CSS - box-sizing box model

box-sizingIs a CSS property that specifies the box model type of an element. The box model determines the dimensions of an element and how the effects of borders and padding on those dimensions are calculated.

box-sizingAttributes have two commonly used values:

1. content-box: This is the default value, which specifies that the width and height of the element include only the content area, excluding borders and padding. In other words, when setting the width and height of an element, borders and padding are not included.

2. border-box: This value specifies that the width and height of the element include the border and padding. That is to say, when setting the width and height of the element, the border and padding will also be calculated.

Use box-sizingthe attribute to change the way the box model is calculated, which is useful for web page layout and design. For example, when designing responsively, using border-boxmakes it easier to control the size of elements without having to worry about the impact of borders and padding on size. This approach is also more intuitive for designers and developers because it is more intuitive and convenient.

The box model used box-sizing: border-box;has several advantages:

1. More intuitive layout: Using border-boxthe box model makes it more intuitive to define the dimensions of elements because it includes borders and padding. In this way, when setting the width and height of the element, there is no need to consider the impact of the border and padding on the element size, making the layout more consistent with the design intent.

2. Simplified calculations: Using border-boxthe box model can simplify calculations, especially when using percentages or fixed values ​​for layout. You no longer have to consider the impact of borders and padding on the size of elements, reducing the complexity of the layout process.

3. Responsive design: In responsive design, using border-boxthe box model makes it easier to control the size of elements, especially when dealing with layouts on different screen sizes and devices, making it more flexible to adapt to various situations.

In general, border-boxthe box model can make layout more intuitive, simplify calculations, and is more suitable for responsive design, so it is widely used in actual development.