/* ============================================================
   Tools — shared styles for /tools.html (index) and /tools/*.html
   Loaded alongside style.css; uses the v2 site tokens
   (Lora display + Inter body + warm-rust accent + ink-blue).
   ============================================================ */

/* Index page header */
.tools-page-header {
  padding: var(--spacing-xl) 0 var(--spacing-lg);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: var(--spacing-xl);
}

.tools-page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw + 1rem, 3rem);
  font-weight: 600;
  font-style: italic;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin: 0 0 var(--spacing-sm);
  line-height: 1.1;
}

.tools-page-header p {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0;
  line-height: 1.6;
}

/* Tool card grid (index) */
.tools-grid {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

.tool-row {
  display: grid;
  grid-template-columns: 1fr 200px;
  gap: var(--spacing-lg);
  align-items: center;
  padding: var(--spacing-lg);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  background: var(--bg-secondary);
  text-decoration: none;
  color: inherit;
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.tool-row:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.tool-row-body h2 {
  font-family: var(--font-display);
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin: 0 0 0.4rem;
  color: var(--text-primary);
}

.tool-row-body p {
  font-size: var(--font-size-base);
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0 0 0.6rem;
}

.tool-row-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.01em;
}

.tool-row-cta::after {
  content: '\2192';
  transition: transform var(--transition-fast);
}

.tool-row:hover .tool-row-cta::after { transform: translateX(3px); }

.tool-row-icon {
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 4rem;
  font-weight: 600;
  font-style: italic;
  color: var(--accent);
  letter-spacing: -0.02em;
}

.tool-row-icon--external {
  position: relative;
}

.tool-row-icon--external::after {
  content: '\2197';
  position: absolute;
  top: 0.6rem;
  right: 0.8rem;
  font-size: 1.25rem;
  font-style: normal;
  color: var(--text-muted);
  font-weight: 400;
}

@media (max-width: 600px) {
  .tool-row {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }
  .tool-row-icon {
    aspect-ratio: 16 / 9;
    font-size: 3rem;
  }
}

/* ============================================================
   Tool page chrome (used on /tools/<slug>.html)
   ============================================================ */
.tool-page {
  padding: var(--spacing-xl) 0 var(--spacing-2xl);
}

.tool-page__back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: var(--spacing-md);
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.tool-page__back:hover {
  color: var(--accent);
  transform: translateX(-2px);
}

.tool-page__header h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw + 1rem, 2.75rem);
  font-weight: 600;
  font-style: italic;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin: 0 0 var(--spacing-xs);
  line-height: 1.15;
}

.tool-page__header p {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin: 0 0 var(--spacing-xl);
  line-height: 1.5;
  max-width: 640px;
}

/* Equation display strip (lives above the plot) */
.tool-equation {
  font-family: 'Cambria Math', 'STIX Two Math', Georgia, serif;
  font-size: clamp(1.1rem, 2vw + 0.6rem, 1.6rem);
  text-align: center;
  padding: var(--spacing-md) var(--spacing-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
  letter-spacing: 0.01em;
  line-height: 1.4;
}

.tool-equation .coef { color: var(--accent); font-weight: 600; }

/* SVG plot */
.tool-canvas-wrap {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.tool-canvas {
  display: block;
  width: 100%;
  height: auto;
  max-width: 600px;
  margin: 0 auto;
  font-family: var(--font-family);
  font-size: 0.6px; /* SVG-internal units */
}

.tool-canvas .grid-line { stroke: var(--border-subtle); stroke-width: 0.05; fill: none; }
.tool-canvas .axis-line { stroke: var(--text-muted); stroke-width: 0.1; fill: none; }
.tool-canvas .axis-label { fill: var(--text-muted); font-size: 0.7px; font-weight: 500; }
.tool-canvas .parabola {
  stroke: var(--accent);
  stroke-width: 0.18;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.tool-canvas .vertex { fill: var(--accent); stroke: var(--bg-secondary); stroke-width: 0.08; }
.tool-canvas .root { fill: var(--text-primary); stroke: var(--accent); stroke-width: 0.08; }

/* Sliders */
.tool-controls {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.tool-slider {
  display: grid;
  grid-template-columns: 2.5rem 1fr 5rem;
  gap: var(--spacing-md);
  align-items: center;
}

.tool-slider__label {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--accent);
  text-align: center;
}

.tool-slider input[type="range"] {
  width: 100%;
  -webkit-appearance: none;
  appearance: none;
  height: 4px;
  border-radius: 2px;
  background: var(--bg-tertiary);
  outline: none;
}

.tool-slider input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-primary);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.tool-slider input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.1); box-shadow: 0 0 0 6px var(--accent-muted); }
.tool-slider input[type="range"]:focus-visible::-webkit-slider-thumb { box-shadow: 0 0 0 4px var(--accent-focus-ring); }

.tool-slider input[type="range"]::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-primary);
  cursor: pointer;
}

.tool-slider input[type="number"] {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  padding: 0.4rem 0.6rem;
  text-align: right;
  width: 100%;
  font-variant-numeric: tabular-nums;
}

.tool-slider input[type="number"]:focus { outline: 2px solid var(--accent); outline-offset: 0; border-color: var(--accent); }

/* Info readout */
.tool-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
}

.tool-info__item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.tool-info__label {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}

.tool-info__value {
  font-family: 'Cambria Math', Georgia, serif;
  font-size: var(--font-size-lg);
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

/* Actions */
.tool-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-xl);
}

.tool-btn {
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  font-weight: 500;
  padding: 0.65rem 1.1rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  border: 1px solid transparent;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}

.tool-btn--primary {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
}
.tool-btn--primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); transform: translateY(-1px); }

.tool-btn--secondary {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border);
}
.tool-btn--secondary:hover { color: var(--text-primary); border-color: var(--accent); }

.tool-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* "How to read this" footnote */
.tool-footnote {
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  line-height: 1.6;
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border-subtle);
}

.tool-footnote strong { color: var(--text-secondary); font-weight: 600; }

@media (max-width: 600px) {
  .tool-slider { grid-template-columns: 2rem 1fr 4.5rem; gap: 0.75rem; }
  .tool-slider__label { font-size: 1.1rem; }
  .tool-info { grid-template-columns: 1fr; padding: var(--spacing-md); }
}