Converted to SASS/SCSS

demo/src/sass/layout/core.scss

@@ -0,0 +1,63 @@
+// ==========================================================================
+// Core
+// ==========================================================================
+
+html,
+body {
+    display: flex;
+    width: 100%;
+}
+
+html {
+    background: $page-background;
+    background-attachment: fixed;
+    height: 100%;
+}
+
+body {
+    align-items: center;
+    display: flex;
+    flex-direction: column;
+    min-height: 100%;
+}
+
+.grid {
+    flex: 1;
+    overflow: auto;
+}
+
+main {
+    margin: auto;
+    text-align: center;
+}
+
+aside {
+    align-items: center;
+    background: #fff;
+    color: $gray;
+    display: flex;
+    flex-shrink: 0;
+    justify-content: center;
+    padding: ($spacing-base * 0.75);
+    position: relative;
+    text-align: center;
+    text-shadow: none;
+    width: 100%;
+
+    .icon {
+        fill: $color-twitter;
+        margin-right: ($spacing-base / 2);
+    }
+
+    p {
+        margin: 0;
+    }
+
+    a {
+        color: $color-twitter;
+
+        &.tab-focus {
+            @include tab-focus($color-twitter);
+        }
+    }
+}

demo/src/sass/layout/error.scss

@@ -0,0 +1,30 @@
+// ==========================================================================
+// Errors (AWS pages)
+// ==========================================================================
+
+// Error page
+html.error,
+.error body {
+    height: 100%;
+}
+
+html.error {
+    background: $page-background;
+    background-attachment: fixed;
+}
+
+.error body {
+    align-items: center;
+    display: flex;
+    width: 100%;
+}
+
+.error main {
+    padding: $spacing-base;
+    text-align: center;
+    width: 100%;
+
+    p {
+        @include font-size($font-size-large);
+    }
+}

demo/src/sass/layout/grid.scss

@@ -0,0 +1,19 @@
+// ==========================================================================
+// Super basic grid
+// ==========================================================================
+
+.grid {
+    margin: 0 auto;
+    padding: $spacing-base;
+
+    @media only screen and (min-width: $screen-md) {
+        align-items: center;
+        display: flex;
+        max-width: $container-max-width;
+        width: 100%;
+
+        > * {
+            flex: 1;
+        }
+    }
+}