:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --bg: #e8e8ff;
  --card: #ffffff;
  --border: #e2e8f0;
  --text: #1e293b;
  --muted: #64748b;
  --input-bg: #f0e6f6;
  --item-bg: #f1f5f9;
  --danger: #dc2626;
  --disabled: #94a3b8;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05);
  --toast-bg: #1e293b;
  --toast-text: #f8fafc;
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    --bg: #0f172a;
    --card: #1e293b;
    --border: #334155;
    --text: #f1f5f9;
    --muted: #94a3b8;
    --input-bg: #334155;
    --item-bg: #334155;
    --danger: #f87171;
    --disabled: #64748b;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.3);
    --toast-bg: #f1f5f9;
    --toast-text: #0f172a;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Noto Sans TC", "Microsoft JhengHei", "PingFang TC", "Noto Sans CJK TC", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

h1 {
  font-size: 1.75rem;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.subtitle {
  color: var(--muted);
  margin-bottom: 0.4rem;
  font-size: 0.95rem;
  text-align: center;
}

.note {
  color: var(--muted);
  margin-bottom: 1.25rem;
  font-size: 0.8rem;
  line-height: 1.55;
  text-align: center;
  max-width: 520px;
  padding: 0 0.75rem;
  opacity: 0.92;
}

.note[hidden] {
  display: none;
}

.method-switcher {
  display: flex;
  flex-wrap: nowrap;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
  justify-content: center;
  max-width: 100%;
  overflow-x: auto;
  padding-bottom: 4px;
  -webkit-overflow-scrolling: touch;
}

.method-btn {
  padding: 0.5rem 0.9rem;
  min-height: 44px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  border-radius: 999px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  white-space: nowrap;
  flex-shrink: 0;
}

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

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

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

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  width: 100%;
  max-width: 480px;
  box-shadow: var(--shadow);
}

.input-group {
  display: flex;
  gap: 0.6rem;
  margin-bottom: 1.5rem;
  width: 100%;
}

input[type="text"] {
  flex: 1;
  min-width: 0;
  padding: 0.7rem 0.9rem;
  min-height: 44px;
  font-size: 1.15rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  text-align: center;
  background: var(--input-bg);
  color: var(--text);
}

input[type="text"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgb(37 99 235 / 0.15);
}

button#searchBtn {
  padding: 0.7rem 1.2rem;
  min-height: 44px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
  white-space: nowrap;
  flex-shrink: 0;
}

button#searchBtn:hover:not(:disabled) {
  background: var(--primary-hover);
}

button#searchBtn:disabled {
  background: var(--disabled);
  cursor: not-allowed;
}

button#searchBtn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.status {
  text-align: center;
  color: var(--muted);
  margin-bottom: 1rem;
  font-size: 0.9rem;
  min-height: 1.4em;
}

.retry-btn {
  margin-left: 0.5rem;
  padding: 0.2rem 0.6rem;
  font-size: 0.85rem;
  border: 1px solid var(--primary);
  background: transparent;
  color: var(--primary);
  border-radius: 6px;
  cursor: pointer;
}

.retry-btn:hover {
  background: var(--primary);
  color: #fff;
}

.result {
  display: none;
  opacity: 0;
  transition: opacity 0.25s ease;
}

.result.show {
  display: block;
  opacity: 1;
}

.char-display {
  text-align: center;
  font-size: 3rem;
  margin-bottom: 1.25rem;
  line-height: 1.2;
}

.code-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.code-item {
  background: var(--item-bg);
  border-radius: 8px;
  padding: 0.9rem 1rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 1rem;
  cursor: pointer;
  transition: box-shadow 0.15s, transform 0.1s;
  border: 1px solid transparent;
}

.code-item:hover {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgb(37 99 235 / 0.12);
}

.code-item:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.code-item:active {
  transform: scale(0.98);
}

.label {
  font-size: 0.8rem;
  color: var(--muted);
}

.value {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.value.radical {
  font-size: 1.35rem;
  letter-spacing: 0.15em;
}

.not-found {
  text-align: center;
  color: var(--danger);
  padding: 1rem;
}

footer {
  margin-top: 2rem;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
  padding: 0 1rem;
  word-break: break-all;
}

footer a {
  color: var(--primary);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

.unicode-info {
  background: var(--item-bg);
  border-radius: 8px;
  padding: 0.9rem 1rem;
  margin-bottom: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.unicode-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.unicode-item .label {
  font-size: 0.85rem;
  color: var(--muted);
  flex-shrink: 0;
}

.unicode-item .value {
  font-size: 0.95rem;
  font-weight: 600;
  font-family: ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, monospace;
  letter-spacing: 0;
  text-align: right;
  word-break: break-all;
}

.toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--toast-bg);
  color: var(--toast-text);
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: 0 4px 12px rgb(0 0 0 / 0.2);
  z-index: 100;
  animation: toast-in 0.2s ease;
}

.toast[hidden] {
  display: none;
}

@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

@media (max-width: 420px) {
  .method-btn {
    padding: 0.4rem 0.7rem;
    font-size: 0.82rem;
    min-height: 40px;
  }

  input[type="text"] {
    font-size: 1.05rem;
    padding: 0.65rem 0.7rem;
  }

  button#searchBtn {
    padding: 0.65rem 1rem;
    font-size: 0.9rem;
  }

  .char-display {
    font-size: 2.5rem;
  }
}

.code-item.reverse-item {
  grid-template-columns: 1fr 1fr;
  cursor: pointer;
}

.value.reverse-char-value {
  font-size: 1.75rem;
  letter-spacing: 0;
}

.value.reverse-meta {
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0;
  word-break: break-all;
}