:root {
  --primary: #2563eb;
  --primary-dk: #1d4ed8;
  --success: #16a34a;
  --danger:  #dc2626;
  --warn:    #d97706;
  --bg:      #f1f5f9;
  --card:    #ffffff;
  --border:  #e2e8f0;
  --text:    #1e293b;
  --muted:   #64748b;
  --hdr:     #0f172a;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* ── Header ─────────────────────────────────────────── */
header {
  background: var(--hdr);
  color: #f1f5f9;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.2rem;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(0,0,0,.4);
  z-index: 50;
}
.header-left { display: flex; align-items: center; gap: 1.25rem; }
.header-right { display: flex; align-items: center; gap: 0.75rem; }
.logo { font-weight: 800; font-size: 1.1rem; color: #60a5fa; letter-spacing: .05em; }

nav { display: flex; gap: 4px; }
nav button {
  background: transparent;
  border: 1px solid transparent;
  color: #94a3b8;
  padding: 5px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-size: .875rem;
  font-weight: 500;
  transition: background .15s, color .15s;
}
nav button:hover  { background: rgba(255,255,255,.1); color: #e2e8f0; }
nav button.active { background: var(--primary); color: #fff; border-color: var(--primary); }

.progress-panel { display: flex; align-items: center; gap: .6rem; font-size: .82rem; color: #94a3b8; }
.progress-panel b { color: #f1f5f9; }
.progress-panel .ok { color: #4ade80; }
.progress-panel .ok b { color: #4ade80; }
.progress-panel .ng { color: #f87171; }
.progress-panel .ng b { color: #f87171; }
.dot-sep::before { content: '·'; color: #475569; }

.btn-pill {
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.15);
  color: #cbd5e1;
  padding: 4px 12px;
  border-radius: 20px;
  cursor: pointer;
  font-size: .8rem;
  transition: background .15s;
}
.btn-pill:hover { background: rgba(255,255,255,.18); color: #fff; }

/* ── Main layout ─────────────────────────────────────── */
main { flex: 1; overflow: hidden; display: flex; }

/* Two-pane layout */
.pane-layout { display: flex; width: 100%; height: 100%; }

.sidebar {
  width: 270px;
  flex-shrink: 0;
  background: var(--card);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.sidebar-search {
  padding: .6rem .75rem;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.sidebar-search input {
  width: 100%;
  padding: .35rem .7rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: .82rem;
  outline: none;
}
.sidebar-search input:focus { border-color: var(--primary); }
.sidebar-list { overflow-y: auto; flex: 1; }

.sitem {
  padding: .55rem 1rem;
  cursor: pointer;
  border-bottom: 1px solid var(--border);
  font-size: .87rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background .1s;
}
.sitem:hover  { background: #f8fafc; }
.sitem.active { background: #eff6ff; color: var(--primary); font-weight: 600; }
.sitem .cnt   { font-size: .72rem; background: var(--bg); color: var(--muted); padding: 2px 7px; border-radius: 10px; }

.titem {
  padding: .45rem 1rem .45rem 2rem;
  cursor: pointer;
  border-bottom: 1px solid #f1f5f9;
  font-size: .82rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fafbfc;
  transition: background .1s;
}
.titem:hover  { background: #eff6ff; }
.titem.active { background: #dbeafe; color: var(--primary); font-weight: 600; }
.titem .cnt   { font-size: .7rem; color: var(--muted); }

/* Specialty group header in two-level sidebar tree */
.spec-hdr {
  background: #f8fafc;
  font-weight: 600;
  font-size: .85rem;
  border-left: 3px solid transparent;
}
.spec-hdr.open { border-left-color: var(--primary); background: #eff6ff; }
.spec-arr { font-size: .75rem; color: var(--muted); }
.spec-subjects { border-left: 3px solid var(--border); margin-left: 0; }

/* Content pane */
.content { flex: 1; overflow-y: auto; padding: 1.25rem; }
.content.no-pad { padding: 0; }

/* Full-width mode */
.full-width { width: 100%; height: 100%; overflow-y: auto; padding: 1.5rem 2rem; }
.full-width.centered { max-width: 760px; margin: 0 auto; }

/* ── Cards ───────────────────────────────────────────── */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}
.card-title { font-size: .95rem; font-weight: 600; margin-bottom: .75rem; color: var(--text); }
.card-subtitle { font-size: .78rem; color: var(--muted); margin-bottom: 1rem; }

