/* ─── Reset & Tokens ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Theme transition ── */
html { transition: background-color .25s, color .25s; }

:root {
  --bg:          #0f0f13;
  --bg2:         #1a1a24;
  --bg3:         #252535;
  --border:      #2e2e42;
  --text:        #e2e2f0;
  --text2:       #9090b0;
  --primary:     #6366f1;
  --primary-h:   #5254cc;
  --primary-rgb: 99, 102, 241;
  --success:     #22c55e;
  --warning:     #f59e0b;
  --danger:      #ef4444;
  --again:       #ef4444;
  --hard:        #f59e0b;
  --good:        #6366f1;
  --easy:        #22c55e;
  --radius:      12px;
  --shadow:      0 4px 20px rgba(0,0,0,.45);
}

/* ─── Themes ────────────────────────────────────────────────────── */

/* Light */
html[data-theme="light"] {
  --bg:          #f5f5ff;
  --bg2:         #ffffff;
  --bg3:         #eaeaf8;
  --border:      #c8c8e8;
  --text:        #1a1a2e;
  --text2:       #5252a0;
  --primary:     #6366f1;
  --primary-h:   #5254cc;
  --primary-rgb: 99, 102, 241;
  --shadow:      0 4px 20px rgba(0,0,0,.12);
}

/* Soft — muted lavender dark */
html[data-theme="soft"] {
  --bg:          #1e1b34;
  --bg2:         #28244a;
  --bg3:         #342f60;
  --border:      #3d3870;
  --text:        #ddd8ff;
  --text2:       #8880c8;
  --primary:     #a78bfa;
  --primary-h:   #9168f0;
  --primary-rgb: 167, 139, 250;
  --shadow:      0 4px 20px rgba(0,0,0,.4);
}

/* Contrast — high-contrast accessible */
html[data-theme="contrast"] {
  --bg:          #000000;
  --bg2:         #0f0f0f;
  --bg3:         #1a1a1a;
  --border:      #555555;
  --text:        #ffffff;
  --text2:       #bbbbbb;
  --primary:     #faff00;
  --primary-h:   #d4d900;
  --primary-rgb: 250, 255, 0;
  --success:     #00ff88;
  --warning:     #ff9900;
  --danger:      #ff3344;
  --good:        #faff00;
  --shadow:      0 4px 20px rgba(0,0,0,.8);
}

/* Glow — neon/cyberpunk */
html[data-theme="glow"] {
  --bg:          #050510;
  --bg2:         #0a0a28;
  --bg3:         #0f0f3f;
  --border:      #1e1e80;
  --text:        #d0e4ff;
  --text2:       #5070d0;
  --primary:     #00e5ff;
  --primary-h:   #00b8cc;
  --primary-rgb: 0, 229, 255;
  --success:     #00ff99;
  --warning:     #ffcc00;
  --danger:      #ff2266;
  --good:        #00e5ff;
  --shadow:      0 4px 30px rgba(0,229,255,.18);
}

/* Cartoon — warm, colorful, fun */
html[data-theme="cartoon"] {
  --bg:          #fff9e6;
  --bg2:         #ffffff;
  --bg3:         #fff3c8;
  --border:      #f0c040;
  --text:        #2d2416;
  --text2:       #786030;
  --primary:     #7c3aed;
  --primary-h:   #6d28d9;
  --primary-rgb: 124, 58, 237;
  --success:     #059669;
  --warning:     #d97706;
  --danger:      #dc2626;
  --good:        #7c3aed;
  --shadow:      0 4px 20px rgba(124,58,237,.2);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
}

/* ─── Loading ──────────────────────────────────────────────────── */
.loading {
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  height: 100vh; gap: 16px; color: var(--text2);
}
.spinner {
  width: 40px; height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin .8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ─── Layout ───────────────────────────────────────────────────── */
.layout { display: flex; flex-direction: column; min-height: 100vh; }

.topbar {
  display: flex; align-items: center;
  padding: 0 24px; height: 56px;
  background: var(--bg2); border-bottom: 1px solid var(--border);
  gap: 16px; position: sticky; top: 0; z-index: 10;
}
.topbar .logo {
  font-weight: 800; font-size: 18px;
  color: var(--primary); letter-spacing: -0.5px; margin-right: auto;
}
.topbar nav { display: flex; gap: 4px; }
.nav-btn {
  padding: 6px 14px; border-radius: 8px;
  border: none; background: transparent;
  color: var(--text2); font-size: 14px; cursor: pointer; transition: all .15s;
}
.nav-btn:hover { background: var(--bg3); color: var(--text); }
.nav-btn.active { background: var(--bg3); color: var(--text); }

.avatar-chip {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--primary); color: #fff;
  font-size: 13px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  border: 2px solid var(--border);
}

.main {
  flex: 1; padding: 32px 24px;
  max-width: 900px; margin: 0 auto; width: 100%;
}

/* ─── Login / Setup ────────────────────────────────────────────── */
.login-page {
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  min-height: 100vh; gap: 20px; padding: 24px;
}
.login-card {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 48px 40px;
  width: 100%; max-width: 440px; text-align: center;
  box-shadow: var(--shadow);
}
.app-name {
  font-size: 36px; font-weight: 900;
  color: var(--primary); letter-spacing: -2px; margin-bottom: 8px;
}
.tagline { color: var(--text2); margin-bottom: 36px; font-size: 14px; }

.google-btn {
  display: flex; align-items: center; justify-content: center;
  gap: 12px; width: 100%; padding: 12px 24px;
  background: #fff; color: #1f1f1f;
  border: none; border-radius: 8px;
  font-size: 15px; font-weight: 500; cursor: pointer;
  transition: all .15s; box-shadow: 0 2px 8px rgba(0,0,0,.3);
}
.google-btn:hover { background: #f0f0f0; transform: translateY(-1px); }

.setup-notice {
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: 8px; padding: 14px 18px;
  font-size: 13px; color: var(--text2); text-align: left; margin-top: 12px;
}
.setup-notice a { color: var(--primary); cursor: pointer; }

/* ─── Shared Form Styles ───────────────────────────────────────── */
.panel {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 32px;
}
.panel h2 { font-size: 20px; font-weight: 700; margin-bottom: 6px; }
.panel .sub { color: var(--text2); font-size: 13px; margin-bottom: 28px; }

.form-group { margin-bottom: 20px; }
.form-group label {
  display: block; font-size: 12px; font-weight: 700;
  color: var(--text2); text-transform: uppercase;
  letter-spacing: .5px; margin-bottom: 8px;
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%; padding: 10px 14px;
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text); font-size: 14px;
  font-family: inherit; transition: border-color .15s;
}
.form-group textarea { min-height: 90px; resize: vertical; }
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus { outline: none; border-color: var(--primary); }
.form-group .hint { font-size: 12px; color: var(--text2); margin-top: 6px; }
.form-group .hint code { background: var(--bg3); padding: 1px 5px; border-radius: 4px; font-family: monospace; color: var(--text); }

