diff --git a/sphinx/builders/html.py b/sphinx/builders/html.py
index 55cf2de2a..fd86e2fa5 100644
--- a/sphinx/builders/html.py
+++ b/sphinx/builders/html.py
@@ -136,6 +136,11 @@ class StandaloneHTMLBuilder(Builder):
         if self.config.html_use_modindex and self.env.modules:
             rellinks.append(('modindex', _('Global Module Index'), 'M', _('modules')))
 
+        if self.config.html_style is not None:
+            stylename = self.config.html_style
+        else:
+            stylename = self.theme.get_confstr('theme', 'stylesheet')
+
         self.globalcontext = dict(
             embedded = self.embedded,
             project = self.config.project,
@@ -144,7 +149,6 @@ class StandaloneHTMLBuilder(Builder):
             last_updated = self.last_updated,
             copyright = self.config.copyright,
             master_doc = self.config.master_doc,
-            style = self.config.html_style,
             use_opensearch = self.config.html_use_opensearch,
             docstitle = self.config.html_title,
             shorttitle = self.config.html_short_title,
@@ -154,6 +158,7 @@ class StandaloneHTMLBuilder(Builder):
             file_suffix = self.out_suffix,
             script_files = self.script_files,
             sphinx_version = __version__,
+            style = stylename,
             rellinks = rellinks,
             builder = self.name,
             parents = [],
diff --git a/sphinx/config.py b/sphinx/config.py
index a3ae34c51..768b69fdb 100644
--- a/sphinx/config.py
+++ b/sphinx/config.py
@@ -59,7 +59,7 @@ class Config(object):
                                    (self.project, self.release),
                       False),
         html_short_title = (lambda self: self.html_title, False),
-        html_style = ('default.css', False),  # XXX
+        html_style = (None, False),
         html_logo = (None, False),
         html_favicon = (None, False),
         html_static_path = ([], False),
diff --git a/sphinx/theming.py b/sphinx/theming.py
index 9493481c2..7c96107c4 100644
--- a/sphinx/theming.py
+++ b/sphinx/theming.py
@@ -46,14 +46,18 @@ class Theme(object):
 
     def __init__(self, name):
         if name not in self.themes:
-            raise ThemeError('no theme named %r found' % name)
+            raise ThemeError('no theme named %r found '
+                             '(missing theme.conf?)' % name)
         self.name = name
         self.themedir = self.themes[name]
 
         self.themeconf = ConfigParser.RawConfigParser()
         self.themeconf.read(path.join(self.themedir, THEMECONF))
 
-        inherit = self.themeconf.get('theme', 'inherit')
+        try:
+            inherit = self.themeconf.get('theme', 'inherit')
+        except ConfigParser.NoOptionError:
+            raise ThemeError('theme %r doesn\'t have "inherit" setting' % name)
         if inherit == 'none':
             self.base = None
         elif inherit not in self.themes:
@@ -62,6 +66,14 @@ class Theme(object):
         else:
             self.base = Theme(inherit)
 
+    def get_confstr(self, section, name):
+        try:
+            return self.themeconf.get(section, name)
+        except ConfigParser.NoOptionError:
+            if self.base is not None:
+                return self.base.get_confstr(section, name)
+            raise
+
     def get_dirchain(self):
         """
         Return a list of theme directories, beginning with this theme's,