body{
  font-family: system-ui, -apple-system, "Noto Sans TC", sans-serif;
  padding: 20px;
}

.tabs{
  display: flex;
  gap: 6px;
  margin-bottom: 12px;
}

.tab{
  border: 1px solid #bbb;
  background: #e9e9e9;
  padding: 8px 10px;
  cursor: pointer;
}

.tab.is-active{
  background: #333;
  color: #fff;
  border-color: #333;
}

.panel{
  border: 1px solid #ccc;
  background: #f5f5f5;
  padding: 12px;
  display: none; /* 標準 tabs：只顯示 active */
}

.panel.is-active{
  display: block;
}