advanced css troubleshooting

orHow to Become a Super CSS Detective in 4 Easy Steps

Denise R. JacobsThe Code Project

Boost Virtual SummitMay 25, 2011

Advanced CSS Advanced CSS Troubleshooting & EfficiencyTroubleshooting & Efficiency

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Twitter Mysteries, Solved!

Who: @denisejacobs

Where: @thecodeproject #CPVTS

What: #cssts

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Whodunnit? I did!

CSSDetectiveGuide.com

InterActWithWebStandards.com

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CSS De-what?

• Preventive/defensive coding

– Focused & efficient

• Can quickly and easily identify and solve problems when they come up

http://www.flickr.com/photos/spotrick/4028499019/

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I can haz trubbleshootin?

Strong troubleshooting skills are one of your best allies in solving CSS “mysteries”…and they also make you feel practically invicincible.

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The 4 Easy Steps

1) Lay the foundation

2) Target your styles

3) Squash browser bugs

4) Employ useful tools

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Lay the Foundation1)

http://www.flickr.com/photos/pgoyette/2280685630/

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Why?A solid CSS foundation of best practices creates an environment where preventing and detecting problems is easier.

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The Foundations1. Set a Baseline

2. Micro-Optimize

3. Macro-Optimize

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Create a Baseline

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Foundation 1: Create a Baseline1. The CSS Reset All-star

2. DIY Resets

3. CSS Reset Compendia

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Why Reset?By deliberately establishing an element’s properties, you can:

• Better control the elements on the page

• More quickly determine the source of problems when they arise

• Ensure better cross-browser compatibility

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CSS Reset All-Star: Eric Meyer’s Pro’s

– One of the most popular, well thought-out– Neutralizes almost every element

Con’s– Can be too far-reaching– Extra work to establish the values for the

elements you want

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Resource: Eric Meyer’s ResetEric Meyer’s Reset:

http://meyerweb.com/eric/tools/css/reset/

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DIY Resets• You can determine exactly which elements

you want to reset

• May save on reestablishing properties

• You know exactly what is changed and why you changed it

• Problems will be that much more obvious

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Top Properties to Reset• Margin and padding

• Borders, especially on linked images

• Link text underlining

• Vertical alignment

• Font size and line-height

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Resource: DIY Resets

Article on DIY resets: http://bit.ly/1D4jSB

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Resource: CSS Reset Compendia

Killer Collection of CSS Resets

http://tinyurl.com/5bdoj2

More Killer CSS Resets

http://tinyurl.com/n746dl

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Micro-Optimize

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Why Micro-Optimize?• Cuts down file size

• Speeds up page load time

• Encourages best practices

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Foundation 2: Micro-Optimize1. Order: alpha

2. Length: short

3. Speed: fast

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Micro-optimize: Alphabetize

Putting your CSS declarations in alphabetical order is a great way to set the stage for clean code and fewer problems. Why? Because your style declarations will be that much easier to target and locate.

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Find “width” - which is easier?Example One:.login {margin-top: 5px;line-height: 1.5em;padding-left: 5px;float: right;list-style-type: none;

width: 80px;font-weight: bold;border-left: 1px solid #69824d;

}

Example Two:.login {border-left: 1px solid #69824d;

float: right;font-weight: bold;line-height: 1.5em;list-style-type: none;

margin-top: 5px;padding-left: 5px;width: 80px;}

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Find “width” - which is easier?Example One:.login {margin-top: 5px;line-height: 1.5em;padding-left: 5px;float: right;list-style-type: none;

width: 80px;font-weight: bold;border-left: 1px solid #69824d;

}

Example Two:.login {border-left: 1px solid #69824d;

float: right;font-weight: bold;line-height: 1.5em;list-style-type: none;

margin-top: 5px;padding-left: 5px;width: 80px;}

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Micro-optimize: SpeedUp the efficiency:

