diff --git a/doc/UsersGuide/requirements.txt b/doc/UsersGuide/requirements.txt
index ef36addc62..9c7258463b 100644
--- a/doc/UsersGuide/requirements.txt
+++ b/doc/UsersGuide/requirements.txt
@@ -1 +1,2 @@
 sphinxcontrib-bibtex
+sphinx_rtd_theme
diff --git a/doc/UsersGuide/source/_static/theme_overrides.css b/doc/UsersGuide/source/_static/theme_overrides.css
new file mode 100644
index 0000000000..60a7f9f029
--- /dev/null
+++ b/doc/UsersGuide/source/_static/theme_overrides.css
@@ -0,0 +1,3 @@
+.wy-nav-content {
+   max-width: 100% !important;
+}
diff --git a/doc/UsersGuide/source/conf.py b/doc/UsersGuide/source/conf.py
index 89ad0dfd01..fa2a93ca5b 100644
--- a/doc/UsersGuide/source/conf.py
+++ b/doc/UsersGuide/source/conf.py
@@ -81,7 +81,7 @@
 exclude_patterns = []
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = None
+pygments_style = 'sphinx'
 
 
 # -- Options for HTML output -------------------------------------------------
@@ -89,7 +89,9 @@
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'classic'
+#html_theme = 'classic'
+html_theme = 'sphinx_rtd_theme'
+html_theme_path = ["_themes", ]
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -102,9 +104,11 @@
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
 html_static_path = ['_static']
+html_context = {}
 
 def setup(app):
     app.add_css_file('custom.css')  # may also be an URL
+    app.add_css_file('theme_overrides.css')  # may also be an URL
 
 # Custom sidebar templates, must be a dictionary that maps document names
 # to template names.