CSS3 makes your job a lot easier with it’s new features.
For example creating an input that will highlight on focus with animation is an easy task now with CSS3 in comparison with all the work it would’ve needed with javascript and CSS2.

Style all the inputs, textareas and combo boxes:

input, select, textarea
{
    background: none repeat scroll 0 0 #FFFFFF;
    border-color: #999;
    border-image: none;
    border-radius: 2px;
    border-style: solid;
    border-width: 1px;
    color: #555555;
    transition: border 0.2s linear 0s, box-shadow 0.2s linear 0s;
}

transition: border 0.2s linear 0s, box-shadow 0.2s linear 0s;
This is the line that insures the transition.
You can also use: transition: all 0.2s linear 0s

On focus just change the border color and shadow:

input:focus, select:focus, textarea:focus
{
    border-color:#12799A;
    box-shadow:0 0 3px rgba(18, 121, 154, 0.6);
}