:root {
  --bg: #f5f6f8;
  --surface: #ffffff;
  --text: #1c1f24;
  --muted: #5d6470;
  --border: #d9dde3;
  --accent: #2557d6;
  --accent-text: #ffffff;
  --error: #b42318;
  --success: #1a7f37;
  --star: #b26a00;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --surface: #1f2226;
    --text: #e8eaed;
    --muted: #9aa1ab;
    --border: #353a41;
    --accent: #7aa2ff;
    --accent-text: #0d1117;
    --error: #ff8a80;
    --success: #56d364;
    --star: #f0b72f;
  }
}

* { box-sizing: border-box; }

/* `hidden` must win over any display rule below. */
[hidden] { display: none !important; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  padding: 16px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  margin: 24px auto;
  max-width: 820px;
}
.card.narrow { max-width: 420px; }

h1 { font-size: 1.5rem; margin: 0 0 16px; }

label { display: block; margin-bottom: 16px; font-weight: 600; }

input {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}

button {
  font: inherit;
  font-weight: 600;
  padding: 10px 18px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-text);
  cursor: pointer;
}
button.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }
button:disabled { opacity: 0.5; cursor: not-allowed; }

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  max-width: 820px;
  margin: 0 auto;
}

.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.error { color: var(--error); }

a { color: var(--accent); }
h2 { font-size: 1.2rem; margin: 0 0 16px; }

select {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}

button.small { padding: 6px 12px; font-size: 0.875rem; }

.actions { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.grow { flex: 1; min-width: 0; }

.inline-form { display: flex; gap: 12px; align-items: flex-end; flex-wrap: wrap; }
.inline-form label { margin-bottom: 0; }
.inline-form input { margin-top: 6px; }
#new-course { margin-bottom: 16px; }

.list { list-style: none; margin: 0; padding: 0; }
.list li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-top: 1px solid var(--border);
}
.archived { color: var(--muted); }

.badge {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
  border: 1px solid var(--border);
  color: var(--muted);
  white-space: nowrap;
}
td .badge { margin-left: 0; }
.status-active { color: var(--accent); border-color: var(--accent); }
.status-invite_expired, .status-disabled { color: var(--error); border-color: var(--error); }

.notice {
  border: 1px solid var(--accent);
  border-radius: 8px;
  padding: 12px 16px;
  margin-bottom: 16px;
}
.notice p { margin: 0 0 8px; }
.notice input { margin-top: 0; }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 10px 8px; border-top: 1px solid var(--border); vertical-align: middle; }
th { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); border-top: 0; }

/* --- Class sessions --- */

textarea {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 10px 12px;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  resize: vertical;
}

fieldset.options { border: 0; padding: 0; margin: 0 0 16px; }
fieldset.options legend { font-weight: 600; margin-bottom: 8px; }
.option-list { list-style: none; margin: 0 0 8px; padding: 0; }
.option-row { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.option-row .option-text { margin-top: 0; }
.option-row .correct-box { width: 20px; height: 20px; flex: none; margin: 0; accent-color: var(--accent); }

label.check { display: flex; align-items: center; gap: 8px; font-weight: 400; }
label.check input { width: auto; margin: 0; }

.session-head { display: flex; align-items: flex-start; gap: 12px; }
.session-head h1 { margin-bottom: 4px; }
.session-head p { margin: 0; }

.join-box {
  text-align: center;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-top: 16px;
}
.join-box p { margin: 2px 0; }
.join-url { font-size: 1.25rem; font-weight: 600; }
.join-code { font-size: 3rem; font-weight: 800; letter-spacing: 0.15em; color: var(--accent); }
.present { margin-top: 8px !important; }

.question {
  border-top: 1px solid var(--border);
  padding: 16px 0;
}
.question.is-open { border-left: 4px solid var(--accent); padding-left: 12px; }
.question-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.question-head .badge { margin-left: 0; }
.prompt { font-size: 1.125rem; font-weight: 600; margin: 8px 0 12px; white-space: pre-wrap; overflow-wrap: anywhere; }

