Fix formatting for mobile

assets/style.scss

@@ -1,7 +1,8 @@
 ---
 ---
 
-// Do not remove the abot 2 lines
+// Do not remove the above 2 lines
+
 // Colors
 $blue: #4183C4;
 $red: #E74C3C;
@@ -98,13 +99,6 @@ table {
   -moz-box-sizing: border-box; -webkit-box-sizing: border-box; box-sizing: border-box;
 }
 
-// Mobile breakpoints
-@mixin mobile {
-  @media screen and (max-width: 640px) {
-    @content;
-  }
-}
-
 /**************/
 /* BASE RULES */
 /**************/
@@ -128,12 +122,26 @@ body {
 }
 
 .one-half {
-  width: 50%;
+  width: 75%;
+  max-width: 800px;
+  flex-direction: column;
 }
 
 .one-fourth {
   display: flex;
-  width: 25%;
+  width: 10%;
+}
+
+@media (max-width: 800px) {
+  .one-fourth {
+    display: flex;
+    width: 0%;
+  }
+
+  .one-half {
+    display: flex;
+    width: 100%;
+  }
 }
 
 h1, h2, h3, h4, h5, h6 {
@@ -145,10 +153,6 @@ h1, h2, h3, h4, h5, h6 {
   margin: 1em 0 15px;
   padding: 0;
   text-align: left;
-
-  @include mobile {
-    line-height: 1.4;
-  }
 }
 
 h1 {
@@ -372,7 +376,6 @@ p > img {
   border-radius: 3px;
 }
 
-
 /// Code
 
 .nt {