diff --git a/invenio_theme/assets/bootstrap3/scss/invenio_theme/cover.scss b/invenio_theme/assets/bootstrap3/scss/invenio_theme/cover.scss
index 42c56e26..c970f61d 100644
--- a/invenio_theme/assets/bootstrap3/scss/invenio_theme/cover.scss
+++ b/invenio_theme/assets/bootstrap3/scss/invenio_theme/cover.scss
@@ -47,10 +47,10 @@ body.cover-page {
   .panel-footer {
     padding-left: $cover-panel-padding;
     padding-right: $cover-panel-padding;
-    padding-top: $cover-panel-padding/2;
-    padding-bottom: $cover-panel-padding/2;
-    border-bottom-left-radius: $border-radius-large*2;
-    border-bottom-right-radius: $border-radius-large*2;
+    padding-top: calc($cover-panel-padding/2);
+    padding-bottom: calc($cover-panel-padding/2);
+    border-bottom-left-radius: calc($border-radius-large*2);
+    border-bottom-right-radius: calc($border-radius-large*2);
     background-color: $cover-panel-footer-bg;
   }
   .panel-container a.text-muted {
diff --git a/invenio_theme/assets/bootstrap3/scss/invenio_theme/header.scss b/invenio_theme/assets/bootstrap3/scss/invenio_theme/header.scss
index d80e2b6e..1f3434fc 100644
--- a/invenio_theme/assets/bootstrap3/scss/invenio_theme/header.scss
+++ b/invenio_theme/assets/bootstrap3/scss/invenio_theme/header.scss
@@ -7,7 +7,7 @@
  */
 
 header .alert {
-  margin-top: -$line-height-computed;
+  margin-top: calc(-1 * $line-height-computed);
   border-radius: 0px;
 }
 
diff --git a/invenio_theme/assets/bootstrap3/scss/invenio_theme/styles.scss b/invenio_theme/assets/bootstrap3/scss/invenio_theme/styles.scss
index 03693c41..2e6dcdad 100644
--- a/invenio_theme/assets/bootstrap3/scss/invenio_theme/styles.scss
+++ b/invenio_theme/assets/bootstrap3/scss/invenio_theme/styles.scss
@@ -7,8 +7,9 @@
  */
 
 // Setting the path to fonts files.
-$icon-font-path: "~bootstrap-sass/assets/fonts/bootstrap/";
-$fa-font-path: "~font-awesome/fonts";
+// double slash for escaping, single slash is interpreted as division
+$icon-font-path: "~bootstrap-sass//assets//fonts//bootstrap//";
+$fa-font-path: "~font-awesome//fonts";
 
 @import "~bootstrap-sass/assets/stylesheets/_bootstrap";
 @import "~font-awesome/scss/font-awesome";
diff --git a/invenio_theme/assets/semantic-ui/scss/invenio_theme/header.scss b/invenio_theme/assets/semantic-ui/scss/invenio_theme/header.scss
index d80e2b6e..1f3434fc 100644
--- a/invenio_theme/assets/semantic-ui/scss/invenio_theme/header.scss
+++ b/invenio_theme/assets/semantic-ui/scss/invenio_theme/header.scss
@@ -7,7 +7,7 @@
  */
 
 header .alert {
-  margin-top: -$line-height-computed;
+  margin-top: calc(-1 * $line-height-computed);
   border-radius: 0px;
 }
 
diff --git a/invenio_theme/assets/semantic-ui/scss/invenio_theme/styles.scss b/invenio_theme/assets/semantic-ui/scss/invenio_theme/styles.scss
index 03693c41..2e6dcdad 100644
--- a/invenio_theme/assets/semantic-ui/scss/invenio_theme/styles.scss
+++ b/invenio_theme/assets/semantic-ui/scss/invenio_theme/styles.scss
@@ -7,8 +7,9 @@
  */
 
 // Setting the path to fonts files.
-$icon-font-path: "~bootstrap-sass/assets/fonts/bootstrap/";
-$fa-font-path: "~font-awesome/fonts";
+// double slash for escaping, single slash is interpreted as division
+$icon-font-path: "~bootstrap-sass//assets//fonts//bootstrap//";
+$fa-font-path: "~font-awesome//fonts";
 
 @import "~bootstrap-sass/assets/stylesheets/_bootstrap";
 @import "~font-awesome/scss/font-awesome";