#myform{
    display: flex;
  }
  #myform input[type=text]{
    padding: 5px 15px;
    border-top: 1px solid #bbb;
    border-left: 1px solid #bbb;
    border-bottom: 1px solid #bbb;
    border-right: none;
  }
  #myform input[type=text]:first-of-type{
    border-top-left-radius: 4px;
    border-bottom-left-radius: 4px;
  }
  #myform input[type=text]:last-of-type{
    border-right: 1px solid #bbb;
  }
  #myform button {
    padding: 5px 15px;
    border-right: 1px solid #537EA5;
    border-top: 1px solid #537EA5;
    border-bottom: 1px solid #537EA5;
    border-left: none;
    border-top-right-radius: 4px;
    border-bottom-right-radius: 4px;
    background-color: #5C97BF;
    color: #fff;
  }