• ID selectors are speedier than element or universal*

• Drop element qualifiers

• Ditch descendent selectors when and where you can

*conflicts with reduce, reuse, & recycle, however

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Micro-Optimization in ActionPre-optimization:#wrapper div#sidebar {background: #fff url(bg.png) repeat-x 0 0;

border: 1px solid #ff0;font: normal 1.33em/1.33 Georgia, serif;margin: 10px 20px;padding: .1em;}

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Micro-Optimization in ActionPost-optimization :#sidebar {background: #fff url(bg.png) repeat-x 0 0;


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Micro-Optimize Your CSS: LengthLess is more:

• Use shortest properties and values (shorthand)

• Avoid duplicate properties

• Condense values and units

• Avoid multiple lines and indenting

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Micro-Optimization in ActionExample:#sidebar {background: #fff url(bg.png) repeat-x 0 0;


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Shorthand: to remember• Default values

• Shorthand property syntax

• Required property values

• Property value order

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Micro-Optimize: LengthLess is more:





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border: 1px solid red;font: normal 1.33em/1.33 Georgia, serif;margin: 10px 20px;padding: .1em;}

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Resource: CSS Optimizers

http://www.cleancss.com

http://www.codebeautifier.com

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Macro-Optimize

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Why Macro-Optimize?Solo: Helps you remember your intentions when you come back to your code.

With others:Helps your colleagues understand your intentions when working with your code.

Ergo:Saves time!

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Foundation 3: Macro-Optimize1. Practice proper nesting

2. Annotate with comments

3. Reduce, reuse, recycle

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Why get your nest in order?Block-level elements inside inline elements as well as improper closing and reopening of elements can create major layout issues.

Validation often won’t help you find the culprit.

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Macro-optimize: Get your nest in order<body><div id="pagewrap"><div id="header"><h1>Website Title</h1><ul id="navigation"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a href="#">Contact</a></li></ul><div id="contentwrap"><div id="maincontent"><h2>Main Content Title</h2><p>Main content, which is so much more important than the secondary

content that it makes one teary with emotion.</p></div><div id="secondarycontent"><h3>Sidebar Title</h3><p>Sidebar content, which is not as important as the primary content

(which is why it is in the sidebar)</p></div><div id="footer"><p>standard copyright and footer information</p></div></body>

<body><div id="pagewrap">

<div id="header"><h1>Website Title</h1>

<ul id="navigation"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a href="#">Contact</a></li></ul>

</div>

<div id="contentwrap"><div id="maincontent"><h2>Main Content Title</h2><p>Main content, which is so much more important than

the secondary content that it makes one teary with emotion.</p>

</div>

<div id="secondarycontent"><h3>Sidebar Title</h3><p>Sidebar content, which is not as important as the

primary content (which is why it is in the sidebar)</p></div>

</div>

<div id="footer"><p>standard copyright and footer information</p>

</div></div></body>

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Why Annotate Your Code?Markup:

Helps you keep track of the element beginning and end, and helps you identify the pieces faster.

CSS:

Helps both you and others know intentions and specific information.

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Macro-optimize: Annotate Your Markup

begin with 

end with or, alternatively

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Macro-optimize: Annotate Your Markup

Example:<div id="content"><div class="promo">...</div>

</div>

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Macro-optimize: Annotate Your CSS/* Comments are good, mmkay? */

Notation is your friend. For:

• Overriding styles

• Creating stylesheet sections

• Listing the color scheme

• Resources and contact info.

