diff --git a/output/js/constants.js b/output/js/constants.js
index 8fe3d67..027fd7f 100644
--- a/output/js/constants.js
+++ b/output/js/constants.js
@@ -33,7 +33,7 @@ export const ATTRIBUTES = {
 		ACTIVE: 'data-sort',
 		ASCENDING: 'data-sort-asc',
 		COLUMN: 'data-sorted-by',
-		COLUMN_LITERAL: 'sorted-by'
+		// COLUMN_LITERAL: 'sorted-by'
 	}
 };
 
@@ -41,7 +41,14 @@ export function columnAscendingByDefault(column) {
 	return column != COLUMN.USERS;
 }
 
-export function columnIsSortable(column) { return column != COLUMN.QR_CODE; }
+export function columnIsSortable(column) {
+	return ![
+		COLUMN.QR_CODE,
+		COLUMN.PREVIEW,
+		// Join URL contents are not guaranteed to have visible text.
+		COLUMN.JOIN_URL
+	].includes(column);
+}
 
 export function columnNeedsCasefold(column) {
 	return [
@@ -64,22 +71,22 @@ export function columnIsNumeric(column) {
  * @returns {HTMLElement}
  */
 function createElement(tag, ...args) {
-  const element = document.createElement(tag);
-  if (args.length === 0) return element;
-  const propsCandidate = args[0];
-  if (typeof propsCandidate !== "string" && !(propsCandidate instanceof Element)) {
-    // args[0] is not child element or text node
-    // must be props object
-    Object.assign(element, propsCandidate);
-    args.shift();
-  }
-  element.append(...args);
-  return element;
+	const element = document.createElement(tag);
+	if (args.length === 0) return element;
+	const propsCandidate = args[0];
+	if (typeof propsCandidate !== "string" && !(propsCandidate instanceof Element)) {
+		// args[0] is not child element or text node
+		// must be props object
+		Object.assign(element, propsCandidate);
+		args.shift();
+	}
+	element.append(...args);
+	return element;
 }
 
 export const element = new Proxy({}, {
-  get(_, key) {
-    return (...args) => createElement(key, ...args)
-  }
+	get(_, key) {
+		return (...args) => createElement(key, ...args)
+	}
 });
 
diff --git a/output/main.js b/output/main.js
index 8865a5a..8f3fb01 100644
--- a/output/main.js
+++ b/output/main.js
@@ -248,17 +248,22 @@ function setSortState(table, { ascending, column }) {
 	}
 	table.setAttribute(ATTRIBUTES.SORTING.ASCENDING, ascending);
 	table.setAttribute(ATTRIBUTES.SORTING.COLUMN, column);
-	// This can be used to style column headers in a consistent way, i.e.
-	// #tbl_communities[data-sort-asc=true][sorted-by=name]::after #th_name, ...
-	table.setAttribute(ATTRIBUTES.SORTING.COLUMN_LITERAL, COLUMN_LITERAL[column]);
+	
+	// No way around this for brief CSS.
+	const headers = table.querySelectorAll("th");
+	headers.forEach((th, colno) => {
+		th.removeAttribute(ATTRIBUTES.SORTING.ACTIVE);
+	});
+	headers[column].setAttribute(ATTRIBUTES.SORTING.ACTIVE, true);
 }
 
 // This is best done in JS, as it would require <noscript> styles otherwise.
 function markSortableColumns() {
 	const table = dom.tbl_communities();
-	for (const th of table.querySelectorAll('th')) {
-		if (th.id.includes("qr_code")) continue;
-		th.classList.add('sortable');
+	const header_cells = table.querySelectorAll('th');
+	for (let colno = 0; colno < header_cells.length; colno++) {
+	  if (!columnIsSortable(colno)) continue;
+		header_cells[colno].classList.add('sortable');
 	}
 }
 
diff --git a/output/styles2.css b/output/styles2.css
index bf4613d..da0de7c 100644
--- a/output/styles2.css
+++ b/output/styles2.css
@@ -32,7 +32,48 @@ header {
 	flex-grow: 1;
 }
 
-#tbl_communities { width:100%; }
+#tbl_communities {
+	/* Browser defaults. */
+	--cell-padding-h: 1px;
+	--cell-padding-v: 1px;
+	width:100%;
+}
+
+#tbl_communities th {
+	white-space: nowrap;
+}
+
+#tbl_communities :is(th, td) {
+	padding: var(--cell-padding-v) var(--cell-padding-h);
+}
+
+#tbl_communities th.sortable {
+	position: relative;
+	padding-right: calc( 1.5em + var(--cell-padding-h) );
+}
+
+#tbl_communities th.sortable::after {
+	position: absolute;
+	right: 0.25em;
+	top: 50%;
+	transform: translateY(-50%);
+	/* content: "\25C7"; */ /* White diamond */
+	/* content: "\2195"; */ /* Up-down arrow */
+	/* content: "\25A1"; */ /* White square */
+	/* content: "\25B8"; */ /* Small right pointing triangle */
+	content: "\2B25"; /* Black medium diamond */
+	color: grey;
+}
+
+#tbl_communities[data-sort-asc=true] th[data-sort=true]::after {
+	content: "\25B2"; /* Black up pointing triangle */
+	color: initial;
+}
+
+#tbl_communities[data-sort-asc=false] th[data-sort=true]::after {
+	content: "\25BC"; /* Black up pointing triangle */
+	color: initial;
+}
 
 #toggle-show-room-ids:not(:checked) 
 ~ #tbl_communities :is(#th_identifier, .td_identifier) { 
@@ -43,6 +84,10 @@ header {
 	font-family: monospace;
 }
 
+.td_language {
+	text-align: center;
+	font-size: 1.25em;
+}
 .td_language:empty::after {
 	content: "\2753";
 }
@@ -84,7 +129,7 @@ header {
 	display: flex;
 	flex-direction: row;
 	align-items: center;
-	justify-content: space-between;
+	justify-content: space-around;
 }
 
 .copy_button     { font-size: inherit }
@@ -232,3 +277,4 @@ label[for=toggle-show-room-ids]::after {
 	to {bottom: 0; opacity: 0;}
 }
 
+
diff --git a/sites/+components/tbl_communities.php b/sites/+components/tbl_communities.php
index dbb5325..d6771ca 100644
--- a/sites/+components/tbl_communities.php
+++ b/sites/+components/tbl_communities.php
@@ -3,14 +3,15 @@
 
 	// Once handlers are attached in JS, this check ceases to be useful.
 	function column_sortable($id) {
-		return $id != "qr";
+		// Join URL contents are not guaranteed to have visible text.
+		return $id != "qr" && $id != "preview" && $id != "join_url";
 	}
 	
 	function sort_onclick($colno) {
 		global $TABLE_COLUMNS;
 		$column = $TABLE_COLUMNS[$colno];
 		if (!column_sortable($column['id'])) return "";
-		return " onclick='sortTable($colno)'";
+		return " onclick='sortTable($colno)' title='Click to sort this column'";
 	}
 	
 	$TABLE_COLUMNS = [