/* ── Buttons ─────────────────────────────────────────── */
.btn {
  padding: .45rem 1.1rem;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: .875rem;
  font-weight: 500;
  transition: background .15s, opacity .15s;
  display: inline-flex;
  align-items: center;
  gap: .4rem;
}
.btn:disabled { opacity: .45; cursor: default; }
.btn-primary   { background: var(--primary); color: #fff; }
.btn-primary:hover:not(:disabled)  { background: var(--primary-dk); }
.btn-success   { background: var(--success); color: #fff; }
.btn-danger    { background: var(--danger);  color: #fff; }
.btn-warn      { background: var(--warn);    color: #fff; }
.btn-outline   { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn-outline:hover:not(:disabled) { background: var(--bg); }
.btn-ghost     { background: transparent; border: none; color: var(--primary); text-decoration: underline; padding: .2rem .4rem; }
.btn-sm        { padding: .3rem .7rem; font-size: .8rem; }
.btn-row       { display: flex; gap: .6rem; flex-wrap: wrap; margin-top: 1rem; align-items: center; }

/* ── Quiz ────────────────────────────────────────────── */
.quiz-controls {
  display: flex; gap: .75rem; flex-wrap: wrap; align-items: center;
  margin-bottom: 1.25rem;
}
.quiz-controls label { font-size: .82rem; color: var(--muted); display: flex; flex-direction: column; gap: .25rem; }
.quiz-controls select {
  padding: .35rem .7rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: .87rem;
  background: white;
  outline: none;
  min-width: 140px;
}
.quiz-controls select:focus { border-color: var(--primary); }

.question-meta { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: .9rem; }
.badge {
  padding: 3px 9px;
  border-radius: 12px;
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .04em;
}
.badge-blue   { background: #dbeafe; color: #1d4ed8; }
.badge-yellow { background: #fef9c3; color: #92400e; }
.badge-red    { background: #fee2e2; color: #991b1b; }
.badge-green  { background: #dcfce7; color: #166534; }
.badge-gray   { background: #f1f5f9; color: var(--muted); }
.badge-purple { background: #ede9fe; color: #6d28d9; }

.question-text { font-size: 1.05rem; line-height: 1.65; margin-bottom: 1.1rem; }

.options { display: flex; flex-direction: column; gap: .5rem; margin-bottom: .75rem; }
.option-btn {
  text-align: left;
  padding: .7rem 1rem;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: white;
  cursor: pointer;
  font-size: .9rem;
  line-height: 1.45;
  transition: border-color .1s, background .1s;
}
.option-btn:hover:not(:disabled) { border-color: var(--primary); background: #eff6ff; }
.option-btn.selected  { border-color: #93c5fd; background: #eff6ff; }
.option-btn.correct   { border-color: var(--success); background: #f0fdf4; color: #166534; font-weight: 500; }
.option-btn.incorrect { border-color: var(--danger);  background: #fef2f2; color: #991b1b; }
.option-btn.reveal    { border-color: var(--success); background: #f0fdf4; color: #166534; }
.option-btn:disabled  { cursor: default; }

.explanation-box {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  border-radius: 8px;
  padding: 1rem;
  margin-top: .75rem;
  font-size: .88rem;
  line-height: 1.55;
}
.explanation-box h4 { color: var(--success); margin-bottom: .4rem; font-size: .9rem; }
.explanation-box .source { color: var(--muted); font-size: .75rem; margin-top: .5rem; font-style: italic; }
.explanation-box .distractors { margin-top: .5rem; color: #374151; }

/* ── Exam ────────────────────────────────────────────── */
.exam-start { max-width: 600px; margin: 3rem auto; text-align: center; }
.exam-start h2 { font-size: 1.6rem; margin-bottom: .75rem; }
.exam-start p  { color: var(--muted); margin-bottom: 2rem; font-size: .9rem; line-height: 1.6; }
.exam-structure { display: grid; grid-template-columns: 1fr 1fr; gap: .75rem; margin-bottom: 2rem; text-align: left; }
.exam-block { background: var(--card); border: 1px solid var(--border); border-radius: 8px; padding: .75rem 1rem; }
.exam-block .label { font-size: .75rem; color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.exam-block .value { font-size: 1.1rem; font-weight: 700; color: var(--primary); }

