:root {
  color-scheme: light;
  --page:#eef1f4; --surface:#fff; --surface-2:#f5f7f9; --ink:#16202b; --muted:#5a6877;
  --line:#cfd7df; --accent:#1c5a88; --accent-dark:#174b72; --green:#1d7448; --green-bg:#e5f2eb;
  --amber:#9a5b00; --amber-bg:#fff3d9; --red:#b02a20; --red-bg:#fbe9e7; --editor:#121a23;
  --editor-text:#dbe4ec; --focus:#bd6418; --shadow:0 12px 32px rgba(31,49,65,.08);
  --sans:"IBM Plex Sans",system-ui,sans-serif; --mono:"IBM Plex Mono",ui-monospace,monospace;
}
@media(prefers-color-scheme:dark){:root{color-scheme:dark;--page:#131b23;--surface:#1c2732;--surface-2:#222f3b;--ink:#e7edf2;--muted:#a2b0bd;--line:#394956;--accent:#76acd4;--accent-dark:#91bee0;--green:#81c69b;--green-bg:#1c382a;--amber:#e5b45b;--amber-bg:#40331c;--red:#f0857d;--red-bg:#402725;--shadow:0 12px 32px rgba(0,0,0,.22)}}
*{box-sizing:border-box} [hidden]{display:none!important}
html{scroll-behavior:smooth} body{margin:0;background:var(--page);color:var(--ink);font:16px/1.55 var(--sans)}
button,input,textarea,select{font:inherit} button{cursor:pointer}
button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible,a:focus-visible,[tabindex]:focus-visible{outline:3px solid var(--focus);outline-offset:2px}
a{color:var(--accent)} code,.mono{font-family:var(--mono)}
.shell{max-width:1180px;margin:0 auto;padding:40px 16px 72px}.start-card{max-width:760px;margin:6vh auto 0;background:var(--surface);border:1px solid var(--line);border-top:5px solid var(--accent);box-shadow:var(--shadow);padding:clamp(24px,5vw,52px)}
.eyebrow{font-size:.76rem;font-weight:700;letter-spacing:.11em;text-transform:uppercase;color:var(--accent)}h1,h2,h3,p{margin-top:0}h1{font-size:clamp(1.9rem,4vw,3rem);line-height:1.08;letter-spacing:-.035em;margin:14px 0 15px}h2{font-size:1.38rem;line-height:1.25}h3{font-size:1.04rem}
.lede{font-size:1.13rem;color:var(--muted);max-width:55ch}.rules{padding-left:1.25rem}.rules li{margin:.55rem 0}.rules li::marker{color:var(--accent)}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:26px}.field{display:flex;flex-direction:column;gap:6px}.field.full{grid-column:1/-1}.field label{font-size:.9rem;font-weight:600}.field input,.field textarea,.field select{width:100%;border:1px solid var(--line);background:var(--surface-2);color:var(--ink);border-radius:4px;padding:11px 12px}.field textarea{min-height:105px;resize:vertical}.checkline{display:flex;gap:10px;align-items:flex-start;margin:18px 0;color:var(--muted)}.checkline input{margin-top:5px;accent-color:var(--accent)}
.btn{border:1px solid var(--accent);background:var(--accent);color:white;padding:10px 16px;border-radius:4px;font-weight:600;transition:transform .15s,background .15s}.btn:hover{background:var(--accent-dark);transform:translateY(-1px)}.btn.secondary{background:transparent;color:var(--accent)}.btn.ghost{background:transparent;color:var(--ink);border-color:var(--line)}.btn.danger{background:var(--red);border-color:var(--red)}.error{color:var(--red);font-weight:600}.notice{padding:12px 14px;border-left:3px solid var(--amber);background:var(--amber-bg);color:var(--ink)}
.test-top{position:sticky;top:0;z-index:5;background:var(--surface);border-bottom:1px solid var(--line);box-shadow:0 3px 12px rgba(20,35,48,.05)}.top-inner{max-width:1180px;margin:auto;padding:10px 16px;display:flex;align-items:center;gap:18px;min-height:64px}.brand{display:flex;align-items:center;gap:10px;font-weight:700;white-space:nowrap}.rsic-mark{width:38px;height:34px;background:var(--accent);color:white;display:grid;place-items:center;font:600 .8rem var(--mono);letter-spacing:.03em}.candidate-name{color:var(--muted);margin-right:auto;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.save-state{font-size:.83rem;color:var(--muted);white-space:nowrap}.save-state.offline{color:var(--amber)}.timer{font:600 1.13rem var(--mono);font-variant-numeric:tabular-nums;padding:7px 10px;border:1px solid var(--line);border-radius:4px}.timer.warn{color:var(--amber);background:var(--amber-bg)}.timer.critical{color:var(--red);background:var(--red-bg)}
