Added CSS for 3 grouped input form fields.

interface/web/themes/default/assets/stylesheets/ispconfig.css

@@ -658,3 +658,25 @@ span.flag-zw {background-position:0 -5435px}
   #logo {
     background-image: url("../images/logo@2x.png");
     background-size: 200px 65px; } }
+
+.input-group-field {
+    display: table-cell;
+    vertical-align: middle;
+    border-radius:4px;
+    min-width:1%;
+    white-space: nowrap;
+}
+.input-group-field .form-control {
+    border-radius: inherit !important;
+}
+.input-group-field:not(:first-child):not(:last-child) {
+    border-radius:0;
+}
+.input-group-field:not(:first-child):not(:last-child) .form-control {
+    border-left-width: 0;
+    border-right-width: 0;
+}
+.input-group-field:last-child {
+    border-top-left-radius:0;
+    border-bottom-left-radius:0;
+}
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interface/web/themes/default/assets/stylesheets/ispconfig.sass

@@ -291,3 +291,24 @@ thead.dark
   #logo
     background-image: url('../images/logo@2x.png')
     background-size: 200px 65px
+
+.input-group-field
+  display: table-cell
+  vertical-align: middle
+  border-radius: 4px
+  min-width: 1%
+  white-space: nowrap
+
+.input-group-field .form-control 
+  border-radius: inherit !important
+
+.input-group-field:not(:first-child):not(:last-child)
+  border-radius: 0
+
+.input-group-field:not(:first-child):not(:last-child) .form-control
+  border-left-width: 0
+  border-right-width: 0
+
+.input-group-field:last-child
+  border-top-left-radius: 0
+  border-bottom-left-radius: 0
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