CSS Reference

A free visual guide to CSS

Learn by example: cssreference.io is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and animated examples.

#align-content

Defines how each line is aligned within a flexbox container. It only applies if flex-wrap: wrap is present, and if there are multiple lines of flexbox items.

default align-content: stretch;

Each line will stretch to fill the remaining space.

In this case, the container is 300px high. All boxes are 50px high, apart from the second one who is 100px high.

  • The first line is 100px high
  • The second line is 50px high
  • The remaing space is 150px

This remaining space is distributed equally amongst the two lines:

  • The first line is now 175px high
  • The second line is now 125px high

align-content: flex-start;

Each line will only fill the space it needs. They will all move towards the start of the flexbox container's cross axis.

align-content: flex-end;

Each line will only fill the space it needs. They will all move towards the end of the flexbox container's cross axis.

align-content: center;

Each line will only fill the space it needs. They will all move towards the center of the flexbox container's cross axis.

align-content: space-between;

Each line will only fill the space it needs. The remaining space will appear between the lines.

align-content: space-around;

Each line will only fill the space it needs. The remaining space will be distributed equally around the lines: before the first line, between the two, and after the last one.

#align-items

Defines how flexbox items are aligned according to the cross axis, within a line of a flexbox container.

align-items: flex-start;

The flexbox items are aligned at the start of the cross axis.

By default, the cross axis is vertical. This means the flexbox items will be aligned vertically at the top.

align-items: flex-end;

The flexbox items are aligned at the end of the cross axis.

By default, the cross axis is vertical. This means the flexbox items will be aligned vertically at the bottom.

align-items: center;

The flexbox items are aligned at the center of the cross axis.

By default, the cross axis is vertical. This means the flexbox items will be centered vertically.

align-items: baseline;

The flexbox items are aligned at the baseline of the cross axis.

By default, the cross axis is vertical. This means the flexbox items will align themselves in order to have the baseline of their text align along a horizontal line.

align-items: stretch;

The flexbox items will stretch across the whole cross axis.

By default, the cross axis is vertical. This means the flexbox items will fill up the whole vertical space.

#align-self

Works like align-items, but applies only to a single flexbox item, instead of all of them.

default align-self: auto;

The target will use the value of align-items.

align-self: flex-start;

If the container has align-items: center and the target has align-self: flex-start, only the target will be at the start of the cross axis.

By default, this means it will be aligned vertically at the top.

align-self: flex-end;

If the container has align-items: center and the target has align-self: flex-end, only the target will be at the end of the cross axis.

By default, this means it will be aligned vertically at the bottom.

align-self: center;

If the container has align-items: flex-start and the target has align-self: center, only the target will be at the center of the cross axis.

By default, this means it will be vertically centered.

align-self: baseline;

If the container has align-items: center and the target has align-self: baseline, only the target will be at the baseline of the cross axis.

By default, this means it will be aligned along the basline of the text.

align-self: stretch;

If the container has align-items: center and the target has align-self: stretch, only the target will stretch along the whole cross axis.

#animation-delay

Defines how long the animation has to wait before starting. The animation will only be delayed on its first iteration.

default animation-delay: 0s;

The animation will wait zero seconds, and thus start right away.

animation-delay: 1.2s;

You can use decimal values in seconds with the keyword s.

animation-delay: 2400ms;

You can use milliseconds instead of seconds, with the keyword ms.

animation-delay: -500ms;

You can use negative values: the animation will start as if it had already been playing for 500ms.

#animation-direction

Defines in which direction the animation is played.

default animation-direction: normal;

The animation is played forwards. When it reaches the end, it starts over at the first keyframe.

animation-direction: reverse;

The animation is played backwards: begins at the last keyframe, finishes at the first keyframe.

animation-direction: alternate;

The animation is played forwards first, then backwards:

  • starts at the first keyframe
  • stops at the last keyframe
  • starts again, but at the last keyframe
  • stops at the first keyframe

animation-direction: alternate-reverse;

The animation is played backwards first, then forwards:

  • starts at the last keyframe
  • stops at the first keyframe
  • starts again, but at the first keyframe
  • stops at the last keyframe

#animation-duration

Defines how long the animation lasts.

default animation-duration: 0s;

The default value is zero seconds: the animation will simply not play.

animation-duration: 1.2s;

You can use decimal values in seconds with the keyword s.

animation-duration: 2400ms;

You can use milliseconds instead of seconds, with the keyword ms.

#animation-fill-mode

Defines what happens before an animation starts and after it ends. The fill mode allows to tell the browser if the animation’s styles should also be applied outside of the animation.

default animation-fill-mode: none;

The animation styles do not affect the default style: the element is set to its default state before the animation starts, and returns to that default state after the animation ends.

animation-fill-mode: forwards;

The last styles applied at the end of the animation are retained afterwards.

animation-fill-mode: backwards;

The animation's styles will already be applied before the animation actually starts.

animation-fill-mode: both;

The styles are applied before and after the animation plays.

#animation-iteration-count

Defines how many times the animation is played.

default animation-iteration-count: 1;

The animation will only play once.

animation-iteration-count: 2;

You can use integer values to define a specific amount of times the animation will play.

animation-iteration-count: infinite;

By using the keyword infinite, the animation will play indefinitely.

#animation-name

Defines which animation keyframes to use.

default animation-name: none;

If no animation name is specified, no animation is played.

animation-name: fadeIn;

If a name is specified, the keyframes matching that name will be used.

For example, the fadeIn animation looks like this:

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

animation-name: moveRight;

Another example: the moveRight animation:

@keyframes moveRight {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(100px);
  }
}

#animation-play-state

Defines if an animation is playing or not.

default animation-play-state: running;

If the animation-duration and animation-name are defined, the animation will start playing automatically.

animation-play-state: paused;

The animation is set paused at the first keyframe.

This is different than having either no animation-duration or animation-name at all. If the animation is paused, the style applied is that of the first keyframe, and not the default style.

In this example, the square is visible by default, but the on the first keyframe of fadeAndMove, the opacity is set to 0. When paused, the animation will be "stuck" on this first keyframe, and will thus be invisible.

@keyframes fadeAndMove {
  from {
    opacity: 0;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(100px);
  }
}

#animation-timing-function

Defines how the values between the start and the end of the animation are calculated.

default animation-timing-function: ease;

The animation starts slowly, accelerates in the middle, and slows down at the end.

animation-timing-function: ease-in;

The animation starts slowly, and accelerates gradually until the end.

animation-timing-function: ease-out;

The animation starts quickly, and decelerates gradually until the end.

animation-timing-function: ease-in-out;

Like ease, but more pronounced.

The animation starts quickly, and decelerates gradually until the end.

animation-timing-function: linear;

The animation has a *constant speed.

animation-timing-function: step-start;

The animation jumps instantly to the final state.

animation-timing-function: step-end;

The animation stays at the initial state until the end, when it instantly jumps to the final state.

animation-timing-function: steps(4, end);

By using steps() with an integer, you can define a specific number of steps before reaching the end. The state of the element will not vary gradually, but rather jump from state to state in separate instants.

