:root {
  --bg: #F3F4F6;
  --paper: #FFFFFF;
  --ink: #172033;
  --ink-2: #5B6472;
  --line: #D7DBE2;
  --blue: #2B5BD7;
  --blue-soft: #E1E8FA;
  --green: #1B7F58;
  --green-soft: #DBF1E5;
  --red: #B4302E;
  --red-soft: #F8E1E0;
  --amber: #9A6700;
  --amber-soft: #FBF0D5;
  --radius: 10px;
  --font: "Pretendard Variable", Pretendard, -apple-system, "Apple SD Gothic Neo",
    "Noto Sans KR", "Malgun Gothic", system-ui, sans-serif;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { font-size: 16px; }
body { margin: 0; font-family: var(--font); color: var(--ink); background: var(--bg); line-height: 1.5; -webkit-font-smoothing: antialiased; }
a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { margin: 0; line-height: 1.25; font-weight: 700; }
h1 { font-size: 1.75rem; }
h2 { font-size: 1.25rem; }
p { margin: 0; }
.muted { color: var(--ink-2); }
.small { font-size: 0.875rem; }
.mono { font-variant-numeric: tabular-nums; letter-spacing: 0.06em; }

button, .btn {
  font: inherit; font-weight: 600; border: 1px solid var(--line); background: var(--paper); color: var(--ink);
  padding: 0.5rem 0.9rem; border-radius: 8px; cursor: pointer; line-height: 1.2;
}
button:hover, .btn:hover { background: #F7F8FA; text-decoration: none; }
button:focus-visible, .btn:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 3px solid var(--blue-soft); outline-offset: 1px; border-color: var(--blue);
}
button.primary, .btn.primary { background: var(--blue); border-color: var(--blue); color: #fff; }
button.primary:hover { background: #2450BE; }
button.danger { color: var(--red); }
button.danger:hover { background: var(--red-soft); }
button.quiet { border-color: transparent; background: transparent; color: var(--ink-2); }
button.quiet:hover { background: var(--bg); color: var(--ink); }
button:disabled { opacity: 0.45; cursor: not-allowed; }

input[type="text"], input[type="password"], input[type="number"], textarea {
  font: inherit; width: 100%; padding: 0.55rem 0.7rem; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); color: var(--ink);
}
textarea { resize: vertical; min-height: 4.5rem; }
label { font-weight: 600; font-size: 0.9rem; }
.field { display: flex; flex-direction: column; gap: 0.35rem; }
.row { display: flex; gap: 0.6rem; align-items: center; flex-wrap: wrap; }
.stack { display: flex; flex-direction: column; gap: 0.9rem; }
.notice { padding: 0.75rem 1rem; border-radius: 8px; background: var(--green-soft); color: var(--green); }
.notice.error { background: var(--red-soft); color: var(--red); }

/* ---------- Admin shell ---------- */

.shell { max-width: 1080px; margin: 0 auto; padding: 1.5rem 1.25rem 4rem; }
.topbar { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; padding-bottom: 1rem; margin-bottom: 1.5rem; border-bottom: 1px solid var(--line); }
.topbar nav { display: flex; gap: 1rem; font-size: 0.9rem; flex-wrap: wrap; }
.panel { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.25rem; }
.two-col { display: grid; grid-template-columns: 320px 1fr; gap: 1.5rem; align-items: start; }
@media (max-width: 860px) { .two-col { grid-template-columns: 1fr; } }

.session-list { list-style: none; margin: 0; padding: 0; }
.session-list li { display: grid; grid-template-columns: 1fr auto; gap: 0.5rem 1rem; align-items: center; padding: 0.9rem 0; border-top: 1px solid var(--line); }
.session-list li:first-child { border-top: 0; }

.qr-box { text-align: center; }
.qr-box img { width: 100%; max-width: 240px; height: auto; display: block; margin: 0 auto; }
.qr-box .link { word-break: break-all; margin-top: 0.5rem; }

