Other Concepts

Cascading Rules

An HTML page is read top-down and hence any CSS included (whether using <link>, <style> tag or style attribute is also read in that order. If properties are redefined, then the values are cascaded, i.e the last encountered value is the one applied.

Vendor Prefixes

Certain browsers implement experimental CSS properties and they have a browser specific vendor prefix.

-webkit-transform: scale(2); // For Safari and Chrome
-ms-transform: scale(2);  // For Internet Explorer
-moz-transform: scale(2); // For Firefox

Sometimes these experimental properties get adopted into CSS and then the vendor prefix gets dropped.

transform: scale(2); // For all browsers

Combining property-value Pairs

Certain hyphenated CSS properties can be combined into one. For example:

margin-top: 10px;
margin-right: auto;
margin-bottom: 20px;
margin-left: auto;

border-width: 1px;
border-style: dotted;
border-color: red;

can be combined as:

margin: 10px auto 20px auto;

border: 1px dotted red;

Other examples include background, padding, list-style, text-decoration, font etc.