/* ── Design System: CIIP Flashcard App ─────────────────────────────────────
   "The Diagnostic Console" — precision study instrument for CIIP exam prep
   ─────────────────────────────────────────────────────────────────────────── */

:root {
  /* Tonal scale (darkest → lightest) */
  --void:     #0a0b0e;
  --console:  #12141b;
  --panel:    #181c24;
  --lift:     #1e2230;
  --trace:    #23262f;
  --signal:   #e4e6f0;
  --static:   #6e7286;
  --platinum: #eceef8;

  /* Semantic — SRS ratings only, never decorative */
  --critical: #d04f46;
  --caution:  #c69138;
  --nominal:  #3ea658;
  --deep:     #8a67d4;

  /* Radius scale */
  --radius-sm: 6px;
  --radius:    10px;
  --radius-lg: 14px;

  /* ── Legacy aliases (backward-compat for inline JS that uses old names) ── */
  --bg:      var(--void);
  --surface: var(--console);
  --card-bg: var(--panel);
  --border:  var(--trace);
  --text:    var(--signal);
  --muted:   var(--static);
  --accent:  var(--platinum);
  --again:   var(--critical);
  --hard:    var(--caution);
  --good:    var(--nominal);
  --easy:    var(--platinum);
  --mastered: var(--deep);
}

/* ── Reset ─────────────────────────────────────────────────────────────────── */
* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--void);
  color: var(--signal);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 14px;
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--platinum); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Buttons ────────────────────────────────────────────────────────────────── */
button {
  cursor: pointer;
  border: none;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  border-radius: var(--radius-sm);
  padding: 8px 16px;
  transition: opacity 0.12s ease-out, transform 0.08s linear, background 0.12s ease-out, color 0.12s ease-out;
}
button:active { transform: scale(0.97); }

.btn-primary {
  background: var(--platinum);
  color: var(--void);
  font-weight: 700;
  padding: 9px 20px;
}
.btn-primary:hover { background: #ffffff; }

.btn-secondary {
  background: var(--panel);
  color: var(--signal);
  border: 1px solid var(--trace);
  padding: 9px 18px;
}
.btn-secondary:hover { background: var(--lift); }

.btn-danger { background: var(--critical); color: #fff; padding: 9px 16px; }
.btn-danger:hover { opacity: 0.88; }

.btn-ghost {
  background: transparent;
  color: var(--static);
  border: 1px solid var(--trace);
  padding: 7px 14px;
  font-size: 13px;
  font-weight: 500;
}
.btn-ghost:hover { background: var(--panel); color: var(--signal); }

/* ── Layout ─────────────────────────────────────────────────────────────────── */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ── Header ─────────────────────────────────────────────────────────────────── */
.app-header {
  background: var(--console);
  border-bottom: 1px solid var(--trace);
  padding: 13px 0;
}
.app-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.app-header h1 {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--signal);
}
.app-header .header-actions { display: flex; gap: 8px; align-items: center; }

.icon-btn {
  background: transparent;
  border: 1px solid var(--trace);
  color: var(--static);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 15px;
}
.icon-btn:hover { color: var(--signal); border-color: var(--static); }

/* ── Banner strip ────────────────────────────────────────────────────────────── */
.banner {
  background: var(--console);
  border-bottom: 1px solid var(--trace);
  padding: 10px 0;
}
.banner .container {
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
}
.banner-stat {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--static);
}
.banner-stat strong { color: var(--signal); font-size: 14px; font-weight: 600; }
.banner-stat .icon { font-size: 14px; }

.daily-goal-bar {
  flex: 1;
  min-width: 120px;
  max-width: 200px;
}
.daily-goal-bar .label {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--static);
  margin-bottom: 4px;
  letter-spacing: 0.03em;
}
.progress-track {
  height: 3px;
  background: var(--trace);
  border-radius: 2px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: var(--nominal);
  border-radius: 2px;
  transition: width 0.4s ease;
}

/* ── Main content ─────────────────────────────────────────────────────────────── */
main { padding: 24px 0 60px; }

/* ── Section headings ──────────────────────────────────────────────────────────── */
.section-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--static);
  margin-bottom: 12px;
}

