[html] Unordered List (<ul>) default indent

Can anyone tell me why an unordered list has a default indent/padding applied to it? Can this be solved with a CSS Browser Reset?

I'll tackle your second question first. Yes, the indentation can be reset by using a browser reset like Eric Meyers. Or a simple ul { margin: 0; padding: 0;} as indentation is, by default, enforced on the ul element.

As to the why, I suspect its to do with the current level of nesting, as unordered lists allow for nesting or maybe to do with the bullets positioning.

Edit: As Guffa mentioned, the list indentation is to ensure that the markers do not fall off the left edge.

When reseting the "Indent" of the list you have to keep in mind that browsers might have different defaults. To make life a lot easier always start off with a "Normalize" file.

The purpose of using these CSS "Normalize" files is to set everything to a know set of values and not relying on what the browser's defaults. Chrome might have a different set of defaults to say FireFox. This way you know that your pages will always display the same no matter what browser you are using, and you know the values to "Reset" your elements.

Now if you are only concerned about lists in particular I would not simply set the padding to 0, this will put your bullets "Outside" of the list not inside like you would expect.

Another thing to keep in mind is not to use the "px" or pixel unit of measurement, you want to use the "em" unit instead. The "em" unit is based on font-size, this way no matter what the font-size is you are guaranteed that the bullet will be on the inside of the list, if you use a pixel offset then on larger font sizes the bullets will be on the outside of the list.

So here is a snippet of the "Normalize" script I use. First set everything to a known value so you know what to set it back to.

ul{
   margin: 0;
   padding: 1em; /* Set the distance from the list edge to 1x the font size */
   list-style-type: disc;
   list-style-position: outside;
   list-style-image: none;
}

If you don't want indention in your list and also don't care about or don't want bullets, there is the CSS-free option of using a "definition list" (HTML 4.01) or "description list" (HTML 5). Use only the non-indenting definition <dt> tags, but not the indenting description <dd> tags, neither of which produces a bullet.

<dl>
  <dt>Item 1</dt>
  <dt>Item 2</dt>
  <dt>Item 3</dt>
</dl>

The output looks like this:

Item 1
Item 2
Item 3

Most html tags have some default properties. A css reset will help you change the default properties.

What I usually do is:

{ padding: 0; margin: 0; font-face:Arial; }

Although the font is up to you!

I found the following removed the indent and the margin from both the left AND right sides, but allowed the bullets to remain left-justified below the text above it. Add this to your css file:

ul.noindent {
    margin-left: 5px;
    margin-right: 0px;
    padding-left: 10px;
    padding-right: 0px;
}

To use it in your html file add class="noindent" to the UL tag. I've tested w/FF 14 and IE 9.

I have no idea why browsers default to the indents, but I haven't really had a reason for changing them that often.

Typical default display properties for ul

ul {
    display: block;
    list-style-type: disc;
    margin-before: 1em;
    margin-after: 1em;
    margin-start: 0;
    margin-end: 0;
    padding-start: 40px;
}

As to why, no idea.

A reset will most certainly fix this:

ul { margin: 0; padding: 0; }