30 Seconds of CSS

Bouncing loaderanimation

Creates a bouncing loader animation.

HTML

<div class="bouncing-loader">
  <div></div>
  <div></div>
  <div></div>
</div>

CSS

@keyframes bouncing-loader {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0.1;
    transform: translateY(-1rem);
  }
}
.bouncing-loader {
  display: flex;
  justify-content: center;
}
.bouncing-loader > div {
  width: 1rem;
  height: 1rem;
  margin: 3rem 0.2rem;
  background: #8385aa;
  border-radius: 50%;
  animation: bouncing-loader 0.6s infinite alternate;
}
.bouncing-loader > div:nth-child(2) {
  animation-delay: 0.2s;
}
.bouncing-loader > div:nth-child(3) {
  animation-delay: 0.4s;
}

Demo

Explanation

Note: 1rem is usually 16px.

1. @keyframes defines an animation that has two states, where the element changes opacity and is translated up on the 2D plane using transform: translateY().

2. .bouncing-loader is the parent container of the bouncing circles and uses display: flex and justify-content: center to position them in the center.

3. .bouncing-loader > div, targets the three child divs of the parent to be styled. The divs are given a width and height of 1rem, using border-radius: 50% to turn them from squares to circles.

4. margin: 3rem 0.2rem specifies that each circle has a top/bottom margin of 3rem and left/right margin of 0.2rem so that they do not directly touch each other, giving them some breathing room.

5. animation is a shorthand property for the various animation properties: animation-name, animation-duration, animation-iteration-count, animation-direction are used.

6. nth-child(n) targets the element which is the nth child of its parent.

7. animation-delay is used on the second and third div respectively, so that each element does not start the animation at the same time.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-animation

Box-sizing resetlayout

Resets the box-model so that widths and heights are not affected by their borders or padding.

CSS

html {
  box-sizing: border-box;
}
*,
*::before,
*::after {
  box-sizing: inherit;
}

Demo

Explanation

1. box-sizing: border-box makes the addition of padding or borders not affect an element's width or height.
2. box-sizing: inherit makes an element respect its parent's box-sizing rule.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css3-boxsizing

Circlevisual

Creates a circle shape with pure CSS.

HTML

<div class="circle"></div>

CSS

.circle {
  border-radius: 50%;
  width: 2rem;
  height: 2rem;
  background: #333;
}

Demo

Explanation

border-radius: 50% curves the borders of an element to create a circle.

Since a circle has the same radius at any given point, the width and height must be the same. Differing values will create an ellipse.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=border-radius

Clearfixlayout

Ensures that an element self-clears its children.

Note: This is only useful if you are still using float to build layouts. Please consider using a modern approach with flexbox layout or grid layout.

HTML

<div class="clearfix">
  <div class="floated">float a</div>
  <div class="floated">float b</div>
  <div class="floated">float c</div>
</div>

CSS

.clearfix::after {
  content: '';
  display: block;
  clear: both;
}
.floated {
  float: left;
}

Demo

Explanation

1. .clearfix::after defines a pseudo-element.
2. content: '' allows the pseudo-element to affect layout.
3. clear: both indicates that the left, right or both sides of the element cannot be adjacent to earlier floated elements within the same block formatting context.

Browser support

⚠️ For this snippet to work properly you need to ensure that there are no non-floating children in the container and that there are no tall floats before the clearfixed container but in the same formatting context (e.g. floated columns).

Constant width to height ratiolayout

Given an element of variable width, it will ensure its height remains proportionate in a responsive fashion (i.e., its width to height ratio remains constant).

HTML

<div class="constant-width-to-height-ratio"></div>

CSS

.constant-width-to-height-ratio {
  background: #333;
  width: 50%;
}
.constant-width-to-height-ratio::before {
  content: '';
  padding-top: 100%;
  float: left;
}
.constant-width-to-height-ratio::after {
  content: '';
  display: block;
  clear: both;
}

Demo

Resize your browser window to see the proportion of the element remain the same.

Explanation

padding-top on the ::before pseudo-element causes the height of the element to equal a percentage of its width. 100% therefore means the element's height will always be 100% of the width, creating a responsive square.

This method also allows content to be placed inside the element normally.

Browser support

✅ No caveats.

Countervisualother

Counters are, in essence, variables maintained by CSS whose values may be incremented by CSS rules to track how many times they're used.

HTML

<ul>
  <li>List item</li>
  <li>List item</li>
  <li>List item</li>
</ul>

CSS

ul {
  counter-reset: counter;
}
li::before {
  counter-increment: counter;
  content: counters(counter, '.') ' ';
}

Demo

Explanation

You can create a ordered list using any type of HTML.