/* ── Study all bar ─────────────────────────────────────────────────────────────── */
.study-all-bar {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

/* ── Domain grid ───────────────────────────────────────────────────────────────── */
.domain-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
  gap: 12px;
}

.domain-tile {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 16px;
  cursor: pointer;
  transition: background 0.12s ease-out, transform 0.08s linear;
  position: relative;
}
.domain-tile:hover {
  background: var(--lift);
  transform: translateY(-1px);
}
.domain-tile:hover .domain-name { color: var(--platinum); }

/* Weak domain: Critical dot indicator — no border-left stripe */
.domain-tile.weak::before {
  content: "";
  position: absolute;
  top: 12px;
  right: 12px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--critical);
}

.domain-num {
  font-size: 10px;
  font-weight: 700;
  color: var(--static);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 3px;
}
.domain-name {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.3;
  margin-bottom: 10px;
  color: var(--signal);
  transition: color 0.12s ease-out;
  padding-right: 14px;
}
.domain-meta {
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.domain-due {
  font-size: 12px;
  color: var(--platinum);
  font-weight: 600;
}
.domain-due.zero { color: var(--static); font-weight: 400; }
.domain-retention { font-size: 11px; color: var(--static); }
.domain-retention .ret-val { color: var(--nominal); font-weight: 600; }
.domain-retention .ret-val.weak { color: var(--critical); }
.domain-retention .ret-none { color: var(--static); }

.maturity-bar {
  display: flex;
  height: 3px;
  border-radius: 2px;
  overflow: hidden;
  margin-top: 10px;
}
.mat-new      { background: var(--static);  }
.mat-learning { background: var(--caution); }
.mat-review   { background: var(--nominal); }
.mat-mastered { background: var(--deep);    }

/* ── STUDY PAGE ─────────────────────────────────────────────────────────────── */
.study-header {
  background: var(--console);
  border-bottom: 1px solid var(--trace);
  padding: 11px 0;
}
.study-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}
.study-domain-label {
  font-size: 12px;
  color: var(--static);
  white-space: nowrap;
  letter-spacing: 0.02em;
}
.study-progress-wrap { flex: 1; }
.study-progress-text {
  font-size: 11px;
  color: var(--static);
  text-align: right;
  margin-bottom: 4px;
  letter-spacing: 0.03em;
}

/* ── Card scene ─────────────────────────────────────────────────────────────── */
.card-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 36px 20px;
  min-height: calc(100vh - 160px);
}

.card-scene {
  perspective: 1200px;
  width: 100%;
  max-width: 720px;
  height: 480px;
  cursor: pointer;
  margin-bottom: 24px;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.42s cubic-bezier(0.4, 0, 0.2, 1);
}
.card-inner.flipped { transform: rotateY(180deg); }

.card-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--panel);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
}
.card-face.back { transform: rotateY(180deg); }

.card-hint {
  font-size: 10px;
  color: var(--static);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
  margin-bottom: 12px;
}
.card-question {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.4;
  flex: 1;
  display: flex;
  align-items: center;
  color: var(--signal);
}
.card-flip-hint {
  font-size: 11px;
  color: var(--static);
  text-align: center;
  margin-top: auto;
  padding-top: 12px;
}
.card-answer {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.4;
  margin-bottom: 14px;
}
.card-context {
  font-size: 13px;
  color: var(--static);
  line-height: 1.6;
  border-top: 1px solid var(--trace);
  padding-top: 12px;
  margin-top: auto;
}
.card-context strong { color: var(--signal); font-weight: 600; }

.leech-badge {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  font-size: 10px;
  font-weight: 700;
  color: var(--critical);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-left: auto;
}
.star-btn {
  background: none;
  border: none;
  font-size: 17px;
  color: var(--static);
  padding: 0;
  cursor: pointer;
  transition: color 0.12s;
}
.star-btn.starred { color: var(--caution); }
.star-btn:hover   { color: var(--caution); }

.card-top-row {
  display: flex;
  align-items: center;
  margin-bottom: 12px;
}

/* ── Rating buttons ─────────────────────────────────────────────────────────── */
.rating-area {
  width: 100%;
  max-width: 720px;
  display: flex;
  gap: 8px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  flex-wrap: wrap;
}
.rating-area.visible { opacity: 1; pointer-events: all; }

