Into the CSS

CSS Comments

Comments are used to explain the code, and may help when you edit the source code at a later date. Comments are ignored by browsers. A CSS comment starts with /* and ends with */

Example:

        
/* This is a single-line comment */

p {
  color: red;
}
        
    

Box Model

• Content - The content of the box, where text and images appear
• Padding - Clears an area around the content. The padding is transparent
• Border - A border that goes around the padding and content
• Margin - Clears an area outside the border. The margin is transparent

Width and Height of an Element

In order to set the width and height of an element correctly in all browsers, you need to know how the box model works.

Important: When you set the width and height properties of an element with CSS, you just set the width and height of the content area. To calculate the full size of an element, you must also add padding, borders and margins.

The total width of an element should be calculated like this:

Total element width = width + left padding + right padding + left border + right border + left margin + right margin


The total height of an element should be calculated like this:

Total element height = height + top padding + bottom padding + top border + bottom border + top margin + bottom margin

        
 div {
  width: 320px;
  padding: 10px;
  border: 5px solid gray;
  margin: 0;
}