.ch-container{width:min(var(--container),100% - 32px);margin-inline:auto}.ch-section{padding:56px 0;border-top:1px solid var(--line-soft)}.ch-section:first-of-type{border-top:0}.ch-grid{display:grid;gap:16px}@media(min-width:720px){.ch-grid-2{grid-template-columns:repeat(2,1fr)}.ch-grid-3{grid-template-columns:repeat(3,1fr)}.ch-grid-4{grid-template-columns:repeat(4,1fr)}}.ch-reg-grid{display:grid;gap:24px}@media(min-width:980px){.ch-reg-grid{grid-template-columns:1.5fr 1fr;align-items:start}}.ch-reg-aside{position:sticky;top:84px}.ch-reg .ch-card+.ch-card,.ch-dash .ch-card+.ch-card{margin-top:16px}.ch-muted{color:var(--muted)}.ch-lead{color:var(--muted);font-size:17px;max-width:62ch}.ch-label{display:block;color:var(--muted);font-size:12px;letter-spacing:.06em;text-transform:uppercase;margin-bottom:10px}.ch-fineprint{font-size:13px;margin-top:12px}.ch-block{width:100%}.ch-code{background:var(--panel2);border:1px solid var(--line);border-radius:var(--r-sm);padding:12px 14px;overflow-x:auto;font-family:var(--mono);font-size:14px}.ch-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:11px 18px;border-radius:var(--r-pill);border:1px solid var(--line);color:var(--ink);font-weight:600;font-size:15px;cursor:pointer;text-decoration:none}.ch-btn:hover{text-decoration:none;border-color:var(--accent)}.ch-btn-primary{background:var(--accent-btn);border-color:var(--accent-btn);color:#fff}.ch-btn-primary:hover{filter:brightness(1.08)}.ch-btn[disabled],.ch-btn[aria-disabled=true]{opacity:.55;pointer-events:none}.ch-btn-sm{padding:7px 12px;font-size:13px}.ch-card{background:var(--panel);border:1px solid var(--line);border-radius:var(--r-md);padding:20px}.ch-card-accent{border-color:var(--accent)}.ch-chip{margin-bottom:12px;display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border-radius:var(--r-pill);background:var(--chip);color:var(--accent);font-size:12px;font-weight:700;letter-spacing:.06em;text-transform:uppercase}.ch-field-label{display:block;font-size:14px;font-weight:600;margin:14px 0 6px}.ch-field-row{display:flex;gap:8px;flex-wrap:wrap}.ch-field-row .ch-input{flex:1 1 220px}.ch-input{width:100%;padding:11px 14px;border-radius:var(--r-sm);border:1px solid var(--line);background:var(--panel2);color:var(--ink);font:inherit}.ch-input option{background-color:var(--panel2);color:var(--ink)}.ch-input:focus{outline:2px solid var(--accent);outline-offset:1px}.ch-input[aria-invalid=true]{border-color:var(--rose)}.ch-field-hint,.ch-field-error{font-size:13px;margin:6px 0 0}.ch-field-error{color:var(--rose)}.ch-alert{border-radius:var(--r-sm);padding:10px 14px;font-size:14px;border:1px solid var(--line)}.ch-alert-error{border-color:var(--rose);color:var(--rose)}.ch-alert-warn{border-color:var(--amber);color:var(--amber)}.ch-alert-ok{border-color:var(--green);color:var(--green)}.ch-tabs{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0}.ch-tab{padding:8px 16px;border-radius:var(--r-pill);border:1px solid var(--line);color:var(--muted);font-size:14px}.ch-tab:hover{text-decoration:none;border-color:var(--accent)}.ch-tab.is-active{background:var(--chip);border-color:var(--accent);color:var(--accent);font-weight:600}.ch-back{display:inline-block;margin-bottom:18px;font-size:14px;color:var(--muted)}.ch-avatar{display:grid;place-items:center;width:36px;height:36px;border-radius:var(--r-pill);background:var(--chip);color:var(--accent);font-weight:700;font-size:13px}.ch-avatar-sm{width:26px;height:26px;font-size:11px;display:inline-grid;vertical-align:middle;margin-right:8px}.ch-avatar-lg{width:64px;height:64px;font-size:22px}.ch-list{padding-left:18px;margin:0 0 14px;color:var(--muted)}.ch-list li{margin-bottom:8px}.ch-doclist{list-style:none;padding:0;margin:0 0 16px;display:grid;gap:12px}.ch-doclist li{display:grid;gap:2px}.ch-roster{list-style:none;padding:0;margin:0 0 16px;display:grid;gap:10px}.ch-roster li{display:flex;align-items:center;gap:12px}.ch-roster-text{display:flex;flex-direction:column;line-height:1.25;margin-right:auto}.ch-table-wrap{overflow-x:auto}.ch-table{width:100%;border-collapse:collapse;font-size:15px}.ch-table th,.ch-table td{padding:12px 10px;text-align:left;border-bottom:1px solid var(--line-soft)}.ch-table th{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.06em}.ch-num{text-align:right;font-variant-numeric:tabular-nums}.ch-board-cards{list-style:none;padding:0;margin:0;display:grid;gap:10px}.ch-board-cards