#animation

#background-attachment

Defines how the background image will behave when scrolling the page.

default background-attachment: scroll;

The background image will scroll with the page. It will also position and resize itself according to the element it's applied to.

background-attachment: fixed;

The background image will not scroll with the page, and remain positioned according to the viewport. It will also position and resize itself according to the viewport. As a result, the background image will probably only be partially visible.

#background-clip

Defines how far the background should extend within the element.

default background-clip: border-box;

The background extends completely throughout the element, even under the border.

background-clip: padding-box;

The background only extends to the edge of the border: it includes the padding but not the border.

background-clip: content-box;

The background only extends to the edge of the content: it doesn't include the padding, nor the border.

#background-color

Defines the color of the element's background.

default background-color: transparent;

By default, the background color is transparent, basically meaning that there is no background color.

background-color: red;

You can use one of the 140+ color names.

background-color: #05ffb0;

You can use hexadecimal color codes.

background-color: rgb(50, 115, 220);

You can use rgb() color codes:

  • the first value is for red
  • the second value is for green
  • the third value is for blue

Each of them can have a value between 0 and 255.

background-color: rgba(50, 115, 220, 0.3);

You can use rgba() color codes:

  • the first 3 values are for rgb
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

background-color: hsl(14, 100%, 53%);

You can use hsl() color codes:

  • the first value is for hue and can go from 0 to 359
  • the second value is for saturation and go from 0% to 100%
  • the third value is for luminosity and go from 0% to 100%

background-color: hsla(14, 100%, 53%, 0.6);

You can use hsl()a color codes:

  • the first 3 values are for hsl
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

#background-image

Defines an image as the background of the element.

default background-image: none;

Removes any background image.

background-image: url(/images/jt.png);

Uses the image defined in the url path. This path can either be relative (to the css file) or absolute (like http://cssreference.io/images/jt.png).

background-image: linear-gradient(red, blue);

You can define a linear gradient as the background image.

You need to define at least two colors. The first one will start at the top, the second one at the bottom.

The default angle is to bottom (or 180deg), which means the gradient is vertical, starting at the top, ending at the bottom of the element.

background-image: linear-gradient(45deg, red, blue);

You can specify an angle, either in degrees, or with keywords.

When using degress, you specify the direction of the gradient, or when it ends. So 0deg means the the top of the element, like 12:00 on a clock.

In this example, 45deg means 2:30, or the top right corner.

background-image: radial-gradient(green, purple);

You can define a radial gradient as the background image.

You need to define at least two colors. The first one will be at the center, the second one at the edges.

background-image: radial-gradient(circle, green, purple);

You can specify the shape of the radial gradient: circle or ellipse (default).

background-image: radial-gradient(circle, green 0%, purple 20%, orange 100%);

You can specify color stops using percentage values.

background-image: radial-gradient(circle closest-side, green 0%, purple 20%, orange 100%);

You can specify where the gradient should end:

  • closest-side
  • closest-corner
  • farthest-side
  • farthest-corner

background-image: radial-gradient(circle closest-side at 45px 45px, green 0%, purple 20%, orange 100%);

Like with the background-position, you can specify the position of the gradient.

#background-origin

Defines the origin of the background image.

default background-origin: padding-box;

The background image starts at the edge of the border: within padding but not the border.

background-origin: border-box;

The background image starts under the border.

background-origin: content-box;

The background image only starts at the edge of the content: it doesn't include the padding, nor the border.

#background-position

Defines the position of the background image.

default background-position: 0% 0%;

The background image will be positioned at 0% on the horizontal axis and 0% on the vertical axis, which means the top left corner of the element.

background-position: bottom right;

You can use a combination of position keywords: center, top, bottom, left and right.

background-position: center center;

The background image will be positioned in the center of the element.

#background-repeat

Defines how the background image repeats itself across the element's background, starting from the background position.

default background-repeat: repeat;

The background image will repeat itself both horizontally and vertically.

background-repeat: repeat-x;

The background image will only repeat itself horizontally.

background-repeat: repeat-y;

The background image will only repeat itself vertically.

background-repeat: no-repeat;

The background image will only appear once.

#background-size

Defines the size of the background image.

default background-size: auto auto;

The background image will retain its original size.

For example, this background image is 960px by 640px large. Its aspect ratio is 3 by 2. It's bigger than its container (which is 150px high) and will thus be clipped.

background-size: 120px 80px;

You can specify a size in pixels:

  • the first value is the horizontal size
  • the second is the vertical size

background-size: 100% 50%;

You can use percentage values as well. Beware that this can alter the aspect ratio of the background image, and lead to unexpected results.

background-size: contain;

The keyword contain will resize the background image to make sure it remains fully visible.

background-size: cover;

The keyword cover will resize the background image to make sure the element is fully covered.

#background

#border-bottom-color

Like border-color, but for the bottom border only.

border-bottom-color: transparent;

Applies a transparent color to the bottom border. The bottom border will still take up the space defined by the border-width value.

border-bottom-color: red;

You can use one of the 140+ color names.

border-bottom-color: #05ffb0;

You can use hexadecimal color codes, rgb(), rgba(), hsl(), hsla()...

#border-bottom-left-radius

Defines the radius of the bottom left corner.

default border-bottom-left-radius: 0;

Removes any border radius.

border-bottom-left-radius: 20px;

You can use pixel values.

border-bottom-left-radius: 50%;

You can use percentage values. In this example, the radius starts halfway on the bottom border, and ends halfway on the left border.

border-bottom-left-radius: 20px 50%;

If you set two values, the first one is for the bottom border, the second one for the left border.

#border-bottom-right-radius

Defines the radius of the bottom right corner.

default border-bottom-right-radius: 0;

Removes any border radius.

border-bottom-right-radius: 20px;

You can use pixel values.

border-bottom-right-radius: 50%;

You can use percentage values. In this example, the radius starts halfway on the bottom border, and ends halfway on the right border.

border-bottom-right-radius: 20px 50%;

If you set two values, the first one is for the bottom border, the second one for the right border.

#border-bottom-style

Like border-style, but for the bottom border only.

default border-bottom-style: none;

Removes the bottom border.

border-bottom-style: dotted;

Turns the bottom border into a sequence of dots.

border-bottom-style: dashed;

Turns the bottom border into a sequence of dashes.

border-bottom-style: solid;

Turns the bottom border into a solid line.

border-bottom-style: double;

Splits the bottom border into two lines.

border-bottom-style: groove;

Sets an inset style to the bottom border.

#border-bottom-width

Like border-width, but for the bottom border only.

default border-bottom-width: 0;

Removes the bottom border.

border-bottom-width: 4px;

You can use pixel values.

#border-bottom

border-bottom: 4px dotted red;

The order is important:

  • width
  • style
  • color

border-bottom: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#border-collapse

Defines whether table borders should be separated or collapsed.

default border-collapse: separate;

Each table cell will display its own borders.

In this example, each cell has a border-width of 4px. As a result, the border between two cells will be 8px.

border-collapse: collapse;

Adjacent table cells will merge their borders together.