1. counter-reset Initializes a counter, the value is the name of the counter. By default, the counter starts in 0. This property can also be used to change its value to any specific number.

2. counter-increment Used in element that will be countable. Once counter-reset initialized, a counter's value can be increased or decreased.

3. counter(name, style) Displays the value of a section counter. Generally used in a content property. This function can recieve two parameters, the first as the name of the counter and the second one can be decimal or upper-roman (decimal by default).

4. counters(counter, string, style) Displays the value of a section counter. Generally used in a content property. This function can recieve three parameters, the first as the name of the counter, the second one you can include a string which comes after the counter and the third one can be decimal or upper-roman (decimal by default).

5. A CSS counter can be especially useful for making outlined lists, because a new instance of the counter is automatically created in child elements. Using the counters() function, separating text can be inserted between different levels of nested counters.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-counters

Custom scrollbarvisual

Customizes the scrollbar style for the document and elements with scrollable overflow, on WebKit platforms.

HTML

<div class="custom-scrollbar">
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iure id exercitationem nulla qui repellat laborum vitae, molestias tempora velit natus. Quas, assumenda nisi. Quisquam enim qui iure, consequatur velit sit?</p>
</div>

CSS

/* Document scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
  border-radius: 10px;
}
::-webkit-scrollbar-thumb {
  border-radius: 10px;
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.5);
}
/* Scrollable element */
.some-element::webkit-scrollbar {
}

Demo

Explanation

1. ::-webkit-scrollbar targets the whole scrollbar element.
2. ::-webkit-scrollbar-track targets only the scrollbar track.
3. ::-webkit-scrollbar-thumb targets the scrollbar thumb.

There are many other pseudo-elements that you can use to style scrollbars. For more info, visit the WebKit Blog

Browser support

⚠️ Scrollbar styling doesn't appear to be on any standards track.

• https://caniuse.com/#feat=css-scrollbar

Custom text selectionvisual

Changes the styling of text selection.

HTML

<p class="custom-text-selection">Select some of this text.</p>

CSS

::selection {
  background: aquamarine;
  color: black;
}
.custom-text-selection::selection {
  background: deeppink;
  color: white;
}

Demo

Explanation

::selection defines a pseudo selector on an element to style text within it when selected. Note that if you don't combine any other selector your style will be applied at document root level, to any selectable element.

Browser support

⚠️ Requires prefixes for full support and is not actually in any specification.

• https://caniuse.com/#feat=css-selection

Custom variablesother

CSS variables that contain specific values to be reused throughout a document.

HTML

<p class="custom-variables">CSS is awesome!</p>

CSS

:root {
  --some-color: #da7800;
  --some-keyword: italic;
  --some-size: 1.25em;
  --some-complex-value: 1px 1px 2px whitesmoke, 0 0 1em slategray, 0 0 0.2em slategray;
}
.custom-variables {
  color: var(--some-color);
  font-size: var(--some-size);
  font-style: var(--some-keyword);
  text-shadow: var(--some-complex-value);
}

Demo

Explanation

The variables are defined globally within the :root CSS pseudo-class which matches the root element of a tree representing the document. Variables can also be scoped to a selector if defined within the block.

Declare a variable with --variable-name:.

Reuse variables throughout the document using the var(--variable-name) function.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-variables

Disable selectioninteractivity

Makes the content unselectable.

HTML

<p>You can select me.</p>
<p class="unselectable">You can't select me!</p>

CSS

.unselectable {
  user-select: none;
}

Demo

Explanation

user-select: none specifies that the text cannot be selected.

Browser support

⚠️ Requires prefixes for full support. ⚠️ This is not a secure method to prevent users from copying content.

• https://caniuse.com/#feat=user-select-none

Display table centeringlayout

Vertically and horizontally centers a child element within its parent element using display: table (as an alternative to flexbox).

HTML

<div class="container">
  <div class="center">
    <span>Centered content</span>
  </div>
</div>

CSS

.container {
  border: 1px solid #333;
  height: 250px;
  width: 250px;
}
.center {
  display: table;
  height: 100%;
  width: 100%;
}
.center > span {
  display: table-cell;
  text-align: center;
  vertical-align: middle;
}

Demo

Explanation

1. display: table on '.center' allows the element to behave like a <table> HTML element.
2. 100% height and width on '.center' allows the element to fill the available space within its parent element.
3. display: table-cell on '.center > span' allows the element to behave like an HTML element.
4. text-align: center on '.center > span' centers the child element horizontally.
5. vertical-align: middle on '.center > span' centers the child element vertically.

