A relative measurement for the height of a font in em spaces. … Because an em unit is equivalent to the size of a given font, if you assign a font to 12pt, each “em” unit would be 12pt; thus, 2em would be 24pt.
What is CSS unit?
CSS has several different units for expressing a length. Many CSS properties take “length” values, such as width , margin , padding , font-size , etc. Length is a number followed by a length unit, such as 10px , 2em , etc.
What are the three types of CSS measurement units?
There are three relative length units: em , ex , and px . The first two stand for “em-height” and “x-height,” which are common typographical measurements; however, in CSS, they have meanings you might not expect if you are familiar with typography.
What is VW CSS?
Viewport Width (vw). This unit is based on the width of the viewport. A value of 1vw is equal to 1% of the viewport width. Viewport Minimum (vmin). This unit is based on the smaller dimension of the viewport.
What is the difference between a relative and an absolute measure unit in CSS?
What is the difference between a relative and an absolute measure unit in CSS? The units in which length is measured can be either absolute such as pixels, points and so on, or relative such as percentages ( % ) and em units. … CSS3 gives us viewport-relative units. 100vw means 100% of the viewport width.
What Is REM size in CSS?
rem values are relative to the root html element, not to the parent element. That is, If font-size of the root element is 16px then 1 rem = 16px for all elements. If font-size is not explicitly defined in root element then 1rem will be equal to the default font-size provided by the browser (usually 16px).
Why a CSS selector is used?
CSS selectors are used to “find” (or select) the HTML elements you want to style. We can divide CSS selectors into five categories: Simple selectors (select elements based on name, id, class) Combinator selectors (select elements based on a specific relationship between them)
How do you use REM units in CSS?
Equal to the computed value of font-size on the root element. When specified on the font-size property of the root element, the rem units refer to the property’s initial value. This means that 1rem equals the font size of the html element (which for most browsers has a default value of 16px).
What is difference between PX and PT in CSS?
A pt is 1/72 of an in, and a px is 1/96 of an in. A px is therefore 0.75 pt [source]. In CSS, everything is somewhat abstracted, so a unit such as a “pt” is not necessarily one point in physical size, especially on a screen, an “in” is not necessarily one inch in size, and so forth.
How do you calculate PX in CSS?
The CSS Pixel Device-Width can be calculated by dividing the Pixel Width by the CSS Pixel Ratio, and rounding it to the nearest integer.
How do you use VW CSS?
To use vh and vw values, just type “Nvh” or “Nvw” (where “N” represents the percentage of the viewport you’d like to cover) into any width or height field. So to cover 100% of the viewport, you’d set 100% for the width and 100vh for the height. To cover half of the viewport height, you’d set a height of 50vh.
What Is REM and EM in CSS?
To recap, the em unit means “my parent element’s font-size” in the case of typography. … So each successive level of nesting gets progressively larger, as each has its font size set to 1.3em — 1.3 times its parent’s font size. To recap, the rem unit means “The root element’s font-size”. (rem stands for “root em”.)
What is CSS 100vw?
CSS3 gives us viewport-relative units. 100vw means 100% of the viewport width. 100vh; 100% of the height.
What are CSS selectors?
A CSS selector is the first part of a CSS Rule. It is a pattern of elements and other terms that tell the browser which HTML elements should be selected to have the CSS property values inside the rule applied to them.
What is display flex in CSS?
A flex container expands items to fill available free space or shrinks them to prevent overflow. Most importantly, the flexbox layout is direction-agnostic as opposed to the regular layouts (block which is vertically-based and inline which is horizontally-based).
What is Z index in CSS?
The z-index property specifies the stack order of an element. An element with greater stack order is always in front of an element with a lower stack order. Note: z-index only works on positioned elements (position: absolute, position: relative, position: fixed, or position: sticky). Default value: auto.