@import url('https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500&display=swap');

:root{
 --bg:#f5f4f0;--surface:#ffffff;--surface-2:#efeee9;--ink:#16171a;--ink-2:#3b3d42;--muted:#7a7c80;--line:#e3e1db;
 --accent:#4a55d6;--accent-soft:#e8e9fb;--danger:#b23b2e;
 --stage:#101216;--stage-2:#181b21;--stage-ink:#f3f4f6;--stage-muted:#8b909a;--stage-line:#262a32;
 --radius:12px;--sans:'Geist',ui-sans-serif,system-ui,-apple-system,'Segoe UI',sans-serif;--mono:'Geist Mono',ui-monospace,'SF Mono',Menlo,monospace;
 color-scheme:light;
}
@media (prefers-color-scheme:dark){:root{
 --bg:#0d0e11;--surface:#15171b;--surface-2:#1c1f24;--ink:#eceef1;--ink-2:#c4c7cd;--muted:#8a8f98;--line:#262930;
 --accent:#8b93ff;--accent-soft:#22254a;--danger:#ef7b6d;--stage:#0a0b0e;--stage-2:#13151a;--stage-line:#22252c;color-scheme:dark;
}}

*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font:14px/1.5 var(--sans);-webkit-font-smoothing:antialiased}
button,input,select{font:inherit;color:inherit}
button{cursor:pointer}
button:disabled{opacity:.4;cursor:not-allowed}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
[hidden]{display:none!important}
h1,h2,h3{margin:0;font-weight:600;letter-spacing:-.02em}

/* top bar */
.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;height:60px;padding:0 max(24px,calc((100vw - 1320px)/2));border-bottom:1px solid var(--line);background:color-mix(in srgb,var(--bg) 85%,transparent);backdrop-filter:blur(10px);position:sticky;top:0;z-index:5}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:600;letter-spacing:-.01em}
.brand-mark{display:flex;align-items:center;gap:2px;width:26px;height:26px;border-radius:7px;background:var(--ink);justify-content:center}
.brand-mark i{display:block;width:2.5px;border-radius:2px;background:var(--bg);height:8px}
.brand-mark i:nth-child(2){height:13px}
.topbar-meta{font:12px var(--mono);color:var(--muted)}

main{max-width:1320px;margin:0 auto;padding:0 24px 40px}

/* library */
.intro{padding:44px 0 28px}
h1{font-size:clamp(28px,3.4vw,40px);line-height:1.1;letter-spacing:-.035em;margin-bottom:8px}
.lede{margin:0;color:var(--muted);font-size:15px}
.setup-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:20px;align-items:start}
.setup-col{display:grid;gap:20px}
.step,.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px}
.step-head{display:flex;align-items:center;gap:10px;margin-bottom:14px}
.step-head h2{font-size:15px}
.step-num{font:11px var(--mono);color:var(--muted)}
.step-aside,.step-head .text-button{margin-left:auto}
.step-aside{font:12px var(--mono);color:var(--muted)}

.paper-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.paper{display:flex;flex-direction:column;align-items:flex-start;text-align:left;padding:14px 16px;border:1px solid var(--line);background:var(--surface);border-radius:10px;transition:border-color .15s,background .15s,transform .15s}
.paper:hover{border-color:color-mix(in srgb,var(--ink) 30%,var(--line))}
.paper:active{transform:scale(.99)}
.paper.selected{border-color:var(--ink);box-shadow:inset 0 0 0 1px var(--ink)}
.paper-kind{font:11px var(--mono);color:var(--muted);text-transform:uppercase;letter-spacing:.04em}
.paper-name{font-size:18px;font-weight:600;letter-spacing:-.02em;margin:6px 0 2px}
.paper-meta{font-size:12px;color:var(--muted)}
.paper-foot{margin-top:12px;font-size:12px;color:var(--muted);display:flex;align-items:center;gap:6px}
.paper-foot::before{content:"";width:12px;height:12px;border-radius:50%;border:1.5px solid var(--line)}
.paper.selected .paper-foot{color:var(--ink);font-weight:500}
.paper.selected .paper-foot::before{border:4px solid var(--ink)}

