/* Rating band pages (/rating/what-is-N-elo-in-chess.html), from Yuval's Claude Design file
   (claude.ai/artifact/UDUpafMPSWE9bjjSSaNvGY, 2026-11-05). The left menu is
   public/css/seo-rail.css, so the design's own rail rules are unused here. */
:root{--ct-bg:#06080d;--ct-t1:#f3f5f8;--ct-t2:#94a3b8;--ct-t3:#64748b;--ct-green:#4ade80;--ct-blue:#38bdf8;--ct-purple:#a855f7;--ct-gold:#f0b54a;--ct-line:rgba(148,163,184,.13);--ct-card:rgba(148,163,184,.05);--ct-tier:#4ade80;--ct-mono:'Space Mono',ui-monospace,Menlo,monospace}
*{box-sizing:border-box}
html,body{margin:0}
body{background:radial-gradient(900px 560px at 88% -8%,rgba(56,189,248,.09),transparent 62%),radial-gradient(820px 620px at -8% 104%,rgba(74,222,128,.08),transparent 60%),var(--ct-bg);background-attachment:fixed;color:var(--ct-t1);font-family:'Manrope',system-ui,-apple-system,'Segoe UI',sans-serif;-webkit-font-smoothing:antialiased;min-height:100vh}
a{color:var(--ct-green);text-decoration:none}a:hover{color:#86efac}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
.ct-ic{flex:none;display:block}
.ct-rail{position:fixed;left:0;top:0;bottom:0;width:238px;display:flex;flex-direction:column;padding:24px 16px 20px;border-right:1px solid var(--ct-line);background:rgba(6,8,13,.6);backdrop-filter:blur(10px);z-index:10}
.ct-brand{display:flex;align-items:center;gap:10px;padding:0 8px;font-size:13px;font-weight:800;letter-spacing:2.4px;color:var(--ct-t1)}
.ct-brand img{width:32px;height:32px;border-radius:9px}
.ct-brand em{font-style:normal;color:var(--ct-green)}
.ct-nav{display:flex;flex-direction:column;gap:2px;margin-top:26px}
.ct-nav a{display:flex;align-items:center;gap:12px;height:42px;padding:0 12px;border-radius:11px;color:var(--ct-t2);font-size:14px;font-weight:600;position:relative}
.ct-nav a:hover{background:rgba(148,163,184,.07);color:var(--ct-t1)}
.ct-nav a.ct-on{background:rgba(74,222,128,.11);color:var(--ct-t1);font-weight:800}
.ct-nav a.ct-on::before{content:"";position:absolute;left:-16px;top:11px;bottom:11px;width:3px;border-radius:0 3px 3px 0;background:var(--ct-green);box-shadow:0 0 8px rgba(74,222,128,.7)}
.ct-sec{font-size:9.5px;font-weight:800;letter-spacing:1.8px;color:var(--ct-t3);padding:0 12px;margin:22px 0 6px}
.ct-sp{flex:1}
.ct-unlock{display:flex;align-items:center;justify-content:center;gap:8px;height:44px;border-radius:12px;background:var(--ct-green);color:#06120b;font-size:14px;font-weight:800;box-shadow:inset 0 1.5px 0 rgba(255,255,255,.35),0 8px 20px rgba(74,222,128,.18)}
.ct-unlock:hover{color:#06120b;filter:brightness(1.05)}
.ct-stores{display:flex;gap:6px;margin-top:12px}
.ct-store{flex:1;display:flex;align-items:center;gap:6px;height:38px;padding:0 9px;border-radius:9px;border:1px solid rgba(148,163,184,.22);background:#0b0f17;color:var(--ct-t1);font-size:9px;line-height:1.1;font-weight:600}
.ct-store b{display:block;font-size:11.5px;font-weight:800}
.ct-top{display:none;position:sticky;top:0;z-index:10;height:56px;align-items:center;justify-content:space-between;padding:0 16px;background:rgba(6,8,13,.82);backdrop-filter:blur(12px);border-bottom:1px solid var(--ct-line)}
.ct-top .ct-brand{padding:0;font-size:12px}
.ct-top .ct-brand img{width:28px;height:28px}
.ct-menu{width:38px;height:38px;border-radius:11px;border:1px solid rgba(148,163,184,.2);display:flex;align-items:center;justify-content:center;color:var(--ct-t2)}
