CSS divider using :after and :before pseudo elements.

divider.scss

%divider {
  &:after, &:before {
    display: block;
    position: absolute;
  }
  &:after {
    text-transform: none;
    text-shadow: none;
    @include rem(font-size, 12px);
    text-align: center;
    color: #EBF7FF;
    left: 46%;
    bottom: -43px;
    height: 16px;
    width: 16px;
    background: #062F4C;
    margin: 0 auto;
    padding: 6px;
    border-radius: 100%;
  }
  &:before {
    width: 100%;
    content: '';
    border-bottom: 2px solid #062F4C;
    bottom: -30px;
  }
}

@mixin divider($text: "or") {
  @extend %divider;
  &:after { content: $text; }
}

example.scss

// @include the divider mixin on the element before the division should take place

div {
  @include divider("or");
}

I get the following error (sass newbie here)

/*
Error: Undefined mixin 'rem'.
        on line 9 of sass/modules/_divider.scss, in `rem'
        from line 9 of sass/modules/_divider.scss
        from line 3 of sass/partials/base.scss
        from line 1 of sass/main.scss

Backtrace:
sass/modules/_divider.scss:9:in `rem'
sass/modules/_divider.scss:9
sass/partials/base.scss:3
sass/main.scss:1

@ben-shepherd The following code on line 9 references a mixin called rem.

@include rem(font-size, 12px);

You can just delete that line and/or replace with any font-size you want.
If you want to learn more about mixins you can give a shot to the sass docs at Mixins guide