:root{--bg:#fff;--alt:#F5F5F7;--ink:#1D1D1F;--muted:#6E6E73;--line:#D2D2D7;--accent:#0066CC;--dune:#B64400;--btn:#0071E3}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){--bg:#000;--alt:#161617;--ink:#F5F5F7;--muted:#A1A1A6;--line:#424245;--accent:#2997FF;--dune:#FF9F0A;color-scheme:dark}}
:root[data-theme="dark"]{--bg:#000;--alt:#161617;--ink:#F5F5F7;--muted:#A1A1A6;--line:#424245;--accent:#2997FF;--dune:#FF9F0A;color-scheme:dark}
.rb-switch{pointer-events:auto!important;cursor:default;-webkit-tap-highlight-color:transparent;outline:none}.rb-switch:focus-visible{outline:2px solid var(--accent);outline-offset:6px;border-radius:12px}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"SF Arabic","IBM Plex Sans Arabic",system-ui,sans-serif;line-height:1.6;padding-inline:20px;-webkit-font-smoothing:antialiased}
html[lang="en"] body{font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","Inter","Helvetica Neue",Arial,sans-serif!important;letter-spacing:-.011em}
.lib-top{position:sticky;top:0;z-index:5;max-width:1120px;margin:0 auto;min-height:48px;display:flex;align-items:center;justify-content:space-between;gap:16px;font-size:13px;background:color-mix(in srgb,var(--bg) 80%,transparent);backdrop-filter:saturate(180%) blur(20px);-webkit-backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid color-mix(in srgb,var(--line) 70%,transparent)}
.lib-top a{color:var(--ink);font-weight:600;font-size:15px;text-decoration:none}
.lib-top>span{color:var(--muted);display:flex;align-items:center;gap:6px}
.lib-top>span a{font-size:13px;font-weight:400;color:var(--accent)}
.lib-lang{border:0!important;color:var(--accent)!important;font-size:13px!important;padding:4px!important}
.lib{max-width:1120px;margin:0 auto;padding-block:88px 96px}
.lib-eyebrow{color:var(--dune);font-size:15px;font-weight:600;margin:0;text-align:center}
.lib h1{font-size:clamp(1.75rem,3.6vw,2.5rem);font-weight:600;letter-spacing:-.03em;line-height:1.08;margin:8px 0 14px;text-align:center}
html[lang="ar"] .lib h1{letter-spacing:0;line-height:1.3}
.lib-lead{color:var(--muted);max-width:34em;margin:0 auto 56px;text-align:center;font-size:clamp(1.0625rem,2vw,1.3125rem);line-height:1.45}
.lib-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.lib-card{display:flex;flex-direction:column-reverse;align-items:center;text-align:center;gap:32px;padding:48px 32px 0;border-radius:18px;background:var(--alt);text-decoration:none;color:var(--ink);overflow:hidden}
.lib-spine{width:200px;aspect-ratio:3/4.2;border-radius:6px 6px 0 0;background:var(--bk);color:#fff;display:flex;flex-direction:column;justify-content:space-between;padding:20px 18px;text-align:start;box-shadow:inset 6px 0 0 rgba(0,0,0,.18),0 18px 40px rgba(0,0,0,.18);transition:transform .4s cubic-bezier(.2,.8,.2,1)}
.lib-card:hover .lib-spine{transform:translateY(-8px)}
.lib-spine b{font-size:1.25rem;line-height:1.25;overflow-wrap:anywhere;hyphens:auto}
.lib-spine span{font-size:11px;opacity:.85}
.lib-meta{display:flex;flex-direction:column;align-items:center}
.lib-meta h3{font-size:clamp(1.5rem,2.8vw,2rem);line-height:1.15;margin:4px 0 6px;letter-spacing:-.02em}
html[lang="ar"] .lib-meta h3{letter-spacing:0;line-height:1.4}
.lib-sub{color:var(--ink)!important;font-size:1.0625rem;margin:0 0 8px}