.ct-main{margin-left:238px;padding:34px 48px 130px}
.ct-wrap{max-width:940px}
.ct-crumb{display:flex;align-items:center;gap:8px;font-size:11px;font-weight:800;letter-spacing:1.5px;text-transform:uppercase;color:var(--ct-t3)}
.ct-crumb a{color:var(--ct-t3)}.ct-crumb a:hover{color:var(--ct-t2)}
.ct-tierchip{letter-spacing:1.2px}
.ct-top-row{display:grid;grid-template-columns:300px minmax(0,1fr);gap:28px;align-items:stretch;margin-top:16px}
.ct-hero{display:flex;flex-direction:column;justify-content:center}
.ct-h1{margin:0;line-height:1}
.ct-h1 .ct-num{display:block;font-family:var(--ct-mono);font-weight:700;font-size:112px;letter-spacing:-6px;line-height:.95;color:var(--ct-tier);text-shadow:0 0 40px color-mix(in srgb,var(--ct-tier) 35%,transparent)}
.ct-h1 .ct-q{display:block;font-size:13px;font-weight:700;color:var(--ct-t3);letter-spacing:.2px;margin-top:10px}
.ct-verdict{margin:6px 0 0;font-size:30px;font-weight:800;letter-spacing:-.8px;line-height:1.1}
.ct-sub{margin:8px 0 0;font-size:15px;font-weight:600;color:var(--ct-t2)}
.ct-sub b{color:var(--ct-t1);font-family:var(--ct-mono);font-weight:700}
.ct-meter{position:relative;padding:18px 18px 14px;border-radius:18px;background:var(--ct-card);border:1px solid var(--ct-line)}
.ct-meter-hd{display:flex;align-items:baseline;justify-content:space-between;gap:10px;font-size:12px;font-weight:700;color:var(--ct-t3)}
.ct-meter-hd b{font-size:10.5px;letter-spacing:1.5px;text-transform:uppercase;font-weight:800}
.ct-meter svg{display:block;width:100%;height:auto;margin-top:6px;overflow:visible}
.ct-ladder{margin-top:22px}
.ct-ladder-hd{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:10px}
.ct-ladder-hd b{font-size:10.5px;font-weight:800;letter-spacing:1.5px;text-transform:uppercase;color:var(--ct-t3)}
.ct-ladder-hd span{font-size:12px;font-weight:600;color:var(--ct-t3)}
.ct-rungs{display:grid;grid-template-columns:repeat(21,minmax(38px,1fr));gap:4px;overflow-x:auto;scrollbar-width:none;padding:4px 2px 2px;margin:0 -2px}
.ct-rungs::-webkit-scrollbar{display:none}
.ct-rung{position:relative;display:flex;flex-direction:column;align-items:center;justify-content:flex-end;gap:6px;height:66px;padding-bottom:8px;border-radius:10px;background:rgba(148,163,184,.04);border:1px solid rgba(148,163,184,.08);color:var(--ct-t2);font-family:var(--ct-mono);font-size:11px;font-weight:700;transition:background .15s,border-color .15s,transform .15s}
.ct-rung i{position:absolute;left:7px;right:7px;bottom:28px;border-radius:3px 3px 1px 1px;background:var(--rc);opacity:.35}
.ct-rung:hover{border-color:rgba(148,163,184,.3);color:var(--ct-t1)}
.ct-rung:hover i{opacity:.6}
.ct-rung.ct-on{background:color-mix(in srgb,var(--rc) 16%,transparent);border-color:var(--rc);color:var(--ct-t1);box-shadow:0 0 18px color-mix(in srgb,var(--rc) 30%,transparent);transform:translateY(-2px)}
.ct-rung.ct-on i{opacity:1}
.ct-rung.ct-med::after{content:"";position:absolute;top:-4px;left:50%;width:6px;height:6px;margin-left:-3px;border-radius:50%;background:var(--ct-t2)}
.ct-tiers{display:grid;grid-template-columns:4fr 5fr 6fr 6fr;gap:4px;margin-top:8px}
.ct-tiers span{font-size:10.5px;font-weight:800;letter-spacing:.4px;padding-top:6px;border-top:2px solid;color:var(--ct-t3)}