.rate-btn {
  flex: 1;
  min-width: 90px;
  padding: 11px 8px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 700;
  text-align: center;
  border: 1px solid transparent;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  transition: background 0.12s ease-out;
}
.rate-btn .key-hint {
  display: block;
  font-size: 10px;
  font-weight: 400;
  opacity: 0.65;
  font-family: monospace;
  margin-top: 1px;
}

.rate-again { background: rgba(208,79,70, 0.12); color: var(--critical); border-color: rgba(208,79,70, 0.28); }
.rate-again:hover { background: rgba(208,79,70, 0.22); }

.rate-hard  { background: rgba(198,145,56, 0.12); color: var(--caution);  border-color: rgba(198,145,56, 0.28); }
.rate-hard:hover  { background: rgba(198,145,56, 0.22); }

.rate-good  { background: rgba(62,166,88, 0.12);  color: var(--nominal);  border-color: rgba(62,166,88, 0.28);  }
.rate-good:hover  { background: rgba(62,166,88, 0.22); }

.rate-easy  { background: rgba(236,238,248, 0.10); color: var(--platinum); border-color: rgba(236,238,248, 0.22); }
.rate-easy:hover  { background: rgba(236,238,248, 0.18); }

/* ── Session summary overlay ─────────────────────────────────────────────────── */
.session-summary {
  position: fixed;
  inset: 0;
  background: rgba(10,11,14, 0.95);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s;
}
.session-summary.visible { opacity: 1; pointer-events: all; }

.summary-card {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 36px;
  max-width: 480px;
  width: 90%;
  text-align: center;
}
.summary-card h2 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}
.summary-card .sub { color: var(--static); font-size: 13px; margin-bottom: 24px; }

.summary-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-bottom: 20px;
  text-align: left;
}
.summary-stat-box {
  background: var(--console);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.summary-stat-box .val {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.summary-stat-box .lbl { font-size: 11px; color: var(--static); margin-top: 2px; letter-spacing: 0.02em; }

.summary-ratings {
  display: flex;
  gap: 6px;
  justify-content: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.rating-pill {
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
}
.pill-again { background: rgba(208,79,70,  0.15); color: var(--critical); }
.pill-hard  { background: rgba(198,145,56, 0.15); color: var(--caution);  }
.pill-good  { background: rgba(62,166,88,  0.15); color: var(--nominal);  }
.pill-easy  { background: rgba(236,238,248, 0.12); color: var(--platinum); }

.summary-actions { display: flex; gap: 10px; justify-content: center; }

/* ── STATS PAGE ──────────────────────────────────────────────────────────────── */
.stats-nav {
  background: var(--console);
  border-bottom: 1px solid var(--trace);
  padding: 11px 0;
}
.stats-nav .container {
  display: flex;
  align-items: center;
  gap: 20px;
}

.stats-tabs {
  display: flex;
  gap: 2px;
  background: var(--void);
  border: 1px solid var(--trace);
  border-radius: var(--radius-sm);
  padding: 3px;
}
.tab-btn {
  background: none;
  color: var(--static);
  border: none;
  padding: 5px 12px;
  border-radius: 4px;
  font-size: 13px;
  font-weight: 500;
  transition: background 0.12s, color 0.12s;
}
.tab-btn.active { background: var(--panel); color: var(--signal); }
.tab-btn:hover:not(.active) { color: var(--signal); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ── Heatmap ─────────────────────────────────────────────────────────────────── */
.heatmap-wrap { margin-bottom: 28px; }
.heatmap-title {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}
.heatmap-grid {
  display: grid;
  grid-template-rows: repeat(7, 14px);
  grid-auto-flow: column;
  grid-auto-columns: 14px;
  gap: 3px;
}
.heatmap-cell {
  width: 14px;
  height: 14px;
  border-radius: 2px;
  background: var(--console);
  border: 1px solid var(--trace);
}
/* Nominal semantic color at opacity steps — no hardcoded hex */
.heatmap-cell[data-level="1"] { background: rgba(62,166,88, 0.22); border-color: rgba(62,166,88, 0.22); }
.heatmap-cell[data-level="2"] { background: rgba(62,166,88, 0.45); border-color: rgba(62,166,88, 0.45); }
.heatmap-cell[data-level="3"] { background: rgba(62,166,88, 0.68); border-color: rgba(62,166,88, 0.68); }
.heatmap-cell[data-level="4"] { background: rgba(62,166,88, 0.90); border-color: rgba(62,166,88, 0.90); }