The outer parent ('.container' in this case) must have a fixed height and width.

Browser support

✅ No caveats.

• https://caniuse.com/#search=display%3A%20table

Donut spinneranimation

Creates a donut spinner that can be used to indicate the loading of content.

HTML

<div class="donut"></div>

CSS

@keyframes donut-spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}
.donut {
  display: inline-block;
  border: 4px solid rgba(0, 0, 0, 0.1);
  border-left-color: #7983ff;
  border-radius: 50%;
  width: 30px;
  height: 30px;
  animation: donut-spin 1.2s linear infinite;
}

Demo

Explanation

Use a semi-transparent border for the whole element, except one side that will serve as the loading indicator for the donut. Use animation to rotate the element.

Browser support

⚠️ Requires prefixes for full support.

• https://caniuse.com/#feat=css-animation
• https://caniuse.com/#feat=transforms2d

Dynamic shadowvisual

Creates a shadow similar to box-shadow but based on the colors of the element itself.

HTML

<div class="dynamic-shadow"></div>

CSS

.dynamic-shadow {
  position: relative;
  width: 10rem;
  height: 10rem;
  background: linear-gradient(75deg, #6d78ff, #00ffb8);
  z-index: 1;
}
.dynamic-shadow::after {
  content: '';
  width: 100%;
  height: 100%;
  position: absolute;
  background: inherit;
  top: 0.5rem;
  filter: blur(0.4rem);
  opacity: 0.7;
  z-index: -1;
}

Demo

Explanation

1. position: relative on the element establishes a Cartesian positioning context for psuedo-elements.
2. z-index: 1 establishes a new stacking context.
3. ::after defines a pseudo-element.
4. position: absolute takes the pseudo element out of the flow of the document and positions it in relation to the parent.
5. width: 100% and height: 100% sizes the pseudo-element to fill its parent's dimensions, making it equal in size.
6. background: inherit causes the pseudo-element to inherit the linear gradient specified on the element.
7. top: 0.5rem offsets the pseudo-element down slightly from its parent.
8. filter: blur(0.4rem) will blur the pseudo-element to create the appearance of a shadow underneath.
9. opacity: 0.7 makes the pseudo-element partially transparent.
10. z-index: -1 positions the pseudo-element behind the parent but in front of the background.

Browser support

⚠️ Requires prefixes for full support.

• https://caniuse.com/#feat=css-filters

Easing variablesanimation

Variables that can be reused for transition-timing-function properties, more powerful than the built-in ease, ease-in, ease-out and ease-in-out.

HTML

<div class="easing-variables"></div>

CSS

:root {
  --ease-in-quad: cubic-bezier(0.55, 0.085, 0.68, 0.53);
  --ease-in-cubic: cubic-bezier(0.55, 0.055, 0.675, 0.19);
  --ease-in-quart: cubic-bezier(0.895, 0.03, 0.685, 0.22);
  --ease-in-quint: cubic-bezier(0.755, 0.05, 0.855, 0.06);
  --ease-in-expo: cubic-bezier(0.95, 0.05, 0.795, 0.035);
  --ease-in-circ: cubic-bezier(0.6, 0.04, 0.98, 0.335);
  --ease-out-quad: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-out-cubic: cubic-bezier(0.215, 0.61, 0.355, 1);
  --ease-out-quart: cubic-bezier(0.165, 0.84, 0.44, 1);
  --ease-out-quint: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-out-expo: cubic-bezier(0.19, 1, 0.22, 1);
  --ease-out-circ: cubic-bezier(0.075, 0.82, 0.165, 1);
  --ease-in-out-quad: cubic-bezier(0.455, 0.03, 0.515, 0.955);
  --ease-in-out-cubic: cubic-bezier(0.645, 0.045, 0.355, 1);
  --ease-in-out-quart: cubic-bezier(0.77, 0, 0.175, 1);
  --ease-in-out-quint: cubic-bezier(0.86, 0, 0.07, 1);
  --ease-in-out-expo: cubic-bezier(1, 0, 0, 1);
  --ease-in-out-circ: cubic-bezier(0.785, 0.135, 0.15, 0.86);
}
.easing-variables {
  width: 50px;
  height: 50px;
  background: #333;
  transition: transform 1s var(--ease-out-quart);
}
.easing-variables:hover {
  transform: rotate(45deg);
}

Demo

Explanation

The variables are defined globally within the :root CSS pseudo-class which matches the root element of a tree representing the document. In HTML, :root represents the <html> element and is identical to the selector html, except that its specificity is higher.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-variables

Etched textvisual

Creates an effect where text appears to be "etched" or engraved into the background.

