写CSS的常用套路(兄弟选择符定制表单元素 )

提示：这里最好将input作为label的子元素，这样用户点击label时就能传到input上默认的input太丑怎么办？那就把它先抹掉，用appearance: none或opacity: 0都可以

然后，利用兄弟选择符~来定制和input相邻的所有元素（+号也行，只不过只能选中最近的元素），例如可以用伪元素生成一个新的方框代替原先的input，利用伪类:checked和动画来表示它被勾选后的状态，本质上还是障眼法哦~

HTML:

<form>
  <fieldset class="todo-list">
    <legend class="todo-list__title">My Special Todo List</legend>
    <label class="todo-list__label">
      <input type="checkbox" name="" id="" />
      <i class="check"></i>
      <span>Make awesome CSS animation</span>
    </label>
    <label class="todo-list__label">
      <input type="checkbox" name="" id="" />
      <i class="check"></i>
      <span>Watch awesome bangumi</span>
    </label>
    <label class="todo-list__label">
      <input type="checkbox" name="" id="" />
      <i class="check"></i>
      <span>Encounter awesome people</span>
    </label>
    <label class="todo-list__label">
      <input type="checkbox" name="" id="" />
      <i class="check"></i>
      <span>Be an awesome man</span>
    </label>
  </fieldset>
</form>

CSS:

// color scheme: https://coolors.co/e63946-585b57-7b9fa1-264456-0b1420
@import url("https://fonts.googleapis.com/css?family=Lato:400,400i,700");

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background: #1A1E23;
}

.todo-list {
  display: flex;
  flex-direction: column;
  padding: 0 75px 10px 30px;
  background: #162740;
  border: transparent;

  .todo-list__title {
    padding: 3px 6px;
    color: #f1faee;
    background-color: #264456;
  }

  .todo-list__label {
    display: flex;
    align-items: center;
    margin: 40px 0;
    font-size: 24px;
    font-family: Lato, sans-serif;
    color: #f1faee;
    cursor: pointer;

    input[type="checkbox"] {
      opacity: 0;
      appearance: none;

      & + .check {
        position: absolute;
        width: 25px;
        height: 25px;
        border: 2px solid #f1faee;
        transition: 0.2s;
      }

      &:checked + .check {
        width: 25px;
        height: 15px;
        border-top: transparent;
        border-right: transparent;
        transform: rotate(-45deg);
      }

      & ~ span {
        position: relative;
        left: 40px;
        white-space: nowrap;
        transition: 0.5s;

        &::before {
          position: absolute;
          content: "";
          top: 50%;
          left: 0;
          width: 100%;
          height: 1px;
          background: #f1faee;
          transform: scaleX(0);
          transform-origin: right;
          transition: transform 0.5s;
        }
      }

      &:checked ~ span {
        color: #585b57;

        &::before {
          transform: scaleX(1);
          transform-origin: left;
        }
      }
    }
  }
}