-
默認值
- left top right bottom width height: 默認值爲 auto
- margin padding: 默認值爲 0
-
百分比參照於誰
- width margin padding: 包含塊的width
- height: 包含塊的height
- left: 包含塊的width
- top: 包含塊的height
-
width: auto與width: 100%區別
- width: auto
子元素(包括content+padding+border+margin)撐滿整個父元素的content區域。
子元素有margin、border、padding時,會減去子元素content區域相對應的width值
父元素的content = 子元素(content + padding + border + margin )
- width: 100%
強制將子元素的content區域 撐滿 父元素的content區域
子元素有margin、border、padding時,不改變子元素content區域的width,而是溢出父盒子,保持原有值
父元素的content = 子元素的content
簡單的例子:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>test</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
.box {
margin:50px auto;
width: 400px;
border: 3px solid red;
padding: 0 50px;
}
.box1 {
width: auto;
height: 100px;
background: pink;
padding: 0 50px;
margin: 0 50px;
border-width: 0 50px;
border-style: solid;
border-color: green;
}
.box2 {
width: 100%;
height: 100px;
background: gold;
padding: 0 50px;
margin: 0 50px;
border-width: 0 50px;
border-style: solid;
border-color: green;
}
.box3 {
width: 100px;height: 100px;background: orange;
}
.box4 {
float: left;
width: 50px;height: 50px;background: pink;
}
</style>
</head>
<body>
<div class="box">
<div class="box1"></div>
<div class="box2"></div>
</div>
</body>
</html>