.exam-header {
  display: flex; align-items: center; gap: 1rem;
  margin-bottom: 1.25rem;
}
.exam-counter { font-size: .9rem; color: var(--muted); white-space: nowrap; flex-shrink: 0; }
.exam-bar { flex: 1; height: 6px; background: var(--border); border-radius: 3px; overflow: hidden; }
.exam-bar-fill { height: 100%; background: var(--primary); border-radius: 3px; transition: width .3s; }

.exam-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(38px, 1fr));
  gap: .35rem;
  margin-bottom: 1.25rem;
}
.edot {
  width: 38px; height: 32px;
  border-radius: 5px; border: 1px solid var(--border);
  background: white; cursor: pointer;
  font-size: .72rem; font-weight: 500;
  display: flex; align-items: center; justify-content: center;
  transition: all .1s;
}
.edot:hover    { border-color: var(--primary); }
.edot.answered { background: var(--primary); color: white; border-color: var(--primary); }
.edot.current  { border-color: var(--primary); border-width: 2px; font-weight: 700; }

.exam-nav { display: flex; justify-content: space-between; align-items: center; margin-top: 1rem; }

/* Results */
.results-header { text-align: center; padding: 1.5rem 0; margin-bottom: 1.5rem; border-bottom: 1px solid var(--border); }
.results-score { font-size: 3.5rem; font-weight: 800; color: var(--primary); line-height: 1; }
.results-label { font-size: 1rem; color: var(--muted); margin-top: .25rem; }
.result-row {
  display: flex; gap: .9rem; align-items: flex-start;
  padding: .65rem .75rem; border-radius: 8px; margin-bottom: .4rem;
  background: var(--bg);
}
.result-row.correct   { background: #f0fdf4; }
.result-row.incorrect { background: #fef2f2; }
.result-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 1px; }
.result-body { flex: 1; min-width: 0; }
.result-q    { font-size: .83rem; color: var(--text); margin-bottom: .2rem; }
.result-ans  { font-size: .75rem; color: var(--muted); }
.result-ans .right { color: var(--success); font-weight: 600; }

/* ── Explore / Matrix ────────────────────────────────── */
.matrix-entity {
  border: 1px solid var(--border); border-radius: 8px;
  padding: .9rem 1rem; margin-bottom: .75rem; background: white;
}
.matrix-entity-title {
  font-size: .92rem; font-weight: 700; color: var(--primary);
  margin-bottom: .6rem; display: flex; justify-content: space-between; align-items: center;
}
.matrix-row { display: grid; grid-template-columns: 130px 1fr; gap: .35rem; margin-bottom: .35rem; font-size: .82rem; }
.matrix-label { color: var(--muted); font-weight: 500; padding-top: 1px; }
.matrix-val li { margin-left: 1rem; margin-bottom: .15rem; }

.tag {
  display: inline-block; padding: 2px 8px; border-radius: 10px;
  background: #dbeafe; color: #1d4ed8; font-size: .72rem;
  cursor: pointer; margin: 2px; transition: background .1s;
}
.tag:hover, .tag.active { background: var(--primary); color: white; }

/* ── Questions list ──────────────────────────────────── */
.q-row {
  display: flex; align-items: flex-start; gap: .75rem;
  padding: .65rem .9rem; border: 1px solid var(--border);
  border-radius: 8px; margin-bottom: .4rem; background: white;
  cursor: pointer; transition: border-color .1s, background .1s;
}
.q-row:hover { border-color: var(--primary); background: #f8fbff; }
.q-status { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; margin-top: 5px; }
.qs-correct   { background: var(--success); }
.qs-incorrect { background: var(--danger); }
.qs-seen      { background: #94a3b8; }
.qs-unseen    { background: var(--border); border: 1px solid #cbd5e1; }
.qs-archived  { background: #f59e0b; }
.q-text { flex: 1; font-size: .84rem; line-height: 1.45; color: var(--text); }
.q-badges { flex-shrink: 0; display: flex; flex-direction: column; gap: 3px; align-items: flex-end; }

