Aligned book and shelf grid item views

Updated the titles so they are limited via CSS rather than by a
estimated hardcoded limit.

For #1469

resources/sass/_colors.scss

@@ -92,6 +92,6 @@
 .bg-chapter {
   background-color: var(--color-chapter);
 }
-.bg-shelf {
+.bg-bookshelf {
   background-color: var(--color-bookshelf);
 }

resources/sass/_text.scss

@@ -352,12 +352,21 @@ li > ol, li > ul {
   overflow-wrap: break-word;
 }
 
-.limit-text {
+.text-limit-lines-1 {
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
 }
 
+.text-limit-lines-2 {
+  // -webkit use here is actually standardised cross-browser:
+  // https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-line-clamp
+  display: -webkit-box;
+  -webkit-box-orient: vertical;
+  -webkit-line-clamp: 2;
+  overflow: hidden;
+}
+
 /**
  * Grouping
  */