:root{color-scheme:dark;--ink:#121712;--paper:#eeeede;--muted:#adb4a4;--line:#3a4438;--accent:#8ecfc9}
*{box-sizing:border-box}body{margin:0;background:var(--ink);color:var(--paper);font-family:'Avenir Next','Trebuchet MS',sans-serif}a{color:inherit}button{font:inherit}.shell{width:min(1240px,calc(100% - 64px));margin:auto}header{height:86px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.wordmark{font-weight:800;letter-spacing:.05em;font-size:16px;text-decoration:none}.wordmark span{font-weight:400;color:var(--muted)}.availability,.eyebrow,.section-label,.stage-top,footer>span{font:11px/1.5 ui-monospace,'SFMono-Regular',monospace;letter-spacing:.08em}.availability{display:flex;align-items:center;gap:9px;color:var(--muted)}.availability i{width:7px;height:7px;border-radius:50%;background:#8ecfc9}.intro{display:flex;align-items:end;justify-content:space-between;padding:40px 0 34px}.eyebrow{color:var(--muted);margin:0 0 20px}h1{font:400 clamp(56px,6.5vw,86px)/.9 'Bodoni 72',Didot,Georgia,serif;letter-spacing:-.045em;margin:0}h1 em{color:#c8ff35;font-weight:400}.intro-copy{margin:0 0 5px;color:var(--muted);font-size:15px;line-height:1.8}.workspace{display:grid;grid-template-columns:1fr 1.05fr;gap:24px;align-items:stretch}.section-label{display:flex;justify-content:space-between;color:var(--muted);margin-bottom:12px}.section-label span:last-child{font-size:10px}#challenge-list{display:grid;grid-template-columns:1fr 1fr;gap:10px}.challenge{position:relative;display:flex;align-items:center;gap:14px;min-height:94px;padding:16px;border:1px solid var(--line);border-left:3px solid var(--tone);text-decoration:none;transition:background .15s,border-color .15s}.challenge:hover{background:#20291f}.challenge[aria-current=true]{border-color:var(--tone);background:color-mix(in srgb,var(--tone) 13%,var(--ink))}.challenge:last-child{grid-column:1/-1;min-height:65px}.challenge svg{width:34px;height:34px;flex-shrink:0;color:var(--tone);fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}.challenge strong{display:block;font-size:17px;font-weight:600}.challenge small{display:block;color:var(--muted);font-size:11px;line-height:1.5;margin-top:3px}.challenge .arrow{margin-left:auto;color:var(--tone);font-size:18px}.stage{min-width:0;display:flex;flex-direction:column;border:1px solid var(--line);background:#1b231b;min-height:430px}.stage-top{display:flex;gap:12px;justify-content:space-between;padding:17px 23px;border-bottom:1px solid var(--line)}#challenge-number{color:var(--accent)}#status{color:var(--muted);letter-spacing:0}#status[data-phase=passed]{color:#8ecfc9}#status[data-phase=error],#status[data-phase=rejected]{color:#ffbe7a}.stage-heading{padding:27px 28px 0}.stage h2{font-size:31px;font-weight:500;letter-spacing:-.03em;margin:0 0 8px}.stage-heading p{margin:0;color:var(--muted);font-size:14px}.captcha-area{position:relative;min-height:170px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:30px 16px;flex:1}.captcha-area>p{font-size:13px;text-align:center;color:var(--muted);max-width:340px;line-height:1.6}.captcha-area>p[hidden]{display:none}#captcha-host{color-scheme:light;max-width:100%}.stage-actions{display:flex;justify-content:space-between;gap:12px;align-items:center;margin:0 28px;padding:19px 0;border-top:1px solid var(--line)}.stage-actions button{border:0;cursor:pointer;padding:11px 16px;font-size:13px;font-weight:600;background:var(--accent);color:var(--ink);display:flex;gap:18px;align-items:center}.stage-actions button:hover{filter:brightness(1.1)}.stage-actions a{font-size:12px;color:var(--muted);text-decoration:none}.stage-actions a:hover{text-decoration:underline}.feedback-note{margin:0;padding:0 28px 23px;color:var(--muted);font-size:12px;line-height:1.6;min-height:42px}.how-to{display:flex;gap:22px;justify-content:space-between;border-top:1px solid var(--line);margin-top:30px;padding:12px 0 25px}.how-to p{font-size:12px;line-height:1.6;color:var(--muted)}.how-to b{color:var(--paper);font:12px ui-monospace,monospace;margin-right:10px}footer{display:flex;justify-content:space-between;align-items:start;gap:24px;border-top:1px solid var(--line);padding:24px 0 30px;color:var(--muted)}footer>span{white-space:nowrap}footer p{max-width:510px;font-size:11px;line-height:1.6;margin:0}footer a{font-size:11px;white-space:nowrap;text-decoration:none}a:focus-visible,button:focus-visible{outline:2px solid var(--paper);outline-offset:4px}
.demo-notice{display:flex;align-items:baseline;gap:18px;margin:0 0 26px;padding:15px 18px;border:1px solid var(--line);border-left:3px solid #ffbe7a;background:#1b231b}
.demo-notice strong{flex-shrink:0;color:#ffbe7a;font:11px/1.7 ui-monospace,'SFMono-Regular',monospace;letter-spacing:.08em}
.demo-notice p{margin:0;color:var(--muted);font-size:13px;line-height:1.7}
.demo-notice a{color:var(--paper);text-underline-offset:3px}
@media(min-width:1550px){.intro{padding-top:55px;padding-bottom:45px}}@media(max-width:850px){.shell{width:calc(100% - 36px)}.workspace{grid-template-columns:1fr}.intro{gap:24px}.intro-copy{font-size:13px}.challenge{min-height:80px}.stage{min-height:390px}.how-to{flex-wrap:wrap;gap:0 20px}footer{flex-wrap:wrap}footer p{max-width:100%}}@media(max-width:480px){header{height:66px}.availability{font-size:8px}.wordmark{font-size:12px}.intro{padding:28px 0;display:block}.intro-copy{margin-top:20px}.eyebrow{font-size:9px}.demo-notice{display:block}.demo-notice strong{display:block;margin-bottom:6px}.challenge{padding:13px 10px;gap:9px}.challenge strong{font-size:15px}.challenge small{font-size:10px}.challenge svg{width:25px;height:25px}.challenge .arrow{display:none}.stage-heading{padding:24px 20px 0}.stage-actions{margin:0 20px}.feedback-note{padding-left:20px;padding-right:20px}.stage-top{padding:15px 20px}.how-to{display:block}.stage h2{font-size:28px}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}