.live { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.25rem; margin-bottom: 1.5rem; }
.pill { display: inline-block; padding: 0.15rem 0.6rem; border-radius: 999px; font-size: 0.8rem; font-weight: 600; background: var(--bg); color: var(--ink-2); margin-right: 0.3rem; }
.pill.on { background: var(--green-soft); color: var(--green); }
.type-tag { display: inline-block; font-size: 0.75rem; font-weight: 600; padding: 0.1rem 0.45rem; border-radius: 4px; background: var(--bg); color: var(--ink-2); margin-left: 0.4rem; vertical-align: middle; }
.type-tag.on { background: var(--green-soft); color: var(--green); }

/* ---------- Bars ---------- */

.bars { display: grid; gap: 0.55rem; }
.bar-row { display: grid; grid-template-columns: 2rem 1fr 5.5rem; align-items: center; gap: 0.75rem; }
.bar-row .letter { font-weight: 800; color: var(--ink-2); }
.bar-row .track { position: relative; height: 1.5rem; background: var(--bg); border-radius: 6px; overflow: hidden; }
.bar-row .fill { position: absolute; inset: 0 auto 0 0; width: 0%; background: var(--blue); border-radius: 6px; transition: width 0.45s ease; }
.bar-row.correct .fill { background: var(--green); }
.bar-row.correct .letter { color: var(--green); }
.bar-row .num { text-align: right; font-variant-numeric: tabular-nums; color: var(--ink-2); font-size: 0.9rem; }
.bar-row .text { grid-column: 2 / span 2; font-size: 0.95rem; margin-top: -0.2rem; }
.bars.mini { margin: 0.5rem 0 0.75rem; max-width: 520px; }
@media (prefers-reduced-motion: reduce) { .bar-row .fill { transition: none; } }

/* ---------- Question cards (admin) ---------- */

.qlist { display: flex; flex-direction: column; }
.qcard { padding: 1.25rem 0; border-top: 1px solid var(--line); }
.qcard:first-child { border-top: 0; padding-top: 0; }
.qcard .head { display: flex; justify-content: space-between; gap: 1rem; align-items: baseline; }
.qcard .ord { font-weight: 800; color: var(--ink-2); }
.qcard.open .ord { color: var(--ink); }
.qcard .stem { font-weight: 600; font-size: 1.05rem; margin: 0.35rem 0 0.7rem; }
.qcard ol.opts { margin: 0 0 0.5rem; padding: 0; list-style: none; display: grid; gap: 0.25rem; }
.qcard ol.opts li { display: grid; grid-template-columns: 1.6rem 1fr; gap: 0.5rem; }
.qcard ol.opts li .l { font-weight: 700; color: var(--ink-2); }
.qcard ol.opts li.ans, .qcard ol.opts li.ans .l { color: var(--green); font-weight: 600; }
.qcard .meta { font-size: 0.85rem; color: var(--ink-2); margin: 0.5rem 0; }
.qcard .summary { font-size: 0.85rem; color: var(--ink-2); margin: 0.25rem 0 0.5rem; }
.qcard .controls { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.qcard details { margin-top: 0.75rem; }
.qcard details summary { cursor: pointer; font-size: 0.9rem; color: var(--blue); font-weight: 600; }
.qcard .editform { margin-top: 0.75rem; display: grid; gap: 0.6rem; }
.qcard .editform .optrow, #manual-form .optrow { display: grid; grid-template-columns: auto 1fr; gap: 0.5rem; align-items: center; }
.qcard .notes { margin: 0.4rem 0 0; padding-left: 1.2rem; font-size: 0.85rem; color: var(--ink-2); }

