#main1 {
    display: flex;
    columns:3;
    height: 85vh; /* Set the height of #main1 to 100% of the viewport height */
    margin-top: 7.5vh;
  }
  
  .athird {
    flex: 1; /* Let each div take equal vertical space */
    padding: 10px;
    box-sizing: border-box;
  }
  

  @media only screen and (max-width: 1000px) {
    #main1 {
        display: flex;
        height: 85vh; /* Set the height of #main1 to 100% of the viewport height */
        margin-top: 7.5vh;
      }
      
      .athird {
        flex: 1; /* Let each div take equal vertical space */
        padding: 10px;
        box-sizing: border-box;
      }
      

}