/* ===== Unit Converter Tool ===== */

.uc-subtitle {
  color: var(--muted);
  margin-top: -0.5rem;
  margin-bottom: 1.5rem;
}

/* ===== Tool layout ===== */
.uc-tool {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.uc-panel {
  flex: 1;
  min-width: 0;
}

.uc-input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1.25rem;
  border: 1px solid #e4e8f0;
  border-radius: 8px;
  background: var(--card);
  color: var(--text);
  margin-bottom: 0.5rem;
  -moz-appearance: textfield;
}

.uc-input::-webkit-inner-spin-button,
.uc-input::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.uc-input:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

/* ===== Swap button ===== */
.uc-swap {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid #e4e8f0;
  background: var(--card);
  color: var(--accent);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 0.6rem;
  transition: background 0.15s, transform 0.3s;
}

.uc-swap:hover {
  background: #f0f4ff;
}

.uc-swap:active {
  transform: rotate(180deg);
}

/* ===== Custom combo box ===== */
.uc-combo {
  position: relative;
}

.uc-combo__trigger {
  width: 100%;
  padding: 0.6rem 1rem;
  border: 1px solid #e4e8f0;
  border-radius: 8px;
  background: var(--card);
  color: var(--muted);
  font-size: 0.95rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
}

.uc-combo__trigger:hover {
  border-color: var(--accent);
}

.uc-combo__value--active {
  color: var(--text);
}

.uc-combo__arrow {
  display: flex;
  align-items: center;
  transition: transform 0.2s;
}

.uc-combo[aria-expanded="true"] .uc-combo__arrow {
  transform: rotate(180deg);
}

.uc-combo__dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  right: 0;
  background: var(--card);
  border: 1px solid #e4e8f0;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
  z-index: 100;
  max-height: 320px;
  overflow: hidden;
  flex-direction: column;
}

.uc-combo[aria-expanded="true"] .uc-combo__dropdown {
  display: flex;
}

.uc-combo__search-wrap {
  padding: 0.5rem;
  border-bottom: 1px solid #e4e8f0;
}

.uc-combo__search {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid #e4e8f0;
  border-radius: 6px;
  font-size: 0.9rem;
  background: var(--card);
  color: var(--text);
}

.uc-combo__search:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

.uc-combo__list {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-y: auto;
  flex: 1;
}

.uc-combo__group-label {
  padding: 0.5rem 1rem 0.25rem;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  pointer-events: none;
}

.uc-combo__option {
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 0.9rem;
}

.uc-combo__option:hover,
.uc-combo__option--highlighted {
  background: #f0f4ff;
  color: var(--accent);
}

.uc-combo__option--selected {
  font-weight: 600;
  color: var(--accent);
}

/* ===== Result ===== */
.uc-result {
  background: var(--card);
  border: 1px solid #e4e8f0;
  border-radius: 10px;
  padding: 1.25rem;
  margin: 1rem 0;
  text-align: center;
  min-height: 3.5rem;
}

.uc-result__text {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0 0 0.75rem;
  word-break: break-all;
}

.uc-result__text:empty {
  margin: 0;
}

.uc-result__actions {
  gap: 0.5rem;
  justify-content: center;
}

.uc-btn {
  padding: 0.5rem 1rem;
  border-radius: 6px;
  border: 1px solid #e4e8f0;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-size: 0.85rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: background 0.15s;
}

.uc-btn:hover {
  background: #f0f4ff;
}

.uc-btn--copy {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.uc-btn--copy:hover {
  background: #0a5ed7;
}

.uc-format-select {
  padding: 0.4rem 0.5rem;
  border: 1px solid #e4e8f0;
  border-radius: 6px;
  background: var(--card);
  color: var(--muted);
  font-size: 0.8rem;
  cursor: pointer;
  margin-left: auto;
}

.uc-format-select:hover {
  border-color: var(--accent);
}

/* ===== Preset unique content ===== */
.preset-info {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid #e4e8f0;
  line-height: 1.7;
}

.preset-info h2 {
  font-size: 1.3rem;
  margin: 0 0 0.75rem;
}

.preset-info h3 {
  font-size: 1.1rem;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
}

.preset-info p {
  color: var(--text);
  margin: 0 0 0.5rem;
}

.preset-formula code {
  font-size: 1.1rem;
  padding: 0.3rem 0.7rem;
  background: #f0f4ff;
  border-radius: 6px;
  font-weight: 600;
  color: var(--accent);
}

.preset-table-wrap {
  overflow-x: auto;
}

.preset-table {
  width: 100%;
  max-width: 400px;
  border-collapse: collapse;
  margin: 0.75rem 0 0;
  font-size: 0.95rem;
}

.preset-table th {
  text-align: left;
  padding: 0.6rem 1rem;
  background: #f0f4ff;
  color: var(--accent);
  font-weight: 600;
  border-bottom: 2px solid #dce3f0;
}

.preset-table td {
  padding: 0.5rem 1rem;
  border-bottom: 1px solid #e4e8f0;
}

.preset-table tr:last-child td {
  border-bottom: none;
}

.preset-table tr:hover td {
  background: #f8faff;
}

/* ===== SEO section ===== */
.uc-seo {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid #e4e8f0;
  line-height: 1.7;
}

.uc-seo h2 {
  font-size: 1.3rem;
}

.uc-seo h3 {
  font-size: 1.1rem;
  margin-top: 1.5rem;
}

.uc-seo ol {
  padding-left: 1.2rem;
}

.uc-seo ol li {
  margin: 0.4rem 0;
}

/* ===== Responsive ===== */
@media (max-width: 540px) {
  .uc-tool {
    flex-direction: column;
    align-items: stretch;
  }

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

  .uc-swap:active {
    transform: rotate(270deg);
  }

  .uc-result__text {
    font-size: 1.1rem;
  }
}

/* ===== Utility ===== */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}