/* Sheet connection status */
.sheet-status { font-size: 13px; color: var(--text2); padding: 6px 0; }
.sheet-status.ok   { color: var(--success); }
.sheet-status.warn { color: var(--danger); }
.sheet-link { color: var(--primary); text-decoration: none; }
.sheet-link:hover { text-decoration: underline; }
.sheet-advanced { margin-top: 8px; }

/* Azure TTS voice grid */
.tts-voice-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 8px; }
.tts-voice-btn { display: flex; flex-direction: column; align-items: center; gap: 3px; padding: 10px 8px; border-radius: 8px; background: var(--surface2); border: 1.5px solid var(--border); cursor: pointer; transition: border-color 0.15s, background 0.15s; }
.tts-voice-btn:hover { border-color: var(--primary); }
.tts-voice-btn.sel { border-color: var(--primary); background: color-mix(in srgb, var(--primary) 14%, transparent); }
.ttsv-label { font-size: 14px; font-weight: 600; }
.ttsv-desc  { font-size: 11px; color: var(--text2); text-align: center; }

/* Browser fallback voice picker */
.voice-list { display: flex; flex-direction: column; gap: 5px; max-height: 220px; overflow-y: auto; padding: 2px 0; }
.voice-item { display: flex; align-items: center; justify-content: space-between; padding: 7px 10px; border-radius: 7px; background: var(--surface2); border: 1.5px solid var(--border); cursor: pointer; transition: border-color 0.15s, background 0.15s; }
.voice-item:hover { border-color: var(--primary); }
.voice-item.sel { border-color: var(--primary); background: color-mix(in srgb, var(--primary) 12%, transparent); }
.voice-info { display: flex; align-items: center; gap: 8px; min-width: 0; }
.voice-name { font-size: 13px; font-weight: 500; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.voice-lang { font-size: 11px; color: var(--text2); flex-shrink: 0; }
.voice-badge { font-size: 10px; background: var(--primary); color: #fff; border-radius: 4px; padding: 1px 5px; font-weight: 700; flex-shrink: 0; }
.voice-sample-btn { flex-shrink: 0; background: none; border: 1px solid var(--border); border-radius: 5px; color: var(--text2); cursor: pointer; padding: 2px 9px; font-size: 12px; transition: color 0.15s, border-color 0.15s; }
.voice-sample-btn:hover { color: var(--primary); border-color: var(--primary); }
.voice-loading { font-size: 13px; color: var(--text2); padding: 8px 2px; }

/* Sheet-as-settings info box */
.sheet-settings-info { background: var(--surface2); border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; margin: 8px 0 16px; font-size: 13px; }
.sheet-settings-info-hd { font-weight: 600; margin-bottom: 6px; }
.sheet-settings-info-hd a { color: var(--primary); text-decoration: none; }
.sheet-settings-info-hd a:hover { text-decoration: underline; }
.sheet-settings-info-body { color: var(--text2); line-height: 1.6; }
.sheet-settings-info .key-list { display: block; margin-top: 6px; color: var(--text); font-size: 12px; }
.sheet-advanced summary {
  font-size: 12px; color: var(--text2); cursor: pointer;
  user-select: none; list-style: none;
}
.sheet-advanced summary::-webkit-details-marker { display: none; }
.sheet-advanced summary::before { content: '▸ '; }
details[open].sheet-advanced summary::before { content: '▾ '; }

.btn {
  padding: 10px 20px; border-radius: 8px; border: none;
  font-size: 14px; font-weight: 600; cursor: pointer; transition: all .15s;
}
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary  { background: var(--primary); color: #fff; }
.btn-primary:hover:not(:disabled)  { background: var(--primary-h); }
.btn-secondary { background: var(--bg3); color: var(--text); border: 1px solid var(--border); }
.btn-secondary:hover:not(:disabled) { background: var(--border); }
.btn-danger   { background: transparent; color: var(--danger); border: 1px solid var(--danger); }
.btn-danger:hover:not(:disabled)   { background: var(--danger); color: #fff; }

.form-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ─── 3-Column Review Layout ───────────────────────────────────── */
.review-body {
  display: flex;
  flex: 1;
  overflow: hidden;
  height: calc(100vh - 56px);
}

/* Left: tag filter column — 3 stacked sections */
.col-tags {
  width: 210px;
  flex-shrink: 0;
  overflow: hidden;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  background: var(--bg);
}
/* Top: header + pills + search */
.col-tags-top {
  flex-shrink: 0;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 7px;
  border-bottom: 1px solid var(--border);
}
/* Middle: tag tree — scrollable, fills remaining space */
.col-tags-tree {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 8px;
}
/* Bottom: groups — always visible, scrollable */
.col-tags-groups {
  flex-shrink: 0;
  min-height: 64px;
  max-height: 38vh;
  overflow-y: auto;
  border-top: 1px solid var(--border);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}

/* Center: question + input + AI — flex column, no overflow here */
.col-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}
/* Scrollable inner area */
.col-main-scroll {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
/* Override max-width constraints inside the scrollable center area */
.col-main-scroll .review-bar,
.col-main-scroll .question-card,
.col-main-scroll .answer-area { max-width: 100%; width: 100%; }

/* Right: correct answer column */
.col-answer {
  width: 280px;
  flex-shrink: 0;
  overflow-y: auto;
  border-left: 1px solid var(--border);
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--bg);
}

/* Expanded: right column takes full body (no fixed offset needed — rating bar is inside center col) */
.col-answer.expanded {
  position: fixed;
  top: 56px; left: 0; right: 0; bottom: 0;
  width: 100%;
  z-index: 30;
  background: var(--bg);
  border-left: none;
  padding: 20px 32px;
  overflow-y: auto;
}

/* Answer HTML in right column — no internal max-height limit */
.col-answer .correct-answer-html {
  max-height: none;
  flex: 1;
  min-height: 120px;
}

/* Column header row */
.col-hd {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .5px; color: var(--text2);
  padding-bottom: 8px; border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.col-hd-clear {
  background: transparent; border: 1px solid var(--border);
  border-radius: 4px; color: var(--text2);
  font-size: 10px; padding: 2px 6px; cursor: pointer;
}
.col-hd-clear:hover { color: var(--danger); border-color: var(--danger); }

