:15px}.panel{margin:20px 0}.math-wrap{margin:16px 0 24px;padding:12px 0;overflow-x:auto}.footer-note{margin-top:32px;padding-top:16px;border-top:1px solid var(--ran-color-border, #e5e5e5);color:var(--ran-color-text-secondary, #666);font-size:13px}