doc/dev/plugins/problems/scss/icons/_icons-navigation.scss

// Icon arrows
.icon-arrow-down,
.icon-arrow-left,
.icon-arrow-right,
.icon-arrow-up,
.icon-downward,
.icon-back,
.icon-forward,
.icon-upward {
  &::before {
    border: $icon-border-width solid currentColor;
    border-bottom: 0;
    border-right: 0;
    content: "";
    height: .65em;
    width: .65em;
  }
}

.icon-arrow-down {
  &::before {
    transform: translate(-50%, -75%) rotate(225deg);
  }
}

.icon-arrow-left {
  &::before {
    transform: translate(-25%, -50%) rotate(-45deg);
  }
}

.icon-arrow-right {
  &::before {
    transform: translate(-75%, -50%) rotate(135deg);
  }
}

.icon-arrow-up {
  &::before {
    transform: translate(-50%, -25%) rotate(45deg);
  }
}

.icon-back,
.icon-forward {
  &::after {
    background: currentColor;
    content: "";
    height: $icon-border-width;
    width: .8em;
  }
}

.icon-downward,
.icon-upward {
  &::after {
    background: currentColor;
    content: "";
    height: .8em;
    width: $icon-border-width;
  }
}

.icon-back {
  &::after {
    left: 55%;
  }
  &::before {
    transform: translate(-50%, -50%) rotate(-45deg);
  }
}

.icon-downward {
  &::after {
    top: 45%;
  }
  &::before {
    transform: translate(-50%, -50%) rotate(-135deg);
  }
}

.icon-forward {
  &::after {
    left: 45%;
  }
  &::before {
    transform: translate(-50%, -50%) rotate(135deg);
  }
}

.icon-upward {
  &::after {
    top: 55%;
  }
  &::before {
    transform: translate(-50%, -50%) rotate(45deg);
  }
}

// Icon caret
.icon-caret {
  &::before {
    border-top: .3em solid currentColor;
    border-right: .3em solid transparent;
    border-left: .3em solid transparent;
    content: "";
    height: 0;
    transform: translate(-50%, -25%);
    width: 0;
  }
}

// Icon menu
.icon-menu {
  &::before {
    background: currentColor;
    box-shadow: 0 -.35em, 0 .35em;
    content: "";
    height: $icon-border-width;
    width: 100%;
  }
}

// Icon apps
.icon-apps {
  &::before {
    background: currentColor;
    box-shadow: -.35em -.35em, -.35em 0, -.35em .35em, 0 -.35em, 0 .35em, .35em -.35em, .35em 0, .35em .35em;
    content: "";
    height: 3px;
    width: 3px;
  }
}