diff --git a/poetry.lock b/poetry.lock
index 6aa1ed18d..0285e2e4d 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -35,7 +35,7 @@ frozenlist = ">=1.1.0"
 name = "astunparse"
 version = "1.6.3"
 description = "An AST unparser for Python"
-category = "main"
+category = "dev"
 optional = false
 python-versions = "*"
 
@@ -110,7 +110,7 @@ uvloop = ["uvloop (>=0.15.2)"]
 name = "cached-property"
 version = "1.5.2"
 description = "A decorator for caching properties in classes."
-category = "main"
+category = "dev"
 optional = false
 python-versions = "*"
 
@@ -207,7 +207,7 @@ python-versions = ">=3.7"
 name = "ghp-import"
 version = "2.1.0"
 description = "Copy your docs directly to the gh-pages branch."
-category = "main"
+category = "dev"
 optional = false
 python-versions = "*"
 
@@ -221,7 +221,7 @@ dev = ["twine", "markdown", "flake8", "wheel"]
 name = "griffe"
 version = "0.19.2"
 description = "Signatures for entire Python programs. Extract the structure, the frame, the skeleton of your project, to generate API documentation or find breaking changes in your API."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -279,7 +279,7 @@ python-versions = "*"
 name = "jinja2"
 version = "3.0.3"
 description = "A very fast and expressive template engine."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -293,7 +293,7 @@ i18n = ["Babel (>=2.7)"]
 name = "markdown"
 version = "3.3.7"
 description = "Python implementation of Markdown."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -307,7 +307,7 @@ testing = ["coverage", "pyyaml"]
 name = "markupsafe"
 version = "2.1.1"
 description = "Safely add untrusted strings to HTML/XML markup."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -315,7 +315,7 @@ python-versions = ">=3.7"
 name = "mergedeep"
 version = "1.3.4"
 description = "A deep merge function for 🐍."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -323,7 +323,7 @@ python-versions = ">=3.6"
 name = "mkdocs"
 version = "1.3.0"
 description = "Project documentation with Markdown."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -346,7 +346,7 @@ i18n = ["babel (>=2.9.0)"]
 name = "mkdocs-autorefs"
 version = "0.4.1"
 description = "Automatically link across pages in MkDocs."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -356,19 +356,19 @@ mkdocs = ">=1.1"
 
 [[package]]
 name = "mkdocs-material"
-version = "7.3.6"
-description = "A Material Design theme for MkDocs"
+version = "8.2.15"
+description = "Documentation that simply works"
 category = "dev"
 optional = false
-python-versions = "*"
+python-versions = ">=3.7"
 
 [package.dependencies]
 jinja2 = ">=2.11.1"
 markdown = ">=3.2"
-mkdocs = ">=1.2.3"
-mkdocs-material-extensions = ">=1.0"
-pygments = ">=2.10"
-pymdown-extensions = ">=9.0"
+mkdocs = ">=1.3.0"
+mkdocs-material-extensions = ">=1.0.3"
+pygments = ">=2.12"
+pymdown-extensions = ">=9.4"
 
 [[package]]
 name = "mkdocs-material-extensions"
@@ -382,7 +382,7 @@ python-versions = ">=3.6"
 name = "mkdocstrings"
 version = "0.18.1"
 description = "Automatic documentation from sources, for MkDocs."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -405,7 +405,7 @@ python-legacy = ["mkdocstrings-python-legacy (>=0.2.1)"]
 name = "mkdocstrings-python"
 version = "0.6.6"
 description = "A Python handler for mkdocstrings."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -417,7 +417,7 @@ mkdocstrings = ">=0.18"
 name = "mkdocstrings-python-legacy"
 version = "0.2.2"
 description = "A legacy Python handler for mkdocstrings."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -480,7 +480,7 @@ python-versions = "*"
 name = "packaging"
 version = "21.3"
 description = "Core utilities for Python packages"
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -559,7 +559,7 @@ python-versions = ">=3.6"
 name = "pymdown-extensions"
 version = "9.4"
 description = "Extension pack for Python Markdown."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -570,7 +570,7 @@ markdown = ">=3.2"
 name = "pyparsing"
 version = "3.0.9"
 description = "pyparsing module - Classes and methods to define and execute parsing grammars"
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6.8"
 
@@ -650,7 +650,7 @@ testing = ["fields", "hunter", "process-tests", "six", "pytest-xdist", "virtuale
 name = "python-dateutil"
 version = "2.8.2"
 description = "Extensions to the standard Python datetime module"
-category = "main"
+category = "dev"
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,>=2.7"
 
@@ -661,7 +661,7 @@ six = ">=1.5"
 name = "pytkdocs"
 version = "0.16.1"
 description = "Load Python objects documentation."
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.7"
 
@@ -677,7 +677,7 @@ numpy-style = ["docstring_parser (>=0.7)"]
 name = "pyyaml"
 version = "6.0"
 description = "YAML parser and emitter for Python"
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -685,7 +685,7 @@ python-versions = ">=3.6"
 name = "pyyaml-env-tag"
 version = "0.1"
 description = "A custom YAML tag for referencing environment variables in YAML files. "
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -712,7 +712,7 @@ jupyter = ["ipywidgets (>=7.5.1,<8.0.0)"]
 name = "six"
 version = "1.16.0"
 description = "Python 2 and 3 compatibility utilities"
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*"
 
