.key-buttons {
  margin-bottom: 12px;
}

.key-buttons button {
  background: #eee;
  border: 1px solid #bbb;
  border-radius: 6px;
  padding: 6px 10px;
  margin: 3px;
  cursor: pointer;
  font-size: 14px;
}

.key-buttons button:hover {
  background: #ddd;
}

.key-buttons button.active {
  background: #77848f;
  color: white;
  border-color: #1e88e5;
  font-weight: 600;
}

.tabs {
  margin-bottom: 10px;
}

.tabs .tab {
  background: #eee;
  border: 1px solid #aaa;
  padding: 6px 12px;
  cursor: pointer;
}

.tabs .tab.active {
  background: #1e88e5;
  color: white;
  font-weight: bold;
}

.key-buttons button.active {
  background: #1e88e5;
  color: white;
}


body {
  margin: 0;
  padding: 0;
  font-family: system-ui, sans-serif;
}

#sheet-container {
  width: 100%;
  overflow-x: auto;
}

#sheet {
  width: 100%;
}

.key-buttons, .tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
}

.tab, .key-buttons button {
  flex: 1 0 auto;
  min-width: 90px;
}

.transposition-table {
  border-collapse: collapse;
  margin: 10px auto;
  font-size: 16px;
  border: 2px solid #888;
}

.transposition-table th,
.transposition-table td {
  border: none;
  border-bottom: 1px solid #bbb;
  padding: 10px 24px;
  text-align: center;
}

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

.transposition-table th {
  background: #1e88e5;
  color: white;
  font-weight: bold;
  border-bottom: 2px solid #888;
}

.transposition-table tr:nth-child(even) {
  background: #f5f5f5;
}

.transposition-table tr:hover {
  background: #e3f2fd;
}

.transposition-table .arrow {
  color: #888;
  padding: 0 72px;
  font-size: 24px;
}

.transposition-table .arrow span {
  display: block;
  transform: scaleX(6);
}