The cell that appears first in the code will "win": its borders will mask those of the following cells.

#border-color

Defines the color of the element's borders.

default border-color: transparent;

Applies a transparent color to the borders. The borders will still take up the space defined by the border-width value.

border-color: red;

You can use one of the 140+ color names.

border-color: #05ffb0;

You can use hexadecimal color codes.

border-color: rgb(50, 115, 220);

You can use rgb() color codes:

  • the first value is for red
  • the second value is for green
  • the third value is for blue

Each of them can have a value between 0 and 255.

border-color: rgba(50, 115, 220, 0.3);

You can use rgba() color codes:

  • the first 3 values are for rgb
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

border-color: hsl(14, 100%, 53%);

You can use hsl() color codes:

  • the first value is for hue and can go from 0 to 359
  • the second value is for saturation and go from 0% to 100%
  • the third value is for luminosity and go from 0% to 100%

border-color: hsla(14, 100%, 53%, 0.6);

You can use hsl()a color codes:

  • the first 3 values are for hsl
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

#border-left-color

Like border-color, but for the left border only.

border-left-color: transparent;

Applies a transparent color to the left border. The left border will still take up the space defined by the border-width value.

border-left-color: red;

You can use one of the 140+ color names.

border-left-color: #05ffb0;

You can use hexadecimal color codes, rgb(), rgba(), hsl(), hsla()...

#border-left-style

Like border-style, but for the left border only.

default border-left-style: none;

Removes the left border.

border-left-style: dotted;

Turns the left border into a sequence of dots.

border-left-style: dashed;

Turns the left border into a sequence of dashes.

border-left-style: solid;

Turns the left border into a solid line.

border-left-style: double;

Splits the left border into two lines.

border-left-style: groove;

Sets an inset style to the left border.

#border-left-width

Like border-width, but for the left border only.

default border-left-width: 0;

Removes the left border.

border-left-width: 4px;

You can use pixel values.

#border-left

border-left: 4px dotted red;

The order is important:

  • width
  • style
  • color

border-left: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#border-radius

Defines the radius of the element's corners.

default border-radius: 0;

Removes any border radius.

border-radius: 20px;

You can use pixel values.

border-radius: 50%;

You can use percentage values. In this example, the radius starts halfway through each border.

border-radius: 20px 50%;

If you set two values, the first one is for the top and bottom borders, the second one for the left and right borders.

#border-right-color

Like border-color, but for the right border only.

border-right-color: transparent;

Applies a transparent color to the right border. The right border will still take up the space defined by the border-width value.

border-right-color: red;

You can use one of the 140+ color names.

border-right-color: #05ffb0;

You can use hexadecimal color codes, rgb(), rgba(), hsl(), hsla()...

#border-right-style

Like border-style, but for the right border only.

default border-right-style: none;

Removes the right border.

border-right-style: dotted;

Turns the right border into a sequence of dots.

border-right-style: dashed;

Turns the right border into a sequence of dashes.

border-right-style: solid;

Turns the right border into a solid line.

border-right-style: double;

Splits the right border into two lines.

border-right-style: groove;

Sets an inset style to the right border.

#border-right-width

Like border-width, but for the right border only.

default border-right-width: 0;

Removes the right border.

border-right-width: 4px;

You can use pixel values.

#border-right

border-right: 4px dotted red;

The order is important:

  • width
  • style
  • color

border-right: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#border-style

Defines the style of the element's borders.

default border-style: none;

Removes the element's borders.

border-style: dotted;

Turns the border into a sequence of dots.

border-style: dashed;

Turns the border into a sequence of dashes.

border-style: solid;

Turns the border into a solid line.

border-style: double;

Splits the border into two lines.

border-style: groove;

Sets an inset style to the borders.

#border-top-color

Like border-color, but for the top border only.

border-top-color: transparent;

Applies a transparent color to the top border. The top border will still take up the space defined by the border-width value.

border-top-color: red;

You can use one of the 140+ color names.

border-top-color: #05ffb0;

You can use hexadecimal color codes, rgb(), rgba(), hsl(), hsla()...

#border-top-left-radius

Defines the radius of the top left corner.

default border-top-left-radius: 0;

Removes any border radius.

border-top-left-radius: 20px;

You can use pixel values.

border-top-left-radius: 50%;

You can use percentage values. In this example, the radius starts halfway on the top border, and ends halfway on the left border.

border-top-left-radius: 20px 50%;

If you set two values, the first one is for the top border, the second one for the left border.

#border-top-right-radius

Defines the radius of the top right corner.

default border-top-right-radius: 0;

Removes any border radius.

border-top-right-radius: 20px;

You can use pixel values.

border-top-right-radius: 50%;

You can use percentage values. In this example, the radius starts halfway on the top border, and ends halfway on the right border.

border-top-right-radius: 20px 50%;

If you set two values, the first one is for the top border, the second one for the right border.

#border-top-style

Like border-style, but for the top border only.

default border-top-style: none;

Removes the top border.

border-top-style: dotted;

Turns the top border into a sequence of dots.

border-top-style: dashed;

Turns the top border into a sequence of dashes.

border-top-style: solid;

Turns the top border into a solid line.

border-top-style: double;

Splits the top border into two lines.

border-top-style: groove;

Sets an inset style to the top border.

#border-top-width

Like border-width, but for the top border only.

default border-top-width: 0;

Removes the top border.

border-top-width: 4px;

You can use pixel values.

#border-top

border-top: 4px dotted red;

The order is important:

  • width
  • style
  • color

border-top: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#border-width

Defines the width of the element's borders.

border-width: 1px;

Defines the width of all borders to 1px.

border-width: 2px 0;

Defines the top and bottom borders to 2px, the left and right to 0.

#border

Shorthand property for border-width border-style and border-color.

border: 4px dotted red;

The order is important:

  • width
  • style
  • color

border: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#bottom

Defines the position of the element according to its bottom edge.

default bottom: auto;

The element will remain in its natural position.

bottom: 20px;

If the element is in position relative, the element will move upwards by the amount defined by the bottom value.

bottom: 0;

If the element is in position absolute, the element will position itself from the bottom of the first positioned ancestor.

#box-shadow

Defines the shadow of the element.

default box-shadow: none;

Removes any box-shadow that was applied to the element.

box-shadow: 2px 6px;

You need at least two values:

  • the first is the horizontal offset
  • the second is the vertical offset

The shadow color will be inherited from the text color.

box-shadow: 2px 6px red;

You can define a color as the last value.

As with color, you can use color names, hexadecimal, rgb, hsl...

box-shadow: 2px 4px 10px red;

The optional third value defines the blur of the shadow.

The color will be diffused across 10px in this example, from opaque to transparent.

box-shadow: 2px 4px 10px 4px red;

The optional fourth value defines the spread of the shadow.

The spread defines how much the shadow should grow: it enhances the shadow.

#box-sizing

Defines how the width and height of the element are calculated: whether they include the padding and borders or not.

default box-sizing: content-box;

The width and height of the element only apply to the content of the element.

