.container{
   width: 100%;
   overflow: hidden;
   margin: 50px auto;
/*    background: pink; */
}

.photobanner {
    height: 100px;
    width: 1550px;
    margin-bottom: 5px;
    overflow: hidden;
    background: transparent;
  }

  .photobanner img {
    margin-bottom: 10px;
    margin-right: 5px;
    height: 100px;
    max-width: 250px;
    width: 250px;
  }

  .photobanner img {
    transition: all 0.5s ease;
  }

  .first {
    animation: bannermove 10s linear infinite;
  }

  @keyframes bannermove {
    0% {
      margin-left: 0px;
    }
    100% {
      margin-left: -1500px;
    }
  }