.full-banner {
    all: unset;              /* 重置所有继承样式，隔离外部影响 */
    display: block;
    width: 100%;
    margin: 0;
    padding: 0;
    line-height: 0;         /* 消除行内元素底部间隙 */
    font-size: 0;           /* 双保险消除间隙 */
    overflow: hidden;
  }
  .full-banner img {
    display: block;
    width: 100%;
    height: auto;
    margin: 0;
    padding: 0;
    border: 0;
  }