diff --git a/_includes/base.html b/_includes/base.html
new file mode 100644
index 0000000..4687d74
--- /dev/null
+++ b/_includes/base.html
@@ -0,0 +1,11 @@
+
+
+{% assign depth = page.url | split: '/' | size | minus: 1 %}
+{% if depth <= 1 %}{% assign base = '.' %}
+{% elsif depth == 2 %}{% assign base = '..' %}
+{% elsif depth == 3 %}{% assign base = '../..' %}
+{% elsif depth == 4 %}{% assign base = '../../..' %}{% endif %}
+
+