.center-div {
  width: 1200px;
  margin: 0 auto; /* 上下外边距为0，左右自动（实现水平居中） */
  /* 可选：如需垂直居中可结合其他属性，比如父元素设置display: flex */
}
.slider {

  width: 100%;
 height: 200px;
  overflow: hidden;
  
}
.slider .slider-row {
  width:  2167px;
  height: 200px;
  background-image: url(gd.jpg);
  background-size: 2167px 200px;
  -webkit-animation: slide 50s linear infinite;
          animation: slide 50s linear infinite;
}

@-webkit-keyframes slide {
  from {
    background-position-x: 0;
  }
  to {
    background-position-x: -2956px;
  }
}

@keyframes slide {
  from {
    background-position-x: 0;
  }
  to {
    background-position-x: -2167px;
  }
}