.lib-meta p{margin:0 0 10px;color:var(--muted);font-size:15px;max-width:30em}
.lib-ednote{font-size:13px!important}
.lib-go{color:#fff;background:var(--btn);border-radius:980px;padding:9px 20px;font-size:15px;margin-top:8px}
.lib-badge{color:var(--dune);font-size:13px;font-weight:600}
@media (max-width:820px){.lib-grid{grid-template-columns:minmax(0,1fr)}.lib{padding-block:56px 72px}}
/* identity mark under section titles */
.rb-mark{width:min(360px,72%);margin:20px auto 8px;pointer-events:none}
.rb-mark.start{margin-inline:0;margin-block:6px 22px;width:min(300px,80%)}
.rb-mark svg{display:block;width:100%;height:auto;overflow:visible}
.rb-mark .rb{transform-box:fill-box;transform-origin:center;animation:rbSway 14s ease-in-out infinite alternate}
.rb-mark .rb1{animation-duration:17s;animation-delay:-4s}.rb-mark .rb2{animation-duration:12s;animation-delay:-7s}.rb-mark .rb3{animation-duration:19s;animation-delay:-2s}
@keyframes rbSway{from{transform:translateY(-5%) scaleY(.94)}to{transform:translateY(5%) scaleY(1.06)}}
@media (prefers-reduced-motion:reduce){.rb-mark .rb{animation:none}}
body{padding-left:max(20px,env(safe-area-inset-left));padding-right:max(20px,env(safe-area-inset-right))}
/* full site navigation on the library page */
.lib-top{flex-wrap:wrap}
.lib-nav{display:flex;gap:26px;align-items:center}
.lib-nav a{font-size:13px!important;font-weight:400!important;color:var(--ink)!important;opacity:.8;padding:14px 0;border-bottom:2px solid transparent}
.lib-nav a:hover{opacity:1}
.lib-nav a[aria-current]{opacity:1;font-weight:600!important;border-bottom-color:var(--dune)}
.lib-end{display:flex;align-items:center;gap:8px}
.lib-menu{display:none;width:36px;height:36px;border:0;background:none;position:relative;cursor:pointer}
.lib-menu i{position:absolute;left:8px;right:8px;height:1.5px;background:var(--ink);transition:transform .3s,top .3s}
.lib-menu i:first-child{top:13px}.lib-menu i:last-child{top:21px}
.lib-top.open .lib-menu i:first-child{top:17px;transform:rotate(45deg)}.lib-top.open .lib-menu i:last-child{top:17px;transform:rotate(-45deg)}
@media (max-width:820px){.lib-nav{display:none}.lib-menu{display:block}
  .lib-top.open{min-height:100dvh;align-content:flex-start;background:var(--bg)}
  .lib-top.open .lib-nav{display:flex;flex-direction:column;align-items:flex-start;gap:0;width:100%;order:3;padding:8px 0 28px}
  .lib-top.open .lib-nav a{font-size:1.5rem!important;font-weight:600!important;opacity:1;padding:10px 0;width:100%}}
@media (max-width:820px){.lib-top.open{position:fixed;inset:0;height:100dvh;max-width:none;margin:0;padding-inline:max(20px,env(safe-area-inset-left));overflow-y:auto;z-index:50}}
.lib-brand-en{font-size:15px!important;font-weight:600!important;margin-inline-end:12px}@media (max-width:820px){.lib-brand-en{display:none!important}}
.lib-top>.lib-end a.lib-brand-en{color:var(--ink)!important;margin-inline:12px 0}
.lib-tools{display:flex;flex-direction:column;gap:6px;margin:28px 0 0;padding:24px 28px;border-radius:18px;background:var(--alt);color:var(--ink);text-decoration:none;text-align:center}
.lib-tools>span{font-size:1.25rem;font-weight:600}.lib-tools b{font-weight:400;color:var(--muted);font-size:.9375rem}
.lib-tools:hover{background:color-mix(in srgb,var(--alt) 85%,var(--ink))}