/* Shared navigation geometry; independent of page typography and content. */
:root{--site-header-height:65px;--site-subnav-height:0px}
html{scroll-behavior:auto;scroll-padding-top:calc(var(--site-header-height) + var(--site-subnav-height) + 16px)}
#switcher{position:fixed;z-index:60;inset:0 0 auto;display:flex;align-items:center;gap:12px;padding:10px 18px;box-sizing:border-box;font:12px/1.2 "Epoch Typewriter","Courier New",monospace;letter-spacing:.08em;background:var(--head-bg,var(--sw-bg,#fff));color:var(--head-ink,var(--sw-ink,#2b2419));border-bottom:1px solid var(--line,var(--sw-line,#d8cdb8))}
#switcher *{box-sizing:border-box}
#switcher [hidden]{display:none!important}
#switcher .brand{display:flex;align-items:center;min-height:44px;margin:0 auto 0 0;padding:0;font:700 12px/1.2 "Epoch Typewriter","Courier New",monospace;letter-spacing:.3em;color:inherit;text-decoration:none;border:0;white-space:nowrap;cursor:pointer}
#switcher .brand-mark{display:block;width:128px;height:auto;flex:none;object-fit:contain}
html[data-philosophy="atlas"] #switcher .brand-mark,html[data-philosophy="instrument"] #switcher .brand-mark{filter:invert(1)}
#switcher .site-links{display:flex;align-items:center;gap:6px;margin:0;padding:0}
#switcher .site-links a{display:flex;align-items:center;justify-content:center;min-height:44px;margin:0;padding:8px 5px;font:inherit;letter-spacing:inherit;color:inherit;text-decoration:none;border:0;opacity:1;white-space:nowrap}
#switcher .session-slot{display:grid;width:calc(8ch + 10px);flex:none}
#switcher .session-slot a,#switcher .session-slot>span{grid-area:1/1}
#switcher .session-slot>span{display:flex;align-items:center;justify-content:center;min-height:44px}
#switcher .site-links a:hover,#switcher .site-links a[aria-current="page"]{color:var(--accent,var(--sw-accent,#8a4b2a));text-decoration:underline;text-underline-offset:5px}
#switcher .opts{display:flex;gap:6px;flex-wrap:nowrap}
#switcher button{font:inherit;color:inherit;background:transparent;cursor:pointer;border:1px solid var(--line,var(--sw-line,#d8cdb8));border-radius:2px;padding:8px;min-height:44px;letter-spacing:.04em;opacity:1;white-space:nowrap}
#switcher button[aria-pressed="true"]{border-color:var(--accent,var(--sw-accent,#8a4b2a));color:var(--accent,var(--sw-accent,#8a4b2a))}
#switcher .hint{font:10px/1.2 "Epoch Typewriter","Courier New",monospace;letter-spacing:0;color:inherit;opacity:1;white-space:nowrap}
#switcher .appearance-select{display:none;font:inherit;color:inherit;background:var(--head-bg,var(--sw-bg,#fff));border:1px solid currentColor;border-radius:2px;min-height:44px;max-width:180px;padding:8px}
#switcher :focus-visible,.subnav a:focus-visible{outline:2px solid var(--accent,var(--sw-accent,#8a4b2a));outline-offset:2px}
@media(max-width:1100px){#switcher .hint{display:none}}
@media(max-width:980px){:root{--site-header-height:115px}#switcher{display:grid;grid-template-columns:1fr auto;gap:6px 12px}#switcher .site-links{grid-column:1/-1;grid-row:2;justify-content:center}}
@media(max-width:600px){#switcher{padding:6px 10px}#switcher .opts{display:none}#switcher .appearance-select{display:block}#switcher .site-links{gap:0;width:100%;justify-content:space-between}#switcher .site-links a{padding:8px 3px}}
@media(max-width:480px){:root{--site-header-height:151px}#switcher .site-links{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:0 6px}#switcher .session-slot{width:auto;min-width:0}}
@media(max-width:360px){#switcher .brand-mark{width:112px}}
/* Research nav offsets follow the shared bar, including font loading and zoom. */
.subnav{top:var(--site-header-height)!important}
.subnav a{display:inline-flex;align-items:center;min-height:44px}
body.viz{padding-top:var(--site-header-height)}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}body,#switcher *{transition:none!important}}