.task{display:flex;align-items:center;gap:14px;padding:13px 0;border-top:1px solid var(--line);cursor:pointer}
.task:first-of-type{border-top:0;padding-top:4px}
.task div{flex:1;min-width:0}
.task strong{display:block;font-size:14px;font-weight:500}
.task small{font-size:12px;color:var(--muted)}
.task>span{font:12px var(--mono);color:var(--muted);white-space:nowrap}
.task input{appearance:none;flex:none;width:34px;height:20px;border-radius:20px;background:var(--surface-2);border:1px solid var(--line);position:relative;margin:0;cursor:pointer;transition:background .2s,border-color .2s}
.task input::after{content:"";position:absolute;top:2px;left:2px;width:14px;height:14px;border-radius:50%;background:var(--surface);box-shadow:0 1px 2px #0003;transition:transform .2s cubic-bezier(.3,.7,.4,1)}
.task input:checked{background:var(--ink);border-color:var(--ink)}
.task input:checked::after{transform:translateX(14px)}
.task.compact{border-top:1px dashed var(--line)}
.segmented{display:flex;gap:2px;padding:3px;margin:0 0 12px 48px;background:var(--surface-2);border-radius:8px}
.segmented button{flex:1;border:0;background:none;padding:7px 8px;border-radius:6px;font-size:12px;color:var(--muted);transition:background .15s,color .15s}
.segmented button.chosen{background:var(--surface);color:var(--ink);font-weight:500;box-shadow:0 1px 2px #0000001a}
#topic-options{display:grid;grid-template-columns:1fr 1.4fr;gap:10px;padding:0 0 14px 48px}

label:not(.task):not(.caption-toggle){display:block;font-size:12px;color:var(--muted)}
select,input:not([type=checkbox]){display:block;width:100%;margin-top:6px;padding:9px 11px;border:1px solid var(--line);border-radius:8px;background:var(--surface);color:var(--ink);font-size:13px}
select:hover,input:not([type=checkbox]):hover{border-color:color-mix(in srgb,var(--ink) 25%,var(--line))}

.primary{display:inline-flex;align-items:center;justify-content:center;gap:10px;border:0;border-radius:9px;padding:11px 18px;background:var(--ink);color:var(--bg);font-weight:500;font-size:14px;transition:transform .12s,opacity .15s}
.primary:hover{opacity:.88}
.primary:active{transform:scale(.98)}
.primary span{transition:transform .2s}
.primary:hover span{transform:translateX(3px)}
.start-row{display:flex;align-items:center;gap:14px;border-top:1px solid var(--line);padding-top:16px;margin-top:4px}
.start-row button{flex:none}
.start-row p{margin:0;font-size:12px;color:var(--muted)}
.text-button{border:0;background:none;padding:4px 0;font-size:13px;color:var(--muted)}
.text-button:hover{color:var(--ink)}

.cards{position:sticky;top:80px}
.card-selects{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:14px}
.preview-tabs{display:flex;align-items:center;gap:4px}
.preview-tabs button{border:0;background:none;padding:6px 10px;border-radius:7px;font-size:13px;color:var(--muted)}
.preview-tabs button:hover{color:var(--ink)}
.preview-tabs .chosen{background:var(--surface-2);color:var(--ink);font-weight:500}
#open-card{margin-left:auto;font-size:12px;color:var(--muted);text-decoration:none}
#open-card:hover{color:var(--ink)}
iframe{display:block;width:100%;border:0;border-radius:8px;background:var(--surface-2)}
#preview{height:min(62vh,560px);margin-top:10px}
footer{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding:28px 0 0;font-size:12px;color:var(--muted)}
.error{color:var(--danger);font-size:13px;margin-top:10px}
.error:empty{display:none}

/* session */
.session-top{display:flex;align-items:center;gap:16px;padding:18px 0}
.session-top>span{flex:1;font:12px var(--mono);color:var(--muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.timer{font:500 20px var(--mono);letter-spacing:-.02em;font-variant-numeric:tabular-nums;padding:6px 12px;border:1px solid var(--line);border-radius:9px;background:var(--surface)}
.exam-layout{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(360px,1fr);gap:16px;align-items:stretch}
.exam-layout.no-card{grid-template-columns:minmax(0,620px);justify-content:center}
.exam-card{display:flex;flex-direction:column;padding:14px}
.card-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:2px 4px 12px}
.card-head h2{font-size:14px}
.exam-card iframe{flex:1;min-height:max(440px,calc(100vh - 190px))}

