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

/* ─── Theme tokens ───────────────────────────────────── */
:root {
  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  14px;
  --radius-pill: 999px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
  --transition: 0.18s ease;
}

/* Dark theme (default) */
[data-theme="dark"] {
  --bg-page:        #0f1117;
  --bg-surface:     #181b23;
  --bg-elevated:    #1e2230;
  --bg-hover:       #252a38;
  --bg-input:       #1a1e2a;

  --border-subtle:  rgba(255,255,255,0.07);
  --border-default: rgba(255,255,255,0.12);
  --border-strong:  rgba(255,255,255,0.22);

  --text-primary:   #e8eaf0;
  --text-secondary: #8b91a8;
  --text-tertiary:  #555d78;
  --text-on-accent: #ffffff;

  --accent:         #7c75e0;
  --accent-dim:     rgba(124,117,224,0.15);
  --accent-border:  rgba(124,117,224,0.4);

  --progress-bg:    rgba(255,255,255,0.08);
  --progress-fill:  #7c75e0;

  --dz-border:      rgba(255,255,255,0.14);
  --dz-bg:          rgba(255,255,255,0.02);
  --dz-bg-hover:    rgba(255,255,255,0.05);

  --tgl-active-bg:  #252a38;
  --tgl-active-text:#e8eaf0;

  --scrollbar-bg:   #181b23;
  --scrollbar-thumb:#2c3045;

  /* Chart.js readable colors stored as CSS vars (referenced in JS via getComputedStyle) */
  --chart-grid:     rgba(255,255,255,0.06);
  --chart-tick:     #555d78;
  --chart-axis-title: #6b7290;
}

/* Light theme */
[data-theme="light"] {
  --bg-page:        #f5f6fa;
  --bg-surface:     #ffffff;
  --bg-elevated:    #ffffff;
  --bg-hover:       #f0f1f7;
  --bg-input:       #f7f8fc;

  --border-subtle:  rgba(0,0,0,0.06);
  --border-default: rgba(0,0,0,0.1);
  --border-strong:  rgba(0,0,0,0.18);

  --text-primary:   #111827;
  --text-secondary: #4b5563;
  --text-tertiary:  #9ca3af;
  --text-on-accent: #ffffff;

  --accent:         #5b54d4;
  --accent-dim:     rgba(91,84,212,0.08);
  --accent-border:  rgba(91,84,212,0.3);

  --progress-bg:    rgba(0,0,0,0.07);
  --progress-fill:  #5b54d4;

  --dz-border:      rgba(0,0,0,0.13);
  --dz-bg:          rgba(0,0,0,0.015);
  --dz-bg-hover:    rgba(0,0,0,0.035);

  --tgl-active-bg:  #f0f1f7;
  --tgl-active-text:#111827;

  --scrollbar-bg:   #f0f1f7;
  --scrollbar-thumb:#d1d5e0;

  --chart-grid:     rgba(0,0,0,0.05);
  --chart-tick:     #9ca3af;
  --chart-axis-title: #6b7280;
}

/* ─── Base ───────────────────────────────────────────── */
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-page);
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; background: var(--scrollbar-bg); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 3px; }

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

/* ─── Topbar ─────────────────────────────────────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  height: 52px;
  background: var(--bg-surface);
  border-bottom: 0.5px solid var(--border-subtle);
  transition: background var(--transition), border-color var(--transition);
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.topbar-logo {
  display: flex;
  align-items: center;
  color: var(--accent);
}

.topbar-title {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
}

.topbar-sub {
  font-size: 12px;
  color: var(--text-tertiary);
  font-family: var(--font-mono);
}

.topbar-right { display: flex; align-items: center; gap: 8px; }

/* Theme toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  border: 0.5px solid var(--border-default);
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 12px;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.theme-toggle:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
  border-color: var(--border-strong);
}
.theme-toggle .icon-sun,
.theme-toggle .icon-moon { flex-shrink: 0; }

/* show moon in dark, sun in light */
[data-theme="dark"]  .icon-sun  { display: none; }
[data-theme="dark"]  .icon-moon { display: block; }
[data-theme="light"] .icon-moon { display: none; }
[data-theme="light"] .icon-sun  { display: block; }

/* ─── Main content ───────────────────────────────────── */
.main-content {
  flex: 1;
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

/* ─── Drop zone ──────────────────────────────────────── */
.drop-zone {
  border: 1.5px dashed var(--dz-border);
  border-radius: var(--radius-lg);
  background: var(--dz-bg);
  padding: 2rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
  margin-bottom: 1rem;
}
.drop-zone:hover,
.drop-zone.over {
  background: var(--dz-bg-hover);
  border-color: var(--accent-border);
}
.drop-zone svg {
  display: block;
  margin: 0 auto 0.6rem;
  color: var(--text-tertiary);
}
.drop-zone h3 {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}
.drop-zone p {
  font-size: 13px;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}
.drop-zone input[type="file"] { display: none; }

/* ─── Progress ───────────────────────────────────────── */
.progress-wrap { display: none; margin-bottom: 1rem; }
.progress-bar {
  height: 3px;
  background: var(--progress-bg);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 6px;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--progress-fill);
  border-radius: 2px;
  transition: width 0.2s ease;
}
.progress-msg {
  font-size: 12px;
  color: var(--text-secondary);
  text-align: center;
}

/* ─── Session pills ──────────────────────────────────── */
.pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 1rem;
  min-height: 0;
}
.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 500;
  border: 0.5px solid transparent;
  white-space: nowrap;
}
.pill-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  flex-shrink: 0;
}
.pill-dur {
  opacity: 0.55;
  font-weight: 400;
}
.pill-x {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 15px;
  line-height: 1;
  padding: 0;
  opacity: 0.45;
  color: inherit;
}
.pill-x:hover { opacity: 1; }

/* ─── Controls section ───────────────────────────────── */
.controls-section { display: none; }

.controls-card {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  align-items: flex-start;
  padding: 1rem 1.25rem;
  background: var(--bg-surface);
  border: 0.5px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  margin-bottom: 1rem;
  transition: background var(--transition), border-color var(--transition);
}

.ctrl-divider {
  width: 0.5px;
  align-self: stretch;
  background: var(--border-subtle);
}
@media (max-width: 640px) {
  .ctrl-divider { width: 100%; height: 0.5px; }
}

.ctrl-group { display: flex; flex-direction: column; gap: 7px; }

.ctrl-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.check-row { display: flex; flex-wrap: wrap; gap: 8px; }

.chk {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  cursor: pointer;
  color: var(--text-primary);
}
.chk input[type="checkbox"] {
  cursor: pointer;
  width: 13px;
  height: 13px;
  accent-color: var(--accent);
}
.chk-sub { color: var(--text-tertiary); font-size: 12px; }

/* Time-axis toggles */
.toggle-row { display: flex; gap: 4px; }
.tgl {
  padding: 4px 13px;
  font-size: 12px;
  border-radius: var(--radius-pill);
  border: 0.5px solid var(--border-default);
  cursor: pointer;
  background: none;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.tgl:hover { background: var(--bg-hover); color: var(--text-primary); }
.tgl.active {
  background: var(--tgl-active-bg);
  color: var(--tgl-active-text);
  border-color: var(--border-strong);
  font-weight: 500;
}

/* ─── Summary cards ──────────────────────────────────── */
.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
  margin-bottom: 1.25rem;
}
.scard {
  background: var(--bg-surface);
  border: 0.5px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  transition: background var(--transition), border-color var(--transition);
}
.scard-lbl { font-size: 11px; color: var(--text-secondary); margin-bottom: 4px; }
.scard-val { font-size: 20px; font-weight: 500; color: var(--text-primary); line-height: 1.1; }
.scard-sub { font-size: 11px; color: var(--text-tertiary); margin-top: 3px; }

/* ─── Chart stack ────────────────────────────────────── */
.chart-stack { display: flex; flex-direction: column; gap: 1.25rem; }

.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-tertiary);
}
.empty-state svg { margin: 0 auto 0.75rem; display: block; }
.empty-state p { font-size: 14px; }

.chart-card {
  background: var(--bg-surface);
  border: 0.5px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  transition: background var(--transition), border-color var(--transition);
}
.chart-title { font-size: 14px; font-weight: 500; color: var(--text-primary); }
.chart-desc { font-size: 12px; color: var(--text-secondary); margin-top: 2px; margin-bottom: 0.75rem; }
.chart-wrap { position: relative; width: 100%; height: 200px; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 0.6rem;
}
.leg-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  color: var(--text-secondary);
}
.leg-dot { width: 10px; height: 10px; border-radius: 2px; flex-shrink: 0; }
/* ─── PSD slice slider ───────────────────────────────── */
.psd-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 0.6rem;
}
.psd-freq-label {
  font-size: 12px;
  color: var(--text-secondary);
  white-space: nowrap;
  min-width: 120px;
}
.psd-freq-label strong {
  color: var(--text-primary);
  font-weight: 500;
}
.psd-band-badge {
  font-size: 11px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  font-weight: 500;
  background: var(--accent-dim);
  color: var(--accent);
  border: 0.5px solid var(--accent-border);
  white-space: nowrap;
}
input[type="range"].psd-slider {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}