.col-expand-btn {
  background: transparent; border: none;
  color: var(--text2); cursor: pointer; font-size: 14px;
  padding: 2px; line-height: 1; flex-shrink: 0;
}
.col-expand-btn:hover { color: var(--text); }

.col-search {
  width: 100%; padding: 7px 10px;
  background: var(--bg3); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text); font-size: 12px;
  flex-shrink: 0;
}
.col-search:focus { outline: none; border-color: var(--primary); }

.col-empty {
  font-size: 12px; color: var(--text2);
  text-align: center; padding: 8px 0;
}

/* Tag filter buttons in left column */
.tag-filter-list {
  display: flex; flex-direction: column; gap: 4px; overflow-y: auto;
}

.tag-filter-item {
  padding: 5px 10px; background: var(--bg3);
  border: 1px solid var(--border); border-radius: 6px;
  font-size: 12px; color: var(--text2); text-align: left;
  cursor: pointer; transition: all .12s; white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis;
}
.tag-filter-item:hover { border-color: var(--primary); color: var(--text); }
.tag-filter-item.active {
  background: rgba(var(--primary-rgb),.15); border-color: var(--primary); color: var(--primary);
}

/* col-tags-groups .col-hd already handles the header; tg-item rows below */

.tg-item {
  display: flex; align-items: center; gap: 6px; padding: 5px 8px;
  background: var(--bg3); border: 1px solid var(--border); border-radius: 6px;
}
.tg-name { flex: 1; font-size: 12px; color: var(--text); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tg-actions { display: flex; gap: 4px; flex-shrink: 0; }
.tg-load-btn, .tg-del-btn {
  background: transparent; border: none;
  color: var(--text2); cursor: pointer; font-size: 11px;
  padding: 2px 4px; border-radius: 3px; transition: all .12s;
}
.tg-load-btn:hover { color: var(--primary); background: rgba(var(--primary-rgb),.1); }
.tg-del-btn:hover  { color: var(--danger);  background: rgba(239,68,68,.1); }

.tg-save-btn {
  padding: 6px 10px; background: transparent;
  border: 1px dashed var(--border); border-radius: 6px;
  color: var(--text2); font-size: 12px; cursor: pointer;
  text-align: center; transition: all .12s;
}
.tg-save-btn:hover { border-color: var(--primary); color: var(--primary); }

/* AI inline panel in center column */
.ai-inline-panel {
  width: 100%; max-width: 100%;
  background: var(--bg2); border: 1px solid var(--primary);
  border-radius: var(--radius); overflow: hidden;
}

.ai-inline-hd {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 14px;
  background: rgba(var(--primary-rgb),.1); border-bottom: 1px solid var(--border);
  font-size: 12px; font-weight: 700; color: var(--primary);
}

.ai-inline-body {
  padding: 14px; font-size: 13px; line-height: 1.8;
  color: var(--text); white-space: pre-wrap;
}

/* ─── Review View ──────────────────────────────────────────────── */
.review-container {
  display: flex; flex-direction: column;
  align-items: center; gap: 20px; padding: 12px 0;
}

.review-bar {
  width: 100%; max-width: 680px;
  display: flex; align-items: center; gap: 14px;
}
.review-bar .count { font-size: 13px; color: var(--text2); white-space: nowrap; }
.progress-track {
  flex: 1; height: 6px; background: var(--bg3);
  border-radius: 3px; overflow: hidden;
}
.progress-fill {
  height: 100%; background: var(--primary);
  border-radius: 3px; transition: width .3s ease;
}

.card-wrap { width: 100%; max-width: 680px; }

/* Question card */
.question-card {
  width: 100%; max-width: 680px;
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 16px; padding: 32px 40px;
  position: relative; box-shadow: var(--shadow);
}
/* Clickable state — answer not yet revealed */
.question-card.clickable {
  cursor: pointer;
  border-color: var(--primary);
  transition: border-color .15s, box-shadow .15s;
}
.question-card.clickable:hover {
  box-shadow: 0 0 0 2px rgba(var(--primary-rgb),.25), var(--shadow);
}
/* Hint shown at bottom of card when answer is hidden */
.qa-hint {
  margin-top: 20px;
  font-size: 12px; color: var(--primary);
  text-align: right; letter-spacing: .3px;
  opacity: .7;
}

.side-label {
  position: absolute; top: 14px; left: 18px;
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 1px; color: var(--text2);
}
.card-tags {
  position: absolute; top: 12px; right: 14px;
  display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end;
}
.tag {
  padding: 3px 10px; background: var(--bg3);
  border-radius: 20px; font-size: 11px;
  color: var(--text2); border: 1px solid var(--border);
}

.card-front { font-size: 20px; font-weight: 500; line-height: 1.5; margin-top: 16px; }
.card-front.sm { font-size: 16px; }

/* Correct answer */
.correct-answer-wrap {
  width: 100%; max-width: 680px;
}

.correct-answer-label {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 1px; color: var(--text2); margin-bottom: 8px;
  padding: 0 2px;
}

.correct-answer-html {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 12px; padding: 18px 20px;
  max-height: 280px; overflow-y: auto;
  font-size: 15px; line-height: 1.8; color: var(--text);
  /* Render HTML content cleanly */
}
.correct-answer-html:empty::before {
  content: 'No answer added yet.';
  color: var(--text2); font-style: italic;
}
/* Basic HTML element styles inside answer */
.correct-answer-html h1,.correct-answer-html h2,.correct-answer-html h3 {
  margin: 8px 0 4px; font-size: 1.1em;
}
.correct-answer-html p  { margin: 4px 0; }
.correct-answer-html ul,.correct-answer-html ol { padding-left: 20px; margin: 4px 0; }
.correct-answer-html li { margin: 2px 0; }
.correct-answer-html code {
  background: var(--bg3); padding: 1px 6px;
  border-radius: 4px; font-size: 13px; font-family: monospace;
}
.correct-answer-html pre {
  background: var(--bg3); padding: 12px; border-radius: 8px;
  overflow-x: auto; font-size: 13px; margin: 8px 0;
}
.correct-answer-html pre code { background: none; padding: 0; }

/* ─── Two-column review layout ────────────────────────────────── */
.review-outer {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  width: 100%;
}

/* When AI eval panel is open, left column shrinks naturally */
.review-outer.has-panel .review-container { min-width: 0; }

/* ─── AI validate button (below mic) ──────────────────────────── */
.answer-btns {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
}

.ai-validate-btn {
  width: 40px; height: 40px;
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 10px; cursor: pointer; font-size: 16px;
  display: flex; align-items: center; justify-content: center;
  color: var(--primary); transition: all .15s;
}
.ai-validate-btn:hover:not(:disabled) {
  background: rgba(var(--primary-rgb),.15);
  border-color: var(--primary);
  box-shadow: 0 0 8px rgba(var(--primary-rgb),.3);
}
.ai-validate-btn:disabled { opacity: .3; cursor: not-allowed; }