For example, this element has

  • border-width: 12px
  • padding: 30px
  • width: 200px

The full width is 24px + 60px + 200px = 284px.

The content has the defined width. The box accomodates for those dimensions.

box-sizing: border-box;

The width and height of the element apply to all parts of the element: the content, the padding and the borders.

For example, this element has

  • border-width: 12px
  • padding: 30px
  • width: 200px

The full width is 200px, no matter what.

The box has the defined width. The content accomodates for those dimensions, and ends up being 200px - 60px - 24px = 116px.

#clear

Moves the element after all the preceding floating elements.

clear: none;

The clear property is only relevant when used with siblings that have a float value.

The element will sit alongside any floated element that precedes it.

clear: left;

The cleared element will move after any left floating element that precedes it, but will remain alongside right float elements.

clear: right;

The cleared element will move after any right floating element that precedes it, but will remain alongside left float elements.

clear: both;

The cleared element will move after any floating element that precedes it. This includes both left floating and right floating elements.

#color

Defines the color of the text.

color: transparent;

Applies a transparent color to the text. The text will still take up the space it should.

color: red;

You can use one of the 140+ color names.

color: #05ffb0;

You can use hexadecimal color codes.

color: rgb(50, 115, 220);

You can use rgb() color codes:

  • the first value is for red
  • the second value is for green
  • the third value is for blue

Each of them can have a value between 0 and 255.

color: rgba(0, 0, 0, 0.5);

You can use rgba() color codes:

  • the first 3 values are for rgb
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

color: hsl(14, 100%, 53%);

You can use hsl() color codes:

  • the first value is for hue and can go from 0 to 359
  • the second value is for saturation and go from 0% to 100%
  • the third value is for luminosity and go from 0% to 100%

color: hsla(14, 100%, 53%, 0.6);

You can use hsl()a color codes:

  • the first 3 values are for hsl
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

#column-count

Defines the number of columns of the element.

default column-count: auto;

Removes any columns from the element (unless another column- property was set).

column-count: 3;

When using an integer value, the element will distribute its child elements across the number of columns defined.

#column-gap

Defines the gap between the columns of the element.

default column-gap: normal;

The gap between the columns is set to the browser's default value, which usually is 1em.

column-gap: 2px;

You can use pixel values for the gap.

Note that the gap only appears between columns, and not on the exterior sides of the edge columns.

#column-width

Defines the number of columns of the element.

default column-width: auto;

The element will not distribute its child elements into columns, unlesse a column-count value is defined. In that case, the column width will be infered from the column count.

column-width: 10px;

You can use pixel values for the column width.

The number of columns will be the minimum needed to distribute all the content across the element.

#content

Defines the text content of the :before and :after pseudo-elements.

default content: normal;

No content is added to the element.

content: "Foo bar";

Considering this HTML element:

<p class="element">
  Hello world
</p>

And this CSS:

.element:before {
  content: "Foo bar";
}

The text content will be prepended to the element's content.

Notice how the end result combines text from the HTML and text from the CSS.

content: url(/images/jt.png);

You can insert images by using the url() function.

content: attr(data-something);

Considering this HTML element:

<p class="element" data-something="cssreference">
  Hello world
</p>

And this CSS:

.element:before {
  content: attr(data-something);
}

The element will grab the text content from the HTML attribute.

#cursor

Sets the mouse cursor when hovering the element.

cursor: default;

Sets the cursor to the element's default value. For a link, it would be a pointer. For text it would be a selection cursor.

cursor: auto;

auto

cursor: pointer;

pointer

cursor: move;

move

cursor: crosshair;

crosshair

cursor: text;

text

cursor: wait;

wait

cursor: help-resize;

help-resize

cursor: ne-resize;

ne-resize

cursor: nw-resize;

nw-resize

cursor: n-resize;

n-resize

cursor: se-resize;

se-resize

cursor: sw-resize;

sw-resize

cursor: s-resize;

s-resize

cursor: w-resize;

w-resize

#display

Sets the display behavior of the element.

display: none;

The element is completely removed, as if it wasn't in the HTML code in the first place.

display: inline;

The element is turned into an inline element: it behaves like simple text.

Any height and width applied will have no effect.

display: block;

The element is turned into a block element: it starts on a new line, and takes up the whole width.

display: inline-block;

The element shares properties of both an inline and a block element:

  • inline because the element behaves like simple text, and inserts itself in a block of text
  • Block because you can apply height and width values

For example, this element has:

.element{
  height: 3em;
  width: 60px;
}

display: list-item;

The element behaves like a list item: <li>. The only difference with block is that a list item has a bullet point.

display: table;

The element behaves like a table: <table>.

Its content and child elements behave like table cells.

display: table-cell;

The element behaves like a table cell: <td> or <th>.

Its content and child elements behave like table cells.

display: table-row;

The element behaves like a table row: <tr>.

Its content and child elements behave like table cells.

display: flex;

The element is turned into an flexbox container. On its own, it behaves like a block element.

Its child elements will be turned into flexbox items.

display: inline-flex;

The element shares properties of both an inline and a flexbox element:

  • inline because the element behaves like simple text, and inserts itself in a block of text
  • flexbox because its child element will be turned into flexbox items

For example, this element has:

.element{
  height: 3em;
  width: 120px;
}

#flex-basis

Defines the initial size of a flexbox item.

default flex-basis: auto;

The element will be automatically sized based on its content, or on any height or width value if they are defined.

flex-basis: 80px;

You can define pixel or (r)em values. The element will wrap its content to avoid any overflow.

#flex-direction

Defines how flexbox items are ordered within a flexbox container.

default flex-direction: row;

The flexbox items are ordered the same way as the text direction, along the main axis.

flex-direction: row-reverse;

The flexbox items are ordered the opposite way as the text direction, along the main axis.

flex-direction: column;

The flexbox items are ordered the same way as the text direction, along the cross axis.

flex-direction: column-reverse;

The flexbox items are ordered the opposite way as the text direction, along the cross axis.

#flex-flow

Shorthand property for flex-direction and flex-wrap.

#flex-grow

Defines how much a flexbox item should grow if there's space available.

default flex-grow: 0;

The element will not grow if there's space available. It will only use the space it needs.

flex-grow: 1;

The element will grow by a factor of 1. It will fill up the remaining space if no other flexbox item has a flex-grow value.

flex-grow: 2;

Because the flex-grow value is relative, its behaviour depends on the value of the flexbox item siblings.

In this example, the remaining space is divided in 3:

  • 1 third goes to the green item
  • 2 thirds go to the pink item
  • Nothing goes to the yellow item, who retains its initial width

#flex-shrink

Defines how much a flexbox item should shrink if there's not enough space available.

default flex-shrink: 1;

If there's not enough space available in the container's main axis, the element will shrink by a factor of 1, and will wrap its content.

flex-shrink: 0;

The element will not shrink: it will retain the width it needs, and not wrap its content. Its siblings will shrink to give space to the target element.

