adjusted border color across all stylesheets

resources/less/metager/general/cards.less

 .card,
 .card-medium {
-    border: 1px solid @card-border-color;
+    border: 1px solid @border-color;
     background-color: @card-background-color;
     box-shadow: 0px 1px 1.5px 0px rgba(0, 0, 0, 0.12), 1px 0px 1px 0px rgba(0, 0, 0, 0.24);
     padding: 8px;

resources/less/metager/pages/help_faq.less

@@ -24,7 +24,7 @@
             img {
                 margin: 10px 0;
                 padding: 8px;
-                border: 1px solid #ccc;
+                border: 1px solid @border-color;
                 border-radius: 3px;
             }
         }

resources/less/metager/pages/privacy.less

@@ -13,8 +13,8 @@
             .card-heavy;
         }
         .kontext {
-            border-bottom: 1px solid #ccc;
-            border-top: 1px solid #ccc;
+            border-bottom: 1px solid @border-color;
+            border-top: 1px solid @border-color;
             padding: 8px 0;
             .datum-list {
                 margin-top: 8px;

resources/less/metager/pages/resultpage/result-page.less

@@ -429,7 +429,7 @@ a {
     max-width: @results-width-max;
     #research-bar {
         background-color: @resultpage-background-color;
-        border: 1px solid #ccc;
+        border: 1px solid @border-color;
         border-bottom: 1px solid @metager-orange;
         box-shadow: 0px 1px 1.5px 0px rgba(0, 0, 0, 0.12), 1px 0px 1px 0px rgba(0, 0, 0, 0.24);
         display: flex;
@@ -437,7 +437,7 @@ a {
         padding: 4px;
         .resultpage-searchbar {
             .search-input-submit .search-input input {
-                border-bottom: 1px solid #ccc;
+                border-bottom: 1px solid @border-color;
             }
             @media (max-width: @sidebar-opener-breakpoint) {
                 .search-focus-selector {
@@ -471,7 +471,7 @@ a {
         background-color: @resultpage-background-color;
         overflow-x: auto;
         padding: 8px;
-        border-bottom: 1px solid #ccc;
+        border-bottom: 1px solid @border-color;
         @media (max-width: @screen-mobile) {
             .card;
             margin: 0;

resources/less/metager/pages/resultpage/result.less

@@ -259,7 +259,7 @@
     &>.result-options {
         max-width: 100%;
         &>.options {
-            border-top: 1px solid #ccc;
+            border-top: 1px solid @border-color;
             width: 100%;
             text-align: right;
             overflow: hidden;

resources/less/metager/parts/sidebar.less

 .sidebar {
-    border-left: 1px solid #ccc;
+    border-left: 1px solid @border-color;
     box-shadow: 0px 1px 1.5px 1px #c0c0c0;
     position: fixed;
     display: block;
@@ -197,7 +197,7 @@
     line-height: 23px;
     border-radius: 5px;
     color: grey;
-    background-color: white;
+    background-color: @background-color;
     &:after {
         content: "≡";
     }

resources/less/metager/variables-dark.less

@@ -12,4 +12,5 @@
 @sidebar-list-hover-color: @color-strong-grey;
 // Card styles
 @card-background-color: @color-strong-grey;
-@card-border-color: #727272;
+// Default Borde Color 
+@border-color: #727272;

resources/less/metager/variables.less

@@ -31,4 +31,5 @@ sans-serif;
 @screen-medium: 1200px;
 // Card styles
 @card-background-color: @background-color;
-@card-border-color: #ccc;
\ No newline at end of file
+// Default Border Color
+@border-color: #ccc;
\ No newline at end of file