.challenge{--ch-ink:#15364c;--ch-teal:#087e83;--ch-border:#d9e3e9;--ch-muted:#536774;color:var(--ch-ink);max-width:1240px;margin:auto;padding:48px 28px 72px}.ch-hero{grid-template-columns:1.5fr 1fr;align-items:center;gap:42px;padding-bottom:40px;display:grid}.ch-eyebrow{letter-spacing:.13em;text-transform:uppercase;color:var(--ch-teal);margin:0 0 12px;font-size:.73rem;font-weight:750}.challenge h1{letter-spacing:-.035em;max-width:820px;margin:12px 0 18px;font-size:clamp(2rem,4.8vw,3.5rem);line-height:1.08}.challenge h2{margin:0 0 12px;font-size:clamp(1.35rem,3vw,1.8rem);line-height:1.2}.challenge h3{margin:0 0 10px;font-size:1.05rem;line-height:1.35}.challenge p{line-height:1.65}.ch-lead{color:var(--ch-muted);max-width:760px;font-size:1.08rem}.ch-muted{color:var(--ch-muted)}.ch-small{font-size:.82rem}.ch-actions{flex-wrap:wrap;align-items:center;gap:12px;margin-top:18px;display:flex}.ch-button{color:var(--ch-ink);cursor:pointer;background:#fff;border:1px solid #bacbd5;border-radius:7px;justify-content:center;align-items:center;gap:8px;min-height:42px;padding:10px 15px;font-size:.86rem;font-weight:650;text-decoration:none;display:inline-flex}.ch-button:hover{border-color:var(--ch-teal);background:#f0f8f8}.ch-button:disabled{opacity:.5;cursor:not-allowed}.ch-primary{background:var(--ch-ink);border-color:var(--ch-ink);color:#fff}.ch-primary:hover{color:#fff;background:#20516b}.ch-text-link{color:#066b74;font-size:.87rem;font-weight:650}.ch-pill{border:1px solid var(--ch-border);background:#f2f7fa;border-radius:30px;align-items:center;gap:6px;padding:5px 10px;font-size:.72rem;font-weight:700;display:inline-flex}.ch-pill-open{color:#07666b;background:#e8f6f4;border-color:#aad8d3}.ch-pill-waiting{color:#735b25;background:#fff8e7;border-color:#e8d7ab}.ch-hero-panel{border:1px solid var(--ch-border);border-top:4px solid var(--ch-teal);background:linear-gradient(140deg,#f6fafb,#fff);border-radius:9px;padding:28px}.ch-hero-panel ol{counter-reset:steps;margin:0;padding:0;list-style:none}.ch-hero-panel li{counter-increment:steps;border-bottom:1px solid var(--ch-border);padding:12px 0 12px 40px;font-weight:650;position:relative}.ch-hero-panel li:last-child{border:0}.ch-hero-panel li:before{content:"0" counter(steps);color:var(--ch-teal);font-size:.75rem;position:absolute;top:14px;left:0}.ch-section{margin-top:36px}.ch-section-heading{justify-content:space-between;align-items:flex-end;gap:24px;margin-bottom:20px;display:flex}.ch-section-heading p{margin:8px 0 0}.ch-card{border:1px solid var(--ch-border);background:#fff;border-radius:9px;min-width:0;padding:24px}.ch-card-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;display:grid}.ch-card-top{justify-content:space-between;align-items:center;gap:12px;margin-bottom:16px;display:flex}.ch-empty{text-align:center;background:#f9f9f5;border:1px dashed #b4c9d4;border-radius:9px;padding:34px 24px}.ch-empty p{max-width:700px;color:var(--ch-muted);margin:10px auto}.ch-empty .ch-actions{justify-content:center}.ch-note{border-left:3px solid var(--ch-teal);background:#eff7f8;border-radius:3px;margin:18px 0;padding:16px 18px;font-size:.86rem}.ch-note p{margin:5px 0}.ch-warning{background:#fff8eb;border-color:#a87a26}.ch-error{color:#9e2525;background:#fff2f0;border-radius:6px;padding:12px 16px}.ch-status{color:var(--ch-teal);padding:10px 0;font-size:.88rem}.ch-definition-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:0 24px;margin:0;display:grid}.ch-definition-list>div{border-bottom:1px solid var(--ch-border);min-width:0;padding:12px 0}.ch-definition-list dt{text-transform:uppercase;letter-spacing:.05em;color:var(--ch-muted);font-size:.74rem;font-weight:700}.ch-definition-list dd{overflow-wrap:anywhere;margin:5px 0 0;font-size:.88rem}.ch-hash{overflow-wrap:anywhere;font-family:ui-monospace,SFMono-Regular,monospace;font-size:.72rem}.ch-details{border:1px solid var(--ch-border);border-radius:7px;margin-top:18px;padding:14px 16px}.ch-details summary{cursor:pointer;font-size:.86rem;font-weight:700}.ch-details p,.ch-details li{font-size:.84rem}.ch-details ul{padding-left:20px}.ch-history{padding-left:24px}.ch-history li{padding:7px 0}.ch-history