2015 update: the flexbox approach
There are two other answers briefly mentioning flexbox; however, that was more than two years ago, and they don't provide any examples. The specification for flexbox has definitely settled now.
Note: Though CSS Flexible Boxes Layout specification is at the Candidate Recommendation stage, not all browsers have implemented it. WebKit implementation must be prefixed with -webkit-; Internet Explorer implements an old version of the spec, prefixed with -ms-; Opera 12.10 implements the latest version of the spec, unprefixed. See the compatibility table on each property for an up-to-date compatibility status.
(taken from https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Flexible_boxes)
All major browsers and IE11+ support Flexbox. For IE 10 or older, you can use the FlexieJS shim.
To check current support you can also see here:
http://caniuse.com/#feat=flexbox
Working example
With flexbox you can easily switch between any of your rows or columns either having fixed dimensions, content-sized dimensions or remaining-space dimensions. In my example I have set the header to snap to its content (as per the OPs question), I've added a footer to show how to add a fixed-height region and then set the content area to fill up the remaining space.
html,
body {
height: 100%;
margin: 0;
}
.box {
display: flex;
flex-flow: column;
height: 100%;
}
.box .row {
border: 1px dotted grey;
}
.box .row.header {
flex: 0 1 auto;
/* The above is shorthand for:
flex-grow: 0,
flex-shrink: 1,
flex-basis: auto
*/
}
.box .row.content {
flex: 1 1 auto;
}
.box .row.footer {
flex: 0 1 40px;
}
<!-- Obviously, you could use HTML5 tags like `header`, `footer` and `section` -->
<div class="box">
<div class="row header">
<p><b>header</b>
<br />
<br />(sized to content)</p>
</div>
<div class="row content">
<p>
<b>content</b>
(fills remaining space)
</p>
</div>
<div class="row footer">
<p><b>footer</b> (fixed height)</p>
</div>
</div>
In the CSS above, the flex property shorthands the flex-grow, flex-shrink, and flex-basis properties to establish the flexibility of the flex items. Mozilla has a good introduction to the flexible boxes model.
Basics
For controlling "cellpadding" in CSS, you can simply use padding on table cells. E.g. for 10px of "cellpadding":
td {
padding: 10px;
}
For "cellspacing", you can apply the border-spacing CSS property to your table. E.g. for 10px of "cellspacing":
table {
border-spacing: 10px;
border-collapse: separate;
}
This property will even allow separate horizontal and vertical spacing, something you couldn't do with old-school "cellspacing".
Issues in IE ≤ 7
This will work in almost all popular browsers except for Internet Explorer up through Internet Explorer 7, where you're almost out of luck. I say "almost" because these browsers still support the border-collapse property, which merges the borders of adjoining table cells. If you're trying to eliminate cellspacing (that is, cellspacing="0") then border-collapse:collapse should have the same effect: no space between table cells. This support is buggy, though, as it does not override an existing cellspacing HTML attribute on the table element.
In short: for non-Internet Explorer 5-7 browsers, border-spacing handles you. For Internet Explorer, if your situation is just right (you want 0 cellspacing and your table doesn't have it defined already), you can use border-collapse:collapse.
table {
border-spacing: 0;
border-collapse: collapse;
}
Note: For a great overview of CSS properties that one can apply to tables and for which browsers, see this fantastic Quirksmode page.
Best Answer
I thought it would be helpful to consolidate the latest information on scroll bars, CSS, and browser compatibility.
Scroll Bar CSS Support
Currently, there exists no cross-browser scroll bar CSS styling definitions. The W3C article I mention at the end has the following statement and was recently updated (10 Oct 2014):
Microsoft
As others have mentioned, Microsoft supports scroll bar styling, but only for IE8 and above.
Example:
Chrome & Safari (WebKit)
Similarly, WebKit now has its own version:
Styling scrollbars: https://www.webkit.org/blog/363/styling-scrollbars/
Demo of all WebKit scroll bar styling
From Custom scrollbars in WebKit, relevant CSS:
Firefox (Gecko)
As of version 64 Firefox supports scrollbar styling through the properties
scrollbar-color(partially, W3C draft) andscrollbar-width(W3C draft). Some good information about the implementation can be found in this answer.Cross-browser Scroll Bar Styling
JavaScript libraries and plug-ins can provide a cross-browser solution. There are many options.
The list could go on. Your best bet is to search around, research, and test the available solutions. I am sure you will be able to find something that will fit your needs.
Prevent Illegal Scroll Bar Styling
Just in case you want to prevent scroll bar styling that hasn't been properly prefixed with "-vendor", this article over at W3C provides some basic instructions. Basically, you'll need to add the following CSS to a user style sheet associated with your browser. These definitions will override invalid scroll bar styling on any page you visit.
Duplicate or Similar Questions / Source Not Linked Above
Note: This answer contains information from various sources. If a source was used, then it is also linked in this answer.