CSS Tips and tricks

Images floating right or left

http://www.tizag.com/cssT/float.php

Descendant selectors

We address this case by supplementing the previous rules with a rule that sets the text color to blue whenever an EM occurs anywhere within an H1:

h1 { color: red }
em { color: red }
h1 em { color: blue }

The third rule will match the EM in the following fragment:

<H1>This <SPAN class="myclass">headline 
is <EM>very</EM> important</SPAN></H1>

Child selectors

A child selector matches when an element is the child of some element. A child selector is made up of two or more selectors separated by ">".

body > P { line-height: 1.3 }

div ol>li p

Box Model

Each box has a content area (e.g., text, an image, etc.) and optional surrounding padding, border, and margin areas; the size of each area is specified by properties defined below. The following diagram shows how these areas relate and the terminology used to refer to pieces of margin, border, and padding:

The margin, border, and padding can be broken down into top, right, bottom, and left segments (e.g., in the diagram, "LM" for left margin, "RP" for right padding, "TB" for top border, etc.).

The perimeter of each of the four areas (content, padding, border, and margin) is called an "edge", so each box has four edges:

content edge or inner edge

The content edge surrounds the rectangle given by the width and height of the box, which often depend on the element's rendered content. The four content edges define the box's content box.

padding edge

The padding edge surrounds the box padding. If the padding has 0 width, the padding edge is the same as the content edge. The four padding edges define the box's padding box.

border edge

The border edge surrounds the box's border. If the border has 0 width, the border edge is the same as the padding edge. The four border edges define the box's border box.

margin edge or outer edge

The margin edge surrounds the box margin. If the margin has 0 width, the margin edge is the same as the border edge. The four margin edges define the box's margin box.

Each edge may be broken down into a top, right, bottom, and left edge.

'margin-top', 'margin-right', 'margin-bottom', 'margin-left'

      UL { 
        background: yellow; 
        margin: 12px 12px 12px 12px;
        padding: 3px 3px 3px 3px;
      }