.bars { list-style: none; margin: 0 0 12px; padding: 0; }
.bars li { margin-bottom: 10px; }
.bar-label { display: flex; align-items: baseline; gap: 8px; margin-bottom: 4px; overflow-wrap: anywhere; }
.bar-count { color: var(--muted); font-size: 0.875rem; white-space: nowrap; }
.bar-track { height: 10px; background: var(--bg); border: 1px solid var(--border); border-radius: 999px; overflow: hidden; }
.bar-fill { display: block; height: 100%; width: 0; background: var(--muted); border-radius: 999px; transition: width 0.3s; }
.bars li.correct .bar-fill { background: var(--success); }
.bars li.mine .bar-label { font-weight: 700; }
.tag { font-size: 0.75rem; font-weight: 700; padding: 1px 8px; border-radius: 999px; white-space: nowrap; }
.tag-correct { color: var(--success); border: 1px solid var(--success); }
.tag-mine { color: var(--accent); border: 1px solid var(--accent); }

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

.code-input { font-size: 1.5rem; letter-spacing: 0.2em; text-transform: uppercase; text-align: center; }
.class-head { display: flex; gap: 8px; margin-bottom: 8px; }
.waiting { font-size: 1.125rem; color: var(--muted); }
.choices { display: flex; flex-direction: column; gap: 10px; margin-bottom: 16px; }
.choice {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-weight: 400;
  cursor: pointer;
  overflow-wrap: anywhere;
}
.choice input { width: 20px; height: 20px; margin: 0; flex: none; accent-color: var(--accent); }
.choice:has(input:checked) { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.answer-form button[type="submit"] { width: 100%; padding: 14px; }
@media (min-width: 600px) { .student .card.narrow { max-width: 560px; } }

/* --- Short-text answers --- */

.segmented { display: inline-flex; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; margin-bottom: 16px; }
.segmented label { display: flex; align-items: center; gap: 6px; margin: 0; padding: 8px 14px; font-weight: 600; cursor: pointer; white-space: nowrap; }
.segmented label + label { border-left: 1px solid var(--border); }
.segmented input { margin: 0; accent-color: var(--accent); }
.segmented label:has(input:checked) { background: var(--bg); color: var(--accent); }

.answer-list, .answer-wall { list-style: none; margin: 0 0 12px; padding: 0; display: grid; gap: 10px; }
@media (min-width: 700px) { .answer-wall { grid-template-columns: repeat(2, 1fr); } }
.answer-card { border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; background: var(--surface); }
.answer-card.is-starred { border-color: var(--star); box-shadow: 0 0 0 1px var(--star); }
.answer-card.is-hidden { opacity: 0.55; border-style: dashed; }
.answer-card .actions { margin-top: 8px; }
.answer-card .badge { margin-left: 0; }
.answer-text { margin: 0; white-space: pre-wrap; overflow-wrap: anywhere; }
.star-label { display: block; font-size: 0.75rem; font-weight: 700; color: var(--star); margin-bottom: 4px; }
.my-answer { border-left: 4px solid var(--accent); padding: 4px 0 4px 12px; margin-bottom: 16px; }
.my-answer p:first-child { margin: 0 0 4px; }
.answer-form textarea { margin: 0 0 4px; min-height: 140px; }
.counter { display: block; text-align: right; margin-bottom: 12px; }

/* --- History & export --- */

.button-link {
  display: inline-block;
  font-weight: 600;
  padding: 10px 18px;
  border-radius: 8px;
  text-decoration: none;
  background: var(--accent);
  color: var(--accent-text);
}
.button-link.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }
.button-link.small { padding: 6px 12px; font-size: 0.875rem; }
.section-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.section-head h2 { margin: 0; }

/* --- More question types --- */

.composer select { max-width: 320px; }
.field-grid { display: grid; gap: 0 16px; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); align-items: end; }

.cloud { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 6px 14px; padding: 12px 0; line-height: 1.2; }
.cloud-word { font-weight: 700; color: var(--accent); background: none; border: 0; padding: 0; font-family: inherit; overflow-wrap: anywhere; }
button.cloud-word { cursor: pointer; }
button.cloud-word:hover { text-decoration: underline; }
.cloud-word.mine { color: var(--success); }
.cloud-word.is-hidden { opacity: 0.35; text-decoration: line-through; }
.cloud-count { font-size: 0.6em; font-weight: 600; color: var(--muted); margin-left: 3px; vertical-align: super; }

