diff --git a/css/ebi-global.scss b/css/ebi-global.scss
index 97da8698c88ea8d71c5da0196e8aa0c25c6ba6ac..ac7a299220331946cca5ee9a3693626dfed40639 100644
--- a/css/ebi-global.scss
+++ b/css/ebi-global.scss
@@ -760,6 +760,7 @@ code { font-size: .95rem; }
 }
 
 /* related / popular */
+// Todo: This should be a mixin...
 .related {
   background: $ebi-colour-dark;
   margin-top: 4.25rem;
diff --git a/css/theme-ebi-industry.css b/css/theme-ebi-industry.css
index 5ed94670d67a1b7e570c48288d433f16bfd5e8b7..18f8339aaf27d61364cb46f43f6799306c508b10 100644
--- a/css/theme-ebi-industry.css
+++ b/css/theme-ebi-industry.css
@@ -33,6 +33,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(0,134,180,.9); }
diff --git a/css/theme-ebi-research.css b/css/theme-ebi-research.css
index 13a514ac086f770dfee8a834e674fd719bbaba31..72e76686e0714213abce4c281d18b89591e54677 100644
--- a/css/theme-ebi-research.css
+++ b/css/theme-ebi-research.css
@@ -33,6 +33,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(109,171,73,.9); }
diff --git a/css/theme-ebi-training.css b/css/theme-ebi-training.css
index eba54986927e3dfc62b70590942add236b92df15..fed0d07a7a79c0c3aa73b36c027047899e382b8b 100644
--- a/css/theme-ebi-training.css
+++ b/css/theme-ebi-training.css
@@ -33,6 +33,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(233,180,0,.9); }
diff --git a/css/theme-embl-petrol.css b/css/theme-embl-petrol.css
index 220a451cf226623269bb7b17a7fb8b4036b9626e..106d5c6efc9fc124168bd242ae5b2d600cb13b6a 100644
--- a/css/theme-embl-petrol.css
+++ b/css/theme-embl-petrol.css
@@ -33,6 +33,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(0,124,130,.9); }
diff --git a/css/theme-pdbe-green.css b/css/theme-pdbe-green.css
index 6d73155b2b053bbff624fba87c3521c0c5d170ca..88c153714aa6888201d0b07df6d429da51951164 100644
--- a/css/theme-pdbe-green.css
+++ b/css/theme-pdbe-green.css
@@ -33,6 +33,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(116,179,96,.9); }
diff --git a/css/theme-template.css b/css/theme-template.css
index e83b68babf5d2b154888408bf0529fedf7646069..286f4be22c17c6d29016c404963989ab9c7c1ce2 100644
--- a/css/theme-template.css
+++ b/css/theme-template.css
@@ -34,6 +34,7 @@ a.tag:hover { color: #fff; }
 .tabs-title > a:hover,
 .button.primary:hover,
 .button.primary:focus,
+.button.hover,
 .button:hover,
 .button:focus,
 .button:active { background: rgba(0,124,130,.9); }