strong{display:block}.ch-field{flex-direction:column;gap:6px;min-width:0;font-size:.82rem;font-weight:650;display:flex}.ch-field input,.ch-field select,.ch-field textarea{width:100%;color:var(--ch-ink);font:inherit;background:#fff;border:1px solid #b8c9d3;border-radius:6px;min-height:42px;padding:10px 11px;font-weight:400}.ch-field textarea{resize:vertical;min-height:98px}.ch-field input[type=file]{padding:8px;font-size:.76rem}.ch-form-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}.ch-full{grid-column:1/-1}.ch-checkbox{align-items:flex-start;gap:9px;font-size:.84rem;font-weight:400;line-height:1.55;display:flex}.ch-checkbox input{width:17px;height:17px;accent-color:var(--ch-teal);flex:none;margin-top:3px}.ch-checkbox span{flex:1}.ch-form-block{border:0;margin:24px 0 0;padding:0}.ch-form-block legend{margin-bottom:16px;font-size:1.08rem;font-weight:700}.ch-workspace-header{border-bottom:1px solid var(--ch-border);padding-bottom:25px}.ch-workspace-grid{grid-template-columns:245px minmax(0,1fr);align-items:start;gap:24px;margin-top:26px;display:grid}.ch-case-list{flex-direction:column;gap:10px;display:flex}.ch-case-button{text-align:left;border:1px solid var(--ch-border);color:var(--ch-ink);cursor:pointer;background:#fff;border-radius:7px;padding:14px}.ch-case-button[aria-pressed=true]{border-color:var(--ch-teal);box-shadow:inset 3px 0 var(--ch-teal);background:#eff8f7}.ch-case-button strong,.ch-case-button small{display:block}.ch-case-button small{color:var(--ch-muted);margin-top:7px}.ch-stats{grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:20px 0;display:grid}.ch-stats>div{border:1px solid var(--ch-border);background:#f8fbfc;border-radius:6px;padding:15px}.ch-stats span,.ch-stats small{color:var(--ch-muted);font-size:.71rem;line-height:1.4;display:block}.ch-stats strong{margin:8px 0;font-size:1.5rem;display:block}.ch-table-wrap{border:1px solid var(--ch-border);border-radius:6px;max-width:100%;margin:16px 0;overflow-x:auto}.challenge table{border-collapse:collapse;text-align:left;width:100%;font-size:.79rem}.challenge caption{caption-side:top;text-align:left;color:var(--ch-muted);padding:12px;font-size:.76rem}.challenge th{white-space:nowrap;background:#eef4f7;font-size:.73rem}.challenge th,.challenge td{border-bottom:1px solid var(--ch-border);vertical-align:top;padding:11px 12px}.challenge td small{color:var(--ch-muted);margin-top:4px;display:block}.ch-chart{margin:20px 0}.ch-chart svg{background:#fff;width:100%;height:auto;max-height:420px;display:block}.ch-chart svg text{fill:#536774;font-size:11px}.ch-chart figcaption{flex-wrap:wrap;gap:14px;padding:7px 0;font-size:.76rem;display:flex}.ch-chart figcaption span{align-items:center;gap:7px;display:inline-flex}.ch-chart figcaption i{width:20px;height:3px;display:inline-block}.ch-chart .ch-axis{fill:none;stroke:#8ca0ae;stroke-width:1px}.ch-chart .ch-grid-line{stroke:#e5edf1;stroke-width:1px}.ch-footer{border-top:1px solid var(--ch-border);color:var(--ch-muted);margin-top:40px;padding-top:24px;font-size:.79rem}.ch-limits{color:var(--ch-muted);font-size:.82rem;line-height:1.65}.challenge :focus-visible{outline-offset:3px;outline:3px solid #129399}.ch-split{grid-template-columns:1fr 1fr;gap:20px;display:grid}.ch-replication{border-left:3px solid #729ab1}.ch-line-break{white-space:pre-wrap}@media (max-width:1000px){.ch-card-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.ch-workspace-grid{grid-template-columns:205px minmax(0,1fr)}.ch-stats{grid-template-columns:repeat(2,minmax(0,1fr))}.ch-hero{gap:24px}}@media (max-width:700px){.challenge{padding:28px 16px 48px}.ch-hero{grid-template-columns:1fr;gap:20px;padding-bottom:20px}.ch-hero-panel{padding:20px}.ch-card-grid,.ch-definition-list,.ch-form-grid,.ch-split,.ch-workspace-grid{grid-template-columns:1fr}.ch-case-list{flex-direction:row;padding-bottom:8px;overflow-x:auto}.ch-case-button{min-width:220px}.ch-section-heading{flex-direction:column;align-items:flex-start;gap:10px}.ch-card{padding:18px}.ch-full{grid-column:auto}.ch-actions{gap:9px}.ch-button{padding:9px 12px;font-size:.81rem}.ch-stats{gap:8px}.ch-stats>div{padding:12px}.ch-empty{padding:26px 18px}.ch-table-wrap{margin-top:12px}}