/* ─── AI evaluation right panel ───────────────────────────────── */
.ai-eval-panel {
  width: 300px;
  flex-shrink: 0;
  background: var(--bg2);
  border: 1px solid var(--primary);
  border-radius: var(--radius);
  overflow: hidden;
  position: sticky;
  top: 72px;
  max-height: calc(100vh - 170px);
  display: flex;
  flex-direction: column;
}

.ai-eval-hd {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 16px;
  background: rgba(var(--primary-rgb),.12);
  border-bottom: 1px solid var(--border);
  font-size: 13px; font-weight: 700;
  color: var(--primary);
  flex-shrink: 0;
}

.ai-eval-close {
  background: transparent; border: none;
  color: var(--text2); cursor: pointer; font-size: 14px;
  padding: 2px 6px; border-radius: 4px; transition: all .15s;
}
.ai-eval-close:hover { background: var(--bg3); color: var(--text); }

.ai-eval-loading {
  display: flex; align-items: center; justify-content: center;
  gap: 12px; padding: 32px;
  color: var(--text2); font-size: 13px;
}

.ai-eval-body {
  padding: 16px;
  font-size: 13px; line-height: 1.8;
  color: var(--text); white-space: pre-wrap;
  overflow-y: auto; flex: 1;
}

/* ─── Answer WYSIWYG editor ────────────────────────────────────── */
.edit-hint { font-size: 10px; font-weight: 400; color: var(--text2); opacity: .6; text-transform: none; letter-spacing: 0; }

.answer-editor-toolbar {
  display: none;       /* shown via JS on dblclick */
  align-items: center;
  flex-wrap: wrap;
  gap: 2px;
  padding: 6px 10px;
  background: var(--bg3);
  border: 1px solid var(--primary);
  border-bottom: none;
  border-radius: 10px 10px 0 0;
}

.tb-btn {
  padding: 4px 8px; border-radius: 4px;
  border: 1px solid transparent;
  background: transparent; color: var(--text2);
  font-size: 13px; cursor: pointer; transition: all .12s;
  min-width: 28px; text-align: center; white-space: nowrap;
}
.tb-btn:hover { background: var(--bg2); color: var(--text); border-color: var(--border); }
.tb-sep { width: 1px; height: 18px; background: var(--border); margin: 0 4px; flex-shrink: 0; }
.tb-save   { background: var(--primary) !important; color: #fff !important; border-color: var(--primary) !important; }
.tb-save:hover { background: var(--primary-h) !important; }
.tb-cancel { color: var(--danger) !important; }
.tb-cancel:hover { background: rgba(239,68,68,.1) !important; border-color: var(--danger) !important; }

/* Answer div in edit mode */
.correct-answer-html.editing {
  border-color: var(--primary);
  border-radius: 0 0 10px 10px;
  outline: none;
  max-height: 420px;
  cursor: text;
}
.correct-answer-html[contenteditable="true"]:focus { outline: none; }

/* Raw HTML textarea */
.answer-raw-ta {
  width: 100%; height: 260px;
  padding: 12px 14px;
  background: var(--bg);
  border: 1px solid var(--primary);
  border-radius: 0 0 10px 10px;
  color: #7ec8a4;   /* green tint for HTML source */
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 12px; line-height: 1.6;
  resize: vertical; overflow-y: auto;
}
.answer-raw-ta:focus { outline: none; }

/* Rating bar — inline at bottom of center column */
.rating-bar-col {
  flex-shrink: 0;
  background: var(--bg2); border-top: 1px solid var(--border);
  padding: 10px 16px;
  box-shadow: 0 -4px 20px rgba(0,0,0,.3);
}
.rating-bar-col .rating-grid {
  max-width: 360px; margin: 0 auto;
}

.audio-btn {
  flex-shrink: 0;
  width: 32px; height: 32px;
  background: transparent; border: 1px solid var(--border);
  border-radius: 8px; cursor: pointer; font-size: 16px;
  display: flex; align-items: center; justify-content: center;
  transition: all .15s; line-height: 1;
}
.audio-btn:hover { background: var(--bg3); border-color: var(--text2); }

/* ─── Answer input area ───────────────────────────────────────── */
.answer-area {
  width: 100%; max-width: 680px;
  display: flex; gap: 10px; align-items: flex-start;
}

.answer-input {
  flex: 1;
  height: 88px;
  padding: 10px 14px;
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text); font-size: 14px;
  font-family: inherit; line-height: 1.6;
  resize: none; overflow-y: auto;
  transition: border-color .15s;
}
.answer-input:focus { outline: none; border-color: var(--primary); }
.answer-input::placeholder { color: var(--text2); opacity: .7; }

.mic-btn {
  flex-shrink: 0;
  width: 40px; height: 40px;
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: 10px; cursor: pointer; font-size: 18px;
  display: flex; align-items: center; justify-content: center;
  transition: all .15s;
}
.mic-btn:hover { background: var(--bg3); border-color: var(--text2); }
.mic-btn.listening {
  background: rgba(239,68,68,.15);
  border-color: var(--danger);
  animation: pulse 1s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(239,68,68,.4); }
  50%       { box-shadow: 0 0 0 6px rgba(239,68,68,0); }
}

/* Rating buttons */
.rating-row {
  width: 100%; max-width: 680px;
  display: flex; flex-direction: column; gap: 10px;
}
.rating-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; }
.rating-btn {
  padding: 12px 8px; border-radius: 10px;
  border: 1px solid transparent; font-size: 13px; font-weight: 700;
  cursor: pointer; transition: all .15s;
  display: flex; flex-direction: column; align-items: center; gap: 4px;
}
.rating-btn .ivl { font-size: 11px; font-weight: 400; opacity: .8; }

.rating-btn[data-r="1"] { background: rgba(239,68,68,.12);  color: var(--again); border-color: rgba(239,68,68,.3); }
.rating-btn[data-r="2"] { background: rgba(245,158,11,.12); color: var(--hard);  border-color: rgba(245,158,11,.3); }
.rating-btn[data-r="3"] { background: rgba(var(--primary-rgb),.12); color: var(--good);  border-color: rgba(var(--primary-rgb),.3); }
.rating-btn[data-r="4"] { background: rgba(34,197,94,.12);  color: var(--easy);  border-color: rgba(34,197,94,.3); }

