Give the start button a whole row, no matter what

stroll.html

@@ -235,16 +235,12 @@
 
       <ul class="flex-outer">
 
-        <div class="custom-category">
-        </div>
 
-        <div class="custom-category">
+        <div class="custom-category wide-category">
           <div>
             <button class="option-button" id="button-start">Start Game</button>
           </div>
         </div>
-        <div class="custom-category">
-        </div>
 
         <div class="custom-category">
           <p>Presets let you play as other players' characters. There are a few groups to choose from.</p>

style.css

@@ -350,6 +350,12 @@ input[type="checkbox"]:checked ~ .reveal-if-active {
   width: 500px;
 }
 
+body.dark .custom-category.wide-category,
+body.light .custom-category.wide-category {
+  width: 90%;
+  background: none;
+}
+
 .custom-category-sub {
   text-align: center;
   margin: 10px;