70 Expert Ideas For Better CSS Coding

CSS isn’t always easy to deal with. Depending on
your skills and your experience, CSS coding can sometimes become a
nightmare, particularly if you aren’t sure which selectors are actually
being applied to document elements. An easy way to minimize the
complexity of the code is as useful as not-so-well-known CSS attributes
and properties you can use to create a semantically correct markup.

We’ve taken a close look at some of the most useful CSS tricks,
tips, ideas, methods, techniques and coding solutions and listed them
below. We also included some basic techniques you can probably use in
every project you are developing, but which are hard to find once you
need them.

And what has come out of it is an overview of over 70 expert CSS ideas
which can improve your efficiency of CSS coding. You might be willing
to check out the list of references and related articles in the end of
this post.

We’d like to express sincere gratitude to all designers
who shared their ideas, techniques, methods, knowledge and experience
with their readers. Thank you, we, coders, designers, developers,
information architects - you name it - really appreciate it.

1.1. Workflow: Getting Started

After you have a design, start with a blank page of content.
“Include your headers, your navigation, a sample of the content, and
your footer. Then start adding your html markup. Then start adding your
CSS. It works out much better.” [CSSing]
Use a master stylesheet. “One of the most common
mistakes I see beginners and intermediates fall victim to when it comes
to CSS is not removing the default browser styling. This leads to
inconsistencies in the appearance of your design across browsers, and
ultimately leaves a lot of designers blaming the browser. It is a
misplaced blame, of course. Before you do anything else when coding a
website, you should reset the styling.” [Master Stylesheet: The Most Useful CSS Technique], [Ryan Parr]
```
master.css
@import url(”reset.css”);
@import url(”global.css”);

@import url(”flash.css”);
@import url(”structure.css”);
```
```
<style type="text/css" media="Screen">
/**/@import url("css/master.css");/**/
</style>
```
Reset your CSS-styles first. “You can often
eliminate the need to specify a value for a property by taking
advantage of that property’s default value. Some people like doing a Global white space reset by zeroing both margin and padding for all elements at the top of their stylesheets. [Roger Johansson]
Keep a library of helpful CSS classes. Useful for
debugging, but should be avoided in the release version (separate
markup and presentation). Since you can use multiple class names (i.e. <p class="floatLeft alignLeft width75">...</p>), make use of them debugging your markup. (updated) [Richard K. Miller]
```
CSS:
.width100 { width: 100%; }
.width75 { width: 75%; }
.width50 { width: 50%; }
.floatLeft { float: left; }
.floatRight { float: right; }
.alignLeft { text-align: left; }
.alignRight { text-align: right; }
```
Eric Meyer’s Global Reset, Christian Montoya’s initial CSS file, Mike Rundle’s initial CSS file, Ping Mag’s initial CSS file.

