I would search the forum for "css"
In doing so I found this example...
viewtopic.php?f=40&t=6391&p=65205&hilit=css#p65205I know there are other code examples that have text boxes with different sizes.
Also always look at others code examples if you can and even better have an esp module for quickly trying out others examples. Even if you don't hook up any inputs or outputs, etc. you can learn a LOT by just loading and running someones code example and taking a look at the resultant web page on the esp module.
hope this helps (I'm no CSS expert)
dwight