/* ============ ClassResponse ============ */
:root {
  --bg: #f2f4f8;
  --card: #ffffff;
  --ink: #1d2433;
  --muted: #667085;
  --line: #e2e6ee;
  --primary: #3b4a9f;
  --primary-dark: #2e3a80;
  --accent: #f5822a;
  --good: #12925c;
  --good-bg: #e2f6ec;
  --bad: #d64545;
  --bad-bg: #fdeaea;
  --neutral-bg: #eef1f6;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(20, 30, 60, .08), 0 4px 16px rgba(20, 30, 60, .06);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg); color: var(--ink); line-height: 1.5;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- layout ---------- */
.topbar {
  background: var(--primary); color: #fff;
  display: flex; align-items: center; gap: 14px;
  padding: 10px 18px;
}
.topbar .brand { font-weight: 700; font-size: 18px; letter-spacing: .3px; color: #fff; }
.topbar .brand span { color: var(--accent); }
.topbar .room-chip {
  background: rgba(255,255,255,.15); border-radius: 8px;
  padding: 3px 12px; font-weight: 600; letter-spacing: 1px;
}
.topbar .spacer { flex: 1; }
.topbar a { color: #e8ebff; font-size: 14px; }
.wrap { max-width: 980px; margin: 0 auto; padding: 22px 16px 60px; }
.wrap.narrow { max-width: 540px; }

.card {
  background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 22px; margin-bottom: 18px;
}
.card h2 { margin-top: 0; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.center { text-align: center; }
.mt { margin-top: 14px; }

/* ---------- forms ---------- */
label.f { display: block; font-weight: 600; font-size: 14px; margin: 12px 0 4px; }
input[type=text], input[type=email], input[type=password], input[type=number], textarea, select {
  width: 100%; padding: 10px 12px; font-size: 16px;
  border: 1px solid var(--line); border-radius: 8px;
  font-family: inherit; background: #fff; color: var(--ink);
}
textarea { resize: vertical; min-height: 64px; }
input:focus, textarea:focus, select:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 74, 159, .15);
}
.big-code {
  text-transform: uppercase; text-align: center;
  font-size: 28px !important; letter-spacing: 6px; font-weight: 700;
}

.btn {
  display: inline-block; border: none; cursor: pointer;
  background: var(--primary); color: #fff;
  padding: 10px 20px; font-size: 15px; font-weight: 600;
  border-radius: 8px; font-family: inherit;
  transition: background .15s;
}
.btn:hover { background: var(--primary-dark); }
.btn.accent { background: var(--accent); }
.btn.accent:hover { background: #db6f1a; }
.btn.ghost { background: transparent; color: var(--primary); border: 1px solid var(--primary); }
.btn.ghost:hover { background: rgba(59,74,159,.06); }
.btn.danger { background: var(--bad); }
.btn.danger:hover { background: #b83636; }
.btn.small { padding: 5px 12px; font-size: 13px; }
.btn.block { display: block; width: 100%; }
.btn:disabled { opacity: .5; cursor: default; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }

.checks label { display: flex; gap: 9px; align-items: center; font-size: 15px; margin: 8px 0; cursor: pointer; }
.checks input { width: 18px; height: 18px; }

/* ---------- student answer options ---------- */
.opt-btn {
  display: flex; align-items: flex-start; gap: 12px; width: 100%;
  text-align: left; background: #fff; color: var(--ink);
  border: 2px solid var(--line); border-radius: 10px;
  padding: 13px 15px; margin: 9px 0; font-size: 17px; cursor: pointer;
  font-family: inherit; transition: border-color .12s, background .12s;
}
.opt-btn:hover { border-color: var(--primary); }
.opt-btn.selected { border-color: var(--primary); background: #eef0fb; }
.opt-btn .letter {
  flex: none; width: 30px; height: 30px; border-radius: 50%;
  background: var(--neutral-bg); color: var(--ink);
  display: flex; align-items: center; justify-content: center; font-weight: 700;
}
.opt-btn.selected .letter { background: var(--primary); color: #fff; }
.opt-btn .otext { padding-top: 3px; overflow-wrap: anywhere; }

.q-progress { font-size: 14px; color: var(--muted); margin-bottom: 8px; font-weight: 600; }
.q-text { font-size: 20px; margin: 6px 0 14px; overflow-wrap: anywhere; }
.qimg { max-width: 100%; max-height: 320px; border-radius: 8px; margin: 8px 0; display: block; }
.opt-btn .qimg { max-height: 140px; margin: 6px 0 0; }