HTML

<p class="etched-text">I appear etched into the background.</p>

CSS

.etched-text {
  text-shadow: 0 2px white;
  font-size: 1.5rem;
  font-weight: bold;
  color: #b8bec5;
}

Demo

Explanation

text-shadow: 0 2px white creates a white shadow offset 0px horizontally and 2px vertically from the origin position.

The background must be darker than the shadow for the effect to work.

The text color should be slightly faded to make it look like it's engraved/carved out of the background.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-textshadow

Evenly distributed childrenlayout

Evenly distributes child elements within a parent element.

HTML

<div class="evenly-distributed-children">
  <p>Item1</p>
  <p>Item2</p>
  <p>Item3</p>
</div>

CSS

.evenly-distributed-children {
  display: flex;
  justify-content: space-between;
}

Demo

Explanation

1. display: flex enables flexbox.
2. justify-content: space-between evenly distributes child elements horizontally. The first item is positioned at the left edge, while the last item is positioned at the right edge.

Alternatively, use justify-content: space-around to distribute the children with space around them, rather than between them.

Browser support

⚠️ Needs prefixes for full support.

• https://caniuse.com/#feat=flexbox

Flexbox centeringlayout

Horizontally and vertically centers a child element within a parent element using flexbox.

HTML

<div class="flexbox-centering">
  <div class="child">Centered content.</div>
</div>

CSS

.flexbox-centering {
  display: flex;
  justify-content: center;
  align-items: center;
}

Demo

Explanation

1. display: flex enables flexbox.
2. justify-content: center centers the child horizontally.
3. align-items: center centers the child vertically.

Browser support

⚠️ Needs prefixes for full support.

• https://caniuse.com/#feat=flexbox

Gradient textvisual

Gives text a gradient color.

HTML

<p class="gradient-text">Gradient text</p>

CSS

.gradient-text {
  background: -webkit-linear-gradient(pink, red);
  -webkit-text-fill-color: transparent;
  -webkit-background-clip: text;
}

Demo

Explanation

1. background: -webkit-linear-gradient(...) gives the text element a gradient background.
2. webkit-text-fill-color: transparent fills the text with a transparent color.
3. webkit-background-clip: text clips the background with the text, filling the text with the gradient background as the color.

Browser support

⚠️ Uses non-standard properties.

• https://caniuse.com/#feat=text-stroke

Grid centeringlayout

Horizontally and vertically centers a child element within a parent element using grid.

HTML

<div class="grid-centering">
  <div class="child">Centered content.</div>
</div>

CSS

.grid-centering {
  display: grid;
  justify-content: center;
  align-items: center;
}

Demo

Explanation

1. display: grid enables grid.
2. justify-content: center centers the child horizontally.
3. align-items: center centers the child vertically.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-grid

Grid layoutlayout

Basic website layout using grid.

HTML

<div class="grid-layout">
  <div class="header">Header</div>
  <div class="sidebar">Sidebar</div>
  <div class="content">
    Content
    <br>
    Lorem ipsum dolor sit amet, consectetur adipisicing elit.
  </div>
  <div class="footer">Footer</div>
</div>

CSS

.grid-layout {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: repeat(3, 1fr);
  grid-template-areas:
    'sidebar header header'
    'sidebar content content'
    'sidebar footer  footer';
  color: white;
}
.grid-layout > div {
  background: #333;
  padding: 10px;
}
.sidebar {
  grid-area: sidebar;
}
.content {
  grid-area: content;
}
.header {
  grid-area: header;
}
.footer {
  grid-area: footer;
}

Demo

Explanation

1. display: grid enables grid.
2. grid-gap: 10px defines spacing between the elements.
3. grid-template-columns: repeat(3, 1fr) defines 3 columns of the same size.
4. grid-template-areas defines the names of grid areas.
5. grid-area: sidebar makes the element use the area with the name sidebar.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-grid

Hairline bordervisual

Gives an element a border equal to 1 native device pixel in width, which can look very sharp and crisp.

