CSS files converted to Sass. Some style fixes. Created file with sponsors.

_sass/vendor/bootstrap/mixins/_table-row.scss

@@ -0,0 +1,28 @@
+// Tables
+
+@mixin table-row-variant($state, $background) {
+  // Exact selectors below required to override `.table-striped` and prevent
+  // inheritance to nested tables.
+  .table > thead > tr,
+  .table > tbody > tr,
+  .table > tfoot > tr {
+    > td.#{$state},
+    > th.#{$state},
+    &.#{$state} > td,
+    &.#{$state} > th {
+      background-color: $background;
+    }
+  }
+
+  // Hover states for `.table-hover`
+  // Note: this is not available for cells or rows within `thead` or `tfoot`.
+  .table-hover > tbody > tr {
+    > td.#{$state}:hover,
+    > th.#{$state}:hover,
+    &.#{$state}:hover > td,
+    &:hover > .#{$state},
+    &.#{$state}:hover > th {
+      background-color: darken($background, 5%);
+    }
+  }
+}