/* StudyExam Lab kit: styles for the step-by-step built-in labs (assets/lab-kit.js). Everything is scoped to .lk */
.lk{font-size:15px;line-height:1.5;color:var(--ink);border-radius:16px;overflow:hidden;background:var(--bench);border:1px solid #e2e8f0}
.lk *,.lk *::before,.lk *::after{box-sizing:border-box}
.lk .lk-bar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 16px;background:var(--paper);border-bottom:1px solid var(--line)}
.lk .lk-bar p{margin:0;color:var(--soft);font-size:.85rem}
.lk .lk-lab{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(290px,1fr);min-height:520px}
.lk .stage{position:relative;display:flex;align-items:center;justify-content:center;padding:8px;min-height:520px}
.lk .stage svg{width:100%;height:100%;max-height:600px;display:block}
.lk .panel{max-height:640px}
.lab-box.lk-box{padding:0;border:1px solid #e2e8f0;box-shadow:0 1px 3px rgba(15,23,42,.06);background:var(--bench)}
.lk .empty{border:0;background:none;padding:0;margin:0;min-height:0;display:block;text-align:left;border-radius:0;box-shadow:none}
.lk td.empty{padding:5px 6px}
.lk .chips>p.empty{width:100%;margin:6px 0 2px}
.lk{--bench:#e6ecf0;--paper:#fff;--ink:#18222c;--soft:#566573;--line:#cfd8df;--glass:#6b7c8c;--act:#0e6f86;--act2:#0a5566;--pos:#177245;--neg:#a1213f;--warn:#9a5b06}
.lk .lang{border:1px solid var(--line);background:var(--bench);border-radius:8px;padding:6px 12px;font:inherit;font-weight:700;cursor:pointer;color:var(--ink);white-space:nowrap}
.lk .panel{background:var(--paper);border-left:1px solid var(--line);overflow-y:auto;padding:12px 14px 20px}
.lk .block{padding:10px 0;border-bottom:1px solid #edf1f4}
.lk .block:last-child{border-bottom:0}
.lk .block h2{font-size:.9rem;margin:0 0 8px;color:var(--soft);font-weight:700}
.lk .chips{display:flex;flex-wrap:wrap;gap:6px}
.lk .chips+.chips{margin-top:8px}
.lk .chip{border:1.5px solid var(--line);background:#fff;border-radius:999px;padding:5px 11px;font:inherit;font-size:.85rem;cursor:pointer;color:var(--ink);display:inline-flex;align-items:center;gap:6px}
.lk .chip .dot{width:11px;height:11px;border-radius:50%;border:1px solid rgba(0,0,0,.2)}
.lk .chip:hover{border-color:var(--glass)}
.lk .chip.on{border-color:var(--act);background:#e4f3f6;font-weight:700}
.lk .chip.done{opacity:.55}
.lk .chip:disabled{cursor:not-allowed;opacity:.45}
.lk .steps{list-style:none;margin:0;padding:0;counter-reset:s}
.lk .steps li{counter-increment:s;display:flex;gap:10px;align-items:flex-start;padding:7px 0}
.lk .steps li::before{content:counter(s);flex:0 0 24px;height:24px;border-radius:50%;display:grid;place-items:center;font-size:.8rem;font-weight:700;background:var(--bench);color:var(--soft)}
.lk .steps li.cur::before{background:var(--act);color:#fff}
.lk .steps li.ok::before{content:"✓";background:#d8efe2;color:var(--pos)}
.lk .steps .txt{flex:1;font-size:.9rem}
.lk .steps li.todo .txt{color:#8a97a3}
.lk .steps button{margin-top:5px}
.lk button.go{background:var(--act);color:#fff;border:0;border-radius:8px;padding:7px 14px;font:inherit;font-weight:700;font-size:.85rem;cursor:pointer}
.lk button.go:hover{background:var(--act2)}
.lk button.go:disabled{background:#9fb3bb;cursor:wait}
.lk button.ghost{background:none;border:1px solid var(--line);border-radius:8px;padding:6px 12px;font:inherit;font-size:.82rem;cursor:pointer;color:var(--soft)}
.lk .row{margin-top:6px}
.lk .obs{background:#f4f8fa;border-radius:10px;padding:10px 12px;margin-top:10px;border:0}
.lk .obs b{display:block;margin-bottom:2px}
.lk .obs .tag{display:inline-block;font-size:.78rem;font-weight:700;border-radius:6px;padding:1px 8px;margin-top:6px}
.lk .tag.pos{background:#d8efe2;color:var(--pos)}.tag.neg{background:#f6dde3;color:var(--neg)}
.lk .obs p{margin:4px 0 0;font-size:.88rem}
.lk .tablewrap{overflow-x:auto}
.lk table{border-collapse:collapse;width:100%;font-size:.82rem}
.lk th,.lk td{text-align:left;padding:5px 6px;border-bottom:1px solid #edf1f4;vertical-align:top}
.lk th{color:var(--soft);font-weight:700}
.lk td .sw{display:inline-block;width:12px;height:12px;border-radius:3px;vertical-align:-2px;margin-right:5px;border:1px solid rgba(0,0,0,.15)}
.lk .empty{color:#8a97a3;font-size:.85rem;margin:0}
.lk .q p{margin:0 0 8px;font-weight:700;font-size:.9rem}
.lk .q .opt{display:block;width:100%;text-align:left;border:1.5px solid var(--line);background:#fff;border-radius:8px;padding:7px 10px;margin-bottom:6px;font:inherit;font-size:.86rem;cursor:pointer;color:var(--ink)}
.lk .q .opt.right{border-color:var(--pos);background:#e5f4ec}
.lk .q .opt.wrong{border-color:var(--neg);background:#fbe9ed}
.lk .q .why{font-size:.85rem;color:var(--soft);margin:4px 0 8px}
.lk .toast{position:absolute;left:50%;top:12px;transform:translateX(-50%);background:var(--ink);color:#fff;border-radius:8px;padding:7px 14px;font-size:.85rem;max-width:90%;text-align:center}
.lk .toast.warn{background:var(--warn)}
.lk .clock{position:absolute;right:14px;top:12px;background:#fff;border:1px solid var(--line);border-radius:8px;padding:4px 10px;font-weight:700;font-size:.85rem}
.lk button:focus-visible,.lk .chip:focus-visible{outline:3px solid #f2b705;outline-offset:2px}
@media (max-width:760px){.lk .lk-lab{grid-template-columns:1fr}.lk .stage{height:auto;min-height:0;aspect-ratio:420/440;max-height:none}.lk .panel{border-left:0;border-top:1px solid var(--line);max-height:none;overflow:visible}}
@media (prefers-reduced-motion:reduce){.lk *{transition:none!important}}
/* the site has its own .q, .chip and .opt styles: reset them inside the lab */
.lk .q{display:block;grid-template-columns:none;gap:0;background:none;border:0;border-radius:0;padding:0;margin:0}
.lk .chip{font-weight:400;text-decoration:none}
.lk .chip.on{color:var(--ink);font-weight:700}
.lk .q .opt{display:block;gap:0}
.lk .q .opt:hover{border-color:var(--glass);background:#fff}
.lk .q .opt.right:hover{background:#e5f4ec;border-color:var(--pos)}
.lk .q .opt.wrong:hover{background:#fbe9ed;border-color:var(--neg)}