.feedback { border-radius: 10px; padding: 15px 17px; margin: 14px 0; }
.feedback.good { background: var(--good-bg); border: 1px solid var(--good); }
.feedback.bad { background: var(--bad-bg); border: 1px solid var(--bad); }
.feedback.neutral { background: var(--neutral-bg); border: 1px solid var(--line); }
.feedback .fb-title { font-weight: 700; font-size: 16px; }
.feedback.good .fb-title { color: var(--good); }
.feedback.bad .fb-title { color: var(--bad); }

.bigscore { font-size: 44px; font-weight: 800; color: var(--primary); margin: 6px 0; }

.waiting { text-align: center; padding: 40px 10px; color: var(--muted); }
.pulse {
  width: 46px; height: 46px; margin: 0 auto 16px; border-radius: 50%;
  background: var(--primary); opacity: .75; animation: pulse 1.4s infinite ease-in-out;
}
@keyframes pulse { 0%,100% { transform: scale(.75); opacity:.4; } 50% { transform: scale(1); opacity:.85; } }

/* open-navigation pills */
.pills { display: flex; flex-wrap: wrap; gap: 7px; margin: 10px 0 16px; }
.pill {
  width: 38px; height: 38px; border-radius: 50%; border: 2px solid var(--line);
  background: #fff; font-weight: 700; cursor: pointer; font-family: inherit; font-size: 14px;
  color: var(--ink);
}
.pill.answered { background: var(--good-bg); border-color: var(--good); color: var(--good); }
.pill.current { border-color: var(--primary); background: var(--primary); color: #fff; }

/* ---------- teacher: live results ---------- */
.results-table-wrap { overflow-x: auto; }
table.results { border-collapse: collapse; width: 100%; font-size: 14px; }
table.results th, table.results td {
  border: 1px solid var(--line); padding: 7px 9px; text-align: center;
  min-width: 56px; max-width: 220px; overflow: hidden; text-overflow: ellipsis;
}
table.results th { background: var(--neutral-bg); font-weight: 600; }
table.results th.qcol { cursor: help; }
table.results th.qcol.t-mc { background: #fff3d6; }
table.results th.qcol.t-tf { background: #ece4fa; }
table.results th.qcol.t-sa { background: #ffe6d2; }
table.results td.name-col, table.results th.name-col { text-align: left; min-width: 140px; }
td.cell-good { background: var(--good-bg); color: var(--good); font-weight: 600; }
td.cell-bad { background: var(--bad-bg); color: var(--bad); font-weight: 600; }
td.cell-neutral { background: var(--neutral-bg); }
tr.totals td { font-weight: 700; background: #f7f8fb; }

.switch { display: inline-flex; align-items: center; gap: 7px; cursor: pointer; font-size: 14px; user-select: none; }
.switch .track {
  width: 38px; height: 21px; border-radius: 11px; background: #c3c9d6; position: relative; transition: background .15s;
}
.switch .track::after {
  content: ""; position: absolute; top: 2px; left: 2px; width: 17px; height: 17px;
  border-radius: 50%; background: #fff; transition: left .15s;
}
.switch.on .track { background: var(--good); }
.switch.on .track::after { left: 19px; }

.bars .bar-row { display: flex; align-items: center; gap: 10px; margin: 10px 0; }
.bars .bar-label { width: 60px; font-weight: 700; text-align: right; }
.bars .bar-track { flex: 1; background: var(--neutral-bg); border-radius: 7px; height: 30px; position: relative; }
.bars .bar-fill {
  height: 100%; border-radius: 7px; background: var(--primary);
  min-width: 2px; transition: width .3s;
}
.bars .bar-count { width: 70px; font-weight: 600; }

.resp-list li { margin: 6px 0; }

/* ---------- teacher: dashboard / editor ---------- */
.qz-row {
  display: flex; align-items: center; gap: 10px; padding: 11px 4px;
  border-bottom: 1px solid var(--line);
}
.qz-row:last-child { border-bottom: none; }
.qz-row .title { flex: 1; font-weight: 600; }

