diff --git a/IPython/html/static/style/ipython.min.css b/IPython/html/static/style/ipython.min.css
index 20a2c464f..3e160b551 100644
--- a/IPython/html/static/style/ipython.min.css
+++ b/IPython/html/static/style/ipython.min.css
@@ -1195,6 +1195,10 @@ h6:hover .anchor-link {
   font-size: 100%;
   font-style: italic;
 }
+.widget-interact > div,
+.widget-interact > input {
+  padding: 2.5px;
+}
 .widget-area {
   /*
     LESS file that styles IPython notebook widgets and the area they sit in.
diff --git a/IPython/html/static/style/style.min.css b/IPython/html/static/style/style.min.css
index a36c23633..feface624 100644
--- a/IPython/html/static/style/style.min.css
+++ b/IPython/html/static/style/style.min.css
@@ -9978,6 +9978,10 @@ h6:hover .anchor-link {
   font-size: 100%;
   font-style: italic;
 }
+.widget-interact > div,
+.widget-interact > input {
+  padding: 2.5px;
+}
 .widget-area {
   /*
     LESS file that styles IPython notebook widgets and the area they sit in.
diff --git a/IPython/html/static/widgets/less/widgets.less b/IPython/html/static/widgets/less/widgets.less
index 08a920e05..ffe3decf8 100644
--- a/IPython/html/static/widgets/less/widgets.less
+++ b/IPython/html/static/widgets/less/widgets.less
@@ -1,6 +1,13 @@
 @widget-width: 350px;
 @widget-width-short: 150px;
 
+// Pad interact widgets by default.
+.widget-interact {
+    >div, >input {
+        padding: 2.5px;
+    }
+}
+
 .widget-area {
     /*
     LESS file that styles IPython notebook widgets and the area they sit in.
diff --git a/IPython/html/widgets/interaction.py b/IPython/html/widgets/interaction.py
index 76d63f524..b9e37defc 100644
--- a/IPython/html/widgets/interaction.py
+++ b/IPython/html/widgets/interaction.py
@@ -181,7 +181,7 @@ def interactive(__interact_f, **kwargs):
     co = kwargs.pop('clear_output', True)
     manual = kwargs.pop('__manual', False)
     kwargs_widgets = []
-    container = Box()
+    container = Box(_dom_classes=['widget-interact'])
     container.result = None
     container.args = []
     container.kwargs = dict()
diff --git a/IPython/html/widgets/widget.py b/IPython/html/widgets/widget.py
index fcb76c0a4..062b6716b 100644
--- a/IPython/html/widgets/widget.py
+++ b/IPython/html/widgets/widget.py
@@ -435,7 +435,7 @@ class DOMWidget(Widget):
     width = CUnicode(sync=True)
     height = CUnicode(sync=True)
     # A default padding of 2.5 px makes the widgets look nice when displayed inline.
-    padding = CUnicode("2.5px", sync=True)
+    padding = CUnicode(sync=True)
     margin = CUnicode(sync=True)
 
     color = Unicode(sync=True)