/* ── profpi — Fourier Explorer (tool page) ── */
/* Expects tokens.css + home.css (shared header/nav/footer) loaded first,
   same as every other /tools/ page. Every color/radius/shadow below falls
   back to profpi's home.css values via var(--x, fallback) so this file is
   still legible if loaded on its own. */

.tool-hero {
  max-width: 1140px;
  margin: 0 auto;
  padding: 48px 24px 8px;
}

.tool-hero .eyebrow {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent, #6366f1);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 10px;
}

.tool-hero h1 {
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.12;
  margin-bottom: 14px;
}

.tool-hero p {
  font-size: 1rem;
  color: var(--text-muted, #64748b);
  line-height: 1.65;
  max-width: 780px;
}

/* ── Tool layout ── */
.tool-section {
  max-width: 1140px;
  margin: 0 auto;
  padding: 24px 24px 56px;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 24px;
  align-items: start;
}

.control-panel {
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-lg, 16px);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  position: sticky;
  top: 88px;
}

.mode-toggle {
  display: flex;
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-md, 10px);
  overflow: hidden;
}

.mode-toggle button {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text-muted, #64748b);
  font-weight: 600;
  font-size: 0.86rem;
  padding: 10px 8px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.mode-toggle button.is-active {
  background: var(--accent, #6366f1);
  color: #fff;
}

.control-panel .field-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.control-panel label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-main, #0f172a);
}

.control-panel .field-hint {
  font-size: 0.78rem;
  color: var(--text-muted, #64748b);
  line-height: 1.5;
}

.control-panel input[type="text"] {
  width: 100%;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 0.88rem;
  padding: 9px 11px;
  border-radius: var(--radius-md, 10px);
  border: 1px solid var(--border-color, #e2e8f0);
  background: var(--bg-space, #f8fafc);
  color: var(--text-main, #0f172a);
}

.control-panel input[type="text"].has-error {
  border-color: var(--danger, #ef4444);
}

.control-panel input[type="range"] {
  width: 100%;
  accent-color: var(--accent, #6366f1);
}

.control-panel select {
  width: 100%;
  font-size: 0.86rem;
  padding: 8px 10px;
  border-radius: var(--radius-md, 10px);
  border: 1px solid var(--border-color, #e2e8f0);
  background: var(--card-bg, #ffffff);
  color: var(--text-main, #0f172a);
}

.range-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.range-row .range-value {
  font-variant-numeric: tabular-nums;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent, #6366f1);
  min-width: 2.6em;
  text-align: right;
}

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

.preset-chip {
  border: 1px solid var(--border-color, #e2e8f0);
  background: var(--card-active, #eef2ff);
  color: var(--text-main, #0f172a);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.preset-chip:hover {
  border-color: var(--accent, #6366f1);
  color: var(--accent, #6366f1);
}

.btn-panel {
  border: 1px solid var(--border-color, #e2e8f0);
  background: var(--card-bg, #ffffff);
  color: var(--text-main, #0f172a);
  font-weight: 700;
  font-size: 0.86rem;
  padding: 10px 14px;
  border-radius: var(--radius-md, 10px);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.btn-panel:hover {
  border-color: var(--accent, #6366f1);
  color: var(--accent, #6366f1);
}

.btn-panel-primary {
  background: var(--accent, #6366f1);
  border-color: var(--accent, #6366f1);
  color: #fff;
}

.btn-panel-primary:hover {
  background: var(--accent-hover, #4f46e5);
  color: #fff;
}

.playback-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.playback-row .btn-panel {
  flex: 0 0 auto;
}

.fidelity-badge {
  font-size: 0.78rem;
  color: var(--text-muted, #64748b);
  background: var(--bg-space, #f8fafc);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-md, 10px);
  padding: 8px 10px;
  line-height: 1.5;
}

.fidelity-badge strong {
  color: var(--text-main, #0f172a);
}

.error-banner {
  font-size: 0.82rem;
  color: var(--danger, #ef4444);
  background: rgba(239, 68, 68, 0.08);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: var(--radius-md, 10px);
  padding: 10px 12px;
  line-height: 1.5;
}

.error-banner.is-hidden {
  display: none;
}

.is-hidden {
  display: none !important;
}

/* ── Canvas area ── */
.canvas-column {
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-width: 0;
}

.canvas-wrap {
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-lg, 16px);
  box-shadow: var(--shadow-lg, 0 12px 24px rgba(0, 0, 0, 0.06));
  padding: 12px;
}

.canvas-stage {
  position: relative;
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-md, 10px);
  overflow: hidden;
  background: var(--bg-space, #f8fafc);
  touch-action: none;
  cursor: crosshair;
}

.canvas-stage canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

.canvas-stage-hint {
  position: absolute;
  bottom: 10px;
  left: 12px;
  right: 12px;
  font-size: 0.8rem;
  color: var(--text-muted, #64748b);
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-md, 10px);
  padding: 6px 10px;
  pointer-events: none;
  width: fit-content;
}

.canvas-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  padding: 10px 4px 2px;
}

.legend-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--text-muted, #64748b);
}

.legend-swatch {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  display: inline-block;
}

/* ── Spectrum panel ── */
.spectrum-panel {
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-lg, 16px);
  padding: 16px;
}

.spectrum-panel h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.spectrum-panel p.field-hint {
  margin-bottom: 10px;
}

.spectrum-stage {
  width: 100%;
  aspect-ratio: 5 / 1.6;
  min-height: 120px;
}

/* ── Explainer / trust cards ── */
.tool-explainer {
  max-width: 1140px;
  margin: 0 auto;
  padding: 8px 24px 56px;
}

.tool-explainer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 20px;
}

.tool-explainer-card {
  background: var(--card-bg, #ffffff);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: var(--radius-lg, 16px);
  padding: 20px;
}

.tool-explainer-card h3 {
  font-size: 0.98rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.tool-explainer-card p {
  font-size: 0.86rem;
  color: var(--text-muted, #64748b);
  line-height: 1.6;
}

/* ── Responsive ── */
@media (max-width: 960px) {
  .tool-section {
    grid-template-columns: 1fr;
  }

  .control-panel {
    position: static;
  }

  .tool-explainer-grid {
    grid-template-columns: 1fr;
  }
}