/* =========================================================
   Classroom Listening Response Platform
   Clean academic UI. Mongolian-first typography.
   ========================================================= */

:root {
  /* Neutral palette */
  --bg: #f6f7f9;
  --bg-elev: #ffffff;
  --border: #e3e6ea;
  --border-strong: #c9cfd6;
  --text: #1f2430;
  --text-muted: #5c6573;
  --text-soft: #8b93a1;
  --accent: #2f5bea;
  --accent-hover: #2348c8;
  --danger: #c23b3b;
  --danger-hover: #a62f2f;
  --success: #2e8b57;
  --warning: #a6661f;

  /* Stage colors (soft) */
  --stage1-bg: #eaf1fb;
  --stage1-border: #bcd1f2;
  --stage1-accent: #3d6fd6;

  --stage2-bg: #fbf2e0;
  --stage2-border: #e8d3a1;
  --stage2-accent: #a6752a;

  --stage3-bg: #e6f3ec;
  --stage3-border: #bad9c7;
  --stage3-accent: #2e7d54;

  --radius: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(20, 28, 44, 0.06);
  --shadow: 0 2px 8px rgba(20, 28, 44, 0.08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "Noto Sans KR", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { margin: 0 0 8px 0; font-weight: 600; }
h1 { font-size: 1.6rem; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1.05rem; }
h4 { font-size: 0.95rem; color: var(--text-muted); }

p { margin: 0 0 8px 0; }

.min-h-screen { min-height: 100vh; }

.page-loading, .landing-loading {
  padding: 48px 20px;
  text-align: center;
  color: var(--text-muted);
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  background: var(--bg-elev);
  color: var(--text);
  font-size: 0.92rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease, color 0.12s ease;
  line-height: 1;
  font-family: inherit;
}
.btn:hover:not(:disabled) { background: #eef1f5; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-danger {
  background: #fff;
  border-color: var(--danger);
  color: var(--danger);
}
.btn-danger:hover:not(:disabled) {
  background: var(--danger);
  color: #fff;
}

.btn-ghost {
  border-color: transparent;
  background: transparent;
}
.btn-ghost:hover:not(:disabled) { background: #eef1f5; }

.btn-sm { padding: 6px 10px; font-size: 0.85rem; }
.btn-lg { padding: 12px 20px; font-size: 1rem; }

.btn-block { width: 100%; }

.btn-active {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

/* ============ Inputs ============ */
.input, .select, .textarea {
  width: 100%;
  padding: 9px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  background: #fff;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text);
}
.input:focus, .select:focus, .textarea:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
  border-color: var(--accent);
}

.input-lg { padding: 14px 16px; font-size: 1.1rem; text-align: center; letter-spacing: 2px; }

.label {
  display: block;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 5px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.field { margin-bottom: 14px; }

/* ============ Layout cards / panels ============ */
.card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 18px;
  box-shadow: var(--shadow-sm);
}

.card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.stack { display: flex; flex-direction: column; gap: 12px; }
.stack-sm { display: flex; flex-direction: column; gap: 6px; }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.row-end { justify-content: flex-end; }
.grow { flex: 1; }

/* ============ Badges / pills ============ */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 9px;
  border-radius: 99px;
  font-size: 0.78rem;
  font-weight: 500;
  background: #eef1f5;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.badge-blue   { background: var(--stage1-bg); color: var(--stage1-accent); border-color: var(--stage1-border); }
.badge-amber  { background: var(--stage2-bg); color: var(--stage2-accent); border-color: var(--stage2-border); }
.badge-green  { background: var(--stage3-bg); color: var(--stage3-accent); border-color: var(--stage3-border); }
.badge-neutral { background: #eef1f5; color: var(--text-muted); }
.badge-success { background: #e4f3eb; color: var(--success); border-color: #bad9c7; }
.badge-danger  { background: #fbe9e9; color: var(--danger); border-color: #ecc0c0; }
.badge-warn    { background: var(--stage2-bg); color: var(--stage2-accent); border-color: var(--stage2-border); }

