refactor: new project structure

scss/core/utilities/_background.scss

@@ -0,0 +1,8 @@
+.bg-primary,
+.bg-success,
+.bg-info,
+.bg-warning,
+.bg-danger,
+.bg-inverse {
+  color: #fff;
+}

scss/core/utilities/_borders.scss

@@ -0,0 +1,18 @@
+//border
+@each $prop, $abbrev in (border: b) {
+  @each $size in (0,1,2) {
+    @if $size == 0 {
+      .#{$abbrev}-a-#{$size} { #{$prop}:        0 !important; } // a = All sides
+      .#{$abbrev}-t-#{$size} { #{$prop}-top:    0 !important; }
+      .#{$abbrev}-r-#{$size} { #{$prop}-right:  0 !important; }
+      .#{$abbrev}-b-#{$size} { #{$prop}-bottom: 0 !important; }
+      .#{$abbrev}-l-#{$size} { #{$prop}-left:   0 !important; }
+    } @else {
+      .#{$abbrev}-a-#{$size} { #{$prop}:        $size * $border-width solid $border-color !important; } // a = All sides
+      .#{$abbrev}-t-#{$size} { #{$prop}-top:    $size * $border-width solid $border-color !important; }
+      .#{$abbrev}-r-#{$size} { #{$prop}-right:  $size * $border-width solid $border-color !important; }
+      .#{$abbrev}-b-#{$size} { #{$prop}-bottom: $size * $border-width solid $border-color !important; }
+      .#{$abbrev}-l-#{$size} { #{$prop}-left:   $size * $border-width solid $border-color !important; }
+    }
+  }
+}

scss/core/utilities/_display.scss

@@ -0,0 +1,18 @@
+//
+// Utilities for common `display` values
+//
+
+@each $breakpoint in map-keys($grid-breakpoints) {
+  @include media-breakpoint-down($breakpoint) {
+    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);
+
+    .d#{$infix}-down-none         { display: none !important; }
+    // .d#{$infix}-inline       { display: inline !important; }
+    // .d#{$infix}-inline-block { display: inline-block !important; }
+    // .d#{$infix}-block        { display: block !important; }
+    // .d#{$infix}-table        { display: table !important; }
+    // .d#{$infix}-table-cell   { display: table-cell !important; }
+    // .d#{$infix}-flex         { display: flex !important; }
+    // .d#{$infix}-inline-flex  { display: inline-flex !important; }
+  }
+}