HTML

<div class="hairline-border">text</div>

CSS

.hairline-border {
  box-shadow: 0 0 0 1px;
}
@media (min-resolution: 2dppx) {
  .hairline-border {
    box-shadow: 0 0 0 0.5px;
  }
}
@media (min-resolution: 3dppx) {
  .hairline-border {
    box-shadow: 0 0 0 0.33333333px;
  }
}
@media (min-resolution: 4dppx) {
  .hairline-border {
    box-shadow: 0 0 0 0.25px;
  }
}

Demo

Explanation

1. box-shadow, when only using spread, adds a pseudo-border which can use subpixels*.
2. Use @media (min-resolution: ...) to check the device pixel ratio (1dppx equals 96 DPI), setting the spread of the box-shadow equal to 1 / dppx.

Browser Support

⚠️ Needs alternate syntax and JavaScript user agent checking for full support.

• https://caniuse.com/#feat=css-boxshadow
• https://caniuse.com/#feat=css-media-resolution

*Chrome does not support subpixel values on border. Safari does not support subpixel values on box-shadow. Firefox supports subpixel values on both.

Height transitionanimation

Transitions an element's height from 0 to auto when its height is unknown.

HTML

<div class="trigger">
  Hover me to see a height transition.
  <div class="el">content</div>
</div>

CSS

.el {
  transition: max-height 0.5s;
  overflow: hidden;
  max-height: 0;
}
.trigger:hover > .el {
  max-height: var(--max-height);
}

JavaScript

var el = document.querySelector('.el')
var height = el.scrollHeight
el.style.setProperty('--max-height', height + 'px')

Demo

Explanation

CSS

1. transition: max-height: 0.5s cubic-bezier(...) specifies that changes to max-height should be transitioned over 0.5 seconds, using an ease-out-quint timing function.
2. overflow: hidden prevents the contents of the hidden element from overflowing its container.
3. max-height: 0 specifies that the element has no height initially.
4. .target:hover > .el specifies that when the parent is hovered over, target a child .el within it and use the --max-height variable which was defined by JavaScript.

JavaScript

1. el.scrollHeight is the height of the element including overflow, which will change dynamically based on the content of the element.
2. el.style.setProperty(...) sets the --max-height CSS variable which is used to specify the max-height of the element the target is hovered over, allowing it to transition smoothly from 0 to auto.

Browser Support

• https://caniuse.com/#feat=css-variables
• https://caniuse.com/#feat=css-transitions

Hover underline animationanimation

Creates an animated underline effect when the text is hovered over.

Credit: https://flatuicolors.com/

HTML

<p class="hover-underline-animation">Hover this text to see the effect!</p>

CSS

.hover-underline-animation {
  display: inline-block;
  position: relative;
  color: #0087ca;
}
.hover-underline-animation::after {
  content: '';
  position: absolute;
  width: 100%;
  transform: scaleX(0);
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: #0087ca;
  transform-origin: bottom right;
  transition: transform 0.25s ease-out;
}
.hover-underline-animation:hover::after {
  transform: scaleX(1);
  transform-origin: bottom left;
}

Demo

Explanation

1. display: inline-block makes the block p an inline-block to prevent the underline from spanning the entire parent width rather than just the content (text).
2. position: relative on the element establishes a Cartesian positioning context for pseudo-elements.
3. ::after defines a pseudo-element.
4. position: absolute takes the pseudo element out of the flow of the document and positions it in relation to the parent.
5. width: 100% ensures the pseudo-element spans the entire width of the text block.
6. transform: scaleX(0) initially scales the pseudo element to 0 so it has no width and is not visible.
7. bottom: 0 and left: 0 position it to the bottom left of the block.
8. transition: transform 0.25s ease-out means changes to transform will be transitioned over 0.25 seconds with an ease-out timing function.
9. transform-origin: bottom right means the transform anchor point is positioned at the bottom right of the block.
10. :hover::after then uses scaleX(1) to transition the width to 100%, then changes the transform-origin to bottom left so that the anchor point is reversed, allowing it transition out in the other direction when hovered off.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=transforms2d
• https://caniuse.com/#feat=css-transitions

Last item with remaining available heightlayout

Take advantage of available viewport space by giving the last element the remaining available space in current viewport, even when resizing the window.

HTML

<div class="container">
  <div>Div 1</div>
  <div>Div 2</div>
  <div>Div 3</div>
</div>

CSS

html,
body {
  height: 100%;
  margin: 0;
}
.container {
  height: 100%;
  display: flex;
  flex-direction: column;
}
.container > div:last-child {
  background-color: #333;
  flex: 1;
}

Demo

Explanation

1. height: 100% set the height of container as viewport height.
2. display: flex enables flexbox.
3. flex-direction: column set the direction of flex items' order from top to down.
4. flex-grow: 1 the flexbox will apply remaining available space of container to last child element.

