diff --git a/theme/epub/epub.css b/theme/epub/epub.css
new file mode 100644
index 00000000..5859f1ca
--- /dev/null
+++ b/theme/epub/epub.css
@@ -0,0 +1 @@
+/* Add your custom CSS styles for the EPUB here */
\ No newline at end of file
diff --git a/theme/html/html.css b/theme/html/html.css
new file mode 100644
index 00000000..b8fffe82
--- /dev/null
+++ b/theme/html/html.css
@@ -0,0 +1 @@
+/* Add your custom CSS styles for the HTML here */
\ No newline at end of file
diff --git a/theme/mobi/mobi.css b/theme/mobi/mobi.css
new file mode 100644
index 00000000..6643145b
--- /dev/null
+++ b/theme/mobi/mobi.css
@@ -0,0 +1 @@
+/* Add your custom CSS styles for the MOBI here */
\ No newline at end of file
diff --git a/theme/pdf/pdf.css b/theme/pdf/pdf.css
new file mode 100644
index 00000000..4fd79cb3
--- /dev/null
+++ b/theme/pdf/pdf.css
@@ -0,0 +1 @@
+/* Add your custom CSS styles for the PDF here */
\ No newline at end of file