diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 500a6c02..ec705071 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -40,7 +40,7 @@ jobs:
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
-  test:
+  tests:
     needs: [core]
     uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@main
     with:
@@ -57,32 +57,47 @@ jobs:
             - pandoc
             - graphviz
       envs: |
-        - macos: py311-sphinx6
-        - windows: py310-sphinx6
+        - macos: py311-sphinx7
+        - windows: py310-sphinx7
+        - linux: py312-devdeps
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
-  docs:
-    needs: [test]
-    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@main
-    with:
-      submodules: false
-      pytest: false
-      envs: |
-        - linux: py312-docs
-
   extras:
-    needs: [core]
+    needs: [tests]
     uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@main
     with:
       submodules: false
-      coverage: codecov
+      pytest: false
       libraries: |
         apt:
             - pandoc
             - graphviz
       envs: |
-        - linux: py312-sphinxdev
-        - linux: py312-conda
-    secrets:
-      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+        - linux: py312-docs
+        - linux: pydata-sphinx-theme-dev
+        - linux: py312-linkcheck
+
+  conda:
+    needs: [tests]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          lfs: true
+      - uses: conda-incubator/setup-miniconda@v3
+        with:
+          activate-environment: ablog-test
+          environment-file: ablog-conda-test-env.yml
+          python-version: "3.12"
+      - name: Install ablog
+        shell: bash -el {0}
+        run: |
+          pip install --no-deps --no-build-isolation .
+      - name: Run test
+        shell: bash -el {0}
+        run: |
+          conda list
+          pytest -vvv -r a --pyargs ablog
+          make tests
diff --git a/.gitignore b/.gitignore
index b3c087f2..ff1e26e3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -185,6 +185,7 @@ $RECYCLE.BIN/
 .github_cache
 src/ablog/version.py
 docs/_build/
+docs/api/
 docs/.doctrees/
 docs/_website/
 docs/_latex/
diff --git a/ablog-conda-test-env.yml b/ablog-conda-test-env.yml
new file mode 100644
index 00000000..b552e1cb
--- /dev/null
+++ b/ablog-conda-test-env.yml
@@ -0,0 +1,22 @@
+channels:
+  - conda-forge
+dependencies:
+  - docutils
+  - feedgen
+  - graphviz
+  - invoke
+  - make
+  - myst-parser
+  - nbsphinx
+  - packaging
+  - pandoc
+  - pip
+  - pytest
+  - python-dateutil
+  - setuptools
+  - setuptools-scm
+  - sphinx
+  - sphinx-automodapi
+  - watchdog
+  - pip:
+      - sunpy-sphinx-theme
diff --git a/docs/conf.py b/docs/conf.py
index 747b3d00..0e735f8a 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -16,7 +16,6 @@
     "sphinx.ext.extlinks",
     "sphinx_automodapi.automodapi",
     "ablog",
-    "alabaster",
     "nbsphinx",
     "myst_parser",
 ]
@@ -67,11 +66,9 @@
 disqus_shortname = "https-ablog-readthedocs-io"
 disqus_pages = True
 fontawesome_link_cdn = "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.1/css/all.min.css"
-html_style = "alabaster.css"
-html_theme = "alabaster"
+html_theme = "sunpy"
 html_sidebars = {
     "**": [
-        "about.html",
         "ablog/postcard.html",
         "ablog/recentposts.html",
         "ablog/tagcloud.html",
@@ -80,16 +77,8 @@
         "ablog/authors.html",
         "ablog/languages.html",
         "ablog/locations.html",
-        "searchbox.html",
     ],
 }
-html_theme_options = {
-    "travis_button": False,
-    "github_user": "sunpy",
-    "github_repo": "ablog",
-    "description": "ABlog for blogging with Sphinx",
-    "logo": "ablog.png",
-}
 intersphinx_mapping = {
     "python": ("https://docs.python.org/", None),
     "sphinx": ("https://www.sphinx-doc.org/en/master/", None),
diff --git a/pyproject.toml b/pyproject.toml
index 3fb15b5a..c9525b13 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,7 +38,7 @@ dependencies = [
   "invoke>=1.6.0",
   "packaging>=19.0",
   "python-dateutil>=2.8.2",
-  "sphinx>=6.0.0",
+  "sphinx>=6.0.0,!=7.3.0,!=7.3.1,!=7.3.2,!=7.3.3,!=7.3.4,!=7.3.5,!=7.3.6",
   "watchdog>=2.1.0",
 ]
 
