Add theme assets;

public/assets/scss/common/mixins/_buttons.scss

@@ -0,0 +1,58 @@
+@mixin social-button($color) {
+  background: $color;
+  color: $white;
+
+  &:hover,
+  &:focus {
+    background: darken($color, 10%);
+    color: $white;
+  }
+  &.btn-social-icon-text {
+    padding: 0 1.5rem 0 0;
+    background: lighten($color, 10%);
+    i {
+      background: $color;
+      padding: .75rem;
+      display: inline-block;
+      margin-right: 1.5rem;
+    }
+  }
+}
+
+@mixin social-outline-button($color) {
+border: 1px solid $color;
+color: $color;
+  &:hover {
+    background: $color;
+    color: $white;
+  }
+}
+
+@mixin button-inverse-variant($color, $color-hover: $white) {
+  background-color: rgba($color, 0.2);
+  background-image: none;
+  border-color: rgba($color, 0);
+  &:not(.btn-inverse-light) {
+    color: $color;      
+  }
+  &:hover,
+  &.active,
+  &:active,
+  .show > &.dropdown-toggle {
+    background-color: rgba($color, 0.3);
+    border-color: rgba($color, 0);
+  }
+
+  &.focus,
+  &:focus {
+    // box-shadow: 0 0 0 3px rgba($color, .5);
+    background-color: rgba($color, 0.3);
+    border-color: transparent;
+  }
+
+  &.disabled,
+  &:disabled {
+    color: $color;
+    background-color: transparent;
+  }
+}