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Macro-optimize: Annotate Your CSS/* made by you on some date */

/* section of the stylesheet */p {border-color: #cf0;border-color-bottom: #ccc; /*this property overrides the previous one */

}

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Why Reduce, Reuse, & Recycle?• Cuts down file size

• Speeds up page load time

• Encourages best practices

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Macro-optimize: Reduce• Identify content patterns

• Use classes instead of ids & elements

• Define defaults

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• Define defaults

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Classes, not IDs<ul id="navmain"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a href="#">Contact</a></li>

</ul>

<ul class="nav"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a href="#">Contact</a></li></ul>

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• Define defaults

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Define DefaultsNot this:#maincontent h1 {...}#maincontent #callout

h2 {...}

But rather this:h1, .h1 {...}h2, .h2 {...}

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Macro-optimize: Reuse• Leverage the cascade and avoid specificity

• Generify your classes

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Leverage the CascadeNot this:html body .nav .hd{...}

or .headerofheadsectionofpage {...}

Instead this:.nav .hd {...}

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Macro-optimize: Reuse• Leverage the cascade and avoid specificity

• Generify your classes

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Class generi-ficationnot.sidebar {...}

instead.module {...}

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Macro-optimize: Recycle• Combine classes

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Class-combininghtml<ul id="navmain"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a

href="#">Contact</a></li></ul>

<ul id="navfoot"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a


css#navmain {(other styles);background-color: green;}#navfoot {(other styles);background-color: black;}

html<ul class="nav main"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a


<ul class="nav foot"><li><a href="#">Home</a></li><li><a href="#">About</a></li><li><a


css.nav {(other styles);}.main {background-color:

green;}.foot {background-color:

black;}

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Resources: OOCSShttp://www.stubbornella.org/content/2009/02

/28/object-oriented-css-grids-on-github/

https://github.com/stubbornella/oocss

http://www.typesett.com/2010/01/object-oriented-css-oocss-the-lowdown/

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Target Your Styles2)

http://www.flickr.com/photos/bhenak/2664680892/

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Why?Having a plan for targeting elements helps speed and efficiency – in both creating and fixing styles.

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How to Hit the Mark1. Technique

2. Selective Specificity

3. Advanced Selectors

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Technique

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My Fave Targeting Technique

outline: 1px solid red;

Why?• outline does not add to dimensions of the

element

• Color names used only for troubleshooting

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Resource: the outline property

http://reference.sitepoint.com/css/outline/

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Selective Specificity

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Specificity Rules!Using selective specificity, you can create selectors that will zero in on your desired element(s), but you’ve got to do it by the rules.

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A little specificity review1. Weight rules

2. Specificity best practices

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Super-Simplified SpecificityThe more specific the selector is, the higher the

specificity

#id: can only be one on the page = high specificity (100)

.class: can be multiple, but not everywhere = medium specificity (10)

element: lots on the page = low specificity (1)

* : everything on the page = no specificity (0)

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Specificity Best Practices• Don’t rely too heavily on specificity – leverage as

many reusable selectors as possible

• Use the cascade and source order so that you don’t have to get too specific

• Trust specificity over source order in terms of which style will win and get applied

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Advanced Selectors

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Getting AdvancedAdvanced selectors are a good way to specifically target styles for modern browsers.

The right selector will help you achieve targeting nirvana, so it’s important to know which selectors you can use now.

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Let’s peek at1. CSS2 Selectors

• browser support

2. CSS3 Selectors • browser support

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CSS 2.1 Selectors• Universal *

• Child CombinatorE > F

• Adjacent/Sibling CombinatorE + F

• Attribute E[~attribute]

• At Rules– @font-face– @media– @page– @charset

• Pseudo elements– :before– :after

• State pseudo-classes– Dynamic

• :hover• :active• :focus

– Language• :lang

– Structural• :first-child

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CSS2.1 Selectors & IE Support• Universal * (ie7/8 – yes)• Child: e > f (ie7/8 – yes)• Sibling/Adjacent: e + f (ie7 no, ie8 – yes)• Attribute: e[attribute] (ie7/8 – yes)• Pseudo elements (ie7/8 – no)

– ::before– ::after

• State pseudo-classes, v2.1– :first-child (ie7/8 – yes)– :hover (ie7/8 – yes)– :active (ie7/8 – yes)– :focus (ie7/8 – no)– :lang (ie7/8 – no)

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CSS2 Selector Support

http://www.quirksmode.org/compatibility.html

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CSS3 Selectors• General sibling

E ~ F

• Attribute presence– a[attribute="value"]