.rating-btn:hover { transform: translateY(-2px); filter: brightness(1.2); }

.ai-bar { display: flex; gap: 10px; align-items: center; width: 100%; max-width: 680px; }
.ai-btn {
  padding: 8px 16px; background: transparent;
  border: 1px solid var(--border); border-radius: 8px;
  color: var(--text2); font-size: 13px; cursor: pointer; transition: all .15s;
}
.ai-btn:hover:not(:disabled) { border-color: var(--primary); color: var(--primary); }
.ai-btn:disabled { opacity: .5; cursor: default; }

.ai-output {
  display: none; background: var(--bg3);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 16px 20px; font-size: 14px; line-height: 1.8;
  color: var(--text2); width: 100%; max-width: 680px;
}
.ai-output.show { display: block; }

/* ─── Theme picker (topbar dots + settings swatches) ────────────── */
.theme-dots {
  display: flex; gap: 5px; align-items: center; flex-shrink: 0;
}
.theme-dot {
  width: 16px; height: 16px; border-radius: 50%;
  border: 2px solid transparent; cursor: pointer;
  padding: 0; transition: transform .15s, border-color .15s;
  flex-shrink: 0;
}
.theme-dot:hover { transform: scale(1.25); }
.theme-dot.active { border-color: var(--text); transform: scale(1.15); }

/* Settings page theme swatches */
.theme-picker {
  display: flex; flex-wrap: wrap; gap: 10px; margin-top: 4px;
}
.theme-swatch {
  display: flex; flex-direction: column; align-items: center; gap: 5px;
  cursor: pointer; border: 2px solid var(--border);
  border-radius: 10px; padding: 8px 12px;
  background: var(--bg2); transition: all .15s;
  min-width: 70px;
}
.theme-swatch:hover { border-color: var(--primary); }
.theme-swatch.sel { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(var(--primary-rgb),.3); }
.ts-preview {
  width: 36px; height: 24px; border-radius: 6px;
  border: 1px solid rgba(0,0,0,.15);
  display: flex; align-items: center; justify-content: center; gap: 2px;
}
.ts-dot { width: 8px; height: 8px; border-radius: 50%; }
.ts-label { font-size: 11px; color: var(--text2); font-weight: 600; }
.theme-swatch.sel .ts-label { color: var(--primary); }

/* Completed */
.done-screen {
  display: flex; flex-direction: column;
  align-items: center; gap: 18px;
  padding: 64px 20px; text-align: center;
}
.done-screen .icon { font-size: 64px; line-height: 1; }
.done-screen h2 { font-size: 28px; font-weight: 800; }
.done-screen p { color: var(--text2); max-width: 380px; }
.done-btns { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; margin-top: 8px; }

/* ─── Browse View — 3-column ───────────────────────────────────── */
.browse-body {
  display: flex; flex: 1; overflow: hidden;
  height: calc(100vh - 56px);
}

/* Left: tag tree */
.browse-col-tags {
  width: 220px; flex-shrink: 0;
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  background: var(--bg); overflow: hidden;
}
.browse-left-content {
  flex: 1; min-height: 0; overflow-y: auto;
  padding: 10px; display: flex; flex-direction: column; gap: 8px;
}

/* ── Left panel tab bar (Tags / Decks) ── */
.left-tab-bar {
  display: flex; flex-shrink: 0;
  border-bottom: 1px solid var(--border);
}
.left-tab {
  flex: 1; padding: 8px 4px; font-size: 11px; font-weight: 700;
  text-transform: uppercase; letter-spacing: .5px;
  background: transparent; border: none; cursor: pointer;
  color: var(--text2); transition: all .15s;
}
.left-tab.active { color: var(--primary); border-bottom: 2px solid var(--primary); margin-bottom: -1px; }
.left-tab:hover:not(.active) { color: var(--text); background: var(--bg3); }

/* Panel collapse toggle button — sits inside the tab bar */
.panel-toggle-btn {
  flex-shrink: 0; background: transparent; border: none;
  border-left: 1px solid var(--border);
  cursor: pointer; color: var(--text2); font-size: 12px;
  padding: 0 8px; align-self: stretch;
  display: flex; align-items: center;
  transition: color .15s, background .12s;
}
.panel-toggle-btn:hover { color: var(--primary); background: var(--bg3); }
/* Right detail panel toggle is on the left edge of its col-hd actions row */
.right-panel-toggle { border-left: none; border-right: 1px solid var(--border); margin-right: 2px; }

/* Strip button — the only visible element when a panel is collapsed */
.panel-strip-btn {
  display: flex; align-items: flex-start; justify-content: center;
  width: 100%; border: none; cursor: pointer;
  background: transparent; color: var(--text2); font-size: 13px;
  padding: 12px 0; flex-shrink: 0;
  transition: color .15s, background .12s;
}
.panel-strip-btn:hover { color: var(--primary); background: var(--bg3); }
/* Right panel strip has a left border to visually separate from card list */
.panel-strip-btn.right-strip { border-left: 1px solid var(--border); }

/* Collapsed left panels — narrow strip showing only the expand button */
.col-tags.collapsed          { width: 28px; min-width: 28px; overflow: hidden; }
.browse-col-tags.collapsed   { width: 28px; min-width: 28px; overflow: hidden; }
/* Collapsed right panel */
.browse-col-detail.right-collapsed { width: 28px; min-width: 28px; overflow: hidden; }

/* ── Deck badge ── */
.deck-badge {
  display: inline-flex; align-items: center; gap: 3px;
  padding: 2px 7px; border-radius: 4px;
  background: var(--bg3); color: var(--text2);
  font-size: 10px; font-weight: 600; letter-spacing: .2px;
  border: 1px solid var(--border);
  max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.bci-deck-row { margin-bottom: 4px; }

/* ── Browse card item: flex layout for checkbox + content ── */
.bci {
  display: flex; align-items: stretch;
  padding: 0; border-bottom: 1px solid var(--border);
  transition: background .12s;
}
.bci:hover { background: var(--bg3); }
.bci.sel { background: rgba(var(--primary-rgb),.08); border-left: 3px solid var(--primary); }
.bci-check {
  flex-shrink: 0; display: flex; align-items: center;
  padding: 0 8px 0 12px; cursor: pointer;
}
.bci-cb { width: 15px; height: 15px; cursor: pointer; accent-color: var(--primary); }
.bci-main { flex: 1; min-width: 0; padding: 10px 14px 10px 0; cursor: pointer; }
.bci.checked { background: rgba(var(--primary-rgb),.05); }

/* ── Bulk action bar ── */
.bulk-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 12px; flex-shrink: 0;
  background: rgba(var(--primary-rgb),.08);
  border-bottom: 1px solid var(--border);
}
.bulk-count { font-size: 12px; font-weight: 700; color: var(--primary); flex: 1; }