.heatmap-legend {
  display: flex;
  align-items: center;
  gap: 3px;
  margin-top: 6px;
  font-size: 11px;
  color: var(--static);
}
.heatmap-legend .heatmap-cell { flex-shrink: 0; }

/* ── Domain stats table ──────────────────────────────────────────────────────── */
.domain-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.domain-table th {
  text-align: left;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--static);
  font-weight: 600;
  padding: 9px 12px;
  border-bottom: 1px solid var(--trace);
  background: var(--console);
  white-space: nowrap;
  position: sticky;
  top: 0;
}
.domain-table th:not(:first-child) { text-align: right; }
.domain-table td {
  padding: 9px 12px;
  border-bottom: 1px solid var(--trace);
  vertical-align: middle;
}
.domain-table td:not(:first-child) { text-align: right; }
.domain-table tr:hover td { background: var(--panel); }

.tag-new      { color: var(--static);  }
.tag-learning { color: var(--caution); }
.tag-review   { color: var(--nominal); }
.tag-mastered { color: var(--deep);    }
.ret-good { color: var(--nominal);  font-weight: 600; }
.ret-warn { color: var(--caution);  font-weight: 600; }
.ret-bad  { color: var(--critical); font-weight: 600; }

/* ── Card browser ────────────────────────────────────────────────────────────── */
.search-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.search-input {
  flex: 1;
  background: var(--panel);
  border: 1px solid var(--trace);
  color: var(--signal);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 13px;
  font-family: inherit;
  min-width: 180px;
}
.search-input::placeholder { color: var(--static); }
.search-input:focus { outline: none; border-color: var(--static); }

.filter-select {
  background: var(--panel);
  border: 1px solid var(--trace);
  color: var(--signal);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
}

.card-list { display: flex; flex-direction: column; gap: 6px; }

.card-list-item {
  background: var(--panel);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  display: flex;
  gap: 10px;
  align-items: flex-start;
}
/* Replace border-left stripe with subtle semantic tint */
.card-list-item.leech        { background: rgba(208,79,70,  0.07); }
.card-list-item.starred-item { background: rgba(198,145,56, 0.07); }

.cli-content { flex: 1; }
.cli-front { font-size: 13px; font-weight: 500; margin-bottom: 3px; line-height: 1.4; }
.cli-back  { font-size: 12px; color: var(--static); line-height: 1.4; }
.cli-meta  { display: flex; gap: 6px; align-items: center; margin-top: 5px; flex-wrap: wrap; }
.cli-tag {
  font-size: 10px;
  background: var(--console);
  border: 1px solid var(--trace);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--static);
}
.cli-status {
  font-size: 10px;
  font-weight: 600;
  padding: 1px 5px;
  border-radius: 3px;
  letter-spacing: 0.03em;
}
.cli-actions { display: flex; gap: 5px; flex-shrink: 0; }
.cli-star { font-size: 15px; background: none; border: none; color: var(--static); padding: 2px; cursor: pointer; transition: color 0.12s; }
.cli-star.on  { color: var(--caution); }
.cli-star:hover { color: var(--caution); }

/* ── Modal ───────────────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10,11,14, 0.88);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s;
}
.modal-overlay.visible { opacity: 1; pointer-events: all; }

.modal-box {
  background: var(--panel);
  border-radius: var(--radius);
  padding: 28px;
  max-width: 400px;
  width: 90%;
}
.modal-box h2 {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}
.modal-box p { color: var(--static); font-size: 13px; margin-bottom: 18px; }

.form-group { margin-bottom: 14px; }
.form-label {
  display: block;
  font-size: 10px;
  font-weight: 600;
  color: var(--static);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 5px;
}
.form-input {
  width: 100%;
  background: var(--console);
  border: 1px solid var(--trace);
  color: var(--signal);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 13px;
  font-family: inherit;
}
.form-input:focus { outline: none; border-color: var(--static); }
.modal-actions { display: flex; gap: 8px; margin-top: 18px; justify-content: flex-end; }

