Html Code

<div class="buttons">
  <h1>Simple hover effects with <code>box-shadow</code></h1>
  <button class="fill">Fill In</button>
  <button class="pulse">Pulse</button>
  <button class="close">Close</button>
  <button class="raise">Raise</button>
  <button class="up">Fill Up</button>
  <button class="slide">Slide</button>
  <button class="offset">Offset</button>

Css Code

  // Make a map with the class names and matching colors
$colors: (
  fill: #a972cb,
  pulse: #ef6eae, 
  close: #ff7f82, 
  raise: #ffa260, 
  up: #e4cb58, 
  slide: #8fc866, 
  offset: #19bc8b

// Sass variables compile to a static string; CSS variables are dynamic and inherited
  // Loop through the map and set CSS custom properties using Sass variables
@each $button, $color in $colors {
  .#{$button} {
    --color: #{$color};
    --hover: #{adjust-hue($color, 45deg)};

// Now every button will have different colors as set above. We get to use the same structure, only changing the custom properties.
button {  
  color: var(--color);
  transition: 0.25s;
  &:focus { 
    border-color: var(--hover);
    color: #fff;

//=== Pen styling, ignore
body {
  color: #fff;
  background: hsl(227, 10%, 10%);
  font: 300 1em 'Fira Sans', sans-serif;
  // Center everything ever
  justify-content: center;
  align-content: center;
  align-items: center;
  text-align: center;
  min-height: 100vh;
  display: flex;

// Basic button styles
button {
  background: none;
  border: 2px solid;
  font: inherit;
  line-height: 1;
  margin: 0.5em;
  padding: 1em 2em;