1.2. Organize your CSS-code

Organize your CSS-styles, using master style sheets.
“Organizing your CSS helps with future maintainability of the site.
Start with a master style sheet. Within this style sheet import your reset.css, global.css, flash.css (if needed) and structure.css and on occasion a typography style sheet. Here is an example of a “master” style sheet and how it is embedded in the document:”
```
h2 { }
#snapshot_box h2 {
	padding: 0 0 6px 0;
	font: bold 14px/14px "Verdana", sans-serif; }
#main_side h2 {
	color: #444;
	font: bold 14px/14px "Verdana", sans-serif; }
.sidetagselection h2 {
	color: #fff;
	font: bold 14px/14px "Verdana", sans-serif; }
```
Organize your CSS-styles, using flags. “Divide
your stylesheet into specific sections: i.e. Global Styles – (body,
paragraphs, lists, etc), Header, Page Structure, Headings, Text Styles,
Navigation, Forms, Comments, Extras. [5 Tips for Organizing Your CSS]
```
/* -----------------------------------*/
/* ---------->>> GLOBAL <<<-----------*/
/* -----------------------------------*/
```
Organize your CSS-styles, making a table of contents.
At the top of your CSS document, write out a table of contents. For
example, you could outline the different areas that your CSS document
is styling (header, main, footer etc). Then, use a large, obvious
section break to separate the areas. [5 Steps to CSS Heaven]
Organize your CSS-styles, ordering properties alphabetically.
“I don’t know where I got the idea, but I have been alphabetizing my
CSS properties for months now, and believe it or not, it makes specific
properties much easier to find.” [Christian Montoya]
```
body {
	background: #fdfdfd;
	color: #333;
	font-size: 1em;
	line-height: 1.4;
	margin: 0;
	padding: 0;
}
```
Separate code into blocks.. “This might be common
sense to some of you but sometimes I look at CSS and it’s not broken
down into “sections.” It’s easy to do an it makes working with code
weeks, months, or years later much easier. You’ll have an easier time
finding classes and elements that you need to change. Examples: /* Structure */, /* Typography */ etc.” [CSS Tips and Tricks]
Hook, line, and sinker. Once you have your CSS and
sections in place start considering where your selector “hooks” will
live by using structural hooks in your mark up. This is your saving
grace for future editing and maintenance of the site. This will also
give you strength in your document.” [Ryan Parr]
Break your style sheet in separate blocks. “I
break down my style sheet into three separate blocks. The first is
straight element declarations. Change the body, some links styles, some
header styles, reset margins and padding on forms, and so on. […] After
element declarations, I have my class declarations; things like classes
for an error message or a callout would go here. [..] I start by
declaring my main containers and then any styles for elements within
those containers are indented. At a quick glance, I can see how my page
is broken down and makes it easier to know where to look for things.
I’ll also declare containers even if they don’t have any rules.” [Jonathan Snook]

1.3. Workflow: Handling IDs, Classes, Selectors, Properties

Keep containers to a minimum. “Save your document
from structural bloat. New developers will use many div’s similar to
table cells to achieve layout. Take advantage of the many structural
elements to achieve layout. Do not add more div’s. Consider all options
before adding additional wrappers (div’s) to achieve an effect when
using a little nifty CSS can get you that same desired effect.” [Ryan Parr]
Keep properties to a minimum. “Work smarter, not
harder with CSS. Under this rule, there are a number of subrules: if
there isn’t a point to adding a CSS property, don’t add it; if you’re
not sure why you’re adding a CSS property, don’t add; and if you feel
like you’ve added the same property in lots of places, figure out how
to add it in only one place.” [CSSing]
Keep selectors to a minimum. “Avoid unnecessary
selectors. Using less selectors will mean less selectors will be needed
to override any particular style — that means it’s easier to
troubleshoot.” [Jonathan Snook]
Keep CSS hacks to a minimum. “Don’t use hacks
unless its a known and documented bug. This is an important point as I
too often see hacks employed to fix things that aren’t really broken in
the first place. If you find that you are looking for a hack to fix a
certain issue in your design then first do some research (Google is
your friend here) and try to identify the issue you are having problems
with. [10 Quick Tips for an easier CSS life]
Use CSS Constants for faster development. “The
concept of constants – fixed values that can be used through your code
[is useful]. [..] One way to get round the lack of constants in CSS is
to create some definitions at the top of your CSS file in comments, to
define ‘constants’. A common use for this is to create a ‘color
glossary’. This means that you have a quick reference to the colors
used in the site to avoid using alternates by mistake and, if you need
to change the colors, you have a quick list to go down and do a search
and replace.” [Rachel Andrew]
```
# /*
# Dark grey (text): #333333
# Dark Blue (headings, links) #000066
# Mid Blue (header) #333399
# Light blue (top navigation) #CCCCFF
# Mid grey: #666666
# */
```
Use a common naming system. Having a naming system
for id’s and classes saves you a lot of time when looking for bugs, or
updating your document. Especially in large CSS documents, things can
get a big confusing quickly if your names are all different. I
recommend using a parent_child pattern. [10 CSS Tips]
Name your classes and IDs properly, according to their semantics.
“We want to avoid names that imply presentational aspects. Otherwise,
if we name something right-col, it’s entirely possible that the CSS
would change and our “right-col” would end up actually being displayed
on the left side of our page. That could lead to some confusion in the
future, so it’s best that we avoid these types of presentational naming
schemes. [Garrett Dimon]
Group selectors with common CSS declarations.
“Group selectors. When several element types, classes, or id:s share
some properties, you can group the selectors to avoid specifying the
same properties several times. This will save space – potentially lots
of it.” [Roger Johansson]
Isolate single properties that you are likely to reuse a lot.
“If you find yourself using a single property a lot, isolate it to save
yourself repeating it over and over again and also enabling you to
change the display of all parts of the site that use it.” [5 Steps to CSS Heaven]
Move ids and class naming as far up the document tree as you can. Leverage contextual selectors
as much as possible. Don’t be afraid to be verbose in your selectors.
Longer selectors can make css documents easier to read while also
cutting down the chances of developing class- or divitis. [Chric Casciano]
Learn to exploit the cascading nature of CSS. “Say
you have two similar boxes on your website with only minor differences
- you could write out CSS to style each box, or you could write CSS to
style both at the same time, then add extra properties below to make
one look different.” [5 Steps to CSS heaven]
Use Your Utility Tags: <small>, <em> and <strong>.
“Many times you’ll have a section in your design that calls for various
typographical weights/looks all on the same line, or very close to each
other. drop in random divs and classes because I feel they’re not
semantic and defeat the purpose of your nice XHTML everywhere else.”
Instead, use semantic tags. [Mike Rundle’s 5 CSS Tips]