The parent must have a viewport height. flex-grow: 1 could be applied to the first or second element, which will have all available space.

Browser support

⚠️ Needs prefixes for full support.

• https://caniuse.com/#feat=flexbox

Mouse cursor gradient trackingvisualinteractivity

A hover effect where the gradient follows the mouse cursor.

Credit: Tobias Reich

HTML

<button class="mouse-cursor-gradient-tracking">
  <span>Hover me</span>
</button>

CSS

.mouse-cursor-gradient-tracking {
  position: relative;
  background: #7983ff;
  padding: 0.5rem 1rem;
  font-size: 1.2rem;
  border: none;
  color: white;
  cursor: pointer;
  outline: none;
  overflow: hidden;
}
.mouse-cursor-gradient-tracking span {
  position: relative;
}
.mouse-cursor-gradient-tracking::before {
  --size: 0;
  content: '';
  position: absolute;
  left: var(--x);
  top: var(--y);
  width: var(--size);
  height: var(--size);
  background: radial-gradient(circle closest-side, pink, transparent);
  transform: translate(-50%, -50%);
  transition: width 0.2s ease, height 0.2s ease;
}
.mouse-cursor-gradient-tracking:hover::before {
  --size: 200px;
}

JavaScript

var btn = document.querySelector('.mouse-cursor-gradient-tracking')
btn.onmousemove = function(e) {
  var x = e.pageX - btn.offsetLeft
  var y = e.pageY - btn.offsetTop
  btn.style.setProperty('--x', x + 'px')
  btn.style.setProperty('--y', y + 'px')
}

Demo

Explanation

TODO

Note!

If the element's parent has a positioning context (position: relative), you will need to subtract its offsets as well.

var x = e.pageX - btn.offsetLeft - btn.offsetParent.offsetLeft
var y = e.pageY - btn.offsetTop - btn.offsetParent.offsetTop

Browser support

• https://caniuse.com/#feat=css-variables

:not selectorvisual

The :not psuedo selector is useful for styling a group of elements, while leaving the last (or specified) element unstyled.

HTML

<ul class="css-not-selector-shortcut">
  <li>One</li>
  <li>Two</li>
  <li>Three</li>
  <li>Four</li>
  <li>Five</li>
</ul>

CSS

.css-not-selector-shortcut {
  display: flex;
}
li {
  list-style-type: none;
  margin: 0;
  padding: 0 0.75rem;
}
li:not(:last-child) {
  border-right: 2px solid #d2d5e4;
}

Demo

Explanation

li:not(:last-child) specifies that the styles should apply to all li elements except the :last-child.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-sel3

Offscreenlayoutvisual

A bulletproof way to completely hide an element visually and positionally in the DOM while still allowing it to be accessed by JavaScript and readable by screen readers. This method is very useful for accessibility ( ADA) development when more context is needed for visually-impaired users. As an alternative to display: none which is not readable by screen readers or visibility: hidden which takes up physical space in the DOM.

HTML

<a class="button" href="http://pantswebsite.com">
  Learn More
  <span class="offscreen"> about pants</span>
</a>

CSS

.offscreen {
  border: 0;
  clip: rect(0 0 0 0);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
}

Demo

Explanation

1. Remove all borders.
2. Use clip to indicate that no part of the element should be shown.
3. Make the height and width of the element 1px.
4. Negate the elements height and width using margin: -1px.
5. Hide the element's overflow.
6. Remove all padding.
7. Position the element absolutely so that it does not take up space in the DOM.

Browser support

✅ No caveats.

(Although clip technically has been depreciated, the newer clip-path currently has very limited browser support.)

• https://caniuse.com/#search=clip

Overflow scroll gradientvisual

Adds a fading gradient to an overflowing element to better indicate there is more content to be scrolled.

HTML

<div class="overflow-scroll-gradient">
  <div class="overflow-scroll-gradient__scroller">
    Content to be scrolled
  </div>
</div>

CSS

.overflow-scroll-gradient {
  position: relative;
}
.overflow-scroll-gradient::after {
  content: '';
  position: absolute;
  bottom: 0;
  width: 240px;
  height: 25px;
  background: linear-gradient(
    rgba(255, 255, 255, 0.001),
    white
  ); /* transparent keyword is broken in Safari */
  pointer-events: none;
}
.overflow-scroll-gradient__scroller {
  overflow-y: scroll;
  background: white;
  width: 240px;
  height: 200px;
  padding: 15px 0;
  line-height: 1.2;
  text-align: center;
}

