:root {
  --base-font-size: 18pt;
  --bg: #ffffff;
  --text: #1a1a1a;
  --border: #cccccc;
  --border-focus: #4a4a4a;
  --accent: #333333;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans JP", sans-serif;
  font-size: var(--base-font-size);
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 32px 24px 64px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* トップバー / ログアウト */
.topbar {
  display: flex;
  justify-content: flex-end;
  max-width: 900px;
  margin: 0 auto;
  padding: 12px 24px 0;
}

.logout-btn {
  font-family: "Noto Sans JP", sans-serif;
  font-size: 0.8rem;
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--accent);
  cursor: pointer;
}

.logout-btn:hover {
  background: #f2f2f2;
}

/* ログイン画面 */
.login-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
  width: 100%;
  max-width: 360px;
}

.login-input {
  font-family: "Noto Sans JP", sans-serif;
  font-size: 1rem;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
}

.login-input:focus {
  outline: none;
  border-color: var(--border-focus);
}

.enter-btn {
  font-family: "Noto Sans JP", sans-serif;
  font-size: 1rem;
  font-weight: 500;
  padding: 12px 14px;
  border: 1px solid var(--border-focus);
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  transition: opacity 0.15s;
}

.enter-btn:hover {
  opacity: 0.88;
}

.enter-btn:disabled {
  opacity: 0.5;
  cursor: default;
}

.login-error {
  min-height: 1.2em;
  margin: 0;
  font-size: 0.85rem;
  color: #c0392b;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
}

.field-label {
  font-size: 1rem;
  font-weight: 500;
}

.text-box {
  width: 100%;
  font-family: "Noto Sans JP", sans-serif;
  font-size: 1rem;
  line-height: 1.5;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  resize: vertical;
  background: #fff;
  color: var(--text);
}

.text-box:focus {
  outline: none;
  border-color: var(--border-focus);
}

/* 上下矢印 */
.swap-row {
  display: flex;
  justify-content: center;
  padding: 4px 0;
}

.swap-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: #fff;
  color: var(--accent);
  cursor: pointer;
  transition: background 0.15s, transform 0.15s;
}

.swap-btn:hover {
  background: #f2f2f2;
}

.swap-btn:active {
  transform: scale(0.94);
}

/* 変換ボタン */
.convert-row {
  display: flex;
  justify-content: center;
  padding: 12px 0 8px;
}

.convert-btn {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  padding: 12px 20px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fff;
  color: var(--accent);
  cursor: pointer;
  transition: background 0.15s, transform 0.15s;
}

.convert-btn:hover {
  background: #f2f2f2;
}

.convert-btn:active {
  transform: scale(0.96);
}

.convert-label {
  font-size: 0.9rem;
  font-weight: 500;
}

/* アコーディオン */
.accordion {
  margin-top: 24px;
  width: 100%;
}

.accordion details {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.accordion-title {
  font-size: 1rem;
  font-weight: 500;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  user-select: none;
}

.accordion-title::-webkit-details-marker {
  display: none;
}

.accordion-title::before {
  content: "▶";
  display: inline-block;
  margin-right: 10px;
  font-size: 0.8em;
  transition: transform 0.15s;
}

.accordion details[open] .accordion-title::before {
  transform: rotate(90deg);
}

.accordion-body {
  padding: 8px 16px 16px;
  border-top: 1px solid var(--border);
}

.accordion-placeholder {
  color: #888;
  margin: 8px 0;
}

/* 変換エラー（赤文字） */
.convert-error {
  min-height: 1.4em;
  margin: 4px 0 0;
  text-align: center;
  font-size: 0.9rem;
  color: #c0392b;
  word-break: break-all;
}

/* 入れ子アコーディオン */
.sub-accordion {
  border: 1px solid var(--border);
  border-radius: 6px;
  margin: 8px 0;
  overflow: hidden;
}

.sub-title {
  font-size: 0.95rem;
  font-weight: 500;
  padding: 10px 14px;
  cursor: pointer;
  list-style: none;
  user-select: none;
  background: #fafafa;
}

.sub-title::-webkit-details-marker {
  display: none;
}

.sub-title::before {
  content: "▶";
  display: inline-block;
  margin-right: 8px;
  font-size: 0.75em;
  transition: transform 0.15s;
}

.sub-accordion[open] > .sub-title::before {
  transform: rotate(90deg);
}

.sub-count {
  color: #999;
  font-size: 0.8em;
  font-weight: 400;
}

.sub-body {
  padding: 10px 14px;
  border-top: 1px solid var(--border);
}

.char-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.char-cell {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 2em;
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  background: #fff;
}