Because the target element will not wrap its content, there is a chance for the flexbox container's content to overflow.

flex-shrink: 2;

Because the flex-shrink value is relative, its behaviour depends on the value of the flexbox item siblings.

In this example, the green item wants to fill 100% of the width. The space it needs is taken from its two siblings, and is divided in 4:

  • 3 quarters are taken from the red item
  • 1 quarter is taken from the yellow item

#flex-wrap

Defines if flexbox items appear on a single line or on multiple lines within a flexbox container.

default flex-wrap: nowrap;

The flexbox items will remain on a single line, no matter what, and will eventually overflow if needed.

flex-wrap: wrap;

The flexbox items will be distributed among multiple lines if needed.

flex-wrap: wrap-reverse;

The flexbox items will be distributed among multiple lines if needed. Any additional line will appear before the previous one.

#float

Pushes the element to either the left or right side. The following siblings will wrap around the floating element

default float: none;

Removes any previously defined float value. The element will remain in the natural flow of the page.

float: left;

Moves the element to the left side of its container. The following elements will wrap around it and fill the space remaining on the right.

float: right;

Moves the element to the right side of its container. The following elements will wrap around it and fill the space remaining on the left.

#font-family

font-family: "Source Sans Pro", "Arial", sans-serif;

When using multiple values, the font-family list of font families defines the priority in which the browser should choose the font family.

The browser will look for each family on the user's computer and in any @font-face resource.

The list is prioritized from left to right: it will use the first value if it's available, or go to the next one, until the end of the list is reached. The default font family is defined by the browser preferences.

In this example, the browser will try to use Source Sans Pro if it's available. If it can't find it, it will try to use Arial. If it's not available either, it will use the browser's sans-serif font.

font-family: serif;

The browser will use a serif font family: all characters have stroke endings.

font-family: sans-serif;

The browser will use a sans-serif font family: no character has stroke endings.

font-family: monospace;

The browser will use a monospace font family: all characters have the same width.

font-family: cursive;

The browser will use a cursive font family.

font-family: fantasy;

The browser will use a fantasy font family.

#font-size

Defines the size of the text.

default font-size: medium;

The text will use the browser's default medium size.

font-size: 20px;

You can use pixel values.

font-size: 1.2em;

You can use em values.

The value is relative to the parent's font-size.
As a result, the value will cascade if used on child elements.

font-size: 1.2rem;

You can use rem values.

The value is relative to the root element's font-size, which is the <html> element.
As a result, the value will not vary depending on the depth of the element in the HTML hierarchy, and will reamin context independent.

font-size: 90%;

You can use percentage values. They act like em values.

The value is relative to the parent's font-size.
As a result, the value will cascade if used on child elements.

font-size: smaller;

You can use relative keywords. The value is relative to the parent.

The following are available:

  • larger
  • smaller

font-size: x-large;

You can use absolute keywords. The value is relative to the root element <html>.

The following are available:

  • xx-small
  • x-small
  • small
  • medium
  • large
  • x-large
  • xx-large

#font-style

Defines how much the text is slanted.

default font-style: normal;

The text is not slanted.

font-style: italic;

Use the italic version of the font: the letters are slightly slanted.

font-style: oblique;

Use the oblique version of the font: the letters are more slanted than italic.

#font-variant

Defines which glyph to use for each letter.

default font-variant: normal;

Each letter uses its normal glyph.

font-variant: small-caps;

Each letter uses its small capitalized version.

#font-weight

Defines the weight of the text.

default font-weight: normal;

The text is in normal weight.

font-weight: bold;

The text becomes bold.

font-weight: 600;

You can use numeric values. They all correspond to a particular named weight:

  • 100 Thin
  • 200 Extra Light
  • 300 Light
  • 400 Normal
  • 500 Medium
  • 600 Semi Bold
  • 700 Bold
  • 800 Extra Bold
  • 900 Ultra Bold

If the font family doesn't provide the requested weight, it will use the closest available one.

font-weight: lighter;

You can use relative keywords: lighter or bolder. The browser will use the next available weight.

#font

#height

Defines the height of the element.

default height: auto;

The element will automatically adjust its height to allow its content to be displayed correctly.

height: 100px;

You can use numeric values like pixels, (r)em, percentages...

If the content does not fit within the specified height, it will overflow. How the container will handle this overflowing content is defined by the overflow property.

#justify-content

Defines how flexbox items are aligned according to the main axis, within a flexbox container.

default justify-content: flex-start;

The flexbox items are pushed towards the start of the container's main axis.

justify-content: flex-end;

The flexbox items are pushed towards the end of the container's main axis.

justify-content: center;

The flexbox items are centered along the container's main axis.

justify-content: space-between;

The remaining space is distributed between the flexbox items.

justify-content: space-around;

The remaining space is distributed around the flexbox items: this adds space before the first item and after the last one.

#left

Defines the position of the element according to its left edge.

default left: auto;

The element will remain in its natural position.

left: 80px;

If the element is in position relative, the element will move left by the amount defined by the left value.

left: -20px;

If the element is in position absolute, the element will position itself from the left of the first positioned ancestor.

#letter-spacing

Defines the spacing between the characters of a block of text.

default letter-spacing: normal;

The spacing between the characters is normal.

letter-spacing: 2px;

You can use pixel values.

letter-spacing: 0.1em;

You can use em values: this allows the spacing to remain relative to the font-size.

#line-height

Defines the height of a single line of text.

default line-height: normal;

Reverts to the default value of the browser.

recommended line-height: 1.6;

You can use unitless values: the line height will be relative to the font size.

line-height: 30px;

You can use pixel values.

line-height: 0.8em;

You can use em values: like with unitless values, the line height will be relative to the font size.

#list-style-image

Defines the image to be used as an list item's bullet point.

default list-style-image: none;

The list items will use the bullet point defined by the list-style-type value, which by default is a disc.

list-style-image: url(/images/list-style-image.png);

The list items will use the image located at the specified URL as their bullet point.
The image can not be resized.

#list-style-position

Defines the position of a list's bullet points.

default list-style-position: outside;

The bullet point will be outside the list item, as if it wasn't part of the list item.

The start of each line of a list item will be aligned vertically.

list-style-position: inside;

The bullet point will be inside the list item.

As it is part of the list item, it will be part of the text and push the text at the start.

#list-style-type

Defines the type of a list item's bullet point.

default list-style-type: disc;

The list items will use a disc as their bullet point.

list-style-type: circle;

The list items will use a circle as their bullet point.

list-style-type: square;

The list items will use a square as their bullet point.

list-style-type: decimal;

The list items will use a decimal as their bullet point.

list-style-type: none;

The list items will have no bullet point.

#list-style

#margin-bottom

Defines the space outside the element, on the bottom side.

default margin-bottom: 0;

Removes any margin at the bottom.

margin-bottom: 30px;

You can use pixel values.

margin-bottom: 2em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

margin-bottom: 10%;

You can use percentage values.
The percentage is based on the width of the container.

