diff --git a/emmental/layout.py b/emmental/layout.py
new file mode 100644
index 0000000..8e10f8b
--- /dev/null
+++ b/emmental/layout.py
@@ -0,0 +1,45 @@
+# Copyright 2023 (c) Anna Schumaker.
+"""Our adaptable layout that can rearrange widgets as the window is resized."""
+from gi.repository import GObject
+from gi.repository import Gtk
+from gi.repository import Adw
+
+
+class Layout(Adw.Bin):
+    """A widget that can rearrange based on window dimensions."""
+
+    show_sidebar = GObject.Property(type=bool, default=False)
+
+    wide_view = GObject.Property(type=bool, default=False)
+
+    def __init__(self, *, content: Gtk.Widget = None,
+                 sidebar: Gtk.Widget = None):
+        """Initialize our Layout widget."""
+        super().__init__()
+        self._split_view = Adw.OverlaySplitView(content=content,
+                                                sidebar=sidebar,
+                                                collapsed=not self.wide_view)
+        self.props.child = self._split_view
+
+        self.bind_property("show-sidebar", self._split_view, "show-sidebar",
+                           GObject.BindingFlags.BIDIRECTIONAL)
+        self.bind_property("wide-view", self._split_view, "collapsed",
+                           GObject.BindingFlags.INVERT_BOOLEAN)
+
+    @GObject.Property(type=Gtk.Widget)
+    def content(self) -> Gtk.Widget:
+        """Get the content widget for the Layout."""
+        return self._split_view.props.content
+
+    @content.setter
+    def content(self, widget: Gtk.Widget) -> None:
+        self._split_view.props.content = widget
+
+    @GObject.Property(type=Gtk.Widget)
+    def sidebar(self) -> Gtk.Widget:
+        """Get the sidebar widget for the Layout."""
+        return self._split_view.props.sidebar
+
+    @sidebar.setter
+    def sidebar(self, widget: Gtk.Widget) -> None:
+        self._split_view.props.sidebar = widget
diff --git a/tests/test_layout.py b/tests/test_layout.py
new file mode 100644
index 0000000..f4789ef
--- /dev/null
+++ b/tests/test_layout.py
@@ -0,0 +1,65 @@
+# Copyright 2023 (c) Anna Schumaker.
+"""Tests our adaptable layout widget."""
+import unittest
+import emmental.layout
+from gi.repository import Gtk
+from gi.repository import Adw
+
+
+class TestLayout(unittest.TestCase):
+    """Test case for our adaptable layout."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.layout = emmental.layout.Layout()
+
+    def test_init(self):
+        """Check that the layout is set up properly."""
+        self.assertIsInstance(self.layout, Adw.Bin)
+        self.assertIsInstance(self.layout._split_view, Adw.OverlaySplitView)
+        self.assertTrue(self.layout._split_view.props.collapsed)
+
+    def test_wide_view(self):
+        """Test the layout when we have a wide window."""
+        self.assertFalse(self.layout.wide_view)
+        self.assertEqual(self.layout.props.child, self.layout._split_view)
+
+        self.layout.wide_view = True
+        self.assertFalse(self.layout._split_view.props.collapsed)
+
+    def test_content(self):
+        """Test the content widget property."""
+        self.assertIsNone(self.layout.content)
+
+        widget = Gtk.Label()
+        self.layout.content = widget
+        self.assertEqual(self.layout._split_view.props.content, widget)
+        self.assertEqual(self.layout.content, widget)
+
+        widget2 = Gtk.Label()
+        layout2 = emmental.layout.Layout(content=widget2)
+        self.assertEqual(layout2.content, widget2)
+
+    def test_sidebar(self):
+        """Test the sidebar widget property."""
+        self.assertIsNone(self.layout.sidebar)
+
+        widget = Gtk.Label()
+        self.layout.sidebar = widget
+        self.assertEqual(self.layout._split_view.props.sidebar, widget)
+        self.assertEqual(self.layout.sidebar, widget)
+
+        widget2 = Gtk.Label()
+        layout2 = emmental.layout.Layout(sidebar=widget2)
+        self.assertEqual(layout2.sidebar, widget2)
+
+    def test_show_sidebar(self):
+        """Test the show-sidebar property."""
+        self.assertFalse(self.layout.show_sidebar)
+        self.assertFalse(self.layout._split_view.props.show_sidebar)
+
+        self.layout.show_sidebar = True
+        self.assertTrue(self.layout._split_view.props.show_sidebar)
+
+        self.layout._split_view.props.show_sidebar = False
+        self.assertFalse(self.layout.show_sidebar)