resurrect css, fixes #3439

Closes #3439

Merge request studip/studip!2336

resources/assets/stylesheets/scss/plus.scss

+.plus {
+    .element_header {
+        display: inline-block;
+        width: 250px;
+        margin-left: 5px;
+    }
+
+    .element_description {
+        display: inline-block;
+        margin-left: 20px;
+    }
+
+    .plugin_icon {
+        width: 16px;
+        height: 16px;
+    }
+
+    .shortdesc {
+        margin-left: 3px;
+    }
+
+    .plus_expert {
+        margin-left: 20px;
+        width: 97%;
+
+        display: flex;
+        flex-wrap: wrap;
+    }
+
+    .screenshot_holder {
+        width: 250px;
+        flex: 0 250px;
+        margin-right: 5mm;
+        box-sizing: border-box;
+    }
+
+    .big_thumb {
+        max-width: 250px;
+        max-height: 250px;
+        padding-top: 5mm;
+    }
+
+    .small_thumb {
+        margin-left: 2px;
+        margin-top: 5px;
+        max-height: 25px;
+    }
+
+    .thumb_holder {
+        width: 250px;
+        text-align: center;
+        background-color: $content-color-20;
+        border-top: 1px solid mix($brand-color-lighter, $white, 80%);
+        border-bottom: 1px solid mix($brand-color-lighter, $white, 80%);
+    }
+
+    .descriptionbox {
+        flex: 1 305px;
+        max-width: 45em;
+    }
+
+    .keywords {
+        padding: 5mm;
+        left: 5mm;
+        position: relative;
+    }
+
+    .longdesc {
+        overflow: hidden;
+    }
+
+    .helplink {
+        float: right;
+    }
+
+    article.studip > section:not(:last-child) {
+        border-bottom: 1px solid $table-header-color;
+    }
+}

resources/assets/stylesheets/studip.scss

@@ -70,6 +70,7 @@
 @import "scss/pagination";
 @import "scss/personal-notifications";
 @import "scss/plugins";
+@import "scss/plus";
 @import "scss/progress_indicator.scss";
 @import "scss/profile";
 @import "scss/qrcode";