What are the css size units?

css size units include pixels, percentage, em, rem, vw, vh, vmin, vmax, pt, pc, in, cm, mm, etc. Detailed introduction: 1. Pixel is one of the most commonly used size units. It is defined relative to the physical pixels of the monitor screen and has a fixed size. For example, the width of an element is set to 100px, which means that its width is 100 pixels. ; 2. The percentage unit is defined relative to the size of the parent element. For example, if the width of an element is set to 50%, it means that its width is the width of the parent element, etc.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

CSS (Cascading Style Sheet) is a language used to describe the style of web pages. It can control the size, color, font and other attributes of elements in web pages. In CSS, we can use different size units to define the size of elements. The following are some common CSS size units:

1. Pixel (px): Pixel is one of the most commonly used size units. It is defined relative to the physical pixels of the monitor screen and has a fixed size. For example, setting the width of an element to 100px means that it is 100 pixels wide.

2. Percent (%): The percentage unit is defined relative to the size of the parent element. For example, if an element's width is set to 50%, it means that its width is half the width of its parent element.

3. em (em): The em unit is defined relative to the font size of the element. For example, if an element's font size is set to 2em, it means that its font size is twice the font size of the parent element.

4. rem (rem): The rem unit is defined relative to the font size of the root element (that is, the html element). Unlike em, rem units are not affected by the font size of the parent element. For example, if the root element's font size is set to 16px and an element's width is set to 2rem, that means its width is 32px (2 times the root element's font size).

5. vw and vh: The vw and vh units represent the percentage of the viewport width and viewport height respectively. The viewport is the visible area of ​​the browser window or device screen. For example, if an element's width is set to 50vw, it means that its width is half the width of the viewport.

6. vmin and vmax: The vmin and vmax units represent the percentage of the smaller and larger values ​​of the viewport width and viewport height respectively. For example, if an element's width is set to 50vmin, it means that its width is half the smaller of the viewport width and the viewport height.

7. pt, pc, in, cm, mm: These units are used for print style sheets and are not commonly used for screen style sheets. pt (point) is a commonly used unit in the printing industry, 1pt is equal to 1/72 inch; pc (pica) is a commonly used unit in the printing industry, 1pc is equal to 12 points; in (inch), cm (centimeter) and mm (millimetre) is a common unit of length.

These are common size units in CSS, and they can be used flexibly as needed. When choosing a size unit, you need to decide which unit to use based on the specific situation to achieve the best results. At the same time, attention should also be paid to the conversion relationship between different size units so that appropriate conversions can be made when necessary.

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