1.4. Workflow: Use shorthand notation

Shorten hexadecimal colour notation. “In CSS, when
you use hexadecimal colour notation and a colour is made up of three
pairs of hexadecimal digits, you can write it in a more efficient way
by omitting every second digit: #000 is the same as #000000, #369 is the same as #336699 [Roger Johansson]
Define pseudo classes for links in the LoVe/HAte-order:
Link, Visited, Hover, Active. “To ensure that you see your various link
styles, you’re best off putting your styles in the order
“link-visited-hover-active”, or “LVHA” for short. If you’re concerned
about focus styles, they may go at the end– but wait until you’ve read
this explanation before you decide.” [Eric Meyer]
```
a:link { color: blue; }
a:visited { color: purple; }
a:hover { color: purple; }
a:active { color: red; }
```
Define element’s margin, padding or border in TRouBLed-order:
Top, Right, Bottom, Left. “When using shorthand to specify an element’s
margin, padding or border, do it clockwise from the top: Top, Right,
Bottom, Left.” [Roger Johansson]

You can use shorthand properties. “Using shorthand for margin, padding and border properties can save a lot of space.

CSS:
margin: top right bottom left;
margin: 1em 0 2em 0.5em;
(margin-top: 1em; margin-right: 0; margin-bottom: 2em; margin-left: 0.5em;)

CSS:
border: width style color;
border: 1px solid #000;

CSS:
background: color image repeat attachment position;
background: #f00 url(background.gif) no-repeat fixed 0 0;

CSS:
font: font-style (italic/normal) font-variant (small-caps) font-weight font-size/line-height font-family;
font: italic small-caps bold 1em/140% “Lucida Grande”,sans-serif;