/* Center: card list */
.browse-col-cards {
  flex: 1; display: flex; flex-direction: column;
  overflow: hidden; min-width: 0;
}

/* Right: card detail — hidden until card is selected */
.browse-col-detail {
  width: 300px; flex-shrink: 0;
  border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow: hidden; background: var(--bg);
}
/* answer col collapsed to strip */
.col-answer.answer-col-strip {
  width: 28px; min-width: 28px; overflow: hidden; padding: 0;
}

/* ── Active tag pills at top of left column ── */
.browse-active-tags {
  display: flex; flex-wrap: wrap; gap: 5px; padding: 8px;
  background: rgba(var(--primary-rgb),.07); border: 1px solid var(--primary);
  border-radius: 8px; flex-shrink: 0;
}
.active-tag-pill {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 3px 8px; background: rgba(var(--primary-rgb),.18);
  border: 1px solid var(--primary); border-radius: 20px;
  font-size: 11px; color: var(--primary); max-width: 160px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.active-tag-rm {
  background: transparent; border: none; color: var(--text2);
  cursor: pointer; font-size: 11px; padding: 0; line-height: 1; flex-shrink: 0;
}
.active-tag-rm:hover { color: var(--danger); }
.clear-browse-tags {
  background: transparent; border: 1px solid var(--border);
  border-radius: 4px; color: var(--text2); font-size: 10px;
  padding: 2px 6px; cursor: pointer; flex-shrink: 0;
}
.clear-browse-tags:hover { color: var(--danger); border-color: var(--danger); }

/* ── Tag tree ── */
.tag-tree { display: flex; flex-direction: column; overflow-y: auto; flex: 1; }
.tree-node-wrap { display: flex; flex-direction: column; }
.tree-row { display: flex; align-items: center; gap: 2px; padding: 2px 0; }
.tree-toggle {
  background: transparent; border: none; color: var(--text2);
  cursor: pointer; font-size: 10px; padding: 1px 4px; border-radius: 3px;
  flex-shrink: 0; transition: color .1s; line-height: 1;
}
.tree-toggle:hover { color: var(--text); }
.tree-indent { width: 20px; flex-shrink: 0; }
.tree-lbl {
  display: inline-flex; align-items: stretch;
  background: transparent; border: none; cursor: pointer;
  border-radius: 6px; overflow: hidden; max-width: 176px;
}
.tree-lbl:hover .tree-tag { background: var(--bg2); border-color: var(--text2); }
.tree-lbl.active .tree-tag { background: rgba(var(--primary-rgb),.18); color: var(--primary); border-color: var(--primary); }
.tree-lbl.active .tree-cnt { background: var(--primary); color: #fff; border-color: var(--primary); }
.tree-tag {
  padding: 3px 8px; font-size: 12px; color: var(--text);
  background: var(--bg3); border: 1px solid var(--border);
  border-right: none; border-radius: 6px 0 0 6px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  max-width: 136px;
}
/* When tree-due follows, tree-cnt loses its right-side rounding */
.tree-cnt {
  padding: 3px 6px; font-size: 11px; font-weight: 700;
  background: var(--border); color: var(--text2);
  border: 1px solid var(--border); border-radius: 0 6px 6px 0;
  flex-shrink: 0;
}
/* tree-due present: flatten right side of tree-cnt */
.tree-lbl:has(.tree-due) .tree-cnt { border-radius: 0; border-right: none; }
.tree-kids { display: flex; flex-direction: column; }

/* Due count badge — shown in review tree */
.tree-due {
  padding: 3px 6px; font-size: 11px; font-weight: 700;
  background: var(--bg3); color: var(--text2);
  border: 1px solid var(--border); border-left: none;
  border-radius: 0 6px 6px 0; flex-shrink: 0;
}
.tree-due.has-due {
  background: rgba(var(--primary-rgb),.2); color: var(--primary); border-color: var(--primary);
}

/* Reset button (↺) beside tree node */
.tree-reset-btn {
  background: transparent; border: none; color: var(--text2);
  cursor: pointer; font-size: 13px; padding: 1px 4px;
  border-radius: 4px; flex-shrink: 0; opacity: 0;
  transition: opacity .15s, color .15s;
}
.tree-row:hover .tree-reset-btn { opacity: 1; }
.tree-reset-btn:hover { color: var(--warning); background: rgba(245,158,11,.12); }

/* Group counts (total + due) */
.tg-counts {
  display: flex; align-items: stretch; gap: 0; flex-shrink: 0; border-radius: 6px; overflow: hidden;
}
.tg-counts .tree-cnt { border-radius: 0; border-right: none; }
.tg-counts .tree-due { border-radius: 0; }

/* Reset button in group row */
.tg-reset-btn {
  background: transparent; border: none;
  color: var(--text2); cursor: pointer; font-size: 12px;
  padding: 2px 4px; border-radius: 3px; transition: all .12s;
}
.tg-reset-btn:hover { color: var(--warning); background: rgba(245,158,11,.12); }

/* ── Browse center header ── */
.browse-cards-hd {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 14px; border-bottom: 1px solid var(--border);
  flex-shrink: 0; gap: 10px; font-size: 14px; font-weight: 700;
  overflow: hidden;
}
.browse-hd-right { display: flex; gap: 8px; align-items: center; flex-shrink: 0; }
.browse-hd-right .col-search { width: 140px; min-width: 80px; }
.btn-sm { padding: 6px 12px; font-size: 13px; }

/* ── Browse card list ── */
.browse-card-list { display: flex; flex-direction: column; overflow-y: auto; flex: 1; }
.bci-q { font-size: 14px; color: var(--text); margin-bottom: 5px; line-height: 1.4; }
.bci-foot { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.bci-tags { display: flex; flex-wrap: wrap; gap: 4px; flex: 1; }
.bci-acts { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }
.bci-due { font-size: 11px; }

/* ── Browse detail column ── */
.browse-detail-q {
  height: 180px; flex-shrink: 0; overflow-y: auto;
  border-bottom: 1px solid var(--border); padding: 12px;
  display: flex; flex-direction: column; gap: 8px;
}
.browse-detail-a {
  flex: 1; overflow-y: auto; padding: 12px;
  display: flex; flex-direction: column; gap: 8px;
}
.browse-detail-text { font-size: 15px; line-height: 1.6; color: var(--text); padding: 4px 0; }
.browse-no-sel {
  display: flex; flex-direction: column; align-items: center;
  justify-content: center; height: 100%;
  color: var(--text2); text-align: center; gap: 8px; padding: 24px;
  font-size: 13px;
}
.browse-answer-html {
  flex: 1; font-size: 14px; line-height: 1.8; color: var(--text);
}
.browse-answer-html h1,.browse-answer-html h2,.browse-answer-html h3 { margin: 8px 0 4px; font-size: 1.1em; }
.browse-answer-html p  { margin: 4px 0; }
.browse-answer-html ul,.browse-answer-html ol { padding-left: 20px; margin: 4px 0; }
.browse-answer-html code { background: var(--bg3); padding: 1px 6px; border-radius: 4px; font-size: 13px; font-family: monospace; }
.browse-answer-html pre { background: var(--bg3); padding: 12px; border-radius: 8px; overflow-x: auto; font-size: 13px; margin: 8px 0; }

