Fix condition for inclusion of css in ebook

_layouts/ebook/page.html

@@ -2,7 +2,7 @@
 
 {% block style %}
     {# Include theme css before plugins css #}
-    {% if config.styles.print|fileExists %}
+    {% if not (config.styles.print|fileExists) %}
         {% if options.format %}
         <link rel="stylesheet" href="{{ (options.format + ".css")|resolveAsset }}">
         {% else %}
@@ -15,7 +15,7 @@
     {# Custom stylesheets for the book #}
 
     {% for type, style in config.styles %}
-        {% if style|fileExists and (style == "ebook" or style == "print" or style == options.format) %}
+        {% if (style|fileExists) and (style == "ebook" or style == "print" or style == options.format) %}
         <link rel="stylesheet" href="{{ style|resolveFile }}">
         {% endif %}
     {% endfor %}