css 画一个心

  <div class="app">
    <div class="heart"></div>
  </div>

  .app {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .heart {
    width: 100px;
    height: 100px;
    position: relative;
    background-color: #f00;
    transform: rotate(45deg);
  }

  .heart::before,
  .heart::after {
    position: absolute;
    content: '';
    background-color: #f00;
    top: 0px;
    left: -50%;
    width: 100%;
    height: 100%;
    border-radius: 50%;
  }

  .heart::after {
    left: 0;
    top: -50%;
  }

效果图