li{display:flex;align-items:center;gap:12px;padding:14px}.ch-rank{font-size:18px;font-weight:800;color:var(--muted);min-width:22px}.ch-board-card-text{display:flex;flex-direction:column;line-height:1.3;margin-right:auto}.ch-board-card-score{font-size:18px;font-weight:700;color:var(--accent);font-variant-numeric:tabular-nums}.ch-countdown-value{font-size:34px;font-weight:800;color:var(--accent);letter-spacing:-1px;line-height:1}.ch-countdown-note{font-size:13px;margin:10px 0 16px}.ch-faq{border-bottom:1px solid var(--line-soft);padding:14px 0}.ch-faq summary{cursor:pointer;font-weight:600}.ch-faq p{margin:10px 0 0}.ch-video{position:relative;aspect-ratio:16 / 9;margin-bottom:24px;border-radius:var(--r-md);overflow:hidden;border:1px solid var(--line)}.ch-video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}.challenge-root{--bg: #0e0b1e;--panel: #131625;--panel2: #1a1e33;--band: #1a1235;--line: #3a3f58;--line-soft: rgba(255, 255, 255, .1);--accent: #2ce3ce;--accent-btn: #1fb9a7;--accent-ink: #04231f;--chip: #0d3b36;--ink: #e0faff;--muted: #8f9cae;--amber: #f5b43c;--rose: #f56a7a;--green: #4fd18b;--r-sm: 8px;--r-md: 14px;--r-lg: 16px;--r-pill: 9999px;--container: 1280px;--font: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;--mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", monospace;background:var(--bg);color:var(--ink);color-scheme:dark}.challenge-root body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font);line-height:1.6}.challenge-root *,.challenge-root *:before,.challenge-root *:after{box-sizing:border-box}.challenge-root a{text-decoration:none}.challenge-root a:hover{text-decoration:underline}.challenge-root h1,.challenge-root h2,.challenge-root h3{line-height:1.15;letter-spacing:-.02em;margin:0 0 12px}.challenge-root h1{font-size:clamp(32px,5vw,56px);font-weight:800}.challenge-root h2{font-size:clamp(24px,3.2vw,34px);font-weight:700}.challenge-root h3{font-size:18px;font-weight:700}.challenge-root p{margin:0 0 14px}.skip{position:absolute;left:-9999px}.skip:focus{left:12px;top:12px;z-index:100;background:var(--accent-btn);color:var(--accent-ink);padding:10px 16px;border-radius:var(--r-sm)}.ch-header{position:sticky;top:0;z-index:40;background:#0e0b1edb;backdrop-filter:blur(10px);border-bottom:1px solid var(--line-soft)}.ch-header-inner{display:flex;align-items:center;gap:20px;min-height:64px}.ch-brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none}.ch-brand:hover{text-decoration:none}.ch-brand-mark{display:grid;place-items:center;width:34px;height:34px;border-radius:var(--r-sm);background:var(--chip);color:var(--accent);font-weight:800;font-size:13px}.ch-brand-text{display:flex;flex-direction:column;line-height:1.15}.ch-brand-text small{color:var(--muted);font-size:12px}.ch-nav{display:none;gap:18px;margin-left:auto;font-size:14px}.ch-nav a{color:var(--muted)}.ch-nav a:hover,.ch-nav a[aria-current=page]{color:var(--ink);text-decoration:none}.ch-header-cta{display:none}.ch-burger{margin-left:auto;display:grid;gap:4px;padding:10px;background:none;border:1px solid var(--line);border-radius:var(--r-sm);cursor:pointer}.ch-burger span{display:block;width:18px;height:2px;background:var(--ink)}@media(min-width:900px){.ch-nav,.ch-header-cta{display:flex}.ch-burger{display:none}.ch-header-cta{margin-left:0}}.ch-drawer{position:fixed;inset:0;z-index:60;background:#0009}.ch-drawer[hidden]{display:none}.ch-drawer-panel{position:absolute;inset:0 0 0 auto;width:min(320px,86%);background:var(--panel);border-left:1px solid var(--line);padding:20px;display:flex;flex-direction:column;gap:8px}.ch-drawer-close{align-self:flex-end;background:none;border:0;color:var(--ink);font-size:20px;cursor:pointer}.ch-drawer-nav{display:flex;flex-direction:column;gap:4px;margin-bottom:12px}.ch-drawer-nav a{color:var(--ink);padding:12px 8px;border-bottom:1px solid var(--line-soft)}.ch-footer{border-top:1px solid var(--line-soft);padding:32px 0 96px;color:var(--muted)}.ch-footer-inner{display:flex;flex-wrap:wrap;gap:20px;justify-content:space-between}.ch-footer-nav{display:flex;flex-wrap:wrap;gap:16px;font-size:14px}.ch-sticky-cta{position:fixed;left:0;right:0;bottom:0;z-index:30;padding:12px 16px calc(12px + env(safe-area-inset-bottom));background:#0e0b1ef0;border-top:1px solid var(--line);backdrop-filter:blur(10px)}.ch-sticky-cta .ch-btn{width:100%}@media(min-width:900px){.ch-sticky-cta{display:none}.ch-footer{padding-bottom:32px}}@media(prefers-reduced-motion:reduce){.challenge-root *{animation:none!important;transition:none!important}}