.template-header {
  -webkit-background-size: cover;
  background-size: cover;
  text-align: center;

  h1 {
    color: $default-light-color;
    font-weight: 800;
		margin: 0;
  }

  .grid-inner {
    padding: 2em $guaranteed-edge-standoff;
    max-width: none;
    width: 100%;
    @include breakpoint($breakpoint-alpha) {
      padding: 6em $guaranteed-edge-standoff;
    }
  }
}

.header-introduction,
.header-php,
.header-javascript,
.header-html,
.header-css,
.header-version-control,
.header-markup,
.header-tools,
.header-migrations,
.header-structure,
.header-systems,
.header-markup {
	background-image: url("img/page-header.png");
}

.template-header {
  -webkit-background-size: cover;
  background-size: cover;
  text-align: center;

  h1 {
    color: $default-light-color;
    font-weight: 800;
		margin: 0;
  }

  .grid-inner {
    padding: 2em $guaranteed-edge-standoff;
    max-width: none;
    width: 100%;
    @include breakpoint($breakpoint-alpha) {
      padding: 6em $guaranteed-edge-standoff;
    }
  }
}

.header-introduction,
.header-php,
.header-javascript,
.header-html,
.header-css,
.header-version-control,
.header-markup,
.header-tools,
.header-migrations,
.header-structure,
.header-systems,
.header-markup,
.header-design {
	background-image: url("img/page-header.png");
}

Include design header in scss rules
Include design header in scss rules