.qcard { border: 1px solid var(--line); border-radius: 10px; padding: 16px; margin: 14px 0; background: #fbfcfe; }
.qcard .qhead { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.qcard .qhead .qnum { font-weight: 700; color: var(--primary); }
.qcard .type-tag {
  font-size: 12px; font-weight: 700; padding: 2px 9px; border-radius: 10px;
  background: var(--neutral-bg); color: var(--muted); text-transform: uppercase;
}
.opt-edit { display: flex; gap: 8px; align-items: flex-start; margin: 7px 0; }
.opt-edit input[type=checkbox] { margin-top: 12px; width: 18px; height: 18px; }
.opt-edit .grow { flex: 1; }
.preview {
  border-left: 3px solid var(--line); padding: 4px 10px; margin: 4px 0 2px;
  color: var(--ink); font-size: 15px; min-height: 10px; overflow-wrap: anywhere;
}
.thumb { max-height: 90px; border-radius: 6px; display: block; margin: 6px 0; }
.icon-btn {
  background: none; border: none; cursor: pointer; font-size: 16px; padding: 4px 6px;
  color: var(--muted); border-radius: 6px;
}
.icon-btn:hover { background: var(--neutral-bg); color: var(--ink); }

.mode-pick { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; margin: 10px 0; }
.mode-pick .mode {
  border: 2px solid var(--line); border-radius: 10px; padding: 13px; cursor: pointer; background: #fff;
}
.mode-pick .mode.selected { border-color: var(--primary); background: #eef0fb; }
.mode-pick .mode b { display: block; margin-bottom: 3px; }
.mode-pick .mode .small { color: var(--muted); }

.status-tag { font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 10px; }
.status-tag.running { background: var(--good-bg); color: var(--good); }
.status-tag.finished { background: var(--neutral-bg); color: var(--muted); }
.status-tag.pending { background: #fff3d6; color: #9a6b00; }
.status-tag.approved { background: var(--good-bg); color: var(--good); }
.status-tag.disabled { background: var(--bad-bg); color: var(--bad); }

.banner {
  background: #eef0fb; border: 1px solid var(--primary); border-radius: 10px;
  padding: 13px 16px; margin-bottom: 16px; display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
}

.tabs { display: flex; gap: 4px; margin-bottom: -1px; }
.tabs button {
  border: 1px solid var(--line); border-bottom: none; background: var(--neutral-bg);
  border-radius: 9px 9px 0 0; padding: 9px 17px; font-family: inherit; font-size: 14px;
  font-weight: 600; cursor: pointer; color: var(--muted);
}
.tabs button.active { background: var(--card); color: var(--ink); }

.err { color: var(--bad); font-size: 14px; margin-top: 8px; min-height: 18px; }

#qr-toast {
  position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%) translateY(80px);
  background: var(--ink); color: #fff; padding: 11px 22px; border-radius: 9px;
  font-size: 15px; opacity: 0; transition: all .25s; z-index: 99; max-width: 90vw;
}
#qr-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
#qr-toast.error { background: var(--bad); }

@media (max-width: 640px) {
  .wrap { padding: 14px 10px 50px; }
  .card { padding: 16px; }
  .q-text { font-size: 18px; }
}

/* ---------- code blocks (API guide) ---------- */
pre.codeblock {
  background: #1d2433; color: #e8ebf5; border-radius: 8px;
  padding: 14px 16px; font-size: 13px; line-height: 1.5;
  overflow-x: auto; white-space: pre-wrap; overflow-wrap: anywhere;
}
code { background: var(--neutral-bg); padding: 1px 5px; border-radius: 4px; font-size: .92em; }
pre.codeblock code { background: none; padding: 0; }

/* ---------- teacher-paced / quick question: projected option rows ---------- */
.paced-opt {
  position: relative; border: 1px solid var(--line); border-radius: 10px;
  margin: 10px 0; overflow: hidden; min-height: 52px; background: #fff;
}
.paced-opt-fill {
  position: absolute; top: 0; left: 0; bottom: 0; z-index: 0;
  transition: width .4s ease;
}
.paced-opt-content {
  position: relative; z-index: 1; display: flex; align-items: center; gap: 12px;
  padding: 13px 16px; font-size: 18px; min-height: 52px;
}
.paced-opt-label { overflow-wrap: anywhere; }
.paced-opt-content .qimg { max-height: 90px; margin: 0; }
.paced-tick { color: var(--good); font-weight: 700; font-size: 20px; }
.paced-count { font-weight: 700; white-space: nowrap; }