See this JSFiddle
input[type="text"]_x000D_
{_x000D_
border: 0;_x000D_
border-bottom: 1px solid red;_x000D_
outline: 0;_x000D_
}
_x000D_
<form>_x000D_
<input type="text" value="See! ONLY BOTTOM BORDER!" />_x000D_
</form>
_x000D_