/* ── Keyboard shortcut hint ──────────────────────────────────────────────────── */
.kb-hint {
  display: inline-block;
  background: var(--console);
  border: 1px solid var(--trace);
  border-radius: 3px;
  padding: 1px 5px;
  font-size: 10px;
  font-family: monospace;
  color: var(--static);
}

/* ── Empty state ─────────────────────────────────────────────────────────────── */
.empty-state {
  text-align: center;
  padding: 52px 20px;
  color: var(--static);
}
.empty-state .icon { font-size: 36px; margin-bottom: 10px; }
.empty-state p { font-size: 14px; line-height: 1.5; }

/* ── Multiple choice options ─────────────────────────────────────────────────── */
.card-options {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin: 12px 0 6px;
}
.mc-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--console);
  border-radius: var(--radius-sm);
  padding: 9px 12px;
  font-size: 13px;
  line-height: 1.4;
}
.mc-option.mc-correct { background: rgba(62,166,88, 0.16); }
.mc-option.mc-wrong   { opacity: 0.40; }

.mc-letter {
  font-weight: 700;
  font-size: 11px;
  color: var(--static);
  min-width: 14px;
  flex-shrink: 0;
  padding-top: 1px;
  letter-spacing: 0.02em;
}
.mc-option.mc-correct .mc-letter { color: var(--nominal); }
.mc-text { color: var(--signal); }
.mc-option.mc-correct .mc-text { color: var(--nominal); }
.mc-option.mc-wrong .mc-text { color: var(--static); }

/* ── Card explanation (back) ─────────────────────────────────────────────────── */
.card-explanation {
  font-size: 12px;
  color: var(--static);
  line-height: 1.6;
  border-top: 1px solid var(--trace);
  padding-top: 10px;
  margin-top: auto;
}
.card-explanation strong { color: var(--nominal); }

/* ── Back question repeat ────────────────────────────────────────────────────── */
.back-question {
  font-size: 13px;
  font-weight: 500;
  color: var(--static);
  margin-bottom: 0;
  line-height: 1.4;
}

/* ── Difficulty badge ────────────────────────────────────────────────────────── */
.diff-badge {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  padding: 2px 6px;
  border-radius: 3px;
  margin-left: 6px;
}
.diff-easy   { background: rgba(62,166,88,  0.15); color: var(--nominal);  }
.diff-medium { background: rgba(198,145,56, 0.15); color: var(--caution);  }
.diff-hard   { background: rgba(208,79,70,  0.15); color: var(--critical); }

/* ── Dashboard layout ────────────────────────────────────────────────────────── */
.dashboard-page {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

.app-header-full {
  background: var(--console);
  border-bottom: 1px solid var(--trace);
  padding: 11px 20px;
  flex-shrink: 0;
}
.app-header-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  max-width: 1400px;
  margin: 0 auto;
}
.app-header-inner h1 {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.02em;
  white-space: nowrap;
}
.header-center {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.dashboard {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: 220px 1fr;
  overflow: hidden;
}

/* ── Domain sidebar ──────────────────────────────────────────────────────────── */
.domain-sidebar {
  background: var(--console);
  border-right: 1px solid var(--trace);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.domain-row {
  display: flex;
  align-items: flex-start;
  padding: 11px 16px;
  cursor: pointer;
  gap: 10px;
  border-bottom: 1px solid var(--trace);
  transition: background 0.10s;
  position: relative;
}
.domain-row:hover { background: var(--panel); }
.domain-row.active { background: var(--lift); }

.domain-row-letter {
  font-size: 11px;
  font-weight: 700;
  color: var(--static);
  min-width: 16px;
  padding-top: 2px;
  flex-shrink: 0;
  letter-spacing: 0.04em;
}
.domain-row.active .domain-row-letter { color: var(--platinum); }

.domain-row-info { flex: 1; min-width: 0; }
.domain-row-name {
  font-size: 12px;
  font-weight: 500;
  color: var(--signal);
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.domain-row.active .domain-row-name { color: var(--platinum); }