/* ── Study ───────────────────────────────────────────── */
.section-header {
  font-size: .75rem; text-transform: uppercase; letter-spacing: .07em;
  color: var(--muted); font-weight: 600;
  margin-bottom: .6rem; margin-top: 1rem;
  padding-bottom: .4rem; border-bottom: 1px solid var(--border);
  display: flex; justify-content: space-between; align-items: center;
}
.section-header:first-child { margin-top: 0; }

/* ── Tabs ────────────────────────────────────────────── */
.tabs { display: flex; border-bottom: 2px solid var(--border); margin-bottom: 1rem; }
.tab {
  padding: .45rem 1rem; background: none; border: none; cursor: pointer;
  font-size: .875rem; color: var(--muted); border-bottom: 2px solid transparent;
  margin-bottom: -2px; transition: color .1s;
}
.tab.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }
.tab:hover:not(.active) { color: var(--text); }

/* ── Stats ───────────────────────────────────────────── */
.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: .75rem; margin-bottom: 1.5rem; }
.stat-card { background: white; border: 1px solid var(--border); border-radius: 10px; padding: 1rem; text-align: center; }
.stat-card .val { font-size: 2rem; font-weight: 800; color: var(--primary); }
.stat-card .lbl { font-size: .75rem; color: var(--muted); margin-top: .25rem; }

.hy-bar { height: 5px; background: var(--border); border-radius: 3px; margin-top: .35rem; overflow: hidden; }
.hy-bar-fill { height: 100%; background: var(--primary); border-radius: 3px; }

/* ── Curriculum ──────────────────────────────────────── */
.curr-subject { margin-bottom: 1.25rem; }
.curr-subject h3 { font-size: .95rem; font-weight: 700; color: var(--primary); margin-bottom: .4rem; }
.curr-req { font-size: .82rem; padding: .25rem 0 .25rem .9rem; border-left: 3px solid var(--border); margin-bottom: .2rem; color: var(--text); }

/* ── Coverage ────────────────────────────────────────── */
.coverage-content {
  font-size: .84rem; line-height: 1.7; color: var(--text);
  white-space: pre-wrap; font-family: inherit;
}

/* ── Modal ───────────────────────────────────────────── */
.modal { position: fixed; inset: 0; background: rgba(0,0,0,.55); z-index: 200; display: flex; align-items: center; justify-content: center; }
.modal.hidden { display: none; }
.modal-box {
  background: white; border-radius: 12px; padding: 1.5rem;
  max-width: 720px; width: 92%; max-height: 84vh; overflow-y: auto; position: relative;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
}
.modal-close {
  position: absolute; top: .9rem; right: 1rem;
  background: none; border: none; font-size: 1.5rem;
  cursor: pointer; color: var(--muted); line-height: 1;
}
.modal-close:hover { color: var(--text); }
.modal-title { font-size: 1.1rem; font-weight: 700; margin-bottom: 1rem; padding-right: 2rem; }

/* ── Quiz progress panel ─────────────────────────────── */
.prog-spec-row {
  padding: .35rem .5rem;
  border-radius: 6px;
  margin-bottom: .2rem;
  cursor: pointer;
  transition: background .1s;
}
.prog-spec-row:hover  { background: #f8fafc; }
.prog-spec-row.prog-active { background: #eff6ff; }

/* ── Exam source cards ────────────────────────────────── */
.exam-source-card {
  border-radius: 10px;
  padding: 1rem;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.exam-source-card:hover { border-color: var(--primary) !important; }

/* ── Difficulty selector panel ───────────────────────── */
.diff-panel {
  display: flex;
  gap: .35rem;
  align-items: center;
}

.diff-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: .42rem .52rem;
  border: 2px solid var(--border);
  border-radius: 10px;
  background: white;
  cursor: pointer;
  transition: transform .2s, border-color .18s, background .18s, box-shadow .18s;
  position: relative;
}
.diff-btn:hover {
  transform: scale(1.1);
  border-color: var(--primary);
  background: #eff6ff;
  box-shadow: 0 2px 12px rgba(37,99,235,.2);
  z-index: 10;
}
.diff-btn.active {
  border-color: var(--primary);
  background: #dbeafe;
  box-shadow: 0 2px 16px rgba(37,99,235,.32);
  transform: scale(1.14);
  z-index: 9;
}
.diff-icon { font-size: 1.4rem; line-height: 1; display: block; }