/* ── Shared small elements ── */
.count-badge { color: var(--text2); font-size: 14px; font-weight: 400; }
.row-actions { display: flex; gap: 8px; }
.icon-btn {
  width: 30px; height: 30px; display: flex; align-items: center; justify-content: center;
  background: transparent; border: 1px solid var(--border);
  border-radius: 6px; color: var(--text2); cursor: pointer; font-size: 14px;
  transition: all .15s;
}
.icon-btn:hover { background: var(--bg3); color: var(--text); }
.icon-btn.del:hover { border-color: var(--danger); color: var(--danger); }

/* ─── Empty State ──────────────────────────────────────────────── */
.empty { text-align: center; padding: 64px 20px; color: var(--text2); }
.empty .icon { font-size: 48px; margin-bottom: 16px; }
.empty h3 { color: var(--text); margin-bottom: 8px; }

/* ─── Stats ────────────────────────────────────────────────────── */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px,1fr)); gap: 16px; margin-bottom: 32px; }
.stat-card {
  background: var(--bg2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px; text-align: center;
}
.stat-value { font-size: 38px; font-weight: 900; color: var(--primary); }
.stat-label { font-size: 11px; color: var(--text2); text-transform: uppercase; letter-spacing: .5px; margin-top: 4px; }

/* ─── Toast ────────────────────────────────────────────────────── */
.toast-container {
  position: fixed; bottom: 24px; right: 24px;
  display: flex; flex-direction: column; gap: 8px; z-index: 999;
}
.toast {
  padding: 12px 20px; background: var(--bg3);
  border: 1px solid var(--border); border-radius: 8px;
  font-size: 14px; box-shadow: var(--shadow);
  animation: slideIn .2s ease; max-width: 320px;
}
.toast.success { border-color: var(--success); }
.toast.error   { border-color: var(--danger); }
@keyframes slideIn { from { transform: translateX(16px); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

/* ─── Mobile-only elements (hidden on desktop) ────────────────── */
.bottom-nav        { display: none; }
.mobile-bar        { display: none; }
.mobile-browse-bar { display: none; }
.detail-close-btn  {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border: none;
  background: transparent;
  color: var(--text2);
  font-size: 16px;
  border-radius: 6px;
  cursor: pointer;
  flex-shrink: 0;
}
.detail-close-btn:hover { background: var(--hover); color: var(--text); }
.drawer-backdrop   { display: none; }

/* ─── Mobile (≤ 680px) ──────────────────────────────────────────── */
@media (max-width: 680px) {
  body    { min-height: 100dvh; }
  .layout { min-height: 100dvh; }

  /* ── Topbar: hide desktop nav & theme dots ── */
  .topbar         { padding: 0 16px; }
  .topbar-desktop { display: none; }

  /* ── Bottom navigation bar ── */
  .bottom-nav {
    display: flex;
    position: fixed; bottom: 0; left: 0; right: 0;
    background: var(--bg2); border-top: 1px solid var(--border);
    z-index: 20;
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }
  .bn-btn {
    flex: 1; display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    gap: 2px; padding: 8px 4px;
    background: transparent; border: none; cursor: pointer;
    color: var(--text2); transition: color .15s;
    min-height: 52px; touch-action: manipulation;
  }
  .bn-btn.active { color: var(--primary); }
  .bn-icon { font-size: 20px; line-height: 1; }
  .bn-label { font-size: 10px; font-weight: 600; text-transform: uppercase; letter-spacing: .4px; }

  /* ── Standard page areas: account for bottom nav ── */
  .main       { padding: 16px 16px calc(72px + env(safe-area-inset-bottom, 0px)); }
  .login-page { min-height: 100dvh; }
  .login-card { padding: 36px 24px; }
  .panel      { padding: 20px 16px; }

  /* ── Browse: fixed height so card list can scroll within bounds ── */
  .browse-body {
    height: calc(100dvh - 56px - 52px - env(safe-area-inset-bottom, 0px));
    position: relative;
    overflow: hidden;
  }

  /* ── Review: rating bar fixed above bottom nav, always reachable ── */
  .review-body {
    height: auto;
    min-height: 0;
    position: relative;
    overflow: visible;
    padding-bottom: 0;
  }
  .col-main { overflow: visible; }
  .col-main-scroll {
    flex: none; overflow: visible; min-height: auto;
    padding-bottom: 90px; /* clear the fixed rating bar */
  }
  /* Rating bar pinned just above the bottom nav tab bar */
  .rating-bar-col {
    position: fixed;
    bottom: calc(52px + env(safe-area-inset-bottom, 0px));
    left: 0; right: 0;
    z-index: 15;
    background: var(--bg2);
    border-top: 1px solid var(--border);
  }

  /* ── Backdrop for drawers ── */
  .drawer-backdrop {
    display: block;
    position: fixed; inset: 0; z-index: 39;
    background: rgba(0,0,0,.55);
  }

  /* ── Review: tags column becomes a slide-up bottom-sheet drawer ── */
  .col-tags {
    display: none;
    width: 100%;
    position: fixed;
    bottom: calc(52px + env(safe-area-inset-bottom, 0px)); left: 0; right: 0;
    max-height: 72vh; z-index: 40;
    border-right: none;
    border-top: 2px solid var(--border);
    border-radius: 20px 20px 0 0;
    box-shadow: 0 -8px 40px rgba(0,0,0,.5);
  }
  .col-tags.drawer-open { display: flex; }

  /* ── Tags trigger bar (above question area) ── */
  .mobile-bar {
    display: flex;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0; background: var(--bg2);
  }
  .mobile-tags-btn {
    padding: 6px 14px; border-radius: 8px;
    background: var(--bg3); border: 1px solid var(--border);
    color: var(--text2); font-size: 13px; cursor: pointer;
    touch-action: manipulation;
  }
  .mobile-tags-btn.has-active {
    background: rgba(var(--primary-rgb),.12);
    border-color: var(--primary); color: var(--primary);
  }

