To change the box model of an element, the most common method is to use the box-sizing property. 1. Set box-sizing: border-box; the element width and height can include content, padding and border; 2. All elements and pseudo-elements can be set globally through the wildcard selector to use the border-box model; 3. Note that this attribute is not inherited by child elements, and compatibility conflicts with third-party components must be considered. For example, the total width of the div under .box { width: 200px; padding: 20px; border: 5px solid #333; box-sizing: border-box; } is still 200px.
To change the box model of an element, the most common method is to use the box-sizing property of CSS. By default, most elements use the content-box model, but you can change it to border-box to control width and height more easily.
Use box-sizing attribute
This is the most direct and effective way. You just need to set the target element:
box-sizing: border-box;
After this setting, the width and height of the element will include content, padding and border, and will not increase the overall size by adding padding or border.
for example:
<div class="box">Content</div>
Corresponding CSS:
.box {
width: 200px;
padding: 20px;
border: 5px solid #333;
box-sizing: border-box;
}The total width of this div is still 200px, not 200 20 2 5 2 = 250px.
Globally modify the box model of all elements
If you want the entire website to use border-box uniformly, you can set it up at once using the wildcard selector:
* {
box-sizing: border-box;
}However, it sometimes affects the behavior of some third-party components or special elements. So a safer approach is:
*, *::before, *::after {
box-sizing: border-box;
}This ensures that the same box model is applied to the pseudo-elements as well.
Pay attention to compatibility and inheritance issues
-
box-sizingproperty is well supported in modern browsers, including IE8 (partially supported by IE8). - It will not be inherited by the child element, which means that even if the parent element has
box-sizing: border-box, the child element may still use the defaultcontent-boxunless set separately. - If you have strict dimension requirements when developing responsive layouts or component libraries, it is recommended to always set
box-sizingexplicitly to avoid unexpected dimension changes.
Basically that's it. Although it is just a small property, reasonable use can save a lot of calculation and layout problems.
The above is the detailed content of How do you change the box sizing model for an element?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
How to change text color in CSS?
Jul 27, 2025 am 04:25 AM
To change the text color in CSS, you need to use the color attribute; 1. Use the color attribute to set the text foreground color, supporting color names (such as red), hexadecimal codes (such as #ff0000), RGB values (such as rgb(255,0,0)), HSL values (such as hsl(0,100%,50%)), and RGBA or HSLA with transparency (such as rgba(255,0,0,0.5)); 2. You can apply colors to any element containing text, such as h1 to h6 titles, paragraph p, link a (note the color settings of different states of a:link, a:visited, a:hover, a:active), buttons, div, span, etc.; 3. Most
How to purge unused CSS?
Jul 27, 2025 am 02:47 AM
UseautomatedtoolslikePurgeCSSorUnCSStoscanandremoveunusedCSS;2.IntegratepurgingintoyourbuildprocessviaWebpack,Vite,orTailwind’scontentconfiguration;3.AuditCSSusagewithChromeDevToolsCoveragetabbeforepurgingtoavoidremovingneededstyles;4.Safelistdynamic
What is a stacking context?
Jul 27, 2025 am 03:55 AM
Astackingcontextisaself-containedlayerinCSSthatcontrolsthez-orderofoverlappingelements,wherenestedcontextsrestrictz-indexinteractions;itiscreatedbypropertieslikez-indexonpositionedelements,opacity
How to use the CSS backdrop-filter property?
Aug 02, 2025 pm 12:11 PM
Backdrop-filter is used to apply visual effects to the content behind the elements. 1. Use backdrop-filter:blur(10px) and other syntax to achieve the frosted glass effect; 2. Supports multiple filter functions such as blur, brightness, contrast, etc. and can be superimposed; 3. It is often used in glass card design, and it is necessary to ensure that the elements overlap with the background; 4. Modern browsers have good support, and @supports can be used to provide downgrade solutions; 5. Avoid excessive blur values and frequent redrawing to optimize performance. This attribute only takes effect when there is content behind the elements.
Describe different CSS units and when to use them
Jul 27, 2025 am 04:24 AM
In web development, the choice of CSS units depends on design requirements and responsive performance. 1. Pixels (px) are used to fix sizes such as borders and icons, but are not conducive to responsive design; 2. Percentage (%) is adjusted according to the parent container, suitable for streaming layout but attention to context dependence; 3.em is based on the current font size, rem is based on the root element font, suitable for elastic fonts and unified theme control; 4. Viewport units (vw/vh/vmin/vmax) are adjusted according to the screen size, suitable for full-screen elements and dynamic UI; 5. Auto, inherit, initial and other values are used to automatically calculate, inherit or reset styles, which helps to flexibly layout and style management. The rational use of these units can improve page flexibility and responsiveness.
How to style links in CSS?
Jul 29, 2025 am 04:25 AM
The style of the link should distinguish different states through pseudo-classes. 1. Use a:link to set the unreached link style, 2. a:visited to set the accessed link, 3. a:hover to set the hover effect, 4. a:active to set the click-time style, 5. a:focus ensures keyboard accessibility, always follow the LVHA order to avoid style conflicts. You can improve usability and accessibility by adding padding, cursor:pointer and retaining or customizing focus outlines. You can also use border-bottom or animation underscore to ensure that the link has a good user experience and accessibility in all states.
What are user agent stylesheets?
Jul 31, 2025 am 10:35 AM
User agent stylesheets are the default CSS styles that browsers automatically apply to ensure that HTML elements that have not added custom styles are still basic readable. They affect the initial appearance of the page, but there are differences between browsers, which may lead to inconsistent display. Developers often solve this problem by resetting or standardizing styles. Use the Developer Tools' Compute or Style panel to view the default styles. Common coverage operations include clearing inner and outer margins, modifying link underscores, adjusting title sizes and unifying button styles. Understanding user agent styles can help improve cross-browser consistency and enable precise layout control.
How to center text in CSS?
Jul 27, 2025 am 03:16 AM
Use text-align:center to achieve horizontal centering of text; 2. Use Flexbox's align-items:center and justify-content:center to achieve vertical and horizontal centering; 3. Single-line text can be vertically centered by setting line-height equal to the container height; 4. Absolute positioning elements can be combined with top: 50%, left: 50% and transform:translate (-50%, -50%) to achieve centering; 5. CSSGrid's place-items:center can also achieve dual-axis centering at the same time. It is recommended to use Flexbox or Grid first in modern layouts.
