CSS实现可切换图标的开关组件：利用Checkbox状态与可见性控制

<label class="ThemeToggler" for="ThemeTogglerID">
  <input id="ThemeTogglerID" class="ThemeTogglerInput" type="checkbox" data-toggle-theme="dark,light" data-act-class="ACTIVECLASS" checked />
  <div class="ThemeTogglerFill" >
    <div class="SunIcon">
      <!-- 太阳SVG图标代码 -->
      <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" >
        <path d="M12,18c-3.3,0-6-2.7-6-6s2.7-6,6-6s6,2.7,6,6S15.3,18,12,18zM12,8c-2.2,0-4,1.8-4,4c0,2.2,1.8,4,4,4c2.2,0,4-1.8,4-4C16,9.8,14.2,8,12,8z" />
        <path d="M12,4c-0.6,0-1-0.4-1-1V1c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,3.6,12.6,4,12,4z" />
        <path d="M12,24c-0.6,0-1-0.4-1-1v-2c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,23.6,12.6,24,12,24z" />
        <path d="M5.6,6.6c-0.3,0-0.5-0.1-0.7-0.3L3.5,4.9c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C6.2,6.5,5.9,6.6,5.6,6.6z" />
        <path d="M19.8,20.8c-0.3,0-0.5-0.1-0.7-0.3l-1.4-1.4c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C20.3,20.7,20,20.8,19.8,20.8z" />
        <path d="M3,13H1c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S3.6,13,3,13z" />
        <path d="M23,13h-2c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S23.6,13,23,13z" />
        <path d="M4.2,20.8c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C4.7,20.7,4.5,20.8,4.2,20.8z" />
        <path d="M18.4,6.6c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C18.9,6.5,18.6,6.6,18.4,6.6z" />
      </svg>
    </div>
    <div class="MoonIcon">
      <!-- 月亮SVG图标代码 -->
      <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
        <path d="M12.1,22c-0.3,0-0.6,0-0.9,0c-5.5-0.5-9.5-5.4-9-10.9c0.4-4.8,4.2-8.6,9-9c0.4,0,0.8,0.2,1,0.5c0.2,0.3,0.2,0.8-0.1,1.1c-2,2.7-1.4,6.4,1.3,8.4c2.1,1.6,5,1.6,7.1,0c0.3-0.2,0.7-0.3,1.1-0.1c0.3,0.2,0.5,0.6,0.5,1c-0.2,2.7-1.5,5.1-3.6,6.8C16.6,21.2,14.4,22,12.1,22zM9.3,4.4c-2.9,1-5,3.6-5.2,6.8c-0.4,4.4,2.8,8.3,7.2,8.7c2.1,0.2,4.2-0.4,5.8-1.8c1.1-0.9,1.9-2.1,2.4-3.4c-2.5,0.9-5.3,0.5-7.5-1.1C9.2,11.4,8.1,7.7,9.3,4.4z" />
      </svg>
    </div>
  </div>
</label>

$width: 80px;
$height: 44px;
$border-radius: 50px;
$circle-size: $height - 4px;
$icon-size: $circle-size - 2px;
$neutral: red;
$secondary: white;
$base-100: white;
$base-200: gray;
$base-300: black;
$base-content: white;

// 整体开关容器样式
.ThemeToggler {
  width: $width;
  height: $height;
  flex-shrink: 0;
  border-radius: $border-radius;
  background-color: $neutral;
  border: 1px solid $base-100;
  display: inline-block;
  cursor: pointer;
  &:hover {
    border-color: $secondary;
  }
}

// 滑动块的轨道和动画
.ThemeTogglerFill {
  position: relative; // 为内部图标和滑动块定位提供参考
  &:before {
    content: "";
    position: absolute;
    top: 1px;
    left: 1px;
    height: $circle-size;
    width: $circle-size;
    background: $base-300;
    box-shadow: 1px 0px 4px rgba(0, 0, 0, 0.15);
    border-radius: $border-radius;
    transition: background-color 0.25s, transform 0.25s; // 添加动画
  }
}

// 隐藏Checkbox并控制图标显示/隐藏
.ThemeTogglerInput {
  display: none; // 隐藏原始checkbox

  // 当checkbox被选中时，滑动块向右移动
  &:checked ~ .ThemeTogglerFill::before {
    transform: translateX($circle-size);
  }

  // 默认状态（checkbox未选中）：月亮图标隐藏，太阳图标显示
  // `+ .ThemeTogglerFill` 表示紧邻的兄弟元素
  & + .ThemeTogglerFill {
    .MoonIcon {
      visibility: hidden;
    }
    .SunIcon {
      visibility: visible;
    }
  }

  // 当checkbox被选中时：太阳图标隐藏，月亮图标显示
  &:checked + .ThemeTogglerFill {
    .SunIcon {
      visibility: hidden;
    }
    .MoonIcon {
      visibility: visible;
    }
  }
}

// 图标基础样式混合器
@mixin icon {
  position: absolute; // 绝对定位，方便控制图标位置
  display: block;
  width: $icon-size;
  height: $icon-size;
  border-radius: 50%;
  overflow: hidden;
  fill: $base-content; // SVG图标填充色
  transition: visibility 0.25s; // 添加可见性过渡
}

// 太阳图标具体位置
.SunIcon {
  @include icon;
  top: 1.8px;
  left: 1.7px;
}

// 月亮图标具体位置
.MoonIcon {
  @include icon;
  top: 1.8px; // 调整为与太阳图标相同的top值，或根据设计需求调整
  left: $circle-size + 1.7px; // 调整为在右侧显示
}