  /* ── Review: answer column — fixed overlay, stops above sticky rating bar ── */
  .col-answer {
    width: 100%;
    position: fixed;
    top: 56px; left: 0; right: 0;
    bottom: calc(52px + 80px + env(safe-area-inset-bottom, 0px));
    z-index: 10;
    border-left: none;
    overflow-y: auto;
  }
  /* Expanded (⤢ button): cover full area between topbar and bottom nav */
  .col-answer.expanded {
    bottom: calc(52px + env(safe-area-inset-bottom, 0px));
    padding: 16px 20px;
  }

  /* ── Browse: filter-tags column becomes a bottom-sheet drawer ── */
  .browse-body { flex-direction: column; }
  .browse-col-tags {
    display: none;
    width: 100%;
    position: fixed;
    bottom: calc(52px + env(safe-area-inset-bottom, 0px)); left: 0; right: 0;
    max-height: 72vh; z-index: 40;
    border-right: none;
    border-top: 2px solid var(--border);
    border-radius: 20px 20px 0 0;
    box-shadow: 0 -8px 40px rgba(0,0,0,.5);
    overflow-y: auto;
  }
  .browse-col-tags.drawer-open { display: flex; flex-direction: column; }

  /* ── Browse: filter trigger bar ── */
  .mobile-browse-bar {
    display: flex;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0; background: var(--bg2);
    gap: 8px; align-items: center;
  }
  .mobile-filter-btn {
    padding: 6px 14px; border-radius: 8px;
    background: var(--bg3); border: 1px solid var(--border);
    color: var(--text2); font-size: 13px; cursor: pointer;
    white-space: nowrap; touch-action: manipulation;
  }
  .mobile-filter-btn.has-active {
    background: rgba(var(--primary-rgb),.12);
    border-color: var(--primary); color: var(--primary);
  }

  /* ── Browse: card detail becomes a full-screen overlay ── */
  .browse-col-detail {
    display: none;
    position: fixed;
    top: 56px; bottom: calc(52px + env(safe-area-inset-bottom, 0px));
    left: 0; right: 0; width: 100%; z-index: 35;
    border-left: none; background: var(--bg);
    overflow: hidden;
  }
  .browse-col-detail.has-selection { display: flex; flex-direction: column; }

  /* ── Detail panel close (✕) button ── */
  .detail-close-btn {
    display: inline-flex; align-items: center;
    background: transparent; border: none;
    color: var(--text2); cursor: pointer;
    font-size: 18px; padding: 2px 6px; line-height: 1;
    touch-action: manipulation;
  }
  .detail-close-btn:hover { color: var(--primary); }

  /* ── Card & form sizing ── */
  .question-card { padding: 24px 20px; }
  .card-front    { font-size: 17px; }

  /* ── Toast: rise above bottom nav ── */
  .toast-container { bottom: calc(72px + env(safe-area-inset-bottom, 0px)); right: 12px; }
}

/* ─── Decks Page ───────────────────────────────────────────────────────────── */
.decks-page {
  max-width: 820px;
  margin: 0 auto;
  padding: 24px 16px 80px;
}

.decks-pg-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.decks-pg-header h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}

/* ── New deck form ── */
.deck-new-form {
  background: var(--bg2);
  border: 1px solid var(--primary);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.deck-new-input {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 9px 13px;
  font-size: 14px;
  font-family: inherit;
}

.deck-new-input:focus { outline: none; border-color: var(--primary); }

.deck-new-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* File inputs hidden but remain in DOM so programmatic .click() works */
.deck-file-input,
#deck-new-file {
  position: absolute;
  width: 1px; height: 1px;
  opacity: 0;
  overflow: hidden;
  pointer-events: none;
}

.deck-cancel-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text2);
  border-radius: 6px;
  padding: 5px 12px;
  font-size: 13px;
  cursor: pointer;
  font-family: inherit;
}

.deck-cancel-btn:hover { border-color: var(--danger); color: var(--danger); }

/* ── Deck tree manager ── */
.deck-tree-mgr {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.deck-tree-mgr-empty {
  padding: 48px 24px;
  text-align: center;
  color: var(--text2);
}

.deck-mgr-node {
  border-bottom: 1px solid var(--border);
}

.deck-mgr-node:last-child { border-bottom: none; }

.deck-mgr-kids {
  background: rgba(0,0,0,.04);
}

html[data-theme="light"] .deck-mgr-kids,
html[data-theme="cartoon"] .deck-mgr-kids { background: rgba(0,0,0,.025); }

.deck-mgr-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  min-height: 46px;
  transition: background .12s;
}

.deck-mgr-row:hover { background: var(--bg3); }

.deck-mgr-toggle {
  width: 22px; height: 22px;
  flex-shrink: 0;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text2);
  cursor: pointer;
  font-size: 15px;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  line-height: 1;
  transition: border-color .12s, color .12s;
}

.deck-mgr-toggle:hover { border-color: var(--primary); color: var(--primary); }

.deck-mgr-name {
  background: none;
  border: none;
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  padding: 3px 7px;
  border-radius: 5px;
  text-align: left;
  font-family: inherit;
  transition: color .12s, background .12s;
}

.deck-mgr-name:hover {
  color: var(--primary);
  background: rgba(var(--primary-rgb), .1);
}

.deck-count-badge {
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text2);
  font-size: 12px;
  padding: 2px 9px;
  border-radius: 10px;
  white-space: nowrap;
  flex-shrink: 0;
}

.deck-mgr-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}

.deck-upload-lbl {
  display: inline-flex; align-items: center; gap: 4px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text2);
  font-size: 12px;
  padding: 4px 10px;
  cursor: pointer;
  white-space: nowrap;
  font-family: inherit;
  transition: color .12s, border-color .12s;
}

.deck-upload-lbl:hover { color: var(--primary); border-color: var(--primary); }

.deck-rename-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text2);
  font-size: 12px;
  padding: 4px 10px;
  cursor: pointer;
  font-family: inherit;
  white-space: nowrap;
  transition: color .12s, border-color .12s;
}

.deck-rename-btn:hover { color: var(--primary); border-color: var(--primary); }

.deck-indent {
  display: inline-block;
  width: 22px;
  flex-shrink: 0;
}

/* ── Upload hint footer ── */
.deck-upload-hint {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 14px;
  color: var(--text2);
  font-size: 12px;
  flex-wrap: wrap;
}

.deck-upload-hint code {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 11px;
  color: var(--text);
}

/* ── Mobile responsive ── */
@media (max-width: 600px) {
  .deck-mgr-actions { gap: 4px; }
  .deck-upload-lbl, .deck-rename-btn { padding: 4px 7px; }
  .deck-mgr-name { font-size: 13px; }
}