select.round {

    /* styling */
    background-color: white;
    border: thin solid blue;
    border-radius: 4px;
    display: inline-block;
    font: inherit;
    line-height: 1.5em;
    padding: 0.5em 3.5em 0.5em 1em;
  
    /* reset */
  
    margin: 0;      
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    -webkit-appearance: none;
    -moz-appearance: none;
  }
select.round {
    background-image:
      linear-gradient(45deg, transparent 50%, gray 50%),
      linear-gradient(135deg, gray 50%, transparent 50%),
      radial-gradient(#ddd 70%, transparent 72%);
    background-position:
      calc(100% - 20px) calc(1em + 2px),
      calc(100% - 15px) calc(1em + 2px),
      calc(100% - .5em) .5em;
    background-size:
      5px 5px,
      5px 5px,
      1.5em 1.5em;
    background-repeat: no-repeat;
  }
  
  select.round:focus {
    background-image:
      linear-gradient(45deg, white 50%, transparent 50%),
      linear-gradient(135deg, transparent 50%, white 50%),
      radial-gradient(gray 70%, transparent 72%);
    background-position:
      calc(100% - 15px) 1em,
      calc(100% - 20px) 1em,
      calc(100% - .5em) .5em;
    background-size:
      5px 5px,
      5px 5px,
      1.5em 1.5em;
    background-repeat: no-repeat;
    border-color: green;
    outline: 0;
  }