/* Custom tooltip */
.diff-panel [data-tip] { position: relative; }

.diff-panel [data-tip]::after {
  content: attr(data-tip);
  position: absolute;
  bottom: calc(100% + 9px);
  left: 50%;
  transform: translateX(-50%);
  background: #1e293b;
  color: #f1f5f9;
  font-size: .7rem;
  font-weight: 400;
  line-height: 1.4;
  padding: .3rem .55rem;
  border-radius: 6px;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity .2s ease;
  z-index: 200;
  border: 1px solid rgba(255,255,255,.1);
  box-shadow: 0 4px 12px rgba(0,0,0,.25);
}
.diff-panel [data-tip]::before {
  content: '';
  position: absolute;
  bottom: calc(100% + 4px);
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: #1e293b;
  pointer-events: none;
  opacity: 0;
  transition: opacity .2s ease;
  z-index: 200;
}
.diff-panel [data-tip]:hover::after,
.diff-panel [data-tip]:hover::before { opacity: 1; }

.diff-off-btn {
  font-size: .67rem;
  color: var(--muted);
  background: none;
  border: 1px dashed var(--border);
  border-radius: 6px;
  padding: .26rem .48rem;
  cursor: pointer;
  transition: color .15s, border-color .15s;
  align-self: center;
  position: relative;
}
.diff-off-btn:hover { color: var(--text); border-color: #94a3b8; }
.diff-off-btn.active { color: var(--text); border-color: #94a3b8; font-weight: 600; }

.diff-mode-label {
  font-size: .7rem;
  color: var(--muted);
  padding-left: .1rem;
}
.diff-mode-label strong { color: var(--text); }

/* ── Recent sessions ─────────────────────────────────── */
.continue-banner {
  display: flex;
  align-items: center;
  gap: .65rem;
  padding: .6rem .85rem;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  margin-bottom: .6rem;
  font-size: .84rem;
  flex-wrap: wrap;
}
.continue-banner > span { flex: 1; color: var(--text); min-width: 0; }

.recent-runs-wrap { margin-top: .25rem; }

.recent-runs-list {
  display: flex;
  gap: .45rem;
  overflow-x: auto;
  padding-bottom: .3rem;
  scrollbar-width: thin;
}

.run-card {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .5rem .7rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
  cursor: pointer;
  transition: border-color .15s, background .15s, box-shadow .15s;
  min-width: 120px;
  flex-shrink: 0;
}
.run-card:hover { border-color: var(--primary); background: #f8fbff; box-shadow: 0 2px 8px rgba(37,99,235,.1); }
.run-card-done { opacity: .65; }

.run-card-icon { font-size: 1.15rem; flex-shrink: 0; line-height: 1; }
.run-card-body { flex: 1; min-width: 0; }
.run-card-mode { font-size: .73rem; font-weight: 600; color: var(--text); }
.run-card-subj { font-size: .66rem; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.run-card-stat { font-size: .66rem; color: var(--muted); margin-top: 1px; }
.run-card-bar  { height: 3px; background: var(--border); border-radius: 2px; margin-top: 3px; overflow: hidden; }
.run-card-fill { height: 100%; background: var(--primary); border-radius: 2px; }
.run-card-resume { font-size: .65rem; color: var(--primary); flex-shrink: 0; opacity: .7; }

/* ── Archive modal ───────────────────────────────────── */
.arch-spec-bar {
  display: flex;
  flex-wrap: wrap;
  gap: .3rem;
  margin-bottom: .75rem;
}

.arch-spec-pill {
  padding: .22rem .65rem;
  border-radius: 14px;
  font-size: .71rem;
  font-weight: 600;
  border: 2px solid var(--border);
  background: white;
  color: var(--muted);
  cursor: pointer;
  transition: transform .18s, border-color .18s, background .18s, box-shadow .18s, color .18s;
  transform: scale(.92);
}
.arch-spec-pill.on {
  border-color: var(--primary);
  background: #eff6ff;
  color: var(--primary);
  box-shadow: 0 0 8px rgba(37,99,235,.2);
  transform: scale(1);
}
.arch-spec-pill:hover { opacity: .8; }
.arch-spec-pill.arch-pill-empty { opacity: .45; cursor: default; }

.arch-card {
  display: flex;
  align-items: flex-start;
  gap: .75rem;
  padding: .5rem .6rem;
  border: 2px solid var(--border);
  border-radius: 6px;
  margin-bottom: .35rem;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  background: white;
  user-select: none;
}
.arch-card:hover { border-color: #93c5fd; background: #f8fbff; }
.arch-card.arch-selected { border-color: var(--primary); background: #eff6ff; }

