如何使复选框及其标签一致地跨浏览器对齐

Question

This is one of the minor CSS problems that plagues me constantly. How do folks around Stack Overflow vertically align checkboxes and their labels consistently cross-browser? Whenever I align them correctly in Safari (usually using vertical-align: baseline on the input), they're completely off in Firefox and IE. Fix it in Firefox, and Safari and IE are inevitably messed up. I waste time on this every time I code a form.

Here's the standard code that I work with:

<form>
    <div>
        <label><input type="checkbox" /> Label text</label>
    </div>
</form>

I usually use Eric Meyer's reset, so form elements are relatively clean of overrides. Looking forward to any tips or tricks that you have to offer!

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转载于:https://stackoverflow.com/questions/306252/how-to-align-checkboxes-and-their-labels-consistently-cross-browsers

Answer 1

After over an hour of tweaking, testing, and trying different styles of markup, I think I may have a decent solution. The requirements for this particular project were:

1. Inputs must be on their own line.
2. Checkbox inputs need to align vertically with the label text similarly (if not identically) across all browsers.
3. If the label text wraps, it needs to be indented (so no wrapping down underneath the checkbox).

Before I get into any explanation, I'll just give you the code:

label {
  display: block;
  padding-left: 15px;
  text-indent: -15px;
}
input {
  width: 13px;
  height: 13px;
  padding: 0;
  margin:0;
  vertical-align: bottom;
  position: relative;
  top: -1px;
  *overflow: hidden;
}

<form>
  <div>
    <label><input type="checkbox" /> Label text</label>
  </div>
</form>

Here is the working example in JSFiddle.

This code assumes that you're using a reset like Eric Meyer's that doesn't override form input margins and padding (hence putting margin and padding resets in the input CSS). Obviously in a live environment you'll probably be nesting/overriding stuff to support other input elements, but I wanted to keep things simple.

Things to note:

• The *overflow declaration is an inline IE hack (the star-property hack). Both IE 6 and 7 will notice it, but Safari and Firefox will properly ignore it. I think it might be valid CSS, but you're still better off with conditional comments; just used it for simplicity.
• As best I can tell, the only vertical-align statement that was consistent across browsers was vertical-align: bottom. Setting this and then relatively positioning upwards behaved almost identically in Safari, Firefox and IE with only a pixel or two of discrepancy.
• The major problem in working with alignment is that IE sticks a bunch of mysterious space around input elements. It isn't padding or margin, and it's damned persistent. Setting a width and height on the checkbox and then overflow: hidden for some reason cuts off the extra space and allows IE's positioning to act very similarly to Safari and Firefox.
• Depending on your text sizing, you'll no doubt need to adjust the relative positioning, width, height, and so forth to get things looking right.

Hope this helps someone else! I haven't tried this specific technique on any projects other than the one I was working on this morning, so definitely pipe up if you find something that works more consistently.

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