.ct-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:26px}
.ct-card{display:flex;flex-direction:column;gap:10px;padding:16px;border-radius:18px;background:var(--ct-card);border:1px solid var(--ct-line)}
.ct-card-hd{display:flex;align-items:center;gap:16px;font-size:15px;font-weight:800;line-height:1.25}
.ct-art{position:relative;width:60px;height:60px;flex:none}.ct-art img{display:block;width:60px;height:60px;filter:drop-shadow(0 7px 8px rgba(0,0,0,.55))}.ct-art svg{position:absolute;right:-8px;top:-6px;width:30px;height:30px;filter:drop-shadow(0 3px 5px rgba(0,0,0,.45))}
.ct-card p{margin:0;font-size:14px;line-height:1.5;color:var(--ct-t2);text-wrap:pretty}
.ct-big{font-family:var(--ct-mono);font-size:30px;font-weight:700;letter-spacing:-1.5px;line-height:1}
.ct-try{align-self:flex-start;display:inline-flex;align-items:center;gap:8px;margin-top:auto;height:40px;padding:0 14px 0 12px;border-radius:11px;border:1.5px solid rgba(148,163,184,.28);color:var(--ct-t1);font-size:13.5px;font-weight:800;white-space:nowrap;transition:border-color .15s,background .15s}
.ct-try:hover{color:var(--ct-t1);border-color:var(--ct-blue);background:rgba(56,189,248,.06)}
.ct-try svg{flex:none;color:var(--ct-blue);transition:transform .15s}
.ct-try:hover svg:last-child{transform:translateX(2px)}
.ct-tagline{display:inline-flex;align-self:flex-start;align-items:center;gap:6px;height:26px;padding:0 10px;border-radius:99px;background:rgba(148,163,184,.08);font-size:12px;font-weight:700;color:var(--ct-t2);margin-top:auto}
.ct-ask{position:fixed;z-index:20;left:238px;right:0;bottom:0;padding:14px 48px calc(14px + env(safe-area-inset-bottom));background:linear-gradient(180deg,rgba(11,17,28,.9),rgba(8,12,20,.97));-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);border-top:1.5px solid rgba(74,222,128,.45);box-shadow:0 -14px 40px rgba(0,0,0,.5),0 -1px 26px rgba(74,222,128,.12)}
.ct-ask-in{max-width:940px;display:flex;align-items:center;gap:18px}
.ct-ask-t{flex:1;min-width:0}
.ct-ask h2{margin:0;font-size:22px;font-weight:800;letter-spacing:-.5px;line-height:1.15;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ct-askn{font-family:var(--ct-mono);font-weight:700;letter-spacing:-1.5px;color:var(--ct-tier);text-shadow:0 0 20px color-mix(in srgb,var(--ct-tier) 60%,transparent)}
.ct-ask p{margin:3px 0 0;font-size:13px;font-weight:600;color:var(--ct-t2);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ct-askf{display:flex;align-items:center;gap:10px;flex:none}
.ct-field{position:relative;display:block}
.ct-field svg{position:absolute;left:14px;top:50%;margin-top:-9px;color:var(--ct-t3);pointer-events:none}
.ct-input{width:300px;height:50px;padding:0 14px 0 42px;border-radius:14px;border:1.5px solid rgba(148,163,184,.3);background:rgba(6,8,13,.85);color:var(--ct-t1);font:inherit;font-size:15px;font-weight:700;outline:none;transition:border-color .15s,box-shadow .15s}
.ct-input::placeholder{color:var(--ct-t3);font-weight:600}
.ct-input:focus{border-color:var(--ct-green);box-shadow:0 0 0 4px rgba(74,222,128,.18)}
.ct-go{position:relative;overflow:hidden;height:50px;padding:0 20px;margin-bottom:4px;border-radius:14px;display:inline-flex;align-items:center;justify-content:center;gap:8px;background:linear-gradient(180deg,#86efac,#4ade80 45%,#3fcf72);color:#062a14;font-size:16px;font-weight:800;white-space:nowrap;box-shadow:inset 0 2px 0 rgba(255,255,255,.5),0 4px 0 #1f8a4c,0 10px 24px rgba(74,222,128,.28);transition:transform .08s,box-shadow .08s,filter .15s}
