blog/src/styles/_buttons.css

.btn,
a.btn {
  text-align: center;
  display: block;
  margin: 0;
  touch-action: manipulation;
  cursor: pointer;
  background-image: none;
  white-space: nowrap;
  user-select: none;
  transition: 0.2s ease-in-out;
  padding: var(--padding-base-vertical) var(--padding-base-horizontal);
  font-size: var(--font-size-small);
  border-radius: var(--border-radius);
  background-color: rgba(255 255 255 / 10%);
  border: 1px solid var(--border-color);
  font-family: var(--font-family-headings);
  font-weight: var(--font-weight-headings);
  color: var(--text-color);
  text-transform: uppercase;
  text-decoration: none;
  box-shadow: var(--box-shadow);
}

.btn:hover,
.btn:focus {
  text-decoration: none;
  outline: 0;
  background-color: rgba(255 255 255 / 15%);
}

.btn:active {
  transition: none;
}

/* Disabled State */
.btn.disabled,
.btn[disabled],
button:disabled,
.btn:disabled {
  /* TODO: cursor & pointer values can't be used together */
  cursor: not-allowed;
  pointer-events: none;
  opacity: 0.5;
  box-shadow: none;
}

.btn span {
  font-size: var(--font-size-mini);
  color: var(--text-color-light);
  margin-left: 0.3em;
}

@media (min-width: 30rem) {
  .btn,
  a.btn {
    max-width: 20rem;
  }
}

button.link {
  color: var(--link-color);
}

button.link:hover,
button.link:focus {
  outline: 0;
}

/* // Primary Button */
.btn-primary,
a.btn-primary {
  /* dark variant of  `--body-background-color` */
  color: #161a1b;
  text-shadow: 0 1px 0 rgba(255 255 255 / 30%);
  background: var(--link-color);
  border-color: var(--link-color);
}

.btn-primary:hover,
.btn-primary:focus,
article a.btn-primary:hover,
article a.btn-primary:focus {
  color: #161a1b;
  background: var(--link-color-hover);
  text-shadow: 0 1px 0 rgba(255 255 255 / 30%);
}

.btn-primary:active {
  background: var(--link-color);
}

.btn-block {
  display: block;
}

.btn[class*='icon-']::before {
  content: '';
  width: 20px;
  height: 20px;
  display: inline-block;
  margin-right: 0.3rem;
  margin-bottom: -0.2rem;
  opacity: 0.75;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: 100%;
}

[data-theme='dark'] .btn[class*='icon-']::before {
  filter: invert(0.75);
}

[data-theme='dark'] .btn.btn-primary[class*='icon-']::before {
  filter: invert(0);
}

/* // some helper classes for old content
///////////////////////////////////// */

.content-download {
  text-align: center;
  display: block;
  margin-top: calc(var(--spacer) * 2);
  margin-bottom: calc(var(--spacer) * 2);
}

@media (min-width: 30rem) {
  .content-download {
    display: flex;
  }
}

.content-download .btn {
  margin-bottom: calc(var(--spacer) / 2);
  text-decoration: none;
}

.content-download .btn:first-child {
  margin-left: 0;
}

.content-download .btn:only-child {
  margin-left: auto;
  margin-right: auto;
}

.content-download .btn span {
  font-size: var(--font-size-mini);
  color: var(--brand-grey);
}

@media (min-width: 30rem) {
  .content-download .btn {
    flex: 1;
    margin-left: calc(var(--spacer) / 2);
    margin-bottom: 0;
  }
}

.icon-download::before {
  background-image: url('../../node_modules/feather-icons/dist/icons/arrow-down-circle.svg');
}

.icon-heart::before {
  background-image: url('../../node_modules/feather-icons/dist/icons/heart.svg');
}

.icon-github::before {
  background-image: url('../../node_modules/feather-icons/dist/icons/github.svg');
}

.icon-compass::before {
  background-image: url('../../node_modules/feather-icons/dist/icons/compass.svg');
}

.icon-code::before {
  background-image: url('../../node_modules/feather-icons/dist/icons/code.svg');
}