.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin: 8px 0 16px; }
.stats div { border: 1px solid var(--border); border-radius: 8px; padding: 8px; text-align: center; }
.stats dt { font-size: 0.75rem; color: var(--muted); }
.stats dd { margin: 0; font-size: 1.25rem; font-weight: 700; }
.actual-answer, .average { font-size: 1.125rem; }
@media (max-width: 480px) { .stats { grid-template-columns: repeat(2, 1fr); } }

.scale { display: grid; gap: 6px; margin-bottom: 6px; }
.scale-5 { grid-template-columns: repeat(5, 1fr); }
.scale-10 { grid-template-columns: repeat(5, 1fr); }
@media (min-width: 520px) { .scale-10 { grid-template-columns: repeat(10, 1fr); } }
.scale-point { margin: 0; position: relative; }
.scale-point input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.scale-point span {
  display: flex; align-items: center; justify-content: center;
  height: 48px; border: 1px solid var(--border); border-radius: 10px; font-size: 1.125rem; font-weight: 700;
}
.scale-point input:checked + span { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.scale-point input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.scale-ends { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 16px; }

.number-input { font-size: 1.5rem; margin-bottom: 8px; }
.word-inputs { display: grid; gap: 8px; margin-bottom: 16px; }
.word-inputs input { margin-top: 0; }

/* --- Question bank --- */

.bank-panel { margin-top: 20px; border-top: 1px solid var(--border); padding-top: 12px; }
.bank-panel summary { cursor: pointer; font-weight: 600; }
.bank-list { list-style: none; margin: 12px 0 0; padding: 0; }
.bank-list li { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding: 10px 0; border-top: 1px solid var(--border); }
.bank-list .badge { margin-left: 0; }
.saved-note { margin: 8px 0 0; }

/* --- Projector view: big type, readable from the back of the room --- */

body.projector { padding: 32px 48px; font-size: 22px; min-height: 100vh; }
.projector-fullscreen { position: fixed; top: 12px; right: 12px; z-index: 1; }
.join-full { text-align: center; padding-top: 4vh; }
.join-full p { margin: 4px 0; }
.join-full .join-host { font-size: 3rem; font-weight: 700; }
.join-code-big { font-size: 9rem; font-weight: 800; letter-spacing: 0.12em; color: var(--accent); line-height: 1.1; }
.qr-big { width: min(32vh, 320px); height: auto; margin: 16px auto; display: block; border-radius: 12px; }
.projector-bar { display: flex; align-items: center; gap: 16px; margin-bottom: 24px; padding-right: 160px; }
.join-mini { font-size: 1.25rem; }
.join-code-mini { color: var(--accent); letter-spacing: 0.08em; }
.qr-mini { width: 96px; height: 96px; border-radius: 8px; }
.projector-prompt { font-size: 2.6rem; line-height: 1.25; margin: 0 0 24px; white-space: pre-wrap; overflow-wrap: anywhere; }
.projector-options { font-size: 1.75rem; padding-left: 1.5em; }
.projector-options li { margin-bottom: 12px; }
.projector-hint { font-size: 1.75rem; color: var(--muted); }
.projector-count { font-size: 1.5rem; color: var(--muted); }
.projector-count strong { color: var(--text); font-size: 2rem; }
.projector .bars li { margin-bottom: 18px; }
.projector .bar-label { font-size: 1.5rem; }
.projector .bar-track { height: 22px; }
.projector .answer-wall { grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }
.projector .answer-card { font-size: 1.25rem; }
.projector .cloud { gap: 12px 28px; }
.projector .stats dd { font-size: 2rem; }
@media (max-width: 700px) {
  body.projector { padding: 16px; font-size: 18px; }
  .join-code-big { font-size: 4.5rem; }
  .projector-prompt { font-size: 1.75rem; }
  .projector-bar { padding-right: 0; flex-wrap: wrap; }
}
.bank-compose { margin-bottom: 12px; }
.bank-compose summary { cursor: pointer; font-weight: 600; margin-bottom: 12px; }
.projector .average, .projector .actual-answer { font-size: 1.75rem; }
.projector .bar-count { font-size: 1.25rem; }
.projector .stats dt { font-size: 1rem; }