/* Unit Converter — Custom Styles */

/* ---- Category tabs ---- */
.uc-categories {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.uc-cat-btn {
  border: 1px solid var(--color-border);
  border-radius: 100px;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--color-text-secondary);
  background: var(--color-surface);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.uc-cat-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.uc-cat-btn.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* ---- Converter card ---- */
.uc-converter {
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 32px;
  background: var(--color-surface);
  max-width: 600px;
  margin: 0 auto;
}

/* ---- Fields row ---- */
.uc-fields {
  display: flex;
  gap: 16px;
  align-items: flex-end;
}

.uc-field {
  display: flex;
  flex-direction: column;
  flex: 1;
  gap: 6px;
}

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

.uc-field input {
  font-size: 1.5rem;
  font-family: var(--font-mono);
  width: 100%;
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  outline: none;
  transition: border-color var(--transition-fast);
}

.uc-field input:focus {
  border-color: var(--color-primary);
}

.uc-field input[readonly] {
  background: var(--color-primary-light);
  color: var(--color-text);
  border-color: var(--color-primary-subtle);
  font-weight: 700;
  cursor: default;
}

.uc-field select {
  width: 100%;
  font-size: 0.9rem;
  font-family: var(--font-body);
  padding: 8px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition-fast);
}

.uc-field select:focus {
  border-color: var(--color-primary);
}

/* ---- Swap button ---- */
.uc-swap {
  width: 40px;
  height: 40px;
  min-width: 40px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--transition-fast);
  margin-bottom: 22px;
}

.uc-swap:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-subtle);
}

/* ---- Formula display ---- */
.uc-formula {
  text-align: center;
  color: var(--color-text-secondary);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 600;
  margin-top: 20px;
  padding: 10px 16px;
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  min-height: 22px;
}

/* ---- Scientific notation note ---- */
.uc-sci-note {
  text-align: center;
  font-size: 0.78rem;
  color: var(--color-text-muted);
  margin-top: 8px;
  min-height: 0;
}

.uc-sci-note:empty {
  display: none;
}

/* ---- Popular conversions ---- */
.uc-popular {
  margin-top: 24px;
}

.uc-popular-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 10px;
}

.uc-quick-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.uc-quick-btn {
  font-size: 0.8rem;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--color-text-secondary);
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 100px;
  padding: 6px 14px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.uc-quick-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ---- SEO table ---- */
.seo-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 20px;
  font-size: 0.92rem;
}

.seo-table th,
.seo-table td {
  padding: 10px 14px;
  border: 1px solid var(--color-border-light);
  text-align: left;
}

.seo-table th {
  background: var(--color-bg);
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
}

.seo-table td {
  color: var(--color-text);
}

.seo-table td:nth-child(3) {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.88rem;
}

.seo-table tbody tr:hover {
  background: var(--color-bg);
}

/* ---- Responsive ---- */
@media (max-width: 600px) {
  .uc-converter {
    padding: 20px 16px;
  }

  .uc-fields {
    flex-direction: column;
    gap: 12px;
  }

  .uc-swap {
    align-self: center;
    margin-bottom: 0;
    transform: rotate(90deg);
  }

  .uc-field input {
    font-size: 1.25rem;
  }
}