/* ── Colour palette (matches R server.R) ─────────────────────────── */
:root {
  --tail-colour:        #619CFF;
  --shelf-colour:       #00BA38;
  --uniques-colour:     #AFCDFF;
  --the100s-colour:     #7FDC9B;
  --tail-covers-colour: #ad89b6;
  --shelf-covers-colour:#7c9853;

  --bg:        #f8f9fa;
  --border:    #dee2e6;
  --text:      #212529;
  --muted:     #6c757d;
  --accent:    #428bca;
  --btn-bg:    #e9ecef;
  --btn-hover: #d0d7de;
  --primary:   #007bff;
  --primary-hover: #0056b3;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 14px;
  color: var(--text);
  background: var(--bg);
  line-height: 1.5;
}

a { color: var(--accent); }

ul { padding-left: 1.4em; }

/* ── Loading overlay ──────────────────────────────────────────────── */
#loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(255,255,255,0.92);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
}
#loading-overlay.hidden { display: none; }
.loading-box {
  text-align: center;
  padding: 2rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  min-width: 260px;
}
.loading-box p { margin-bottom: 1rem; font-size: 1rem; }
progress { width: 100%; }

/* ── App wrapper ──────────────────────────────────────────────────── */
#app { display: flex; flex-direction: column; min-height: 100vh; }

/* ── Header ───────────────────────────────────────────────────────── */
header {
  padding: 1rem 1.5rem;
  background: #fff;
  border-bottom: 1px solid var(--border);
}
header h1 { font-size: 1.6rem; margin-bottom: 0.5rem; }
header p  { margin-bottom: 0.4rem; color: var(--text); }

/* ── Main layout: sidebar + content ──────────────────────────────── */
#main-layout {
  display: flex;
  flex: 1;
  gap: 0;
}

#sidebar {
  width: 240px;
  min-width: 200px;
  padding: 1rem;
  background: #fff;
  border-right: 1px solid var(--border);
}
#sidebar details { margin-top: 0.75rem; }
#sidebar summary { cursor: pointer; font-weight: 600; color: var(--accent); }
#sidebar ul { margin-top: 0.5rem; }
#sidebar li { margin-bottom: 0.3rem; }

#main-content {
  flex: 1;
  padding: 1.25rem 1.5rem;
  overflow-x: hidden;
}

/* ── Slider section ───────────────────────────────────────────────── */
#slider-section {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
}
#slider-section p { margin-bottom: 0.5rem; }
#slider-section ul { margin-bottom: 1rem; }

#slider-labels {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
}
#slider-labels span { color: var(--muted); }
#slider-labels strong { color: var(--text); }

#threshold-slider {
  margin: 0.5rem 0.5rem 1.25rem;
}

/* noUiSlider overrides */
.noUi-connect { background: var(--accent); }
.noUi-handle  { border-radius: 50%; cursor: pointer; }

/* ── Tab navigation ───────────────────────────────────────────────── */
#tab-nav {
  display: flex;
  gap: 0;
  border-bottom: 2px solid var(--border);
  margin-bottom: 1rem;
}
.tab-btn {
  padding: 0.5rem 1.1rem;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
  margin-bottom: -2px;
  transition: color 0.15s, border-color 0.15s;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ── Tab panels ───────────────────────────────────────────────────── */
.tab-panel { }

/* ── Sub-tab navigation ───────────────────────────────────────────── */
.sub-tab-nav {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin: 0.75rem 0;
}
.sub-tab-btn {
  padding: 0.4rem 0.9rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: -1px;
  transition: color 0.15s, border-color 0.15s;
}
.sub-tab-btn:hover { color: var(--text); }
.sub-tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

/* ── Controls ─────────────────────────────────────────────────────── */
.control-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}
.control-row label { font-weight: 500; white-space: nowrap; }
.control-row select {
  flex: 1;
  min-width: 200px;
  max-width: 480px;
  font-size: 0.9rem;
}

.control-row .ts-wrapper,
#tour-select {
  width: 280px;
  flex: none;
  font-size: 0.9rem;
}

.control-row select {
  padding: 0.35rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
}

.ts-wrapper .ts-control {
  width: 100%;
  box-sizing: border-box;
}

/* ── Artist info box ──────────────────────────────────────────────── */
.info-box {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.6rem 0.9rem;
  margin-bottom: 0.75rem;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.7;
}

/* ── Fieldsets / radio groups ─────────────────────────────────────── */
fieldset {
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.6rem 1rem;
  margin-bottom: 0.75rem;
}
legend { font-weight: 600; padding: 0 0.4rem; font-size: 0.88rem; }
fieldset label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-right: 1.2rem;
  margin-top: 0.3rem;
  cursor: pointer;
  font-size: 0.88rem;
}

/* ── Plot containers ──────────────────────────────────────────────── */
.plot-container {
  width: 100%;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  margin-bottom: 1rem;
  min-height: 400px;
}

/* ── Buttons ──────────────────────────────────────────────────────── */
.button-row {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}
button {
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--btn-bg);
  cursor: pointer;
  font-size: 0.88rem;
  transition: background 0.15s;
}
button:hover { background: var(--btn-hover); }
button:disabled { opacity: 0.55; cursor: not-allowed; }
.primary-btn {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  font-weight: 600;
}
.primary-btn:hover { background: var(--primary-hover); border-color: var(--primary-hover); }
.primary-btn:disabled { background: var(--primary); border-color: var(--primary); }

/* ── Checkbox groups ──────────────────────────────────────────────── */
.checkbox-group {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.6rem 0.9rem;
  margin-bottom: 0.75rem;
  max-height: 220px;
  overflow-y: auto;
}
.checkbox-group label {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  margin-right: 1rem;
  margin-bottom: 0.25rem;
  font-size: 0.85rem;
  cursor: pointer;
}
.artist-checkbox-group { max-height: 280px; }

/* ── Progress bar (run analysis) ──────────────────────────────────── */
#run-progress {
  margin-bottom: 0.75rem;
  padding: 0.6rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 4px;
}
#run-progress-text { margin-bottom: 0.4rem; font-size: 0.88rem; color: var(--muted); }
#run-progress-bar { width: 100%; }

/* ── Comparison controls ──────────────────────────────────────────── */
#comparison-controls {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
}
#comparison-controls fieldset { flex: 1; min-width: 220px; }

/* ── Hint tooltip (first-visit) ───────────────────────────────────── */
#hint-tooltip {
  position: fixed;
  background: #2c3e50;
  color: #fff;
  padding: 0.5rem 0.85rem;
  border-radius: 6px;
  font-size: 0.83rem;
  max-width: 160px;
  line-height: 1.4;
  text-align: center;
  box-shadow: 0 2px 6px rgba(0,0,0,0.22);
  opacity: 0;
  transition: opacity 0.35s;
  pointer-events: none;
  z-index: 998;
}
#hint-tooltip.visible { opacity: 1; }
#hint-tooltip::before {
  content: '';
  position: absolute;
  top: 50%;
  left: -12px;
  transform: translateY(-50%);
  border: 6px solid transparent;
  border-right-color: #2c3e50;
}
#hint-tooltip.below::before {
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  border-right-color: transparent;
  border-bottom-color: #2c3e50;
}

/* ── Responsive ───────────────────────────────────────────────────── */
@media (max-width: 720px) {
  #main-layout { flex-direction: column; }
  #sidebar { width: 100%; border-right: none; border-bottom: 1px solid var(--border); }
  #comparison-controls { flex-direction: column; }
}