/* ============ Alerts ============ */
.alert {
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  margin-bottom: 10px;
  border: 1px solid transparent;
}
.alert-error  { background: #fbe9e9; color: var(--danger); border-color: #ecc0c0; }
.alert-success { background: #e4f3eb; color: var(--success); border-color: #bad9c7; }
.alert-info    { background: #eaf1fb; color: var(--stage1-accent); border-color: #bcd1f2; }

/* ============ Landing page ============ */
.landing {
  max-width: 760px;
  margin: 0 auto;
  padding: 64px 20px;
  text-align: center;
}
.landing h1 { font-size: 2rem; margin-bottom: 6px; }
.landing .subtitle { color: var(--text-muted); margin-bottom: 40px; font-size: 1rem; }

.landing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}

.landing-card {
  display: block;
  padding: 28px 20px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: left;
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s ease, transform 0.12s ease, box-shadow 0.15s ease;
  cursor: pointer;
}
.landing-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.landing-card .icon {
  display: inline-block;
  width: 42px; height: 42px;
  line-height: 42px;
  text-align: center;
  border-radius: 8px;
  background: var(--stage1-bg);
  color: var(--stage1-accent);
  font-size: 1.3rem;
  margin-bottom: 12px;
}
.landing-card.variant-student .icon { background: var(--stage3-bg); color: var(--stage3-accent); }
.landing-card.variant-classroom .icon { background: var(--stage2-bg); color: var(--stage2-accent); }

.landing-card h2 { font-size: 1.1rem; margin-bottom: 4px; }
.landing-card p  { color: var(--text-muted); font-size: 0.9rem; margin: 0; }

.landing-quick {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px;
  text-align: left;
  max-width: 460px;
  margin: 0 auto;
}
.landing-quick .label { margin-bottom: 8px; }
.landing-quick .row { align-items: stretch; }

/* ============ Teacher dashboard ============ */
.teacher-root {
  max-width: 1280px;
  margin: 0 auto;
  padding: 16px 20px 40px;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 16px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.topbar .title { font-weight: 600; font-size: 1rem; }
.topbar .divider {
  width: 1px; height: 20px; background: var(--border);
}

.teacher-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
@media (max-width: 960px) {
  .teacher-grid { grid-template-columns: 1fr; }
}

.stage-buttons {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.stage-buttons .btn { white-space: normal; text-align: center; font-size: 0.88rem; padding: 10px 8px; }

.room-code-display {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 6px;
  text-align: center;
  padding: 16px;
  background: var(--stage1-bg);
  border: 1px solid var(--stage1-border);
  border-radius: var(--radius);
  color: var(--stage1-accent);
  font-family: "Inter", monospace;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.stat {
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fafbfc;
  text-align: center;
}
.stat .stat-num { font-size: 1.4rem; font-weight: 700; color: var(--text); }
.stat .stat-label { font-size: 0.78rem; color: var(--text-muted); }

.participants-list {
  max-height: 220px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fafbfc;
}
.participants-list .p-row {
  display: flex;
  justify-content: space-between;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
}
.participants-list .p-row:last-child { border-bottom: none; }

.toggle-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

/* ============ Student page ============ */
.student-root {
  max-width: 820px;
  margin: 0 auto;
  padding: 16px 20px 40px;
}

.student-join {
  max-width: 420px;
  margin: 64px auto;
  padding: 28px 24px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}
.student-join h1 { text-align: center; margin-bottom: 8px; }
.student-join .subtitle { text-align: center; color: var(--text-muted); margin-bottom: 24px; font-size: 0.9rem; }

.waiting-card {
  text-align: center;
  padding: 48px 24px;
}
.waiting-card .big-room {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: 8px;
  color: var(--accent);
  margin: 12px 0;
}

