diff --git a/aio/src/styles/2-modules/_alert.scss b/aio/src/styles/2-modules/_alert.scss
index f8049f48f9..cd5b7becca 100644
--- a/aio/src/styles/2-modules/_alert.scss
+++ b/aio/src/styles/2-modules/_alert.scss
@@ -3,6 +3,9 @@
     margin: 24px 0px;
     font-size: 14px;
     color: $darkgray;
+    width: 100%;
+    box-sizing: border-box;
+
     &.is-critical {
         border-left: 10px solid $brightred;
         background-color: rgba($brightred, 0.05);
diff --git a/aio/src/styles/2-modules/_subsection.scss b/aio/src/styles/2-modules/_subsection.scss
index a6f47bd0e8..20dc06cd55 100644
--- a/aio/src/styles/2-modules/_subsection.scss
+++ b/aio/src/styles/2-modules/_subsection.scss
@@ -6,6 +6,8 @@
     margin-bottom: 8px;
     display: table;
     clear: both;
+    width: 100%;
+    box-sizing: border-box;
 
     h3 {
         margin: 8px 0 0;