Grav2023/themes/quark/scss/spectre/icons/_icons-core.scss

// Icon variables
$icon-border-width: $border-width-lg;
$icon-prefix: "icon";

// Icon base style
.#{$icon-prefix} {
  box-sizing: border-box;
  display: inline-block;
  font-size: inherit;
  font-style: normal;
  height: 1em;
  position: relative;
  text-indent: -9999px;
  vertical-align: middle;
  width: 1em;
  &::before,
  &::after {
    content: "";
    display: block;
    left: 50%;
    position: absolute;
    top: 50%;
    transform: translate(-50%, -50%);
  }

  // Icon sizes
  &.icon-2x {
    font-size: 1.6rem;
  }

  &.icon-3x {
    font-size: 2.4rem;
  }

  &.icon-4x {
    font-size: 3.2rem;
  }
}

// Component icon support
.accordion,
.btn,
.toast,
.menu {
  .#{$icon-prefix} {
    vertical-align: -10%;
  }
}

.btn-lg {
  .#{$icon-prefix} {
    vertical-align: -15%;
  }
}