1.5. Workflow: Setting Up Typography

To work with EMs like with pxs, set font-size on the body-tag with 62.5%. Default-value of the font-size
is 16px; applying the rule, you’ll get one Em standing for roughly ten
pixels (16 x 62.5% = 10). “I tend to put a font-size on the body tag
with value: 62.5%. This allows you to use EMs to specify sizes while
thinking in PX terms, e.g. 1.3em is approximately 1.3px. ” [Jonathan Snook]
Use universal character set for encoding. “[..]
The answer is to use a single universal character set that’s able to
cover most eventualities. Luckily one exists: UTF-8, which is based on
Unicode. Unicode is an industry standard that’s designed to enable text
and symbols from all languages to be consistently represented and
manipulated by computers. UTF- 8 should be included in your web page’s
head like this. [20 pro tips]
```
<meta http-equiv="content-type" content="text/ html;charset=utf-8" />
```
You can change capitalisation using CSS. If you
need something written in capitals, such as a headline, rather than
rewriting the copy, let CSS do the donkey work. The following code will
transform all text with an h1 attribute into all capitals, regardless
of format”. [20 pro tips]
```
h1 {
	text-transform: uppercase;
}
```
You can display text in small-caps automatically. The font-variant
property is used to display text in a small-caps font, which means that
all the lower case letters are converted to uppercase letters, but all
the letters in the small-caps font have a smaller font-size compared to
the rest of the text.
```
h1 {
	font-variant: small-caps;
}
```
Cover all the bases - define generic font-families.
“When we declare a specific font to be used within our design, we are
doing so in the hope that the user will have that font installed on
their system. If they don’t have the font on their system, then they
won’t see it, simple as that. What we need to do is reference fonts
that the user will likely have on their machine, such as the ones in
the font-family property below. It is important that we finish the list
with a generic font type. [Getting into good coding habits]
```
p {
	font-family: Arial, Verdana, Helvetica, sans-serif;
}
```
Use 1.4em - 1.6em for line-height. “line-height:1.4”
for readable lines, reasonable line-lengths that avoid lines much
longer than 10 words, and colors that provide contrast without being too
far apart. For example, pure black on pure white is often too strong
for bright CRT displays, so I try to go with an off-white (#fafafa is a good one) and a dark gray (#333333, another good one).” [Christian Montoya]
Set 100.01% for the html-element.
This odd 100.01% value for the font size compensates for several
browser bugs. First, setting a default body font size in percent
(instead of em) eliminates an IE/Win problem with growing or shrinking
fonts out of proportion if they are later set in ems in other elements.
Additionally, some versions of Opera will draw a default font-size of
100% too small compared to other browsers. Safari, on the other hand,
has a problem with a font-size of 101%. The current “best” suggestion
is to use the 100.01% value for this property.” [CSS: Getting into good habits]

1.6. Workflow: Debugging

Add borders to identify containers. “Use plenty of test styles like extra borders or background colors when building your documents or debugging layout issues. div { border:1px red dashed; } works like a charm. There are also bookmarklets that apply borders and do other things for you.” You can also use * { border: 1px solid #ff0000; }. [Chric Casciano]. Adding a border to specific elements can help identify overlap and extra white space that might not otherwise be obvious. [CSS Crib Sheet]
```
* { border: 1px solid #f00; }
```
Check for closed elements first when debugging.
“If you ever get frustrated because it seemed like you changed one
minor thing, only to have your beautiful holy-grail layout break, it
might be because of an unclosed element. [10 CSS Tips]

2.1. Technical Tips: IDs, Classes

1 ID per page, many classes per page. “Check your
IDs: Only one element in a document can have a certain value for the id
attribute, while any number of elements can share the same class name.
[..] Class and id names can only consist of the characters [A-Za-z0-9]
and hyphen (-), and they cannot start with a hyphen or a digit (see
CSS2 syntax and basic data types).” [Roger Johansson]
Element names in selectors are case sensitive.
“Remember case sensitivity. When CSS is used with XHTML, element names
in selectors are case sensitive. To avoid getting caught by this I
recommend always using lowercase for element names in CSS selectors.
Values of the class and id attributes are case sensitive in both HTML
and XHTML, so avoid mixed case for class and id names.” [Roger Johansson]
CSS classes and IDs must be valid. “I.e. beginning with a letter, not a number or an underscore. IDs must be unique. Their names should be generic, describe functionality rather than appearance.” [CSS Best Practices]
You can assign multiple class names to a given element.
“You can assign multiple class names to an element. This allows you to
write several rules that define different properties, and only apply
them as needed.” [Roger Johansson]

2.2. Technical Tips: Use the power of selectors

Roger Johansson has written an extremely useful series of articles about CSS 2.1 Selectors. These articles are highly recommended
to read - some useful aspects can be found in the list below. Note that
selectors ‘>’ and ‘+’ aren’t supported in IE6 and earlier versions
of Internet Explorer (updated).