.arch-check {
  width: 15px;
  height: 15px;
  border-radius: 4px;
  border: 2px solid var(--border);
  flex-shrink: 0;
  margin-top: 3px;
  transition: border-color .15s, background .15s;
  position: relative;
}
.arch-check.on {
  border-color: var(--primary);
  background: var(--primary);
}
.arch-check.on::after {
  content: '✓';
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .6rem;
  color: white;
  line-height: 1;
  top: 0; left: 1px;
}

/* ── Misc ────────────────────────────────────────────── */
.empty { text-align: center; padding: 2.5rem; color: var(--muted); font-size: .9rem; }
.loading { text-align: center; padding: 2rem; color: var(--muted); }
.divider { height: 1px; background: var(--border); margin: 1rem 0; }
.text-muted { color: var(--muted); font-size: .82rem; }
.chip { display: inline-block; background: var(--bg); border: 1px solid var(--border); border-radius: 6px; padding: 3px 8px; font-size: .75rem; color: var(--muted); margin: 2px; }

/* ── Study back button ───────────────────────────────── */
.study-back-btn {
  display: flex;
  align-items: center;
  width: 100%;
  padding: .72rem 1rem;
  background: rgba(239,68,68,.04);
  border: 1px solid rgba(239,68,68,.42);
  border-radius: 8px;
  color: rgba(239,68,68,.85);
  font-size: .84rem;
  font-weight: 600;
  letter-spacing: .08em;
  cursor: pointer;
  box-shadow: 0 0 9px rgba(239,68,68,.26), inset 0 0 7px rgba(239,68,68,.06);
  transition: background .15s, box-shadow .15s, color .15s;
}
.study-back-btn:hover {
  background: rgba(239,68,68,.09);
  color: #ef4444;
  box-shadow: 0 0 16px rgba(239,68,68,.5), inset 0 0 10px rgba(239,68,68,.12);
}

/* ── Specialty overview panel ────────────────────────── */
.spec-ov { padding: 1.5rem; max-width: 680px; }

.spec-ov-head {
  margin-bottom: 1.1rem;
  padding-bottom: .85rem;
  border-bottom: 1px solid var(--border);
}
.spec-ov-title { font-size: 1.35rem; font-weight: 700; color: var(--text); margin-bottom: .3rem; }
.spec-ov-meta  { font-size: .8rem; color: var(--muted); display: flex; align-items: center; gap: .35rem; flex-wrap: wrap; }

.spec-ov-progress {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: .8rem 1rem;
  margin-bottom: 1rem;
  display: flex;
  flex-direction: column;
  gap: .45rem;
}
.spec-ov-stat-row { display: flex; align-items: center; gap: .75rem; }
.spec-ov-lbl { font-size: .72rem; color: var(--muted); width: 58px; flex-shrink: 0; }
.spec-ov-bar-wrap { flex: 1; height: 6px; background: var(--border); border-radius: 3px; overflow: hidden; }
.spec-ov-bar-fill { height: 100%; border-radius: 3px; transition: width .4s; }
.spec-ov-val { font-size: .72rem; font-weight: 600; color: var(--text); width: 32px; text-align: right; flex-shrink: 0; }

.spec-ov-actions { display: flex; gap: .45rem; flex-wrap: wrap; }

/* Subject rows inside overview */
.subj-ov-list { display: flex; flex-direction: column; gap: .15rem; margin-top: .35rem; }
.subj-ov-row {
  display: grid;
  grid-template-columns: 1fr 110px 36px 42px;
  gap: .6rem;
  align-items: center;
  padding: .45rem .55rem;
  border-radius: 7px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .15s, border-color .15s;
}
.subj-ov-row:hover { background: var(--bg); border-color: var(--border); }
.subj-ov-name { font-size: .84rem; font-weight: 500; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.subj-ov-bar  { height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; }
.subj-ov-fill { height: 100%; background: var(--primary); border-radius: 2px; }
.subj-ov-pct  { font-size: .7rem; color: var(--muted); text-align: right; }
.subj-ov-acc  { font-size: .7rem; font-weight: 600; text-align: right; }