@@ -782,7 +782,7 @@ testing = ["coverage (>=4)", "coverage-enable-subprocess (>=1)", "flaky (>=3)",
 name = "watchdog"
 version = "2.1.8"
 description = "Filesystem events monitoring"
-category = "main"
+category = "dev"
 optional = false
 python-versions = ">=3.6"
 
@@ -817,7 +817,7 @@ testing = ["pytest (>=6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytest-
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.7"
-content-hash = "f32bca17ffa867133de5437f87390b1122fb84ee9c0b6eafab03f8c518fe6c15"
+content-hash = "bfa71851a0d29adf2bf6de97054967e2122355bdefe859439bca5ec4377c9992"
 
 [metadata.files]
 aiohttp = [
@@ -1166,8 +1166,8 @@ mkdocs-autorefs = [
     {file = "mkdocs_autorefs-0.4.1-py3-none-any.whl", hash = "sha256:a2248a9501b29dc0cc8ba4c09f4f47ff121945f6ce33d760f145d6f89d313f5b"},
 ]
 mkdocs-material = [
-    {file = "mkdocs-material-7.3.6.tar.gz", hash = "sha256:1b1dbd8ef2508b358d93af55a5c5db3f141c95667fad802301ec621c40c7c217"},
-    {file = "mkdocs_material-7.3.6-py2.py3-none-any.whl", hash = "sha256:1b6b3e9e09f922c2d7f1160fe15c8f43d4adc0d6fb81aa6ff0cbc7ef5b78ec75"},
+    {file = "mkdocs-material-8.2.15.tar.gz", hash = "sha256:93b57e53733051431cc83216446e774bdf08bf516a6251ff2f24974f45f98149"},
+    {file = "mkdocs_material-8.2.15-py2.py3-none-any.whl", hash = "sha256:9d6c4ca1ceecc00b2e38c214665ed7605d275321dcaa22f38b9d1175edc58955"},
 ]
 mkdocs-material-extensions = [
     {file = "mkdocs-material-extensions-1.0.3.tar.gz", hash = "sha256:bfd24dfdef7b41c312ede42648f9eb83476ea168ec163b613f9abd12bbfddba2"},
diff --git a/pyproject.toml b/pyproject.toml
index cf50856ac..b4222f52e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,6 @@ click = "8.1.2"
 importlib-metadata = "^4.11.3"
 typing-extensions = { version = "^4.0.0", python = "<3.8" }
 msgpack = "^1.0.3"
-mkdocstrings = {extras = ["python"], version = "^0.18.1"}
 
 [tool.poetry.dev-dependencies]
 pytest = "^6.2.3"
@@ -36,8 +35,8 @@ black = "^22.3.0"
 mypy = "^0.950"
 pytest-cov = "^2.12.1"
 mkdocs = "^1.3.0"
-mkdocstrings = "^0.18.1"
-mkdocs-material = "^7.3.6"
+mkdocstrings = {extras = ["python"], version = "^0.18.1"}
+mkdocs-material = "^8.2.15"
 pre-commit = "^2.13.0"
 pytest-aiohttp = "^1.0.4"
 time-machine = "^2.6.0"
diff --git a/src/textual/app.py b/src/textual/app.py
index 136d440d3..366d733f0 100644
--- a/src/textual/app.py
+++ b/src/textual/app.py
@@ -32,7 +32,7 @@ import rich.repr
 from rich.console import Console, RenderableType
 from rich.measure import Measurement
 from rich.protocol import is_renderable
-from rich.segment import Segments
+from rich.segment import Segments, SegmentLines
 from rich.traceback import Traceback
 
 from . import actions
@@ -441,7 +441,9 @@ class App(Generic[ReturnType], DOMNode):
             color_system="truecolor",
             record=True,
         )
-        console.print(self.screen._compositor.render(full=True))
+        lines = self.screen._compositor.render(full=True).lines
+
+        console.print(SegmentLines(lines, new_lines=True))
         return console.export_svg(title=self.title)
 
     def save_screenshot(self, path: str | None = None) -> str:
@@ -524,7 +526,7 @@ class App(Generic[ReturnType], DOMNode):
                 self.screen.refresh(layout=True)
 
     def render(self) -> RenderableType:
-        return Blank()
+        return ""
 
     def query(self, selector: str | None = None) -> DOMQuery:
         """Get a DOM query in the current screen.
diff --git a/src/textual/css/_style_properties.py b/src/textual/css/_style_properties.py
index 1b891355c..061a4bd75 100644
--- a/src/textual/css/_style_properties.py
+++ b/src/textual/css/_style_properties.py
@@ -938,6 +938,8 @@ class FractionalProperty:
 
 
 class AlignProperty:
+    """Combines the horizontal and vertical alignment properties in to a single property."""
+
     def __set_name__(self, owner: StylesBase, name: str) -> None:
         self.horizontal = f"{name}_horizontal"
         self.vertical = f"{name}_vertical"
diff --git a/src/textual/screen.py b/src/textual/screen.py
index 6fa8947de..12b8565e8 100644
--- a/src/textual/screen.py
+++ b/src/textual/screen.py
@@ -28,7 +28,12 @@ class Screen(Widget):
     """A widget for the root of the app."""
 
     CSS = """
-
+    Screen {
+        layout: vertical;
+        overflow-y: auto;
+        background: $surface;
+        color: $text-surface;
+    }
     """
 
     dark = Reactive(False)