CSS 2.1 Reference: max-width Property

CSS max-width Property
Syntax	selector {max-width: value ;} value is specified by using a length, percentage, or one of the following keywords: none or inherit.
Usage	The max-width property is used to specify the maximum width of the content area of an element's box. (See CSS Box Model for information concerning the boxes that are generated for elements.) The max-width property does NOT include the width of the padding, border, or margin areas. This property is specified by using a length, percentage, or keyword, according to the syntax shown above. Negative values are not permitted. If a percentage value is used, the value will be a percentage of the containing block. CSS Example: The max-width property is set using a length value. p {max-width: 300px; background-color: yellow;}
Keywords	none - The maximum width is not limited. inherit - The inherit keyword is used to specify that the value for this property should be taken from the parent element. If inherit is used with the root element, then the initial value for this property will be used.
Applies To	In general, this property applies to block-level elements and replaced elements.
Inherited	No
Initial Value	none

max-width Property Examples
The max-width property is set using a length value.