.site-back-to-top{box-sizing:border-box;position:fixed;left:max(18px,env(safe-area-inset-left));bottom:max(24px,env(safe-area-inset-bottom));z-index:80;display:grid;place-items:center;width:58px;height:56px;padding:0;border:0;border-radius:12px;background:transparent;box-shadow:none;cursor:pointer;transition:transform .18s,filter .18s;filter:drop-shadow(0 4px 4px #0a254440)}
.site-back-to-top[hidden]{display:none}
.site-back-to-top img{display:block;width:50%;height:50%;object-fit:contain;pointer-events:none}
.site-back-to-top:hover{transform:translateY(-3px);filter:drop-shadow(0 6px 5px #0a254450) brightness(1.1)}
.site-back-to-top:focus-visible{outline:3px solid #bc9a5a;outline-offset:4px}
.overview-scroll{padding-top:64px}
/* Letterpress lettering cut into the site's pale blue surface. */
.research-history{position:relative;box-sizing:border-box;width:fit-content;max-width:calc(100% - 32px);margin:10px auto 0;padding:4px 0;text-align:center;font:700 15.6px/1.9 'Site TheSans',Tahoma,sans-serif;color:#577183;text-shadow:0 1px 0 #fff,0 -.7px .5px #223c5059;background:transparent;border:0;border-radius:0;box-shadow:none}
.research-history [data-research-since]{white-space:nowrap}
.research-history audio:not([hidden]){display:block;width:280px;max-width:100%;margin:12px auto 0}
.research-history .research-heart{position:relative;display:inline-flex;align-items:center;justify-content:center;width:22px;height:24px;margin-inline-end:.5cm;padding:0;border:0;border-radius:50%;background:none;color:#d73e48;text-shadow:none;font:inherit;vertical-align:middle;transform-origin:center;transition:color .18s;cursor:pointer;touch-action:manipulation}
.research-history .research-heart svg{display:block;flex-shrink:0;pointer-events:none}
.research-history .research-heart:is(:hover,:focus-visible){color:#b92c38}
.research-history .research-heart.is-beating{animation:research-heartbeat 1.7s ease-in-out 1}
.research-history .research-heart:focus-visible{outline:2px solid #bc9a5a;outline-offset:5px}
@keyframes research-heartbeat{0%,35%,85%,100%{transform:scale(1)}11%{transform:scale(1.17)}27%{transform:scale(1.06)}63%{transform:scale(1.16)}79%{transform:scale(1.05)}}
.overview-interactive-link{position:absolute;inset:0;z-index:3;pointer-events:none;opacity:0;transition:opacity .18s}
.overview-interactive-link.is-visible{opacity:1}
.overview-interactive-link>svg{position:absolute;inset:0;width:100%;height:100%;overflow:visible}
.overview-interactive-link path{fill:none;stroke:#123c61;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.overview-interactive-link .interactive-arrow-line{vector-effect:non-scaling-stroke}
.overview-interactive-link>span{position:absolute;transform:translate(-50%,-100%);width:max-content;max-width:calc(100% - 16px);padding:3px 12px;border:1px solid #cbdbe5;border-radius:20px;background:#f5f9fc;color:#123c61;font:700 14px/1.7 'Site TheSans',Tahoma,sans-serif;text-align:center;white-space:nowrap;box-shadow:0 2px 8px #123c6109}
@media(max-width:760px){
 .overview-scroll{padding-top:64px}
 .section-overview.overview-tree{grid-template-rows:repeat(2,calc(var(--overview-size) + var(--overview-tail))) calc(var(--overview-size) + var(--overview-tail) + 36px)}
 .overview-tree>.overview-item:nth-child(4),.overview-tree>.overview-item:nth-child(5){padding-top:36px}
 .overview-interactive-link>span{font-size:13px}
 .site-back-to-top{left:max(12px,env(safe-area-inset-left));bottom:max(18px,env(safe-area-inset-bottom));width:52px;height:50px}
}
@media(prefers-reduced-motion:reduce){.site-back-to-top,.overview-interactive-link{transition:none}.site-back-to-top:hover{transform:none}}
@media(prefers-reduced-motion:reduce){.research-history .research-heart{transition:none}.research-history .research-heart.is-beating{animation:none}}