.student-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.stage-panel {
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  margin-bottom: 14px;
}
.stage-panel.stage-1 { background: var(--stage1-bg); border-color: var(--stage1-border); }
.stage-panel.stage-2 { background: var(--stage2-bg); border-color: var(--stage2-border); }
.stage-panel.stage-3 { background: var(--stage3-bg); border-color: var(--stage3-border); }

.stage-panel .stage-title {
  font-weight: 600; font-size: 1.05rem; margin-bottom: 4px;
}
.stage-panel .instruction {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 0;
}

/* questions */
.question-block {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 12px;
}
.question-block .q-prompt {
  font-size: 1rem;
  margin-bottom: 10px;
  font-weight: 500;
}

.options { display: flex; flex-direction: column; gap: 6px; }
.option-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: #fafbfc;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.95rem;
  text-align: left;
  font-family: inherit;
  color: var(--text);
  transition: background 0.1s ease, border-color 0.1s ease;
}
.option-btn:hover:not(:disabled) { background: #eef1f5; }
.option-btn:disabled { cursor: not-allowed; }
.option-btn.selected {
  background: #e6edfb;
  border-color: var(--accent);
  color: var(--accent);
}
.option-btn.correct {
  background: #e4f3eb;
  border-color: var(--success);
  color: var(--success);
}
.option-btn.incorrect {
  background: #fbe9e9;
  border-color: var(--danger);
  color: var(--danger);
}
.option-btn .opt-key {
  display: inline-block;
  width: 26px; height: 26px;
  line-height: 26px;
  text-align: center;
  border-radius: 50%;
  background: #fff;
  border: 1px solid var(--border-strong);
  font-weight: 600;
  font-size: 0.85rem;
  flex-shrink: 0;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 10px;
  margin-bottom: 14px;
}
.info-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
}
.info-card .term {
  font-family: "Noto Sans KR", sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 2px;
}
.info-card .meaning {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 2px;
}
.info-card .func-label {
  font-size: 0.75rem;
  color: var(--stage2-accent);
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.gap-line {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  margin-bottom: 10px;
  font-family: "Noto Sans KR", sans-serif;
  font-size: 1.02rem;
  line-height: 1.8;
}
.gap-input {
  display: inline-block;
  width: 150px;
  padding: 4px 8px;
  border: none;
  border-bottom: 2px solid var(--stage2-accent);
  background: transparent;
  font-family: inherit;
  font-size: 1rem;
  margin: 0 4px;
  text-align: center;
}
.gap-input:focus { outline: none; background: var(--stage2-bg); }
.gap-input.correct { color: var(--success); border-color: var(--success); }
.gap-input.incorrect { color: var(--danger); border-color: var(--danger); }
.gap-input.revealed { background: #e4f3eb; color: var(--success); border-color: var(--success); }

/* script block for stage 3 */
.script-block {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
}
.script-line {
  display: flex;
  gap: 10px;
  padding: 7px 0;
  border-bottom: 1px dashed #e6ebf0;
  font-family: "Noto Sans KR", sans-serif;
  font-size: 1.05rem;
}
.script-line:last-child { border-bottom: none; }
.script-line .speaker {
  flex-shrink: 0;
  font-weight: 600;
  color: var(--stage3-accent);
  min-width: 48px;
}

.shadow-line {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  margin-bottom: 8px;
  font-family: "Noto Sans KR", sans-serif;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 12px;
}
.shadow-line .idx {
  flex-shrink: 0;
  width: 26px; height: 26px;
  line-height: 26px;
  border-radius: 50%;
  background: var(--stage3-bg);
  color: var(--stage3-accent);
  text-align: center;
  font-size: 0.85rem;
  font-weight: 600;
}
.shadow-line .self-check {
  margin-left: auto;
  display: flex;
  gap: 4px;
}

.audio-player {
  width: 100%;
  margin-bottom: 12px;
}

/* submission / result banners */
.submit-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: #fafbfc;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-top: 14px;
}

