ionic-framework/ionic/components/form/label.scss

// Label
// -------------------------------

$input-label-color:         #000 !default;


.input-label {
  display: table;
  padding: 9px 10px 7px 0px;
  max-width: 200px;
  width: 30%;
  min-width: 100px;
  color: $input-label-color;
  font-size: 1.6rem;
  white-space: nowrap;
}

.placeholder-icon {
  color: #aaa;
  &:first-child {
    padding-right: 6px;
  }
  &:last-child {
    padding-left: 6px;
  }
}

.item-stacked-label {
  display: block;
  background-color: transparent;
  box-shadow: none;

  .input-label, .icon {
    display: inline-block;
    padding: 4px 0 0 0px;
    vertical-align: middle;
  }
}

.item-stacked-label input,
.item-stacked-label textarea {
  border-radius: 2px;
  padding: 4px 8px 3px 0;
  border: none;
  background-color: $input-bg;
}
.item-stacked-label input {
  overflow: hidden;
  height: $line-height-computed + $font-size-base + 0.5rem;
}

.item-floating-label {
  display: block;
  background-color: transparent;
  box-shadow: none;

  .input-label {
    position: relative;
    padding: 5px 0 0 0;
    opacity: 0;
    top: 10px;
    transition: opacity .15s ease-in, top .2s linear;

    &.has-input {
      opacity: 1;
      top: 0;
      transition: opacity .15s ease-in, top .2s linear;
    }
  }
}