– a[attribute~="value"]

– a[attribute|="value"]

• Attribute substrings– a[attribute^="value"]

– a[attribute$="value"]

– a[attribute*="value"]

• Pseudo-elements*

*all pseudo-elements indicated with :: in CSS3

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CSS3 Selectors (cont’d)• Pseudo-classes

– Target• :target

– Negation• :not(s)

– State• :enabled

• :disabled

• :checked

• :indeterminate

– Structural• :nth-child(n)

• :nth-last-child(n)

• :nth-of-type(n)

• :nth-last-of-type(n)

• :last-child

• :first-of-type

• :last-of-type

• :only-child

• :only-of-type

• :empty

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http://www.findmebyip.com/litmus

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http://www.standardista.com/css3/css3-selector-browser-support

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Resources: nth-child testers

http://leaverou.me/demos/nth.html

http://css-tricks.com/examples/nth-child-tester/

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Advanced Selectors: Usage Tips• All of the CSS2 selectors are supported by the

modern browsers, and almost all of the CSS3 ones are, so use them!

• It’s easy to target styles away from the IEs, but target them to the IEs with simpler combinatorselectors

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Uses for advanced selectors• Great for progressive enhancement

• Styling first, last or x-number of elements

• Styling generated content

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Squash Browser Bugs3)

http://www.flickr.com/photos/slappytheseal/3687999392/

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Gettin’ Buggy With ItDespite your best efforts towards clean, efficient, optimized code, browsers will always have issues that throw a wrench in the works.

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Achieving Cross-browser Compatibility

1. Decide on your approach to deal with IE6

2. Target other browsers

3. Know IE 7 & IE 8 bugs

4. Know Firefox bugs

5. Know Webkit bugs

6. Know Opera bugs

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Deal with IE6

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Dealing with IE6 (Still? Yes, still.)Whether it’s by force or by choice, you need to know how you are going to deal with IE6 until it’s completely gone.

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The IE6 Deathwatch

ie6countdown.com

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Approaches for IE6Options:

• Kick it to the curb

• Display tolerant indifference

• Show some love: be graceful in your degradation

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Kicked: Go home IE6!

http://www.flickr.com/photos/robotjohnny/3629069606/

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Kicked: IE6, get stuffed.

http://tumblr.9gag.com/post/285107173

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Kicked: IE6, I just won’t support you.

In IE6In modern browsers

paulcarbo.net

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Tolerance: IE6? Meh.

http://www.flickr.com/photos/rickharris/430890004/

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Tolerance: Serve stripped-down style

makephotoshopfaster.com


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Resource: Universal IE CSS

Universal IE6 stylesheet: http://code.google.com/p/universal-ie6-css/

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Tolerance: Make a helpful suggestion

http://yaronschoen.com/blog/sudden_metanoia


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Resource: BrowseSad.com

browsesad.com

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Tolerance: Limit Your Support

http://gowalla.com

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Show an old IE browser some love

http://www.flickr.com/photos/brunkfordbraun/391876102/

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Graceful IE6 Degradation• Serve IE6 targeted properties with conditional

comments– display: inline– zoom: 1

• Use the * html hack

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Showin’ love, with grace

aposd.org


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Targeting Other Browsers

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Other browser hacksThere are “hacks” to target styles to specific browsers,

other than the IEs if you really want to use them…

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Resource: Hacks for Other Browsershttp://paulirish.com/2009/

browser-specific-css-hacks/

http://htmlcsstutorials.blogspot.com/2009/06/web-browser-hacks-css-hacks-ie-firefox.html

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Some IE7 & IE8 Bugs

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IE7 is color buggin’color and background-color with rgba

The problem:

An rgba color is correctly set to override the rgbfor the IEs , but the rgb color doesn’t show up at all.

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IE7 is color buggin’The solution:Use the shorthand property backgroundinstead of background-color

OR

Use a hexidecimal color instead of rgb, and then continue the override with rgba.