@@ -50,12 +50,13 @@ notebook = [
 ]
 markdown = ["myst-parser>=0.17.0"]
 docs = [
-  "alabaster",
+  "sunpy-sphinx-theme",
   "sphinx-automodapi"
 ]
 tests = [
-  "pytest",
   "defusedxml>=0.8.0rc2",
+  "pytest-cov",
+  "pytest",
 ]
 
 [project.urls]
diff --git a/src/ablog/__init__.py b/src/ablog/__init__.py
index 9875abce..d7c96ec0 100755
--- a/src/ablog/__init__.py
+++ b/src/ablog/__init__.py
@@ -8,7 +8,6 @@
 from pathlib import PurePath
 
 from sphinx.builders.html import StandaloneHTMLBuilder
-from sphinx.errors import ThemeError
 from sphinx.jinja2glue import BuiltinTemplateLoader, SphinxFileSystemLoader
 from sphinx.locale import get_translation
 
@@ -127,13 +126,7 @@ def builder_inited(app):
     theme = app.builder.theme
     loaders = app.builder.templates.loaders
     templatepathlen = app.builder.templates.templatepathlen
-    try:
-        # Modern Sphinx now errors instead of returning the default if there is not a value
-        # in any of the config files.
-        after_theme = theme.get_config("ablog", "inject_templates_after_theme", False)
-    except ThemeError:
-        after_theme = False
-    if after_theme:
+    if theme.get_config("ablog", "inject_templates_after_theme", False):
         # Inject *after* the user templates and the theme templates,
         # allowing themes to override the templates provided by this
         # extension while those templates still serve as a fallback.
diff --git a/tox.ini b/tox.ini
index 81710d14..98e18ae8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,14 +1,11 @@
 [tox]
 envlist =
-    py{310,311,312}{-sphinx6,-sphinx7,-sphinx8,-sphinxdev,-docs,-linkcheck}
-
+    py{310,311,312}{-sphinx6,-sphinx7,-sphinx8,-devdeps,-docs,-linkcheck}
+    pydata-sphinx-theme-dev
 [testenv]
 allowlist_externals =
-    conda
     make
     git
-deps =
-    pytest-cov
 extras =
     all
     docs
@@ -18,19 +15,13 @@ commands =
     sphinx6: pip install -U "sphinx>=6.0,<7.0"
     sphinx7: pip install -U "sphinx>=7.0,<8.0"
     sphinx8: pip install -U "sphinx>=8.0,<9.0"
-    sphinxdev: pip install -U "git+https://repo.or.cz/docutils.git#egg=docutils&subdirectory=docutils"
-    sphinxdev: pip install -U "git+https://github.com/sphinx-doc/sphinx"
+    devdeps: pip install -U "docutils @ git+https://github.com/docutils/docutils.git\#\&subdirectory=docutils"
+    devdeps: pip install -U "git+https://github.com/sphinx-doc/sphinx"
     pip freeze --all --no-input
     pytest -vvv -r a --pyargs ablog
     make tests
 
-[testenv:pydata-sphinx-theme]
-deps =
-    git+https://github.com/pydata/pydata-sphinx-theme.git
-    pytest-cov
-extras =
-    all
-    docs
+[testenv:pydata-sphinx-theme-dev]
 commands =
     rm -rf pydata-sphinx-theme || true
     git clone git@github.com:pydata/pydata-sphinx-theme.git --depth 1 pydata-sphinx-theme
@@ -50,33 +41,3 @@ changedir = docs
 description = Invoke sphinx-build to check linkcheck works
 commands =
     sphinx-build --color -W --keep-going -b linkcheck . _build/html {posargs}
-
-# Requires tox-conda
-[testenv:py{310,311,312}-conda]
-extras =
-deps =
-conda_deps =
-    alabaster
-    docutils
-    feedgen
-    graphviz
-    invoke
-    make
-    myst-parser
-    nbsphinx
-    packaging
-    pandoc
-    pip
-    pytest
-    python-dateutil
-    setuptools
-    setuptools-scm
-    sphinx
-    sphinx-automodapi
-    watchdog
-conda_channels = conda-forge
-install_command = pip install --no-deps --no-build-isolation {opts} {packages}
-commands =
-    conda list
-    pytest -vvv -r a --pyargs ablog
-    make tests