add: more space before titles

Author: BeaMarton13

doc/source/_static/custom.css

@@ -91,4 +91,10 @@
 .card-deep-blue { background-color: #0056b3; }
 .card-light-purple { background-color: #BF40BF; } 
 .card-medium-purple { background-color: #800080; } 
-.card-deep-purple { background-color: #4B0082; } 
+.card-deep-purple { background-color: #4B0082; } 
+
+section h1,
+section h2,
+section h3 {
+    margin-top: 35px;
+}