diff --git a/assets/css/main.css b/assets/css/main.css
index bb7b935..fea5051 100644
--- a/assets/css/main.css
+++ b/assets/css/main.css
@@ -38,6 +38,11 @@ ul {
 }
 
 /* Layouting */
+* {
+    /* To fix sizing issues */
+    box-sizing: border-box;
+}
+
 .container {
     display: flex;
     justify-content: center;
@@ -87,3 +92,12 @@ ul {
     border-color: gray;
     padding-left: 4px;
 }
+
+.warning {
+    border-left: 2px;
+    border-left-style: solid;
+    border-color: gray;
+    padding-left: 4px;
+
+    color: #f1c40f;
+}