#margin-left

Defines the space outside the element, on the left side.

default margin-left: 0;

Removes any margin on the left.

margin-left: 50px;

You can use pixel values.

margin-left: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

margin-left: 30%;

You can use percentage values.
The percentage is based on the width of the container.

margin-left: auto;

The auto keyword will give the left side a share of the remaining space.

When combined with margin-right: auto, it will center the element, if a fixed width is defined.

#margin-right

Defines the space outside the element, on the right side.

default margin-right: 0;

Removes any margin on the right.

margin-right: 50px;

You can use pixel values.

margin-right: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

margin-right: 30%;

You can use percentage values.
The percentage is based on the width of the container.

margin-right: auto;

The auto keyword will give the right side a share of the remaining space.

When combined with margin-left: auto, it will center the element, if a fixed width is defined.

#margin-top

Defines the space outside the element, on the top side.

default margin-top: 0;

Removes any margin at the top.

margin-top: 30px;

You can use pixel values.

margin-top: 2em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

margin-top: 10%;

You can use percentage values.
The percentage is based on the width of the container.

#margin

Shorthand property for margin-top margin-right margin-bottom and margin-left.

default margin: 0;

Removes all margins.

margin: 30px;

When using 1 value, the margin is set for all 4 sides.

margin: 30px 60px;

When using 2 values:

  • the first value is for top/bottom
  • the second value is for right/left

To remember the order think about the values you haven't defined.

If you enter 2 values (top/right), you omit setting bottom and left. Because bottom is the vertical counterpart of top, it will use top’s value. And because left is the horizontal counterpart of right, it will use right’s value.

margin: 30px 60px 45px;

When using 3 values:

  • the first value is for top
  • the second value is for right/left
  • the third value is for bottom

To remember the order think about the values you haven't defined.

If you enter 3 values (top/right/bottom), you omit setting left. As right’s counterpart, it will use its value.

margin: 30px 60px 45px 85px;

When using 4 values:

  • the first value is for top
  • the second value is for right
  • the third value is for bottom
  • the fourth value is for left

To remember the order, start at the top and go clockwise.

#max-height

Defines the maximum height the element can be.

default max-height: none;

The element has no limit in terms of height.

max-height: 2000px;

You can use numeric values like pixels, (r)em, percentages...

If the maximum height is larger than the element's actual height, the max height has no effect.

max-height: 100px;

If the content does not fit within the maximum height, it will overflow. How the container will handle this overflowing content is defined by the overflow property.

#max-width

Defines the maximum width the element can be.

default max-width: none;

The element has no limit in terms of width.

max-width: 2000px;

You can use numeric values like pixels, (r)em, percentages...

If the maximum width is larger than the element's actual width, the max width has no effect.

max-width: 150px;

If the content does not fit within the maximum width, it will automatically change the height of the element to accomodate for the wrapping of the content.

#min-height

Defines the minimum height of the element.

default min-height: 0;

The element has no minimum height.

min-height: 200px;

You can use numeric values like pixels, (r)em, percentages...

If the minimum height is larger than the element's actual height, the min height will be applied.

min-height: 5px;

If the minimum height is smaller than the element's actual height, the min height has no effect.

#min-width

Defines the minimum width of the element.

default min-width: 0;

The element has no minimum width.

min-width: 300px;

You can use numeric values like pixels, (r)em, percentages...

If the minimum width is larger than the element's actual width, the min width will be applied.

min-width: 5px;

If the minimum width is smaller than the element's actual width, the min width has no effect.

#mix-blend-mode

Defines how the element should blend with the background.

default mix-blend-mode: normal;

The element does not blend.

mix-blend-mode: multiply;

The element uses the multiply blend mode.

mix-blend-mode: screen;

The element uses the screen blend mode.

mix-blend-mode: overlay;

The element uses the overlay blend mode.

mix-blend-mode: darken;

The element uses the darken blend mode.

mix-blend-mode: lighten;

The element uses the lighten blend mode.

mix-blend-mode: color-dodge;

The element uses the color-dodge blend mode.

mix-blend-mode: color-burn;

The element uses the color-burn blend mode.

mix-blend-mode: hard-light;

The element uses the hard-light blend mode.

mix-blend-mode: soft-light;

The element uses the soft-light blend mode.

mix-blend-mode: difference;

The element uses the difference blend mode.

mix-blend-mode: exclusion;

The element uses the exclusion blend mode.

mix-blend-mode: hue;

The element uses the hue blend mode.

mix-blend-mode: saturation;

The element uses the saturation blend mode.

mix-blend-mode: color;

The element uses the color blend mode.

mix-blend-mode: luminosity;

The element uses the luminosity blend mode.

#opacity

Defines how opaque the element is.

default opacity: 1;

The element is fully opaque.

opacity: 0;

The element is fully transparent.

opacity: 0.3;

Any value between 0 (zero) and 1 (one) will make the element semi transparent.

#order

Defines the order of a flexbox item.

default order: 0;

The order of the flexbox items is the one defined in the HTML code.

order: 1;

The order is relative to the flexbox item's siblings. The final order is defined when all individual flexbox item order values are taken into account.

order: -1;

You can use negative values.

order: 9;

You can set a different value for each flexbox item.

#outline-color

Defines the color of the element's outlines.

default outline-color: transparent;

Applies a transparent color to the outlines. The outlines will still take up the space defined by the outline-width value.

outline-color: red;

You can use one of the 140+ color names.

outline-color: #05ffb0;

You can use hexadecimal color codes.

outline-color: rgb(50, 115, 220);

You can use rgb() color codes:

  • the first value is for red
  • the second value is for green
  • the third value is for blue

Each of them can have a value between 0 and 255.

outline-color: rgba(50, 115, 220, 0.3);

You can use rgba() color codes:

  • the first 3 values are for rgb
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

outline-color: hsl(14, 100%, 53%);

You can use hsl() color codes:

  • the first value is for hue and can go from 0 to 359
  • the second value is for saturation and go from 0% to 100%
  • the third value is for luminosity and go from 0% to 100%

outline-color: hsla(14, 100%, 53%, 0.6);

You can use hsl()a color codes:

  • the first 3 values are for hsl
  • the 4th value is for the alpha channel and defines the opacity of the color

The alpha value can go from zero 0 (transparent) to one 1 (opaque).

#outline-style

Defines the style of the element's outlines.

default outline-style: none;

Removes the element's outlines.

outline-style: dotted;

Turns the outline into a sequence of dots.

outline-style: dashed;

Turns the outline into a sequence of dashes.

outline-style: solid;

Turns the outline into a solid line.

outline-style: double;

Splits the outline into two lines.

outline-style: groove;

Sets an inset style to the outlines.

#outline-width

Defines the width of the element's outlines.

default outline-width: medium;

Defines the width of all outlines to medium.

outline-width: 1px;

Defines the width of all outlines to 1px.

#outline

Shorthand property for outline-width outline-style and outline-color.

outline: 4px dotted red;

The order is important:

  • width
  • style
  • color

outline: 2px solid;

Only the color is optional. If you omit it, the color applied will be the color of the text.