/* ---------- Results (projector) ---------- */

body.present { background: #fff; }
.results-shell { max-width: 1100px; margin: 0 auto; padding: 3vh 4vw 6vh; }
.present-top { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; color: var(--ink-2); font-size: 1.15rem; padding-bottom: 1rem; border-bottom: 1px solid var(--line); }
.result-block { padding: 2.5rem 0; border-bottom: 1px solid var(--line); }
.result-head { display: grid; grid-template-columns: 3rem 1fr; gap: 1rem; align-items: baseline; }
.result-ord { font-size: 1.8rem; font-weight: 800; color: var(--ink-2); }
.result-stem { font-size: clamp(1.2rem, 2.4vw, 1.8rem); font-weight: 700; line-height: 1.35; }
.result-meta { color: var(--ink-2); font-size: 1.1rem; margin: 0.75rem 0 1rem 4rem; }
.present-bars { margin-left: 4rem; gap: 1rem; }
.present-bars .bar-row { grid-template-columns: 2.5rem 1fr 6rem; }
.present-bars .letter { font-size: 1.5rem; }
.present-bars .track { height: 2.2rem; border-radius: 8px; }
.present-bars .num { font-size: 1.2rem; color: var(--ink); }
.present-bars .text { font-size: 1.1rem; color: var(--ink-2); }

/* ---------- Student ---------- */

body.student { background: var(--paper); }
.student-shell { max-width: 520px; margin: 0 auto; padding: 1.25rem 1.1rem 3rem; min-height: 100vh; display: flex; flex-direction: column; gap: 1rem; }
.student-top { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; font-size: 0.9rem; color: var(--ink-2); }
.student-stem { font-size: 1.25rem; font-weight: 700; line-height: 1.4; }
.chips { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.chip { width: 2.3rem; height: 2.3rem; padding: 0; border-radius: 999px; font-weight: 700; color: var(--ink-2); background: var(--bg); border-color: transparent; }
.chip.done { background: var(--blue-soft); color: var(--blue); }
.chip.correct { background: var(--green-soft); color: var(--green); }
.chip.wrong { background: var(--red-soft); color: var(--red); }
.chip.current { outline: 2px solid var(--ink); outline-offset: 1px; }
.choices { display: grid; gap: 0.7rem; }
.choice {
  display: grid; grid-template-columns: 2.4rem 1fr; gap: 0.75rem; align-items: center; text-align: left;
  padding: 0.9rem 1rem; border: 2px solid var(--line); border-radius: 12px; background: var(--paper);
  font-size: 1.05rem; font-weight: 500; line-height: 1.35; min-height: 3.6rem;
}
.choice .l { font-weight: 800; color: var(--ink-2); font-size: 1.15rem; }
.choice.selected { border-color: var(--blue); background: var(--blue-soft); }
.choice.selected .l { color: var(--blue); }
.choice.correct { border-color: var(--green); background: var(--green-soft); }
.choice.correct .l { color: var(--green); }
.choice.wrong { border-color: var(--red); background: var(--red-soft); }
.choice.wrong .l { color: var(--red); }
.choice:disabled { opacity: 1; cursor: default; }
.feedback { font-size: 0.95rem; color: var(--ink-2); min-height: 1.4rem; }
.feedback.ok { color: var(--green); font-weight: 600; }
.feedback.err { color: var(--red); font-weight: 600; }
.explain { padding: 1rem; background: var(--bg); border-radius: 10px; line-height: 1.55; }
#s-nav { justify-content: space-between; margin-top: 0.5rem; }
#s-nav .primary { padding: 0.8rem 1.4rem; font-size: 1rem; }
.waiting { flex: 1; display: grid; place-items: center; text-align: center; color: var(--ink-2); gap: 0.5rem; padding: 3rem 0; }
.chapter-list { display: grid; gap: 0.7rem; }
.chapter { display: flex; flex-direction: column; gap: 0.25rem; padding: 1rem 1.1rem; border: 2px solid var(--line); border-radius: 12px; color: var(--ink); }
.chapter:hover { text-decoration: none; border-color: var(--blue); }
.chapter.done { border-color: var(--green); background: var(--green-soft); }
.chapter-title { font-weight: 700; font-size: 1.05rem; }
.chapter-meta { font-size: 0.85rem; color: var(--ink-2); }

/* ---------- Login ---------- */

.login { min-height: 100vh; display: grid; place-items: center; padding: 1rem; }
.login form { width: min(100%, 360px); }