.ct-go svg{transition:transform .15s}
.ct-go:hover{filter:brightness(1.05)}.ct-go:hover svg{transform:translateX(3px)}
.ct-go:active{transform:translateY(3px);box-shadow:inset 0 2px 0 rgba(255,255,255,.5),0 1px 0 #1f8a4c,0 5px 12px rgba(74,222,128,.25)}
.ct-go::after{content:"";position:absolute;top:0;bottom:0;left:-40%;width:28%;background:linear-gradient(100deg,transparent,rgba(255,255,255,.6),transparent);transform:skewX(-18deg);animation:ct-shine 3.8s ease-in-out infinite}
@keyframes ct-shine{0%,60%{left:-40%}100%{left:135%}}
@media (prefers-reduced-motion:reduce){.ct-go::after{display:none}}
.ct-gs{display:none}
.ct-note{margin:18px 0 0;font-size:11.5px;font-weight:600;color:var(--ct-t3)}
@media (max-width:1023px){
html:not(.ct-d) .ct-rail{display:none}html:not(.ct-d) .ct-top{display:flex}
html:not(.ct-d) .ct-main{margin-left:0;padding:18px 16px 160px}
html:not(.ct-d) .ct-top-row{grid-template-columns:1fr;gap:14px;margin-top:12px}
html:not(.ct-d) .ct-h1 .ct-num{font-size:84px;letter-spacing:-5px}
html:not(.ct-d) .ct-verdict{font-size:25px}
html:not(.ct-d) .ct-sub{font-size:14px;margin-top:6px}
html:not(.ct-d) .ct-meter{padding:14px 14px 10px}
html:not(.ct-d) .ct-ladder{margin-top:18px}
html:not(.ct-d) .ct-rungs{grid-template-columns:repeat(21,44px);margin:0 -16px;padding:4px 16px 2px}
html:not(.ct-d) .ct-tiers{display:none}
html:not(.ct-d) .ct-cards{grid-template-columns:1fr;gap:10px;margin-top:18px}
html:not(.ct-d) .ct-ask{left:0;padding:16px 14px calc(22px + env(safe-area-inset-bottom))}
html:not(.ct-d) .ct-ask-in{flex-direction:column;align-items:stretch;gap:12px}
html:not(.ct-d) .ct-ask h2{font-size:16.5px;letter-spacing:-.3px}html:not(.ct-d) .ct-ask p{display:none}
html:not(.ct-d) .ct-askf{width:100%}html:not(.ct-d) .ct-field{flex:1;min-width:0}html:not(.ct-d) .ct-input{width:100%;height:46px;font-size:16px}
html:not(.ct-d) .ct-go{height:46px;padding:0 15px;font-size:15px}html:not(.ct-d) .ct-gl{display:none}html:not(.ct-d) .ct-gs{display:inline}
}
@media (max-width:1023px) and (min-width:600px){html:not(.ct-m):not(.ct-d) .ct-top-row{grid-template-columns:260px 1fr}html:not(.ct-m):not(.ct-d) .ct-cards{grid-template-columns:repeat(3,1fr)}}
html.ct-m .ct-rail{display:none}html.ct-m .ct-top{display:flex}
html.ct-m .ct-main{margin-left:0;padding:18px 16px 160px}
html.ct-m .ct-top-row{grid-template-columns:1fr;gap:14px;margin-top:12px}
html.ct-m .ct-h1 .ct-num{font-size:84px;letter-spacing:-5px}
html.ct-m .ct-verdict{font-size:25px}
html.ct-m .ct-sub{font-size:14px;margin-top:6px}
html.ct-m .ct-meter{padding:14px 14px 10px}
html.ct-m .ct-ladder{margin-top:18px}
html.ct-m .ct-rungs{grid-template-columns:repeat(21,44px);margin:0 -16px;padding:4px 16px 2px}
html.ct-m .ct-tiers{display:none}
html.ct-m .ct-cards{grid-template-columns:1fr;gap:10px;margin-top:18px}
html.ct-m .ct-ask{left:0;padding:16px 14px calc(22px + env(safe-area-inset-bottom))}
html.ct-m .ct-ask-in{flex-direction:column;align-items:stretch;gap:12px}
html.ct-m .ct-ask h2{font-size:16.5px;letter-spacing:-.3px}html.ct-m .ct-ask p{display:none}
html.ct-m .ct-askf{width:100%}html.ct-m .ct-field{flex:1;min-width:0}html.ct-m .ct-input{width:100%;height:46px;font-size:16px}
