CSS Grid System for Forms (Multi-Column)

Question

First off, do not use a table. Putting form elements in a table does not solve your problem and complicates your maintenance. Using tables to supplement form presentation is a sign of incompetence and complexity. It is also entirely non-semantic. Instead you might actually have to write some CSS. Honestly, if you are going to use tables for non-tabular data then don't even bother using CSS as that multiplies the complexity of maintenance.

Here are some things to keep in mind:

1) Define all your units in "em" units. Most form elements are intended to contain text. Those elements, like text fields and textarea blocks, can be increased and decreased as a feature of accessibility. This means your pixel perfect pretty CSS grid will break the moment a user changes text size on the page.

2) Don't wrap your form element in a div. Like a div, your form is a block level element. Unless the form has peer nodes under a div parent simply direct any presentation directly to the form element and not a parent element that exists only to contain the form.

3) Group your form elements. If you are floating text fields things can get all messed up if the forms are floated independently of their respective label elements. It will be easier to put an ordered list inside your form and then wrap each form element in a list item. This way you only have to worry about defining layout of the label element relative to its form control and then layout of them together by defining presentation of the list item. This method is also semantic and informs text readers of an order upon your form controls.

4) Don't use the !important declaration. This makes for a quick fix in your CSS but completely screws up inheritance and absolutely complicates maintenance. Instead take the extra time to write your code correctly the first time, so that future maintenance is a quick and minor event.

5) Don't use position absolute, unless you really know what you are doing, even if your form is set to position relative. Position absolute results in unexpected behaviors in many cases and unexpected problems.

6) To ensure your CSS code actually defines a true grid use the Firefox MeasureIt plug in. It will help you achieve stunning accuracy and save you incredible time when making your grid.

7) Do everything correctly the first time using as little code as necessary to get the job complete and present your form perfectly. Only then test your form for cross browser accuracy. Make one correction for cross browser accuracy at a time to limit unnecessary bloating to your CSS code.

Something like this may help. This is how I did it on a form. It will take some fine tuning though to make it work at your desired width. This might help you get started though.

The CSS:

.contact ul {margin:0; padding:0; list-style:none;}
.contact li {margin-bottom:10px; overflow:hidden;}
.contact label {display:block; margin-bottom:2px;}
.contact label span {color:#999;}
.contact .input {width:592px; border:1px solid #E0E0E0; background:#F6F6F6;}
.contact select.input {border:1px solid #E0E0E0; background:#F6F6F6;}
.contact .third {float:left; width:193px; margin-right:10px;}
.contact .third .input {width:185px;}
.contact .half {float:left; width:294px; margin-right:10px;}
.contact .half .input {width:286px;}
.contact .half select.input {width:294px;}
.contact .omega {margin-right:0;}

The HTML:

<form action="/contact-us" method="post" class="contact">
    <ul>
        <li>
            <div class="half">
                <label for="name">Name:</label>
                <input type="text" id="name" name="name" class="input" />
            </div>
        </li>
        <li>
            <label for="address">Address:</label>
            <input type="text" id="address" name="address" class="input" />
        </li>
        <li>
            <div class="third">
                <label for="city">City:</label>
                <input type="text" id="city" name="city" class="input" />
            </div>
            <div class="third">
                <label for="state">State:</label>
                <input type="text" id="state" name="state" class="input" />
            </div>
            <div class="third omega">
                <label for="zip">Zip:</label>
                <input type="text" id="zip" name="zip" class="input" />
            </div>
        </li>
    </ul>
</form>

Here's a basic kickoff example which may be of use:

<!doctype html>
<html lang="en">
    <head>
        <style>
            fieldset { width: 400px; padding: 1%; }
            input[type=text], select, textarea { width: 98%; }
            .half { float: left; width: 48%; padding: 1%; }
            .full { clear: both; width: 98%; padding: 1%; }
            .right { text-align: right; }
        </style>
    </head>
    <body>
        <fieldset>
            <legend>Contact form</legend>
            <form>
                <div class="half">
                    <label for="name">Name</label>
                    <input type="text" id="name" name="name">
                </div>
                <div class="half">
                    <label for="email">Email</label>
                    <input type="text" id="email" name="email">
                </div>
                <div class="half">
                    <label for="zip">Zip / Postal code</label>
                    <input type="text" id="zip" name="zip">
                </div>
                <div class="half">
                    <label for="country">Country</label>
                    <select id="country" name="country"><option></option></select>
                </div>
                <div class="full">
                    <label for="message">Message</label>
                    <textarea id="message" name="message"></textarea>
                </div>
                <div class="half">
                    <input type="checkbox" id="copy" name="copy">
                    <label for="copy">Send me a copy</label>
                </div>
                <div class="half right">
                    <input type="submit" value="send">
                </div>
            </form>
        </fieldset>
    </body>
</html>

Note that I am using left-floated div's of half-width instead of unordered list items.

As you insist in using percentages, don't expect it to be pixelperfect in all browsers. If you want to have it all pixelperfect, you really need to use pixels.

I think this is what you are looking for:

http://www.alistapart.com/articles/prettyaccessibleforms/

It should help simplify your structure a little bit. It doesn't explicitly describe how to make multiple column forms, but the technique could probably expand to that with some creativity on your part.

No need for the fluid 960 system here, unless you want the form to expand and contract with the browser.

I would recommend the regular old 960 grid system for this. 960 width is great for grids because it divides evenly by 12 and 16 which allows you to set up pixel perfect three and four column layouts.

The best way to get familiar with the 960 grid system is to look at the souce css and the source of the html demo

<div class="grid_6">
        <p>
            contact form
        </p>
    </div>

<div class="grid_3">
        <p>
            name
        </p>
    </div>

I had to do something similar and ended up setting my half-columns to 46%. It leaves an extra bit of room for the padding and gets all your input fields consistently sized.