/* ══════════════════════════════════════════════════════════
   DARK MODE — global overrides
   ══════════════════════════════════════════════════════════ */

/* ── Variables ─────────────────────────────────────────── */
:root {
  --primary:    #3b82f6;
  --primary-dk: #2563eb;
  --success:    #22c55e;
  --danger:     #ef4444;
  --warn:       #f59e0b;
  --bg:         #0a0a0a;
  --card:       #151515;
  --border:     #2a2a2a;
  --text:       #eaeaea;
  --muted:      #9ca3af;
  --hdr:        #0d0d0d;
}

#nav-explore { display: none; }

/* ── Scrollbars ─────────────────────────────────────────── */
* { scrollbar-color: #2e2e2e #0a0a0a; }
::-webkit-scrollbar             { width: 7px; height: 7px; }
::-webkit-scrollbar-track       { background: #0a0a0a; }
::-webkit-scrollbar-thumb       { background: #2e2e2e; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #3a3a3a; }

/* ── Sidebar ────────────────────────────────────────────── */
.sitem:hover  { background: #1c1c1c; }
.sitem.active { background: #172133; color: var(--primary); }
.sitem .cnt   { background: #222; color: var(--muted); }
.titem        { background: #111; }
.titem:hover  { background: #172133; }
.titem.active { background: #172133; color: var(--primary); }
.titem .cnt   { color: var(--muted); }
.spec-hdr      { background: #161616; color: var(--text); }
.spec-hdr.open { background: #172133; }

/* ── Inputs & selects ───────────────────────────────────── */
.sidebar-search input,
.quiz-controls select {
  background: #1c1c1c;
  border-color: var(--border);
  color: var(--text);
  color-scheme: dark;
}
.sidebar-search input::placeholder { color: var(--muted); }
.sidebar-search input:focus { border-color: var(--primary); }
.quiz-controls select:focus { border-color: var(--primary); }

/* ── Buttons ────────────────────────────────────────────── */
.btn-outline { background: #2a2a2a; border-color: var(--border); color: var(--text); }
.btn-outline:hover:not(:disabled) { background: #3a3a3a; }
.btn-ghost { color: #60a5fa; }

/* ── Option buttons ─────────────────────────────────────── */
.option-btn { background: #1c1c1c; border-color: var(--border); color: var(--text); }
.option-btn:hover:not(:disabled) { background: #172133; border-color: var(--primary); }
.option-btn.selected  { background: #172133; border-color: #3b82f6; }
.option-btn.correct   { background: #052e16; border-color: #22c55e; color: #86efac; font-weight: 500; }
.option-btn.incorrect { background: #300a0a; border-color: #ef4444; color: #fca5a5; }

/* ── Explanation box ────────────────────────────────────── */
.explanation-box { background: #0c1d12; border-color: #166534; color: var(--text); }
.explanation-box h4 { color: #4ade80; }

/* ── Badges ─────────────────────────────────────────────── */
.badge-blue   { background: #1e3a5f; color: #93c5fd; }
.badge-yellow { background: #3d2a00; color: #fcd34d; }
.badge-red    { background: #3d0909; color: #fca5a5; }
.badge-green  { background: #052e16; color: #86efac; }
.badge-gray   { background: #222;    color: var(--muted); }
.badge-purple { background: #2e1a5e; color: #c4b5fd; }

/* ── Tags & chips ───────────────────────────────────────── */
.tag        { background: #1a2a45; color: #93c5fd; }
.tag:hover, .tag.active { background: var(--primary); color: #fff; }
.chip { background: #1c1c1c; border-color: var(--border); }

/* ── Cards & surfaces ───────────────────────────────────── */
.card      { background: var(--card); border-color: var(--border); }
.stat-card { background: var(--card); border-color: var(--border); }
.modal-box { background: #151515; color: var(--text); box-shadow: 0 24px 64px rgba(0,0,0,.75); }
.modal     { background: rgba(0,0,0,.82); }
.modal-close       { color: var(--muted); }
.modal-close:hover { color: var(--text); }

/* ── Question rows ──────────────────────────────────────── */
.q-row       { background: var(--card); border-color: var(--border); }
.q-row:hover { background: #172133; border-color: var(--primary); }

/* ── Matrix ─────────────────────────────────────────────── */
.matrix-entity { background: var(--card); border-color: var(--border); }

