/* ============================================
   UNIT CONVERTER — additions
   Append to tools.css after the existing .unit-converter rule.
   All new classes namespaced .uc-*.
   ============================================ */

.unit-converter {
  max-width: 920px;
  margin: 0 auto;
}

/* ===== Category tabs (horizontally scrollable) ===== */
.uc-cat-tabs {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
  scroll-snap-type: x proximity;
}

.uc-cat-tab {
  flex-shrink: 0;
  min-height: 44px;
  padding: 0.55rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  scroll-snap-align: start;
  white-space: nowrap;
}

.uc-cat-tab:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-1px);
}

.uc-cat-tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--on-primary);
  box-shadow: 0 2px 8px rgba(var(--primary-rgb), 0.25);
}

/* ===== Input row ===== */
.uc-input-row {
  display: grid;
  grid-template-columns: 1fr 1.3fr;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.uc-input-row .input-group { margin-bottom: 0; }

/* ===== Warning ===== */
.uc-warning {
  background: rgba(var(--warning-rgb), 0.1);
  border: 1px solid var(--warning);
  border-radius: var(--radius);
  padding: 0.6rem 0.875rem;
  margin-bottom: 1rem;
  color: var(--text);
  font-size: 0.9rem;
}

/* ===== Preset chips ===== */
.uc-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.uc-presets:empty { display: none; }

.uc-chip {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  min-height: 40px;
  display: inline-flex;
  align-items: center;
}

.uc-chip:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-1px);
}

/* ===== Precision slider ===== */
.uc-precision-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.7rem 1rem;
  margin-bottom: 1.25rem;
}

.uc-precision-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  white-space: nowrap;
  min-width: 140px;
}

.uc-precision-value {
  display: inline-block;
  min-width: 1.5rem;
  text-align: center;
  padding: 0.1rem 0.4rem;
  background: var(--primary);
  color: var(--on-primary);
  border-radius: 4px;
  font-weight: 700;
  font-family: 'SF Mono', monospace;
  font-size: 0.85rem;
  margin: 0 0.25rem;
}

.uc-slider {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 6px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  outline: none;
  cursor: pointer;
}

.uc-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--primary);
  cursor: pointer;
  box-shadow: 0 2px 4px rgba(var(--shadow-color-rgb), 0.15);
}

.uc-slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--primary);
  cursor: pointer;
  box-shadow: 0 2px 4px rgba(var(--shadow-color-rgb), 0.15);
}

/* ===== Live grid ===== */
.uc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.uc-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.875rem 1rem;
  text-align: left;
  transition: var(--transition);
}

.uc-card:hover {
  border-color: var(--primary);
  transform: translateY(-1px);
}

.uc-card.active-unit {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.3);
}

.uc-card.active-unit .uc-card-label,
.uc-card.active-unit .uc-card-value,
.uc-card.active-unit .uc-card-symbol {
  color: var(--on-primary);
}

.uc-card.active-unit .uc-card-label { opacity: 0.8; }
.uc-card.active-unit .uc-card-symbol { opacity: 0.8; }

.uc-card-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}

.uc-card-value {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  word-break: break-word;
  line-height: 1.2;
}

.uc-card-symbol {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
  font-family: 'SF Mono', monospace;
}

.uc-card-error {
  grid-column: 1 / -1;
  text-align: center;
  border-color: var(--danger);
  color: var(--danger);
  background: rgba(var(--danger-rgb), 0.06);
  padding: 1.5rem 1rem;
  font-weight: 500;
}

/* ===== Action buttons ===== */
.uc-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
  justify-content: center;
}

.uc-actions .btn {
  min-height: 44px;
  flex: 1 1 auto;
  min-width: 140px;
}

/* ===== Mobile (< 600px) ===== */
@media (max-width: 600px) {
  .uc-cat-tabs {
    margin-bottom: 1rem;
    padding: 0 0.25rem 0.5rem;
  }
  .uc-cat-tab {
    font-size: 0.85rem;
    padding: 0.5rem 0.85rem;
  }
  .uc-input-row {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  .uc-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
  }
  .uc-card {
    padding: 0.7rem 0.85rem;
  }
  .uc-card-value {
    font-size: 1rem;
  }
  .uc-precision-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.6rem;
  }
  .uc-precision-label {
    text-align: center;
    min-width: 0;
  }
  .uc-actions .btn {
    flex: 1 1 100%;
  }
}