html.ct-m .ct-go{height:46px;padding:0 15px;font-size:15px}html.ct-m .ct-gl{display:none}html.ct-m .ct-gs{display:inline}
.ct-swipe{display:none;align-items:center;gap:6px;font-size:12px;font-weight:800;color:var(--ct-green)}
.ct-swipe i{width:18px;height:2px;border-radius:1px;background:var(--ct-green);position:relative;animation:ct-sw 1.6s ease-in-out infinite}
.ct-swipe i::after{content:"";position:absolute;right:-1px;top:-3px;width:6px;height:6px;border-top:2px solid var(--ct-green);border-right:2px solid var(--ct-green);transform:rotate(45deg)}
@keyframes ct-sw{0%,100%{transform:translateX(-3px)}50%{transform:translateX(4px)}}
.ct-rwrap{position:relative}
.ct-rarr{display:none;position:absolute;top:50%;margin-top:-17px;width:34px;height:34px;border-radius:50%;align-items:center;justify-content:center;background:#f3f5f8;color:#06080d;box-shadow:0 4px 14px rgba(0,0,0,.5);z-index:2;transition:opacity .2s}
.ct-rarr.l{left:4px}.ct-rarr.r{right:4px}
.ct-rarr.off{opacity:0;pointer-events:none}
@media (max-width:1023px){html:not(.ct-d) .ct-swipe{display:inline-flex}html:not(.ct-d) .ct-lh-d{display:none}html:not(.ct-d) .ct-rarr{display:flex}html:not(.ct-d) .ct-rwrap.fr .ct-rungs{-webkit-mask-image:linear-gradient(90deg,#000 82%,transparent);mask-image:linear-gradient(90deg,#000 82%,transparent)}html:not(.ct-d) .ct-rwrap.fl.fr .ct-rungs{-webkit-mask-image:linear-gradient(90deg,transparent,#000 18%,#000 82%,transparent);mask-image:linear-gradient(90deg,transparent,#000 18%,#000 82%,transparent)}html:not(.ct-d) .ct-rwrap.fl:not(.fr) .ct-rungs{-webkit-mask-image:linear-gradient(90deg,transparent,#000 18%);mask-image:linear-gradient(90deg,transparent,#000 18%)}}
html.ct-m .ct-swipe{display:inline-flex}html.ct-m .ct-lh-d{display:none}html.ct-m .ct-rarr{display:flex}
html.ct-m .ct-rwrap.fr .ct-rungs{-webkit-mask-image:linear-gradient(90deg,#000 82%,transparent);mask-image:linear-gradient(90deg,#000 82%,transparent)}
html.ct-m .ct-rwrap.fl.fr .ct-rungs{-webkit-mask-image:linear-gradient(90deg,transparent,#000 18%,#000 82%,transparent);mask-image:linear-gradient(90deg,transparent,#000 18%,#000 82%,transparent)}
html.ct-m .ct-rwrap.fl:not(.fr) .ct-rungs{-webkit-mask-image:linear-gradient(90deg,transparent,#000 18%);mask-image:linear-gradient(90deg,transparent,#000 18%)}

/* Our rail (seo-rail.css) already insets <body> on desktop. */
@media (min-width:1024px){.ct-main{margin-left:0}}
.ct-top .ct-login{font-size:13px;font-weight:700;color:var(--ct-t2);border:1px solid var(--ct-line);border-radius:10px;padding:7px 12px}
.ct-faq{margin-top:34px;max-width:940px}
.ct-faq h2{font-size:12px;font-weight:800;letter-spacing:1.6px;text-transform:uppercase;color:var(--ct-t3);margin:0 0 10px}
.ct-faq details{border-top:1px solid var(--ct-line)}
.ct-faq details:last-child{border-bottom:1px solid var(--ct-line)}
.ct-faq summary{cursor:pointer;list-style:none;display:flex;justify-content:space-between;gap:16px;padding:15px 2px;font-size:15px;font-weight:700;color:var(--ct-t1)}
.ct-faq summary::-webkit-details-marker{display:none}
.ct-faq summary::after{content:"+";color:var(--ct-t3);font-weight:800}
.ct-faq details[open] summary::after{content:"\2212"}
.ct-faq p{margin:0 2px 16px;font-size:14px;line-height:1.65;color:var(--ct-t2)}
h2.ct-card-hd{margin:0;font-family:inherit}