Added basic floating content box.

public/styles/tools/_absolute-centering.scss

@@ -0,0 +1,63 @@
+/*
+ *  Absolute Centering
+ *    Provides tools to absolutely center elements in various center stlyes.
+ *
+ *  Dependencies:
+ *    styles/tools/_transform.scss
+ *
+ *  Version:
+ *    1.0.0 - 2018/05/11
+ *
+ */
+@mixin t-absolute-center-x-y() {
+  position: absolute;
+  left: 50%;
+  top: 50%;
+  @include t-translate(-50%, -50%);
+}
+
+@mixin t-absolute-center-x() {
+  position: absolute;
+  left: 50%;
+  @include t-translate-x(-50%);
+}
+
+@mixin t-absolute-center-y() {
+  position: absolute;
+  top: 50%;
+  @include t-translate-y(-50%);
+}
+
+@mixin t-absolute-position-options($inset: 0) {
+  position: absolute;
+
+  &.is-top {
+    top: $inset;
+  }
+
+  &.is-bottom {
+    bottom: $inset;
+  }
+
+  &.is-left {
+    left: $inset;
+  }
+
+  &.is-right {
+    right: $inset;
+  }
+
+  &.is-middle {
+    top: 50%;
+    @include t-translate-y(-50%);
+  }
+
+  &.is-center {
+    left: 50%;
+    @include t-translate-x(-50%);
+  }
+
+  &.is-middle.is-center {
+    @cinlude t-translate(-50%, -50%);
+  }
+}