#overflow-wrap

Defines if words should break when reaching the end of a line.

default overflow-wrap: normal;

Words with no space will not break. Sequences of uninterrupted characters will be displayed on a single line.

overflow-wrap: break-word;

Words with no space will break as soon as they reach the end of a line.

#overflow-x

Defines how overflowing content on the horizontal axis is displayed.

default overflow-x: visible;

The overflowing content is visible, while the element itself stays at the specified width.

overflow-x: hidden;

The overflowing content is hidden and can not be accessed.

overflow-x: scroll;

The overflowing content is accessible thanks to a horizontal scrollbar.

overflow-x: auto;

The browser decides whether to display a horizontal scrollbar or not.

#overflow-y

Defines how overflowing content on the vertical axis is displayed.

default overflow-y: visible;

The overflowing content is visible, while the element itself stays at the specified height.

overflow-y: hidden;

The overflowing content is hidden and can not be accessed.

overflow-y: scroll;

The overflowing content is accessible thanks to a vertical scrollbar.

overflow-y: auto;

The browser decides whether to display a vertical scrollbar or not.

#overflow

Defines how overflowing content on both horizontal and vertical axis is displayed.

default overflow: visible;

The overflowing content is visible, while the element itself stays at the specified height.

overflow: hidden;

The overflowing content is hidden and can not be accessed.

overflow: scroll;

The overflowing content is accessible thanks to a vertical scrollbar.

overflow: auto;

The browser decides whether to display a vertical scrollbar or not.

#padding-bottom

Defines the space inside the element, on the bottom side.

default padding-bottom: 0;

Removes any padding on the bottom.

padding-bottom: 50px;

You can use pixel values.

padding-bottom: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

padding-bottom: 30%;

You can use percentage values.
The percentage is based on the width of the element.

#padding-left

Defines the space inside the element, on the left side.

default padding-left: 0;

Removes any padding on the left.

padding-left: 50px;

You can use pixel values.

padding-left: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

padding-left: 30%;

You can use percentage values.
The percentage is based on the width of the element.

#padding-right

Defines the space inside the element, on the right side.

default padding-right: 0;

Removes any padding on the right.

padding-right: 50px;

You can use pixel values.

padding-right: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

padding-right: 30%;

You can use percentage values.
The percentage is based on the width of the element.

#padding-top

Defines the space inside the element, on the top side.

default padding-top: 0;

Removes any padding on the top.

padding-top: 50px;

You can use pixel values.

padding-top: 7em;

You can use (r)em values.

The value is relative to the font size:

  • em: relative to the element's current font size
  • rem: relative to <html> the root element's font size

padding-top: 30%;

You can use percentage values.
The percentage is based on the width of the element.

#padding

default padding: 0;

Removes all paddings.

padding: 30px;

When using 1 value, the padding is set for all 4 sides.

padding: 30px 60px;

When using 2 values:

  • the first value is for top/bottom
  • the second value is for right/left

To remember the order think about the values you haven't defined.

If you enter 2 values (top/right), you omit setting bottom and left. Because bottom is the vertical counterpart of top, it will use top’s value. And because left is the horizontal counterpart of right, it will use right’s value.

padding: 30px 60px 45px;

When using 3 values:

  • the first value is for top
  • the second value is for right/left
  • the third value is for bottom

To remember the order think about the values you haven't defined.

If you enter 3 values (top/right/bottom), you omit setting left. As right’s counterpart, it will use its value.

padding: 30px 60px 45px 85px;

When using 4 values:

  • the first value is for top
  • the second value is for right
  • the third value is for bottom
  • the fourth value is for left

To remember the order, start at the top and go clockwise.

#pointer-events

Defines if the element reacts to pointer events or not.

default pointer-events: auto;

The element reacts to pointer events, like :hover or click.

pointer-events: none;

The element does not react to pointer events, like :hover or click. As a result, elements that are behind are accessible.

#position

Defines the position behavior of the element.

default position: static;

The element will remain in the natural flow of the page.

As a result, it will not act as anchor point for the absolutely positioned pink block.

Also, it will not react to the following properties:

  • top
  • bottom
  • left
  • right
  • z-index

position: relative;

The element will remain in the natural flow of the page.

It also makes the element positioned: it will act as an anchor point for the absolutely positioned pink block.

Also, it will react to the following properties:

  • top
  • bottom
  • left
  • right
  • z-index

position: absolute;

The element will not remain in the natural flow of the page. It will position itself according to the closest positioned ancestor.

Because it's positioned, it will act as an anchor point for the absolutely positioned pink block.

Also, it will react to the following properties:

  • top
  • bottom
  • left
  • right
  • z-index

position: fixed;

The element will not remain in the natural flow of the page. It will position itself according to the viewport.

Because it's positioned, it will act as an anchor point for the absolutely positioned pink block.

Also, it will react to the following properties:

  • top
  • bottom
  • left
  • right
  • z-index

#resize

Defines if the textarea is resizable or not.

default resize: none;

The textarea is not resizable.

resize: horizontal;

The textarea is resizable horizontally.

resize: vertical;

The textarea is resizable vertically.

resize: both;

The textarea is resizable both horizontally and vertically.

#text-align

Defines how the text content of the element is horizontally aligned.

text-align: left;

The text content is aligned to the left.

text-align: right;

The text content is aligned to the right.

text-align: center;

The text content is centered.

text-align: justify;

The text content is justified.

#text-decoration

Defines how the text content of the element is decorated.

default text-decoration: none;

Removes any text decoration.

text-decoration: underline;

Underlines the text content.

#text-indent

Defines the indentation of the element's first line of text.

default text-indent: 0;

The text is not indented.

text-indent: 40px;

You can use numeric values like pixels, (r)em, percentages...

Notice how only the first line is indented.

text-indent: -2em;

You can also use negative values.

#text-overflow

Defines how the hidden text content behaves if it's overflowing.

default text-overflow: clip;

The text content is clipped and not accessible.

text-overflow: ellipsis;

The overflowing content is replaced by an ellipsis:

#text-shadow

Defines the shadow of the text content.

default text-shadow: none;

The text content has no shadow.

text-shadow: 2px 6px;

You need at least two values:

  • the first is the horizontal offset
  • the second is the vertical offset

The shadow color will be inherited from the text color.

text-shadow: 2px 6px red;

You can define a color as the last value.

As with color, you can use color names, hexadecimal, rgb, hsl...

text-shadow: 2px 4px 10px red;

The optional third value defines the blur of the shadow.

The color will be diffused across 10px in this example, from opaque to transparent.

#text-transform

Defines how the text content should be transformed.

default text-transform: none;

Removes any text transformation: the text will appear the same as in the HTML code.

text-transform: capitalize;

Turns the first letter of each word into a capital letter.

text-transform: uppercase;

Turns all letters into capital letters.

text-transform: lowercase;

Turns all letters into lowercase letters.

#top

Defines the position of the element according to its top edge.

default top: auto;

The element will remain in its natural position.

top: 20px;

If the element is in position relative, the element will move downwards by the amount defined by the top value.

top: 0;

If the element is in position absolute, the element will position itself from the top of the first positioned ancestor.

