diff --git a/size.scss b/size.scss
index a25215e..02dc072 100644
--- a/size.scss
+++ b/size.scss
@@ -95,4 +95,18 @@
 .fw-66 {
     width: 66%;
     margin: 5px;;
+}
+
+@media only screen and (min-width: 501px) and (max-width: 900px) {
+    .box.w-33, .box.w-25 {
+        width: 49%;
+        width: calc(50% - 5px);
+    }
+}
+
+@media only screen and (max-width: 500px) {
+    .box.w-33, .box.w-50, .box.w-25 {
+        width: 100%;
+        width: calc(100% - 5px);
+    }
 }
\ No newline at end of file
diff --git a/styles.css b/styles.css
index 9df6277..b33e4fa 100644
--- a/styles.css
+++ b/styles.css
@@ -229,6 +229,14 @@ article {
   width: 66%;
   margin: 5px; }
 
+@media only screen and (min-width: 501px) and (max-width: 900px) {
+  .box.w-33, .box.w-25 {
+    width: 49%;
+    width: calc(50% - 5px); } }
+@media only screen and (max-width: 500px) {
+  .box.w-33, .box.w-50, .box.w-25 {
+    width: 100%;
+    width: calc(100% - 5px); } }
 .center {
   margin: 0 auto; }