/* One quiet response across links, disclosures and photograph controls. */
:root{--control-time:180ms;--control-ease:cubic-bezier(.2,.65,.3,1)}
:is(a,button,input,summary):focus-visible{outline:2px solid currentColor;outline-offset:4px}
.chapter-menu nav a,.chapters a,.reference-close,.reference-step,.atlas-observations button,
.swift-study summary,.study-notes summary,#motion-toggle,.film-control{
 transition:color var(--control-time) ease,background-color var(--control-time) ease,border-color var(--control-time) ease;
}
.circle,.text-link span,.quiet-link span,.contact-arrow,.atlas-expand,.reference-step>span[aria-hidden],
.primary-nav a>span,.footer-nav a>span,.footer-meta a>span{
 transition:transform var(--control-time) var(--control-ease),background-color var(--control-time) ease,color var(--control-time) ease;
}
.primary-nav a:after,.atlas-observations button:after,.switch:after,.swift-study-toggle,
.chapter-menu .menu-symbol,.study-notes summary>span{transition-duration:var(--control-time)}
.chapters a>span:first-child{position:relative}
.chapters a[aria-current]>span:first-child:before{position:absolute;left:-9px;top:50%;margin:0;transform:translateY(-50%)}
.chapter-menu nav a:focus-visible{background:#38141d0c;outline-offset:-2px}
.chapters a:focus-visible,.quiet-link:focus-visible{color:var(--chalk)}
.circle-link:focus-visible .circle{background:var(--chalk);color:var(--oxblood)}
:is(.editorial,.swift-chapter) .circle-link:focus-visible .circle{background:var(--oxblood);color:var(--chalk)}
.atlas-expand:focus-visible{outline-color:var(--chalk);background:var(--oxblood);color:var(--chalk)}
.atlas-observations button:focus-visible:after{transform:scaleX(1)}
.swift-study summary:focus-visible .swift-study-toggle{background:#38141d14}
.reference-close:focus-visible,.reference-step:focus-visible,.study-notes summary:focus-visible{background:#f1e8de0b}
.footer-nav a:focus-visible,.footer-meta a:focus-visible,.atlas-credit a:focus-visible{text-decoration:underline;text-underline-offset:6px}
.circle-link[data-go=encounter]{--arrow-y:-2px}
.circle-link{--arrow-y:2px}
@media(hover:hover){
 .circle-link:hover .circle{transform:translateY(var(--arrow-y))}
 .text-link:hover span,.quiet-link:hover span,.primary-nav a:hover>span,.footer-nav a:hover>span,.footer-meta a:hover>span{transform:translate(2px,-2px)}
 .atlas-expand:hover{transform:translate(1px,-1px)}
 .reference-close:hover,.reference-step:hover,.study-notes summary:hover{background:#f1e8de0b}
 .reference-step[data-photo-step='-1']:hover>span[aria-hidden]{transform:translateX(-2px)}
 .reference-step[data-photo-step='1']:hover>span[aria-hidden]{transform:translateX(2px)}
 .atlas-observations button:hover:after{transform:scaleX(1)}
 #motion-toggle:hover .switch,.film-control:hover .film-icon{background:#38141d14}
}
.circle-link:active .circle,.atlas-expand:active{transform:scale(.96)}
.reference-step:active,.reference-close:active{background:#f1e8de18}
.chapter-menu nav a:active,.swift-study summary:active,.atlas-observations button:active{background:#38141d10}
.text-link:active span,.quiet-link:active span{transform:translate(1px,-1px)}

/* The print keeps its dimensions while the next photograph decodes. */
.reference-viewer{padding:18px 24px 16px;overflow:auto}
.reference-viewer-top{margin-bottom:12px}
.reference-viewer .reference-print{width:min(100%,calc((100svh - 290px)*1.496));aspect-ratio:4272/2856;max-width:100%;border-width:5px}
.reference-viewer img{width:100%;height:100%;max-height:none;object-fit:contain}
.reference-viewer figcaption{margin-top:14px;max-width:750px;line-height:1.6}
.reference-navigation{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:20px;border-top:1px solid #f1e8de30;margin-top:18px;padding-top:10px}
.reference-step{display:inline-flex;align-items:center;justify-content:center;gap:16px;min-width:100px;min-height:48px;padding:6px 12px;background:none;font-size:12px;justify-self:start}
.reference-step:last-child{justify-self:end}
.reference-step>span[aria-hidden]{font-size:22px;line-height:1}
#reference-position{margin:0;text-align:center;font-size:11px;line-height:1.6;font-variant-numeric:tabular-nums;letter-spacing:.06em}
#reference-position>span{display:block;font-size:12px;letter-spacing:0;color:var(--copy-light)}
.reference-help{min-height:20px;display:flex;justify-content:space-between;gap:12px;margin:8px 0 0;font-size:11px;line-height:1.6;color:var(--copy-light)}
#reference-load-status{text-align:right}
@media(max-width:760px){
 .reference-viewer{padding:12px 14px 14px}
 .reference-viewer .reference-print{width:min(100%,calc((100svh - 320px)*1.496));border-width:4px}
 .reference-navigation{gap:5px;margin-top:15px;padding-top:8px}
 .reference-step{min-width:44px;gap:8px;padding:6px}
 .reference-help{display:block;min-height:36px;font-size:10px;margin-top:5px}
 #reference-load-status{display:block;text-align:left;min-height:16px}
}
@media(max-width:380px){
 .reference-step>span:not([aria-hidden]){display:none}
 .reference-viewer .reference-print{width:min(100%,calc((100svh - 344px)*1.496))}
}
body[data-motion=off] :is(.circle-link:hover .circle,.text-link:hover span,.quiet-link:hover span,.atlas-expand:hover,.reference-step:hover>span[aria-hidden]){transform:none}
@media(prefers-reduced-motion:reduce){
 .circle-link:hover .circle,.text-link:hover span,.quiet-link:hover span,.atlas-expand:hover,.reference-step:hover>span[aria-hidden]{transform:none}
}