You can use child selectors. “A child selector
targets an immediate child of a certain element. A child selector
consists of two or more selectors separated by a greater than sign,
“>”. The parent goes to the left of the “>”, and whitespace is
allowed around the combinator. This rule will affect all strong
elements that are children of a div element. [Roger Johansson]
```
div > strong { color:#f00; }
```
You can use adjacent sibling selectors. An
adjacent sibling selector is made up of two simple selectors separated
by a plus sign, “+”. Whitespace is allowed around the adjacent sibling
combinator. The selector matches an element which is the next sibling
to the first element. The elements must have the same parent and the
first element must immediately precede the second element. [Roger Johansson]
```
p + p { color:#f00; }
```

You can use attribute selectors. Attribute
selectors match elements based on the presence or value of attributes.
There are four ways for an attribute selector to match:

[att]
Matches elements that have an att attribute, regardless of its value.
[att=val]
Matches elements that have an att attribute with a value of exactly “val”.
[att~=val]
Matches elements whose att attribute value is a space-separated list that contains “val”. In this case “val” cannot contain spaces.
[att|=val]
Matches elements whose att attribute value is a hyphen-separated list that begins with “val”. The main use for this is to match language subcodes specified by the lang attribute (xml:lang in XHTML), e.g. “en”, “en-us”, “en-gb”, etc.

The selector in the following rule matches all p elements that have a title attribute, regardless of which value it has:
```
p[title] { color:#f00; }
```
The selector matches all div elements that have a class attribute with the value error:
```
div[class=error] { color:#f00; }
```
Multiple attribute selectors can be used in the same selector. This
makes it possible to match against several different attributes for the
same element. The following rule would apply to all blockquote elements
that have a class attribute whose value is exactly “quote”, and a cite
attribute (regardless of its value):
```
blockquote[class=quote][cite] { color:#f00; }
```
You should use descendant selectors. “Descendant
selectors can help you eliminate many class attributes from your markup
and make your CSS selectors much more efficient. ” [Roger Johansson]

2.3. Technical Tips: Styling Links

Be careful when styling links if you’re using anchors. “If you use a classic anchor in your code (<a name="anchor">) you’ll notice it picks up :hover and :active pseudo-classes. To avoid this, you’ll need to either use id for anchors instead, or style with a slightly more arcane syntax: :link:hover, :link:active” [Dave Shea]

Define relationships for links. “The rel attribute is supposed to indicate a semantic link relationship from one resource to another.

a[rel~="nofollow"]::after {
	content: "2620";
	color: #933;
	font-size: x-small;
}
a[rel~="tag"]::after {
	content: url(http://www.technorati.com/favicon.ico);
}

“These make use of the attribute selector for space separated lists
of values. Any a element with a relationship containing those values
will be matched. Links with the nofollow relationship will be followed
by a dark red skull and crossbones (?) and those with the tag
relationship will be followed by the Technocrati icon.” [Handy CSS]
You can mark external links automatically. Many people make use of the non-standard rel="external"
relationship to indicate a link to an external site. However, adding
that to each and every link is time consuming and and unnecessary. This
style rule will place an north east arrow after any link on your site
to an external site. [Handy CSS]
```
a[href^="http://"]:not([href*="smashingmagazine.com"])::after {
	content: "2197";
}
```
You can remove dotted links with outline: none;. To remove dotted links use outline: none;
```
a:focus {
	outline: none;
}
```

