vuepress-theme-system/styles/system/forms.css

a vuepress theme

/*
      Forms
-------------------------------
*/

input[type='text'],
input[type='email'],
input[type='search'],
input[type='password'],
input[type='tel'],
select,
textarea,
.input {
  width: 100%;
  border: 0 none;
  background-color: var(--color-alt);
  height: auto;
  color: inherit;
}

select {
  background-image: svg-load(
    './icons/24-chevron-b.svg',
    fill=none,
    stroke= '#666',
    stroke-linecap=round,
    stroke-linejoin=round,
    stroke-miterlimit=10,
    stroke-width=1px
  );
  background-position: right var(--unit-s) center;
  background-repeat: no-repeat;

  /* for FF: http://stackoverflow.com/a/18317228/2112538 */
  -moz-appearance: none;
  text-indent: 0.01px;
  text-overflow: ellipsis;
}

textarea {
  /* http://stackoverflow.com/a/5196591/2112538 */
  vertical-align: top;
  resize: vertical;
}

textarea:focus,
input:focus,
select:focus {
  border-right: var(--unit-s) solid var(--color-highlight);
}

input[type='text'].bg-bg,
input[type='email'].bg-bg,
input[type='search'].bg-bg,
input[type='password'].bg-bg,
input[type='tel'].bg-bg,
select.bg-bg,
textarea.bg-bg {
  background-color: var(--color-bg);
}

input.success {
  border-right: var(--unit-s) solid var(--color-success);
}

input.error {
  border-right: var(--unit-s) solid var(--color-error);
}

input:disabled,
textarea:disabled,
select:disabled,
.input-disabled {
  background-color: color-mod(var(--color-alt) alpha(50%));
}

input.bg-bg:disabled,
textarea.bg-bg:disabled,
select.bg-bg:disabled {
  background-color: color-mod(var(--color-bg) alpha(50%));
}

*::placeholder {
  font-style: italic;
  color: var(--color-neutral);
}