Demo

Explanation

1. position: relative on the parent establishes a Cartesian positioning context for pseudo-elements.
2. ::after defines a pseudo element.
3. background-image: linear-gradient(...) adds a linear gradient that fades from transparent to white (top to bottom).
4. position: absolute takes the pseudo element out of the flow of the document and positions it in relation to the parent.
5. width: 240px matches the size of the scrolling element (which is a child of the parent that has the pseudo element).
6. height: 25px is the height of the fading gradient pseudo-element, which should be kept relatively small.
7. bottom: 0 positions the pseudo-element at the bottom of the parent.
8. pointer-events: none specifies that the pseudo-element cannot be a target of mouse events, allowing text behind it to still be selectable/interactive.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-gradients

Popout menuinteractivity

Reveals an interactive popout menu on hover.

HTML

<div class="reference">
  <div class="popout-menu">
    Popout menu
  </div>
</div>

CSS

.reference {
  position: relative;
}
.popout-menu {
  position: absolute;
  visibility: hidden;
  left: 100%;
}
.reference:hover > .popout-menu {
  visibility: visible;
}

Demo

Explanation

1. position: relative on the reference parent establishes a Cartesian positioning context for its child.
2. position: absolute takes the popout menu out of the flow of the document and positions it in relation to the parent.
3. left: 100% moves the the popout menu 100% of its parent's width from the left.
4. visibility: hidden hides the popout menu initially and allows for transitions (unlike display: none).
5. .reference:hover > .popout-menu means that when .reference is hovered over, select immediate children with a class of .popout-menu and change their visibility to visible, which shows the popout.

Browser support

✅ No caveats.

Pretty text underlinevisual

A nicer alternative to text-decoration: underline where descenders do not clip the underline. Natively implemented as text-decoration-skip-ink: auto but it has less control over the underline.

HTML

<p class="pretty-text-underline">Pretty text underline without clipping descending letters.</p>

CSS

.pretty-text-underline {
  display: inline;
  text-shadow: 1px 1px #f5f6f9, -1px 1px #f5f6f9, -1px -1px #f5f6f9, 1px -1px #f5f6f9;
  background-image: linear-gradient(90deg, currentColor 100%, transparent 100%);
  background-position: bottom;
  background-repeat: no-repeat;
  background-size: 100% 1px;
}
.pretty-text-underline::-moz-selection {
  background-color: rgba(0, 150, 255, 0.3);
  text-shadow: none;
}
.pretty-text-underline::selection {
  background-color: rgba(0, 150, 255, 0.3);
  text-shadow: none;
}

Demo

Explanation

1. text-shadow uses 4 values with offsets that cover a 4x4 px area to ensure the underline has a "thick" shadow that covers the line where descenders clip it. Use a color that matches the background. For a larger font, use a larger px size. Additional values can create an even thicker shadow, and subpixel values can also be used.
2. background-image: linear-gradient(...) creates a 90deg gradient using the text color (currentColor).
3. The background-* properties size the gradient as 100% of the width of the block and 1px in height at the bottom and disables repetition, which creates a 1px underline beneath the text.
4. The ::selection pseudo selector rule ensures the text shadow does not interfere with text selection.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-textshadow
• https://caniuse.com/#feat=css-gradients

Reset all stylesvisual

Resets all styles to default values with one property. This will not affect direction and unicode-bidi properties.

HTML

<div class="reset-all-styles">
  <h4>Title</h4>
  <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iure id exercitationem nulla qui repellat laborum vitae, molestias tempora velit natus. Quas, assumenda nisi. Quisquam enim qui iure, consequatur velit sit?</p>
</div>

CSS

.reset-all-styles {
  all: initial;
}

Demo

Explanation

The all property allows you to reset all styles (inherited or not) to default values.

Browser support

⚠️ MS Edge status is under consideration.

• https://caniuse.com/#feat=css-all

Shape separatorvisual

Uses an SVG shape to separate two different blocks to create more a interesting visual appearance compared to standard horizontal separation.

