diff --git a/docs/_static/custom.css b/docs/_static/custom.css
deleted file mode 100644
index eacd69c15a0..00000000000
--- a/docs/_static/custom.css
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Make the sidebar scrollable. Fixes https://github.com/psf/black/issues/990 */
-div.sphinxsidebar {
-  max-height: calc(100% - 18px);
-  overflow-y: auto;
-}
-
-/* Hide scrollbar for Chrome, Safari and Opera */
-div.sphinxsidebar::-webkit-scrollbar {
-  display: none;
-}
-
-/* Hide scrollbar for IE 6, 7 and 8 */
-@media \0screen\, screen\9 {
-  div.sphinxsidebar {
-    -ms-overflow-style: none;
-  }
-}
-
-/* Hide scrollbar for IE 9 and 10 */
-/* backslash-9 removes ie11+ & old Safari 4 */
-@media screen and (min-width: 0\0) {
-  div.sphinxsidebar {
-    -ms-overflow-style: none\9;
-  }
-}
-
-/* Hide scrollbar for IE 11 and up */
-_:-ms-fullscreen,
-:root div.sphinxsidebar {
-  -ms-overflow-style: none;
-}
-
-/* Hide scrollbar for Edge */
-@supports (-ms-ime-align: auto) {
-  div.sphinxsidebar {
-    -ms-overflow-style: none;
-  }
-}
-
-/* Nicer style for local document toc */
-.contents.topic {
-  background: none;
-  border: none;
-}
diff --git a/docs/conf.py b/docs/conf.py
index 55d0fa99dc6..2801e0eed19 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -115,29 +115,8 @@ def make_pypi_svg(version: str) -> None:
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = "alabaster"
-
-html_sidebars = {
-    "**": [
-        "about.html",
-        "navigation.html",
-        "relations.html",
-        "searchbox.html",
-    ]
-}
-
-html_theme_options = {
-    "show_related": False,
-    "description": "“Any color you like.”",
-    "github_button": True,
-    "github_user": "psf",
-    "github_repo": "black",
-    "github_type": "star",
-    "show_powered_by": True,
-    "fixed_sidebar": True,
-    "logo": "logo2.png",
-}
-
+html_theme = "furo"
+html_logo = "_static/logo2-readme.png"
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
diff --git a/docs/index.rst b/docs/index.rst
index 1515697f556..2f4a7efbf08 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -99,6 +99,7 @@ Contents
 .. toctree::
    :maxdepth: 3
    :includehidden:
+   :caption: User Guide
 
    getting_started
    usage_and_configuration/index
@@ -109,6 +110,7 @@ Contents
 .. toctree::
    :maxdepth: 3
    :includehidden:
+   :caption: Development
 
    contributing/index
    change_log
@@ -116,10 +118,11 @@ Contents
 
 .. toctree::
    :hidden:
+   :caption: Project Links
 
-   GitHub ↪ <https://github.com/psf/black>
-   PyPI ↪ <https://pypi.org/project/black>
-   Chat ↪ <https://discord.gg/RtVdv86PrH>
+   GitHub <https://github.com/psf/black>
+   PyPI <https://pypi.org/project/black>
+   Chat <https://discord.gg/RtVdv86PrH>
 
 Indices and tables
 ==================
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 56dbf3ffe13..b157730d6a9 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,6 +1,7 @@
 # Used by ReadTheDocs; pinned requirements for stability.
 
-MyST-Parser==0.14.0
-Sphinx==3.5.4
+myst-parser==0.15.1
+Sphinx==4.1.1
 sphinxcontrib-programoutput==0.17
-sphinx_copybutton==0.3.1
+sphinx_copybutton==0.4.0
+furo==2021.7.5b38