/* ── Results ────────────────────────────────────────────── */
.result-row           { background: #1c1c1c; }
.result-row.correct   { background: #071a10; }
.result-row.incorrect { background: #1f0707; }
.result-ans .right    { color: #4ade80; }

/* ── Exam dots ──────────────────────────────────────────── */
.edot { background: #1c1c1c; border-color: var(--border); color: var(--text); }
.edot.answered { background: var(--primary); border-color: var(--primary); color: #fff; }
.edot.current  { border-color: var(--primary); }

/* ── Tabs ───────────────────────────────────────────────── */
.tabs { border-color: var(--border); }
.tab { color: var(--muted); }
.tab.active             { color: var(--primary); }
.tab:hover:not(.active) { color: var(--text); }

/* ── HY rows ────────────────────────────────────────────── */
.hy-row { border-radius: 5px; }
.hy-row:hover { background: #172133; }

/* ── Exam source cards ──────────────────────────────────── */
.exam-source-card { background: var(--card) !important; }

/* ── Progress panel ─────────────────────────────────────── */
.prog-spec-row:hover     { background: #1c1c1c; }
.prog-spec-row.prog-active { background: #172133; }

/* ── Difficulty selector ────────────────────────────────── */
.diff-btn { background: #1c1c1c; border-color: var(--border); }
.diff-btn:hover  { background: #172133; border-color: var(--primary); box-shadow: 0 2px 12px rgba(59,130,246,.22); }
.diff-btn.active { background: #1a2a4a; border-color: var(--primary); box-shadow: 0 2px 16px rgba(59,130,246,.38); }
.diff-off-btn { color: var(--muted); border-color: #333; }
.diff-off-btn:hover  { color: var(--text); border-color: #666; }
.diff-off-btn.active { color: var(--text); border-color: #666; font-weight: 600; }

/* ── Tooltip ────────────────────────────────────────────── */
.diff-panel [data-tip]::after {
  background: #111;
  border-color: rgba(255,255,255,.1);
  color: #f1f5f9;
  box-shadow: 0 4px 14px rgba(0,0,0,.65);
}
.diff-panel [data-tip]::before { border-top-color: #111; }

/* ── Run / session cards ────────────────────────────────── */
.run-card { background: var(--card); border-color: var(--border); }
.run-card:hover { background: #172133; border-color: var(--primary); box-shadow: 0 2px 10px rgba(59,130,246,.15); }
.continue-banner { background: #131f30; border-color: #1e3a5f; }

/* ── Archive modal ──────────────────────────────────────── */
.arch-card { background: var(--card); border-color: var(--border); }
.arch-card:hover { background: #172133; border-color: #3b82f6; }
.arch-card.arch-selected { background: #1a2a4a; border-color: var(--primary); }
.arch-check { border-color: #444; background: transparent; }
.arch-spec-pill { background: #1c1c1c; border-color: var(--border); color: var(--muted); }
.arch-spec-pill.on {
  background: #1a2a4a;
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: 0 0 8px rgba(59,130,246,.28);
}

/* ── Inline-style overrides (JS-generated HTML) ─────────── */
/* These catch hardcoded colors injected via template literals */
*[style*="background:white"]    { background: var(--card) !important; }
*[style*="background: white"]   { background: var(--card) !important; }
*[style*="background:#f8fafc"]  { background: #161616    !important; }
*[style*="background: #f8fafc"] { background: #161616    !important; }
*[style*="background:#f8fbff"]  { background: #161820    !important; }
*[style*="background: #f8fbff"] { background: #161820    !important; }
*[style*="background:#eff6ff"]  { background: #172133    !important; }
*[style*="background: #eff6ff"] { background: #172133    !important; }
*[style*="background:#dbeafe"]  { background: #1a2a4a    !important; }
*[style*="background: #dbeafe"] { background: #1a2a4a    !important; }
*[style*="background:#fef2f2"]  { background: #300a0a    !important; }
*[style*="background: #fef2f2"] { background: #300a0a    !important; }
*[style*="background:#f0fdf4"]  { background: #0c1d12    !important; }
*[style*="background: #f0fdf4"] { background: #0c1d12    !important; }
*[style*="background:#fef9c3"]  { background: #2a1f00    !important; }
*[style*="background: #fef9c3"] { background: #2a1f00    !important; }