.examiner{
 --orb-a:#7c86ff;--orb-b:#45d0c0;--orb-ring:#c9ceff;
 position:relative;display:flex;flex-direction:column;align-items:center;text-align:center;gap:0;
 padding:18px 22px 20px;border-radius:var(--radius);overflow:hidden;
 background:radial-gradient(120% 70% at 50% 0%,var(--stage-2),var(--stage) 70%);color:var(--stage-ink);border:1px solid var(--stage-line);
}
.examiner::before{content:"";position:absolute;inset:0;pointer-events:none;opacity:.5;background-image:radial-gradient(var(--stage-line) 1px,transparent 1px);background-size:18px 18px;mask-image:radial-gradient(70% 50% at 50% 30%,#000,transparent)}
.examiner>*{position:relative}
.examiner[data-state=listening]{--orb-a:#5aa9ff;--orb-b:#7c86ff}
.examiner[data-state=prep],.examiner[data-state=idle]{--orb-a:#6d74c9;--orb-b:#3f9e94}
.examiner-top{display:flex;align-items:center;justify-content:space-between;width:100%}
.eyebrow{font:11px var(--mono);text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0}
.examiner .eyebrow{color:var(--stage-muted)}
.state-pill{display:inline-flex;align-items:center;gap:7px;font:12px var(--mono);color:var(--stage-ink);padding:5px 10px;border:1px solid var(--stage-line);border-radius:20px;background:#ffffff08}
.state-pill::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--stage-muted)}
.examiner[data-state=speaking] .state-pill::before{background:var(--orb-b);box-shadow:0 0 0 3px #45d0c033;animation:blink 1s infinite}
.examiner[data-state=listening] .state-pill::before{background:#5aa9ff;box-shadow:0 0 0 3px #5aa9ff33;animation:blink 1.4s infinite}
.examiner[data-state=connecting] .state-pill::before{background:#e8c26a;animation:blink .8s infinite}
.examiner[data-state=error] .state-pill::before{background:#ef7b6d}
.voice-avatar{width:min(300px,78%);aspect-ratio:1;margin:4px auto 0}
.voice-avatar canvas{display:block;width:100%;height:100%}
.examiner h2{font-size:22px;letter-spacing:-.025em;margin-top:-6px}
#phase-detail{margin:6px 0 0;font-size:13px;color:var(--stage-muted);max-width:340px}
#question{width:100%;margin:16px 0 0;padding:12px 14px;text-align:left;font-size:14px;line-height:1.6;background:#ffffff0a;border:1px solid var(--stage-line);border-radius:10px;max-height:9.5em;overflow:auto}
#question::before{content:"Examiner";display:block;font:10px var(--mono);text-transform:uppercase;letter-spacing:.08em;color:var(--stage-muted);margin-bottom:4px}
#student-transcript{width:100%;margin:10px 0 0;font-size:13px;line-height:1.6;color:var(--stage-muted);text-align:left;max-height:7em;overflow:auto}
#student-transcript:not(:empty){padding:10px 14px;border-left:2px solid #5aa9ff66}
.exam-controls{display:flex;gap:8px;flex-wrap:wrap;justify-content:center;margin-top:auto;padding-top:20px}
.examiner .primary{background:var(--stage-ink);color:var(--stage)}
.exam-controls>button:not(.primary){border:1px solid var(--stage-line);background:#ffffff08;color:var(--stage-ink);border-radius:9px;padding:11px 16px;font-size:14px;transition:background .15s}
.exam-controls>button:not(.primary):hover{background:#ffffff14}
.examiner-foot{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;margin-top:16px;padding-top:14px;border-top:1px solid var(--stage-line)}
.caption-toggle{display:inline-flex;align-items:center;gap:8px;font-size:12px;color:var(--stage-muted);cursor:pointer}
.caption-toggle input{accent-color:var(--orb-a);margin:0}
.hint{margin:0;font-size:12px;color:var(--stage-muted)}
.examiner .error{color:#ef9a8f}

/* results */
#results{max-width:820px;padding:44px 0 0}
#results>.eyebrow{margin-bottom:8px}
.result-panel{margin:24px 0 0;padding:24px}
#score-label{margin:0;font:12px var(--mono);color:var(--muted);text-transform:uppercase;letter-spacing:.06em}
.score-total{font:600 56px/1.05 var(--sans);letter-spacing:-.04em;margin:6px 0 18px;font-variant-numeric:tabular-nums}
#marks section{padding:14px 0;border-top:1px solid var(--line)}
#marks h3{font-size:14px;margin-bottom:6px}
#marks p{margin:4px 0;font-size:13px;color:var(--ink-2);line-height:1.55}
.result-panel h2{font-size:15px;margin:20px 0 6px;padding-top:18px;border-top:1px solid var(--line)}
#feedback{white-space:pre-wrap;line-height:1.65;margin:0;color:var(--ink-2)}
#retry-marks{margin-top:12px;border:1px solid var(--line);background:var(--surface);border-radius:9px;padding:9px 14px}
.muted{font-size:12px;color:var(--muted);line-height:1.6;white-space:pre-wrap}
.muted:empty{display:none}
.result-actions{display:flex;gap:8px;flex-wrap:wrap;margin:18px 0}
.result-actions>button:not(.primary){border:1px solid var(--line);background:var(--surface);border-radius:9px;padding:11px 16px;font-size:14px}
.result-actions>button:not(.primary):hover{border-color:color-mix(in srgb,var(--ink) 30%,var(--line))}

@keyframes blink{50%{opacity:.35}}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

@media (max-width:980px){
 .setup-grid,.exam-layout{grid-template-columns:1fr}
 .cards{position:static}
 .exam-card iframe{min-height:420px}
}
@media (max-width:560px){
 main{padding:0 16px 32px}.topbar{padding:0 16px}.topbar-meta{display:none}
 .paper-grid,.card-selects,#topic-options{grid-template-columns:1fr}
 .segmented,#topic-options{margin-left:0;padding-left:0}
 .start-row{flex-direction:column;align-items:stretch}
 .examiner-foot{flex-direction:column;align-items:flex-start}
}