.test-shell{max-width:1180px;margin:auto;padding:20px 16px 70px}.part-tabs{display:flex;overflow-x:auto;gap:6px;padding:0 0 15px;border-bottom:1px solid var(--line)}.part-tab{flex:1;min-width:128px;text-align:left;background:var(--surface);color:var(--ink);border:1px solid var(--line);padding:10px;border-radius:4px}.part-tab[aria-selected=true]{border-color:var(--accent);box-shadow:inset 0 -3px var(--accent)}.part-tab.complete{border-color:var(--green);color:var(--green)}.part-tab strong{display:block}.part-tab small{font-size:.76rem;color:var(--muted)}.tab-points{display:block;font-size:.72rem;font-weight:600;color:var(--muted);margin:3px 0}
.part-panel{padding:30px 0 0}.panel-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:20px}.points{font:500 .82rem var(--mono);color:var(--muted);white-space:nowrap}.section-card{background:var(--surface);border:1px solid var(--line);padding:clamp(16px,3vw,25px);margin:18px 0;border-radius:4px}.question{padding:15px 0;border-bottom:1px solid var(--line)}.question:last-child{border:0}.question p{font-weight:600;margin:0 0 10px}.option{display:flex;gap:10px;align-items:flex-start;padding:7px 5px;color:var(--muted)}.option input{margin-top:5px;accent-color:var(--accent)}.editor{display:block;width:100%;min-height:330px;resize:vertical;background:var(--editor);color:var(--editor-text);border:1px solid #354655;border-radius:4px;padding:16px;font:13px/1.55 var(--mono);tab-size:2;white-space:pre;overflow:auto}.editor.short{min-height:130px}.editor.ui-editor{min-height:500px}.editor-label{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:8px;font-weight:600}.button-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin:12px 0}.test-results{padding:12px;background:var(--surface-2);border:1px solid var(--line);font:13px/1.5 var(--mono);white-space:pre-wrap}.pass{color:var(--green)}.fail{color:var(--red)}.schema-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.schema{background:var(--surface-2);border:1px solid var(--line);padding:15px}.schema table,.result-table{width:100%;border-collapse:collapse;font-size:.9rem}.schema td,.schema th,.result-table td,.result-table th{padding:7px 9px;border-bottom:1px solid var(--line);text-align:left}.schema th,.result-table th{background:var(--surface-2);font-weight:600}.null-cell{color:var(--muted);font-style:italic}.sql-task{border-top:1px solid var(--line);padding:18px 0}.sql-task:first-of-type{border-top:0}.two-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:18px}.preview-frame{width:100%;height:540px;border:1px solid var(--line);background:white}.preview-frame.phone{width:min(375px,100%);height:620px}.preview-wrap{display:flex;align-items:flex-start;justify-content:center;background:var(--surface-2);padding:12px;overflow:hidden}.word-count{font:500 .85rem var(--mono);color:var(--muted);text-align:right}.part-footer{display:flex;justify-content:flex-end;margin-top:24px;padding-top:20px;border-top:1px solid var(--line)}
.overlay{position:fixed;inset:0;z-index:20;background:rgba(10,20,30,.55);display:grid;place-items:center;padding:18px}.dialog{width:min(620px,100%);max-height:90dvh;overflow:auto;background:var(--surface);border:1px solid var(--line);padding:26px;box-shadow:var(--shadow)}.dialog-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:22px}.submitted{max-width:650px;margin:10vh auto;padding:40px;background:var(--surface);border:1px solid var(--line);border-top:5px solid var(--green)}
@media(max-width:760px){.shell{padding-top:18px}.top-inner{flex-wrap:wrap;gap:8px}.candidate-name{flex:1}.save-state{order:3}.timer{margin-left:auto}.top-inner>.btn{padding:8px 10px}.part-tab{min-width:115px}.two-col,.schema-grid{grid-template-columns:1fr}.panel-heading{display:block}.points{margin-top:-10px}.editor.ui-editor{min-height:370px}}
@media(max-width:520px){.form-grid{grid-template-columns:1fr}.field.full{grid-column:auto}.start-card{padding:24px 18px}.brand span:last-child{font-size:.88rem}.candidate-name{font-size:.85rem}.test-shell{padding-top:13px}.timer{font-size:1rem}.dialog-actions{flex-direction:column-reverse}.dialog-actions .btn{width:100%}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}