The border of the box model is the line surrounding the content and filler. You can set the thickness and style of this line and color (three attributes of the border).
For example, the following code is for a div to set a border with a border thickness of 2px, a solid style, and a red color:
div{ border:2px solid red;}
The above is the abbreviation of the border code The form can be written separately:
div{ border-width:2px; border-style:solid; border-color:red;}
Note:
1. Border-style (border style) common styles are:
dashed (dashed line) | dotted (dotted line) | solid (solid line).
2. The color in border-color (border color) can be set to hexadecimal color, such as:
border-color:#888;//前面的井号不要忘掉。
3. border-width ( The width in border width) can also be set to:
thin | medium | thick (but not very commonly used), and pixels (px) are most commonly used.
The distance between the element content and the border can be set, which is called "padding". Filling can also be divided into upper, right, lower and left (clockwise). The following code:
div{padding:20px 10px 15px 30px;}
Do not mix up the order. You can write the above code separately:
div{ padding-top:20px; padding-right:10px; padding-bottom:15px; padding-left:30px;}
If the top, right, bottom, and left padding are all 10px; you can write like this
div{padding:10px;}
If the top and bottom padding is the same 10px, and the left and right padding is the same 20px, you can write it like this:
div{padding:10px 20px;}
The distance between an element and other elements can be set using margins. The boundaries can also be divided into upper, right, lower and left. The following code:
div{margin:20px 10px 15px 30px;}
can also be written separately:
div{ margin-top:20px; margin-right:10px; margin-bottom:15px; margin-left:30px;}
If the upper, right, lower and left borders are both 10px; ok Write like this:
div{ margin:10px;}
If the upper and lower borders are the same 10px, and the left and right borders are the same 20px, you can write like this:
div{ margin:10px 20px;}
Summary Let’s look at the difference between padding and margin. Padding is inside the border and margin is outside the border.
The width and height of the box model are the same as what we usually call objects Width and height are understood differently. The width and height defined in CSS refer to the content range within the padding.
So the actual width of an element (the width of the box) = left border, left border, left padding, content width, right padding, right border, right border.
The same goes for the height of the element.
For example:
css code:
div{ width:200px; padding:20px; border:1px solid red; margin:10px; }
html code:
<body> <div>文本内容</div></body>
The actual length of the element is: 10px 1px 20px 200px 20px 1px 10px=262px. You can view the element box model under the chrome browser, as shown below: