:root{--ink:#172536;--muted:#61788c;--line:#d7e2e5;--surface:#f4f8f8;--teal:#0b7a5a;--orange:#e67534}*{box-sizing:border-box}body{margin:0;background:#f7faf9;color:var(--ink);font:15px/1.5 system-ui,-apple-system,"Segoe UI",sans-serif}.practice-header{background:#fff;border-bottom:1px solid var(--line)}.practice-shell{max-width:1500px;margin:auto;padding:34px clamp(18px,4vw,56px) 60px}.practice-hero{max-width:760px;margin-bottom:26px}.eyebrow{margin:0 0 10px;color:var(--orange);font-size:12px;font-weight:800;letter-spacing:.14em;text-transform:uppercase}.practice-hero h1{margin:0;font-size:clamp(32px,4vw,56px);line-height:1.05;letter-spacing:-.04em}.practice-hero p:last-child{color:var(--muted);font-size:18px}.practice-layout{display:grid;grid-template-columns:260px minmax(0,1fr);gap:18px}.challenge-sidebar,.challenge-workspace{border:1px solid var(--line);border-radius:18px;background:#fff;box-shadow:0 10px 26px rgba(23,37,54,.06)}.challenge-sidebar{padding:18px}.challenge-sidebar label,.practice-actions label{display:block;font-size:12px;font-weight:800;margin:11px 0 5px}.challenge-sidebar select,.practice-actions select{width:100%;padding:10px;border:1px solid var(--line);border-radius:9px;background:#fff;color:var(--ink);font:inherit}.challenge-list{margin-top:18px}.challenge-item{display:block;width:100%;text-align:left;border:1px solid var(--line);border-radius:10px;background:var(--surface);padding:11px;margin:8px 0;cursor:pointer}.challenge-item.active{border-color:var(--orange);box-shadow:0 0 0 2px #e6753422}.challenge-item strong,.challenge-item small{display:block}.challenge-item small{color:var(--muted);margin-top:3px}.challenge-workspace{padding:24px}.challenge-meta{color:var(--teal);font-weight:800;font-size:12px;text-transform:uppercase;letter-spacing:.08em}.challenge-workspace h2{font-size:32px;margin:8px 0}.challenge-workspace>p{color:var(--muted);font-size:17px}.challenge-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.challenge-grid>div{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:12px}.challenge-grid h3{margin:0 0 6px;font-size:13px}.challenge-grid pre{margin:0;white-space:pre-wrap;color:var(--muted);font:13px/1.5 Consolas,monospace}.practice-actions{display:flex;align-items:end;gap:8px;margin:20px 0 8px}.practice-actions label{margin:0}.practice-actions select{width:150px}.practice-actions button{padding:10px 13px;border:1px solid var(--line);border-radius:9px;background:#fff;cursor:pointer}.practice-actions .primary{background:var(--teal);border-color:var(--teal);color:#fff}.practice-actions button:hover{border-color:var(--teal)}#practice-editor{display:block;width:100%;min-height:300px;resize:vertical;padding:16px;border:0;border-radius:10px;background:#101820;color:#ddf7e9;font:14px/1.6 Consolas,monospace;outline:0}.practice-result{margin-top:15px;border:1px solid var(--line);border-radius:10px;overflow:hidden}.practice-result strong{display:block;padding:9px 12px;background:var(--surface)}.practice-result pre{min-height:95px;margin:0;padding:13px;white-space:pre-wrap;background:#f8fbfa;font:13px/1.5 Consolas,monospace}.hint-box{margin-top:15px;padding:12px;background:#fff7e7;border:1px solid #eed79c;border-radius:10px}.hint-box p{margin:8px 0 0}.runner-note{font-size:12px!important;color:var(--muted)!important}code{background:#eef3f2;padding:2px 5px;border-radius:4px}@media(max-width:900px){.practice-layout{grid-template-columns:1fr}.challenge-sidebar{order:2}.challenge-workspace{order:1}.challenge-grid{grid-template-columns:1fr}.practice-actions{flex-wrap:wrap}.practice-actions select{width:100%}.practice-actions button{flex:1}}
