max-width

摘要

max-width 属性用来给元素设置最大宽度值. 定义了max-width的元素会在达到max-width值之后避免进一步按照width属性设置变大.

max-width 会覆盖width设置, 但 min-width设置会覆盖 max-width.

语法

/* <长度> 值 */
max-width: 3.5em;

/* <百分比> 值 */
max-width: 75%;

/* 关键字 */
max-width: none;
max-width: max-content;
max-width: min-content;
max-width: fit-content;
max-width: fill-available;

/* 全局设置 */
max-width: inherit;
max-width: initial;
max-width: unset;

可选值

none

元素未设置最大值

<长度>

请参阅<length>所提及的长度单位.

<百分比>

以父级块级容器宽度的百分比<percentage>作为最大宽度.

max-content

The intrinsic preferred width.

min-content

The intrinsic minimum width.

fill-available

The containing block width minus horizontal margin, border, and padding. Some browsers implement an ancient name for this keyword, available.

fit-content

与max-content等价.

形式语法

<length> | <percentage> | none | max-content | min-content | fit-content | fill-available

例子

在下面的例子里,id为"child"的<div>元素设置了width值, 使它的宽度与父元素"parent"相等(100%),但是max-width值限制了它最大宽度只能到150px.

<div id="parent">
    <div id="child">
        The Mozilla community produces a lot of great software.
    </div>
</div>

#parent { width: 300px; }

#child  { background: gold;
          width: 100%;
          max-width: 150px;
        }

fit-content 值可以用来给元素设置基于其内容大小的宽度:

<div id="parent">
    <div id="child">
        Child Text
    </div>
</div>

#parent { background: lightblue;
          width: 300px; }

#child  { background: gold;
          width: 100%;
          max-width: -moz-fit-content;
          max-width: -webkit-fit-content;
        }

规范

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

[1] CSS 2.1 explicitly leaves the behavior of max-width with <table> undefined. Therefore any behavior is CSS2.1-compliant; newer CSS specifications may define this behavior, so Web developers shouldn't rely on a specific one now.

[2] Gecko experimentally implements the definitions given in CSS3 Basic Box. This one defines available and not fill-available. Also the definition of fit-content is simpler than in CSS3 Sizing.

[3] WebKit implements an earlier proposal for setting the height to an intrinsic height: the keywords intrinsic, instead of max-content, and min-intrinsic, instead of min-content There is no equivalent for fill-available or fit-content.

参考链接

• width, min-width, max-height
• The box model, box-sizing