2.4. Technical Tips: CSS-Techniques

You can specify body tag ID. “In most cases
placing an ID in the body tag will allow you manipulate CSS
presentational items and markup elements by page by page basis. Not
only will you be able to organize your sections you will be able to
create multiple CSS presentations without changing your markup from
template to template or page to page.” [Ryan Parr, Invasion of Body Switchers]
You can create columns with equal heights with CSS. Equal Height Technique: a method to make all columns appear to be the same height. But without the need for faux column style background images. Faux Columns: with background images.
You can align vertically with CSS. “Say you have a
navigation menu item whose height is assigned 2em. Solution: specify
the line height to be the same as the height of the box itself in the
CSS. In this instance, the box is 2em high, so we would insert
line-height: 2em into the CSS rule and the text now floats in the
middle of the box!” [Evolt.org]
You can use pseudo-elements and classes to generate content dynamically. Pseudo-classes and pseudo-elements.
Pseudo-classes and pseudo-elements can be used to format elements based
on information that is not available in the document tree. For example,
there is no element that refers to the first line of a paragraph or the
first letter of an element’s text content. You can use :first-child,
:hover, :active, :focus, :first-line, :first-letter, :before, :after
and more.
You can set <hr> to separate posts beautifully. “Restyling the horizontal rule (<hr>) with an image can be a beautiful addition to a web page. [CSS: Best Practices]
You can use the same navigation (X)HTML-code on every page.
“Most websites highlight the navigation item of the user’s location in
the website. But it can be a pain as you’ll need to tweak the HTML code
behind the navigation for each and every page. So can we have the best
of both worlds?” [Ten More CSS Tricks you may not know]
```
XHTML:
<ul>
<li><a href=”#” class=”home”>Home</a></li>
<li><a href=”#” class=”about”>About us</a></li>

<li><a href=”#” class=”contact”>Contact us</a></li>
</ul>
```
Insert an id into the <body> tag.
The id should be representative of where users are in the site and
should change when users move to a different site section.
```
CSS:
#home .home, #about .about, #contact .contact
{
	commands for highlighted navigation go here
}
```
You can use margin: 0 auto; to horizontally centre the layout. “To horizontally centre an element with CSS, you need to specify the element’s width and horizontal margins.” [Roger Johansson]
```
XHTML:
<div id=”wrap”>
<!– Your layout goes here –>
</div>
```
```
CSS:
#wrap {
width:760px; /* Change this to the width of your layout */

margin:0 auto;
}
```
You can add CSS-styling to RSS-feeds. “You can do
a lot more with an XSL stylesheet (turn links into clickable links,
etc), but CSS can make your feed look much less scary for the
non-technical crowd. [Pete Freitag]
```
<?xml version="1.0" ?>
<?xml-stylesheet type="text/css" href="http://you.com/rss.css" ?>

...
```
You can hide CSS from older browsers. “A common way of hiding CSS files from old browsers is to use the @import trick. [Roger Johansson]
```
@import "main.css";
```
Always declare margin and padding in block-level elements. [10 CSS Tips]
Set a width OR margin and padding. “My rule of
thumb is, if I set a width, I don’t set margin or padding. Likewise, if
I’m setting a margin or padding, I don’t set a width. Dealing with the
box model can be such a pain, especially if you’re dealing with
percentages. Therefore, I set the width on the containers and then set
margin and padding on the elements within them. Everything usually
turns out swimmingly.” [Jonathan Snook]
Avoid applying padding/borders and a fixed width to an element.
“IE5 gets the box model wrong, which really makes a mess of things.
There are ways around this, but it’s best to side-step the issue by
applying the padding to the parent element instead of the child that
gets a fixed-width. [CSS Crib Sheet]

Provide print styles. “You can add a print stylesheet in exactly the same way that you would add a regular stylesheet to your page:

<link rel="stylesheet" type="text/css" href="print.css" media="print">
or
<style type=”text/css” media=”print”> @import url(print.css); </style>

This ensures that the CSS will only apply to printed output and not
affect how the page looks on screen. With your new printed stylesheet
you can ensure you have solid black text on a white background and
remove extraneous features to maximise readability. More about CSS-based print-Layouts. [20 pro tips]

2.5. Technical Tips: IE Tweaks

You can force IE to apply transparence to PNGs.
“In theory, PNG files do support varied levels of transparency;
however, an Internet Explorer 6 bug prevents this from working
cross-browser.” [CSS Tips, Outer-Court.com]

#regular_logo
{
	background: url('test.png'); width:150px; height:55px;
}
/*  */
* html #regular_logo
{
	background:none;
	float:left;
	width:150px;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='test.png', sizingMethod='scale');
}
/* */

You can define min-width and max-width in IE. You can use Microsoft’s dynamic expressions to do that. [Ten More CSS Trick you may not know]

#container
{
	min-width: 600px;
	max-width: 1200px;
	width:expression(document.body.clientWidth < 600? "600px" : document.body.clientWidth > 1200? "1200px" : "auto");
}

You can use Conditional Comments for IE. “The safest way of taking care of IE/Win is to use conditional comments.
It feels more future-proof than CSS hacks – is to use Microsoft’s
proprietary conditional comments. You can use this to give IE/Win a
separate stylesheet that contains all the rules that are needed to make
it behave properly. ” [Roger Johansson]
```

```