#transform-origin

Defines the origin for transformations defined by the transform property.

default transform-origin: 50% 50% 0;

The transform origin is in the center of the element.

transform-origin: 20px 70%;

You can use 2 values:

  • the first value is the horizontal axis
  • the second is the vertical axis

transform-origin: top right;

You can use a combination of position keywords: center, top, bottom, left and right.

transform-origin: center bottom;

When using keywords, you can change the order of the axis, as long as each keywords is unambiguous.

#transform

Defines how the element is transformed.

default transform: none;

Removes any transformation.

transform: translateX(40px);

Move the element on the horizontal axis.

transform: translateY(20px);

Move the element on the vertical axis.

transform: translateY(100%);

You can use percentage values: the percentage is relative to the element itself, and not the parent.

transform: translate(20px, -10%);

You can use translate() with two values:

  • the first value is for the horizontal axis
  • the second value is for the vertical axis

transform: scaleX(1.5);

Scale the element on the horizontal axis.

transform: scaleY(0.4);

Scale the element on the vertical axis.

transform: scaleY(-2);

You can use negative values: it will invert the element.

transform: scale(0.8, 0.8);

You can use scale() with two values:

  • the first value is for the horizontal axis
  • the second value is for the vertical axis

By using the same value for both, you can scale proportionally.

transform: rotate(45deg);

Rotate the element.

You can use:

  • degrees from 0 to 360deg
  • gradians from 0 to 400grad
  • radians from 0 to 2πrad
  • turns from 0 to 1turn

transform: skewX(15deg);

Skew the element on the horizontal axis.

transform: skewY(45deg);

Skew the element on the vertical axis.

transform: skew(10deg, -20deg);

You can use skew() with two values:

  • the first value is for the horizontal axis
  • the second value is for the vertical axis

transform: rotate(5deg) scale(1.1, 1.1) translate(-20%, 30px);

You can combine multiple transformations by separating them with a space.

#transition-delay

Defines how long the transition has to wait before starting.

default transition-delay: 0s;

The transition will wait zero seconds, and thus start right away.

transition-delay: 1.2s;

You can use decimal values in seconds with the keyword s.

transition-delay: 2400ms;

You can use milliseconds instead of seconds, with the keyword ms.

transition-delay: -500ms;

You can use negative values: the transition will start as if it had already been playing for 500ms.

#transition-duration

Defines how long the transition lasts.

default transition-duration: 0s;

The transition will last zero seconds, and is thus instant.

transition-duration: 1.2s;

You can use decimal values in seconds with the keyword s.

transition-duration: 2400ms;

You can use milliseconds instead of seconds, with the keyword ms.

#transition-property

Defines which properties will transition.

default transition-property: all;

The element will transition all properties:

transition-property: none;

The element will transition no property: the transition is thus instant.

transition-property: background;

The element will only transtion the background property.

transition-property: color;

The element will only transtion the color property.

transition-property: transform;

The element will only transtion the transform property.

#transition-timing-function

Defines how the values between the start and the end of the transition are calculated.

default transition-timing-function: ease;

The transition starts slowly, accelerates in the middle, and slows down at the end.

transition-timing-function: ease-in;

The transition starts slowly, and accelerates gradually until the end.

transition-timing-function: ease-out;

The transition starts quickly, and decelerates gradually until the end.

transition-timing-function: ease-in-out;

Like ease, but more pronounced.

The transition starts quickly, and decelerates gradually until the end.

transition-timing-function: linear;

The transition has a *constant speed.

transition-timing-function: step-start;

The transition jumps instantly to the final state.

transition-timing-function: step-end;

The transition stays at the initial state until the end, when it instantly jumps to the final state.

transition-timing-function: steps(4, end);

By using steps() with an integer, you can define a specific number of steps before reaching the end. The state of the element will not vary gradually, but rather jump from state to state in separate instants.

#transition

Shorthand property for transition-property transition-duration transition-timing-function and transition-delay.

Only transition-duration is required.

transition: 1s;

  • transition-duration is set to 1s
  • transition-property defaults to all
  • transition-timing-function defaults to ease
  • transition-delay defaults to 0s

transition: 1s linear;

  • transition-duration is set to 1s
  • transition-property defaults to all
  • transition-timing-function is set to linear
  • transition-delay defaults to 0s

transition: background 1s linear;

  • transition-duration is set to 1s
  • transition-property is set to background
  • transition-timing-function is set to linear
  • transition-delay defaults to 0s

transition: background 1s linear 500ms;

  • transition-duration is set to 1s
  • transition-property is set to background
  • transition-timing-function is set to linear
  • transition-delay is set to 500ms

transition: background 4s, transform 1s;

You can combine multiple properties with their own transition duration.

#white-space

Defines how the element's white space is handled.

default white-space: normal;

Sequences of spaces are combined into one.
Line breaks are ignored.
The text content is wrapped.

white-space: nowrap;

Sequences of spaces are combined into one.
Line breaks are ignored.
The text content is not wrapped and remains on a single line.

white-space: pre;

The white space is exactly preserved.

  • Sequences of spaces are preserved
  • Lines break only on new lines and <br>

white-space: pre-wrap;

The white space is mostly preserved.

  • Sequences of spaces are preserved
  • Lines break on new lines, <br>, but also when reaching the end of the element

white-space: pre-line;

Only new lines are preserved.

  • Sequences of spaces are combined into one
  • Lines break on new lines, <br>, but also when reaching the end of the element

#width

Defines the width of the element.

default width: auto;

The element will automatically adjust its width to allow its content to be displayed correctly.

width: 240px;

You can use numeric values like pixels, (r)em, percentages...

width: 50%;

If you use percentages, the value is relative to the container's width.

#will-change

Defines which properties are expected to change in the future (either through CSS or JavaScript).

default will-change: auto;

Doesn't tell the browser to optimize any property.

will-change: scroll-position;

Tells the browser to optimize for the element's scroll position, as it might change in the future.

will-change: contents;

Tells the browser to optimize for the element's contents, as it might change in the future.

will-change: box-shadow;

You can specify any other CSS property. For example, this tells the browser to optimize for the element's box-shadow, as it might change in the future.

#word-break

Defines how words should break when reaching the end of a line.

default word-break: normal;

Words with no space will not break. Sequences of uninterrupted characters will be displayed on a single line.

word-break: break-all;

Words with no space will break as soon as they reach the end of a line.

#word-spacing

Defines the spacing between words of a block of text.

default word-spacing: normal;

The spacing between the characters is normal.

word-spacing: 5px;

You can use pixel values.

word-spacing: 2em;

You can use em values: this allows the spacing to remain relative to the font-size.

#z-index

Defines the order of the elements on the z-axis. It only works on positioned elements (anything apart from static).

default z-index: auto;

The order is defined by the order in the HTML code:

  • first in the code = behind
  • last in the code = in front

z-index: 1;

The z-index value is relative to the other ones. The target element is move in front of its siblings.

z-index: -1;

You can use negative values. The target element is move in behind its siblings.