Add custom.css

docs/source/_static/custom.css

@@ -0,0 +1,9 @@
+/* 24px margin from readthedocs theme */
+div.nblast {
+    margin-bottom: 19px !important;  /* padding has already 5px */
+}
+
+/* ... except between notebook cells! */
+div.nblast + div.nbinput {
+    margin-top: -19px !important;
+}

docs/source/conf.py

@@ -186,6 +186,10 @@ html_theme = 'sphinx_rtd_theme'
 #       since it is needed to properly generate _static in the build directory
 html_static_path = ['_static']
 
+html_context = {
+    'css_files': ['_static/custom.css'],
+}
+
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
 # directly to the root of the documentation.