HTML

<div class="shape-separator"></div>

CSS

.shape-separator {
  position: relative;
  height: 48px;
  background: #333;
}
.shape-separator::after {
  content: '';
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 12'%3E%3Cpath d='m12 0l12 12h-24z' fill='%23fff'/%3E%3C/svg%3E");
  position: absolute;
  width: 100%;
  height: 12px;
  bottom: 0;
}

Demo

Explanation

1. position: relative on the element establishes a Cartesian positioning context for pseudo elements.
2. ::after defines a pseudo element.
3. background-image: url(...) adds the SVG shape (a 24x12 triangle) as the background image of the pseudo element, which repeats by default. It must be the same color as the block that is being separated. For other shapes, we can use the URL-encoder for SVG.
4. position: absolute takes the pseudo element out of the flow of the document and positions it in relation to the parent.
5. width: 100% ensures the element stretches the entire width of its parent.
6. height: 12px is the same height as the shape.
7. bottom: 0 positions the pseudo element at the bottom of the parent.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=svg

Sibling fadeinteractivity

Fades out the siblings of a hovered item.

HTML

<div class="sibling-fade">
  <span>Item 1</span>
  <span>Item 2</span>
  <span>Item 3</span>
  <span>Item 4</span>
  <span>Item 5</span>
  <span>Item 6</span>
</div>

CSS

span {
  padding: 0 1rem;
  transition: opacity 0.2s;
}
.sibling-fade:hover span:not(:hover) {
  opacity: 0.5;
}

Demo

Explanation

1. transition: opacity 0.2s specifies that changes to opacity will be transitioned over 0.2 seconds.
2. .sibling-fade:hover span:not(:hover) specifies that when the parent is hovered, select any span children that are not currently being hovered and change their opacity to 0.5.

Browser support

✅ No caveats.

• https://caniuse.com/#feat=css-sel3
• https://caniuse.com/#feat=css-transitions

System font stackvisual

Uses the native font of the operating system to get close to a native app feel.

HTML

<p class="system-font-stack">This text uses the system font.</p>

CSS

.system-font-stack {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu,
    Cantarell, 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

Demo

Explanation

The browser looks for each successive font, preferring the first one if possible, and falls back to the next if it cannot find the font (on the system or defined in CSS).

1. -apple-system is San Francisco, used on iOS and macOS (not Chrome however)
2. BlinkMacSystemFont is San Francisco, used on macOS Chrome
3. Segoe UI is used on Windows 10
4. Roboto is used on Android
5. Oxygen-Sans is used on GNU+Linux
6. Ubuntu is used on Linux
7. "Helvetica Neue" and Helvetica is used on macOS 10.10 and below (wrapped in quotes because it has a space)
8. Arial is a font widely supported by all operating systems
9. sans-serif is the fallback sans-serif font if none of the other fonts are supported

Browser support

✅ No caveats.

Transform centeringlayout

Vertically and horizontally centers a child element within its parent element using position: absolute and transform: translate() (as an alternative to flexbox or display: table). Similar to flexbox, this method does not require you to know the height or width of your parent or child so it is ideal for responsive applications.

HTML

<div class="parent">
  <div class="child">Centered content</div>
</div>

CSS

.parent {
  border: 1px solid #333;
  height: 250px;
  position: relative;
  width: 250px;
}
.child {
  left: 50%;
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
}

Demo

Explanation

1. position: absolute on the child element allows it to be positioned based on its containing block.
2. left: 50% and top: 50% offsets the child 50% from the left and top edge of its containing block.
3. transform: translate(-50%, -50%) allows the height and width of the child element to be negated so that it is vertically and horizontally centered.

Note: Fixed height and width on parent element is for the demo only.

Browser support

⚠️ Requires prefix for full support.

• https://caniuse.com/#search=transform

Trianglevisual

Creates a triangle shape with pure CSS.

HTML

<div class="triangle"></div>

CSS

.triangle {
  width: 0;
  height: 0;
  border-top: 20px solid #333;
  border-left: 20px solid transparent;
  border-right: 20px solid transparent;
}

Demo

Explanation

View this link for a detailed explanation.

The color of the border is the color of the triangle. The side the triangle tip points corresponds to the opposite border-* property. For example, a color on border-top means the arrow points downward.

Experiment with the px values to change the proportion of the triangle.

Browser support

✅ No caveats.

Truncate textlayout

If the text is longer than one line, it will be truncated and end with an ellipsis ….

HTML

<p class="truncate-text">If I exceed one line's width, I will be truncated.</p>

CSS

.truncate-text {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  width: 200px;
}

Demo

Explanation

1. overflow: hidden prevents the text from overflowing its dimensions (for a block, 100% width and auto height).
2. white-space: nowrap prevents the text from exceeding one line in height.
3. text-overflow: ellipsis makes it so that if the text exceeds its dimensions, it will end with an ellipsis.
4. width: 200px; ensures the element has a dimension, to know when to get ellipsis

Browser support

⚠️ Only works for single line elements.

• https://caniuse.com/#feat=text-overflow