styling dropdown buttons

by Felis Catus

HTML

<h1>SELECT right-arrow without external image. CSS only</h1>

<select class="classic">
  <option>CSS SELECT arrow (classic)</option>
  <option>No external background image</option>
  <option>No wrapper</option>
</select>
<br><br>
<select class="round">
  <option>CSS SELECT arrow (round)</option>
  <option>No external background image</option>
  <option>No wrapper</option>
</select>
<br><br>
<select class="minimal">
  <option>CSS SELECT arrow (minimal)</option>
  <option>No external background image</option>
  <option>No wrapper</option>
</select>

CSS

select {

  /* 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;
}


/* arrows */

select.classic {
  background-image:
    linear-gradient(45deg, transparent 50%, blue 50%),
    linear-gradient(135deg, blue 50%, transparent 50%),
    linear-gradient(135deg, transparent 50%, blue 50%),
    linear-gradient(45deg, blue 50%, transparent 50%),
    linear-gradient(to right, skyblue, skyblue);
  background-position:
    calc(100% - 20px) calc(1em + 2px),
    calc(100% - 15px) calc(1em + 2px),
    calc(100% - 20px) calc(1em - 5px),
    calc(100% - 15px) calc(1em - 5px),
    100% 0;
  background-size:
    5px 5px,
    5px 5px,
    5px 5px,
    5px 5px,
    2.5em 2.5em;
  background-repeat: no-repeat;
}

select.classic:focus {
  background-image:
    linear-gradient(45deg, white 50%, transparent 50%),
    linear-gradient(135deg, transparent 50%, white 50%),
    linear-gradient(to right, gray, gray);
  background-position:
    calc(100% - 15px) 1em,
    calc(100% - 20px) 1em,
    100% 0;
  background-size:
    5px 5px,
    5px 5px,
    2.5em 2.5em;
  background-repeat: no-repeat;
  border-color: grey;
  outline: 0;
}




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,...