*{
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
  /* 核心属性：缓动滚动 */
  scroll-padding-top: 20px;
  /* 可选：滚动到锚点时顶部预留间距（避免被导航栏遮挡） */
}
/* header start */
header{
  width: 100%;
  height: 80px;
  background-color: #fdfdfd;
  position: sticky;
  top: 0;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}
header ul{
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: center;
  align-items: center;
}
header ul li{
  list-style: none;
  margin: 0 50px;
}
header ul li a{
  text-decoration: none;
  color: #000;
}
header ul li a:hover{
  color: rgb(167, 0, 0);
}
/* header end */

div{
  width: 100%;
  display: flex;
  justify-content: center;
}
div img{
  width: 100%;
}

footer{
  width: 100%;
  height: 80px;
  background-color: #323232;
}
footer p{
  width: 100%;
  height: 80px;
  line-height: 80px;
  color: #fff;
  text-align: center;
}