.domain-row-due {
  font-size: 11px;
  font-weight: 600;
  color: var(--platinum);
  margin-top: 2px;
}
.domain-row-due.zero { color: var(--static); font-weight: 400; }

.domain-row-weak {
  font-size: 8px;
  color: var(--critical);
  padding-top: 3px;
  flex-shrink: 0;
}

/* ── Domain detail panel ─────────────────────────────────────────────────────── */
.domain-detail-panel {
  overflow-y: auto;
  padding: 40px 48px;
  display: flex;
  flex-direction: column;
}

.detail-empty {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--static);
  font-size: 14px;
}

.detail-domain-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--static);
  margin-bottom: 6px;
}
.detail-domain-name {
  font-size: 30px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--signal);
  line-height: 1.15;
  margin-bottom: 32px;
}

.detail-stats-row {
  display: grid;
  grid-template-columns: repeat(4, auto);
  gap: 1px;
  margin-bottom: 36px;
  background: var(--trace);
  border-radius: var(--radius-sm);
  overflow: hidden;
  width: fit-content;
}
.detail-stat { display: flex; flex-direction: column; gap: 3px; background: var(--console); padding: 14px 20px; }
.detail-stat-val {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--signal);
}
.detail-stat-val.highlight { color: var(--platinum); }
.detail-stat-lbl {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--static);
}

.detail-maturity { margin-bottom: 36px; }
.detail-maturity-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 8px;
}
.detail-mat-label {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  width: 62px;
  flex-shrink: 0;
}
.detail-mat-bar-wrap {
  flex: 1;
  height: 4px;
  background: var(--trace);
  border-radius: 2px;
  overflow: hidden;
}
.detail-mat-bar { height: 100%; border-radius: 2px; transition: width 0.3s ease; }
.mat-bar-new      { background: var(--static);  }
.mat-bar-learning { background: var(--caution); }
.mat-bar-review   { background: var(--nominal); }
.mat-bar-mastered { background: var(--deep);    }
.detail-mat-count {
  font-size: 12px;
  color: var(--static);
  width: 24px;
  text-align: right;
  flex-shrink: 0;
}

.detail-action {
  display: flex;
  gap: 12px;
  align-items: center;
  padding-top: 4px;
}
.detail-caught-up {
  font-size: 12px;
  color: var(--static);
}

/* ── Exam date countdown preview ─────────────────────────────────────────────── */
.exam-preview {
  display: flex;
  align-items: baseline;
  gap: 7px;
  margin-top: 8px;
  padding: 10px 12px;
  background: var(--console);
  border-radius: var(--radius-sm);
}
.exam-preview-num {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--platinum);
}
.exam-preview-lbl { font-size: 12px; color: var(--static); }

/* ── Responsive ──────────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .dashboard { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }

  .domain-sidebar {
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--trace);
    padding: 0;
    overflow: hidden;
  }
  #domain-list {
    display: flex;
    flex-direction: row;
    overflow-x: auto;
    overflow-y: hidden;
    gap: 6px;
    padding: 10px 12px;
    scrollbar-width: none;
  }
  #domain-list::-webkit-scrollbar { display: none; }
  .domain-row {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 52px;
    padding: 8px 6px;
    border-bottom: none;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
    background: var(--panel);
    text-align: center;
    gap: 2px;
  }
  .domain-row.active { background: var(--lift); }
  .domain-row-name { display: none; }
  .domain-row-letter { font-size: 14px; padding-top: 0; }
  .domain-row-due { font-size: 10px; margin-top: 0; }
  .domain-row-weak { display: none; }

  .domain-detail-panel { padding: 24px 20px; }
  .detail-domain-name { font-size: 22px; }
  .detail-stats-row { grid-template-columns: repeat(2, 1fr); width: auto; }
  .detail-stat-val { font-size: 22px; }
}
@media (max-width: 600px) {
  .card-question { font-size: 17px; }
  .card-answer   { font-size: 15px; }
  .card-scene    { height: 520px; }
  .summary-stats { grid-template-columns: repeat(2, 1fr); }
  .rating-area   { gap: 5px; }
  .rate-btn      { min-width: 70px; font-size: 12px; padding: 9px 6px; }
  .header-center { display: none; }
}