.result-banner {
  padding: 12px 16px;
  background: #eaf1fb;
  border: 1px solid var(--stage1-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  font-size: 0.95rem;
}

/* ============ Classroom page ============ */
.classroom-root {
  min-height: 100vh;
  background: var(--bg);
  display: flex;
  flex-direction: column;
}

.classroom-header {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 16px 32px;
  background: var(--bg-elev);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.classroom-header h1 { font-size: 1.4rem; margin: 0; }
.classroom-header .room-code {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 4px;
  color: var(--accent);
  margin-left: auto;
}

.classroom-main {
  flex: 1;
  padding: 32px 48px;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

.classroom-footer {
  display: flex;
  gap: 40px;
  padding: 14px 32px;
  background: var(--bg-elev);
  border-top: 1px solid var(--border);
  font-size: 1rem;
  color: var(--text-muted);
}
.classroom-footer .metric { display: flex; gap: 8px; align-items: center; }
.classroom-footer .metric .val { font-size: 1.3rem; font-weight: 700; color: var(--text); }

.classroom-waiting {
  text-align: center;
  padding: 72px 20px;
}
.classroom-waiting .big-code {
  font-size: 5.2rem;
  font-weight: 700;
  letter-spacing: 16px;
  color: var(--accent);
  margin: 24px 0;
  font-family: "Inter", monospace;
}
.classroom-waiting p { font-size: 1.4rem; color: var(--text-muted); }

.classroom-stage-title {
  font-size: 2rem;
  margin-bottom: 14px;
}
.classroom-stage-title .label-text { display: block; font-size: 1rem; color: var(--text-muted); font-weight: 500; margin-bottom: 4px; }

.classroom-instruction {
  font-size: 1.3rem;
  padding: 18px 24px;
  border-radius: var(--radius-lg);
  margin-bottom: 24px;
}
.classroom-instruction.stage-1 { background: var(--stage1-bg); border: 1px solid var(--stage1-border); }
.classroom-instruction.stage-2 { background: var(--stage2-bg); border: 1px solid var(--stage2-border); }
.classroom-instruction.stage-3 { background: var(--stage3-bg); border: 1px solid var(--stage3-border); }

.classroom-content { font-size: 1.15rem; }
.classroom-content .question-block { font-size: 1.1rem; padding: 18px 22px; }
.classroom-content .q-prompt { font-size: 1.2rem; }
.classroom-content .info-card .term { font-size: 1.3rem; }
.classroom-content .info-card .meaning { font-size: 1rem; }
.classroom-content .script-line { font-size: 1.3rem; padding: 10px 0; }
.classroom-content .gap-line { font-size: 1.3rem; }

.classroom-completed {
  text-align: center;
  padding: 80px 20px;
}
.classroom-completed h2 { font-size: 2.4rem; margin-bottom: 12px; }
.classroom-completed p { font-size: 1.2rem; color: var(--text-muted); }

/* Results summary */
.result-summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}
.result-summary-card {
  padding: 18px 20px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.result-summary-card .stage-name { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 6px; }
.result-summary-card .metric-big { font-size: 2rem; font-weight: 700; color: var(--text); }
.result-summary-card .metric-sub { font-size: 0.85rem; color: var(--text-muted); }

/* fullscreen helper */
.fs-btn {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 10;
  opacity: 0.7;
}
.fs-btn:hover { opacity: 1; }

/* Self-check radio group */
.self-check-group {
  display: inline-flex;
  gap: 4px;
  background: #fafbfc;
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: 2px;
}
.self-check-group button {
  padding: 5px 12px;
  border: none;
  background: transparent;
  border-radius: 99px;
  font-size: 0.82rem;
  cursor: pointer;
  color: var(--text-muted);
  font-family: inherit;
}
.self-check-group button.active { background: var(--stage3-accent); color: #fff; }

/* utility */
.text-muted { color: var(--text-muted); }
.text-small { font-size: 0.85rem; }
.text-center { text-align: center; }
.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.hidden { display: none !important; }