/* Keep each complete label on one line; wrap whole controls when space is tight. */
html[lang] body .home-navigation-band{display:flex;flex-wrap:wrap;align-items:stretch;justify-content:space-evenly;gap:0 clamp(.25rem,1vw,.75rem)}
html[lang] .home-navigation-band>a,html[lang] .home-navigation-band>.navigation-audio{box-sizing:border-box;flex:1 0 auto;width:auto;min-width:max-content;max-width:none}
html[lang] .home-navigation-band>a,html[lang] .home-navigation-band .recitation-toggle{white-space:nowrap}
html[lang] .home-navigation-band>a>span,html[lang] .home-navigation-band .recitation-toggle>span{flex:none;white-space:nowrap;text-wrap:nowrap;overflow-wrap:normal;word-break:normal}
html[lang] .home-navigation-band .navigation-icon{flex:none}
.home-navigation-band>.compare-nav .navigation-icon{width:26px;height:26px;object-fit:contain}
.home-navigation-band>.names-map-nav{gap:7px}
.names-map-nav svg{width:22px;height:22px;flex-shrink:0;fill:currentColor;opacity:.85}
.home-navigation-band>.explorers-nav{gap:7px}
/* Keep compact navigation in complete rows with one continuous center divider.
   An unpaired final section fills its row, including after member links change. */
@media(max-width:900px){
 html[lang] body .home-navigation-band{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));grid-auto-flow:row;grid-auto-columns:auto;gap:0;padding-inline:0;border-top:1px solid #D6B875}
 html[lang] .home-navigation-band>a,html[lang] .home-navigation-band>.navigation-audio{width:100%;min-width:0;max-width:100%;border:0;grid-column:auto}
 html[lang] .home-navigation-band>:nth-child(n+3){border-top:1px solid #D6B87599}
 html[lang] .home-navigation-band>:nth-child(odd):not(:last-child){border-inline-end:1px solid #D6B87599}
 html[lang] .home-navigation-band>:last-child:nth-child(odd){grid-column:1 / -1}
}
@media(max-width:700px){
 html[lang] .home-navigation-band>.names-map-nav svg{width:clamp(16px,4vw,22px);height:clamp(16px,4vw,22px)}
 html[lang] .home-navigation-band>a,html[lang] .home-navigation-band .recitation-toggle{min-height:44px;padding:8px 4px;gap:4px;font-size:clamp(10px,2.5vw,16px)}
 html[lang=en] .home-navigation-band>a,html[lang=en] .home-navigation-band .recitation-toggle{font-size:clamp(9px,2.25vw,14px)}
 html[lang] .home-navigation-band .navigation-icon{width:clamp(16px,4vw,22px);height:clamp(16px,4vw,22px)}
}

/* English encyclopedia title: 65% of the existing desktop and phone sizes. */
html[lang=en] .hero-copy .hero-title{font-size:clamp(.9425rem,1.495vw,1.56rem)}
@media(max-width:560px){
 html[lang=en] .hero-copy .hero-title{font-size:clamp(.845rem,3.445vw,1.235rem)}
}

/* Footer Atlas wordmark: a fine white rule with its upcoming label beneath. */
html[lang="ar"] .site-footer .atlas-brand-link>span{
 display:block;text-align:center;line-height:1.4;
}
html[lang="ar"] .site-footer .atlas-brand-link>span::after{
 content:"قريباً";display:block;margin-top:1px;color:#fff;
 font-size:12px;font-weight:400;line-height:1.4;letter-spacing:0;
 text-shadow:none;-webkit-text-stroke:0;
 background:linear-gradient(#fff,#fff) left center/calc(50% - 21px) 1px no-repeat,
            linear-gradient(#fff,#fff) right center/calc(50% - 21px) 1px no-repeat;
}

/* An open research timeline balances the Atlas identity at upper right. */
html[lang="ar"] body>header .research-anniversary-badge{
 position:absolute;top:20px;right:clamp(16px,2vw,28px);z-index:3;
 display:block;width:184px;height:auto;max-width:calc(50% - 32px);
 background:transparent;border:0;box-shadow:none;
}
@media(min-width:1101px){
 html[lang="ar"] body>header:not(.home-hero){padding-inline-start:max(228px,calc((100vw - 1240px)/2))}
}
@media(min-width:561px) and (max-width:1100px){
 html[lang="ar"] body>header{padding-top:144px}
}
@media(max-width:560px){
 html[lang="ar"] body>header .research-anniversary-badge{top:16px;right:16px;width:148px}
 html[lang="ar"] body>header{padding-top:120px}
}