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IE7 is color buggin’Example:div {

background: rgb(200, 54, 54); /* fallback color */

background: rgba(200, 54, 54, 0.5);}OR

div {background-color: #fd7e7e;background-color: rgba(255,0,0,0.5);

}

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IE7 & IE8 are both font buggin’@font-face super bullet-proofing

The problem:

@font-face doesn’t work, even with the proper normal syntax. What gives?

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Solution: IE7 & IE8 font issuesExample:@font-face {font-family: 'MyFontFamily';src: url('myfont-webfont.eot?#iefix‘) format('embedded-opentype'), url('myfont-webfont.woff') format('woff'), url('myfont-webfont.ttf')format('truetype'),url('myfont-webfont.svg#svgFontName') format('svg');}

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A Webkit Bug

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Get Your Webkit Bug On@font-face bold and italics “bug”

The problem:

Applying font-weight: bold or font-style: italic to @font-face'd text doesn’t work.

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Get Your Webkit Bug OnThe solution:Add the value normal to font weight, style, and variant in the @font-face declaration to set a baseline.

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@font-face + faux variationsExample:@font-face {font-family: 'MyFontFamily';src: url('myfont-webfont.eot?#iefix‘) format('embedded-opentype'),

url('myfont-webfont.woff') format('woff'), url('myfont-webfont.ttf')format('truetype'),

url('myfont-webfont.svg#svgFontName') format('svg');

font-weight:normal;font-style:normal;font-variant:normal;}

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A Firefox Bug

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Firefox? Buggin’.The Outline Overflow Bug

The problem:

Firefox will draw an outline around the content of an element that has overflowed its boundaries rather than around the element’s actual set dimensions.

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Firefox? Buggin’.The Outline Overflow Bug

A solution:

Use border instead and adjust the dimensions of the element.

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An Opera Bug

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An Ode to Opera BugsHiding elements bug

The problem:

When hiding elements offscreen for image replacement, etc. em units are not recognized.

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An Ode to Opera BugsThe solution:Use px instead of em

Example:h2 {margin-left: -4999px;}

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Have the Proper Tools4)

http://www.flickr.com/photos/ebarney/3348965637/

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Tools rockHaving a strong arsenal of tools helps with workflow, removes guesswork, and makes life a ton easier.

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Tools: Browser support charts

http://www.findmebyip.com/litmus

http://www.standardista.com/css3/css3-selector-browser-support

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Tools: CSS SpecificationsThe CSS3 Specifications are THE resource

for finding out the exact intended behavior and use of any given property.

http://www.w3.org/standards/techs/css#w3c_all

129

Tools: ValidatorsHTML:

http://validator.w3.org/

CSS:

http://jigsaw.w3.org/css-validator/

130

Tools: CSS Redundancy Checkershttp://www.sitepoint.com/

dustmeselectors/

(Firefox extension)

http://code.google.com/p/css-redundancy-checker/

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Tools: CSS Compressorshttp://www.csscompressor.com

http://www.cssdrive.com/index.php/main/csscompressoradvanced/

132

RecapTaking all of these steps:

1. Lay the foundation

2. Target your styles

3. Squash browser bugs

4. Have the proper tools

Will yield:

1. Code that is easier to read and find problems in

2. Speed of use and in use

3. Finding solutions faster

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And you’ll become...

…one baaad CSS detectin’ mutha!

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Resources

http://delicious.com/denisejacobs/csstroubleshoot/

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The CSS Detective Guide

CSSDetectiveGuide.comtwitter.com/cssdetective

Want even more tips? Get the book!

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InterAct With Web Standards:A Holistic Approach to Web Design

InterActWithWebStandards.comtwitter.com/waspinteract

Web design, served up holistically

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Thank You!

denisejacobs.com

[email protected]

twitter.com/denisejacobs

slideshare.net/denisejacobs

http://www.flickr.com/photos/aarronwalter/4629076165/

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“It’s elementary, my dear Watson.”

advanced css troubleshooting

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