diff --git a/docs/css/imerss-core.css b/docs/css/imerss-core.css
index 7130d261..6f7b3fa4 100644
--- a/docs/css/imerss-core.css
+++ b/docs/css/imerss-core.css
@@ -349,6 +349,14 @@
     overflow: auto;
 }
 
+/** These "panels" currently only exist in the old-style jQuery tabbed panes. This definition is here to make
+ * Xetthecum phase II panel labels show up in the right place but might be helpful in future.
+ * These two uses of "imerss-panel-label" (in Xetthecum and BBEAS) are unconnected.
+ */
+.imerss-panel {
+    position: relative;
+}
+
 .imerss-panel-label {
     font-size: 1.5rem;
     padding-bottom: 5px;
diff --git a/docs/css/imerss-viz-all.css b/docs/css/imerss-viz-all.css
index 176f379d..9c0474b3 100644
--- a/docs/css/imerss-viz-all.css
+++ b/docs/css/imerss-viz-all.css
@@ -1057,6 +1057,14 @@ a.ui-button:active,
     overflow: auto;
 }
 
+/** These "panels" currently only exist in the old-style jQuery tabbed panes. This definition is here to make
+ * Xetthecum phase II panel labels show up in the right place but might be helpful in future.
+ * These two uses of "imerss-panel-label" (in Xetthecum and BBEAS) are unconnected.
+ */
+.imerss-panel {
+    position: relative;
+}
+
 .imerss-panel-label {
     font-size: 1.5rem;
     padding-bottom: 5px;
diff --git a/docs/css/xetthecum-core.css b/docs/css/xetthecum-core.css
index 244d4390..a4bb4da7 100644
--- a/docs/css/xetthecum-core.css
+++ b/docs/css/xetthecum-core.css
@@ -1,3 +1,5 @@
+/** New-age file for Phase III, referenced from xetthecum-storymap **/
+
 .imerss-cultural-values {
     display: flex;
     flex-wrap: wrap;
diff --git a/docs/css/xetthecum-external.css b/docs/css/xetthecum-external.css
index 673b20b1..972ec0fc 100644
--- a/docs/css/xetthecum-external.css
+++ b/docs/css/xetthecum-external.css
@@ -1,4 +1,5 @@
-/* This is currently used primarily for Valdes map view which has dataset
+/* Phase II-era old codebase file
+  This is currently used primarily for Valdes map view which has dataset
    controls but also Xetthecum-style panels
  */
 
diff --git a/docs/css/xetthecum-shared.css b/docs/css/xetthecum-shared.css
index 26fd69e1..d03521c4 100644
--- a/docs/css/xetthecum-shared.css
+++ b/docs/css/xetthecum-shared.css
@@ -1,3 +1,5 @@
+/** Old-era (Phase II) file referenced from bioblitz, Valdes and other old viz **/
+
 :root {
   --imerss-map-width: 500px;
   --imerss-eco-colour: #DEE0B0;
diff --git a/docs/css/xetthecum.css b/docs/css/xetthecum.css
index 80f7dacf..cbe6a0d2 100644
--- a/docs/css/xetthecum.css
+++ b/docs/css/xetthecum.css
@@ -88,6 +88,7 @@ body {
 
 .imerss-container {
     margin: 1.5rem 0.5rem 0.5rem 0.5rem;
+    flex-direction: row;
 }
 
 .imerss-map-holder {
@@ -233,6 +234,8 @@ body {
 
 .imerss-map {
     height: 450px;
+    min-width: 480px;
+    min-height: 320px;
 }
 
 .imerss-tabs {
@@ -287,6 +290,8 @@ body {
 
 .imerss-checklist-holder {
     padding: 1em 1.4em;
+    /** Override definition which ended up in imerss-viz.css of 0.5em 1.2em in May 2024 */
+    margin: 0;
 }
 
 .checklist-hulq-name {
@@ -433,6 +438,11 @@ body {
     width: auto;
 }
 
+/** Override core definition from May 2024 onwards - make sure images are flush in row in Xetthecum **/
+.taxonDisplay-image-holder {
+    padding-left: 0;
+}
+
 .taxonDisplay-wikipediaSummary {
     display: block;
     margin-left: 2.5rem;
diff --git a/src/client/css/imerss-core.css b/src/client/css/imerss-core.css
index 7130d261..6f7b3fa4 100644
--- a/src/client/css/imerss-core.css
+++ b/src/client/css/imerss-core.css
@@ -349,6 +349,14 @@
     overflow: auto;
 }
 
+/** These "panels" currently only exist in the old-style jQuery tabbed panes. This definition is here to make
+ * Xetthecum phase II panel labels show up in the right place but might be helpful in future.
+ * These two uses of "imerss-panel-label" (in Xetthecum and BBEAS) are unconnected.
+ */
+.imerss-panel {
+    position: relative;
+}
+
 .imerss-panel-label {
     font-size: 1.5rem;
     padding-bottom: 5px;
diff --git a/src/client/css/xetthecum-core.css b/src/client/css/xetthecum-core.css
index 244d4390..a4bb4da7 100644
--- a/src/client/css/xetthecum-core.css
+++ b/src/client/css/xetthecum-core.css
@@ -1,3 +1,5 @@
+/** New-age file for Phase III, referenced from xetthecum-storymap **/
+
 .imerss-cultural-values {
     display: flex;
     flex-wrap: wrap;
diff --git a/src/client/css/xetthecum-external.css b/src/client/css/xetthecum-external.css
index 673b20b1..972ec0fc 100644
--- a/src/client/css/xetthecum-external.css
+++ b/src/client/css/xetthecum-external.css
@@ -1,4 +1,5 @@
-/* This is currently used primarily for Valdes map view which has dataset
+/* Phase II-era old codebase file
+  This is currently used primarily for Valdes map view which has dataset
    controls but also Xetthecum-style panels
  */
 
diff --git a/src/client/css/xetthecum-shared.css b/src/client/css/xetthecum-shared.css
index 26fd69e1..d03521c4 100644
--- a/src/client/css/xetthecum-shared.css
+++ b/src/client/css/xetthecum-shared.css
@@ -1,3 +1,5 @@
+/** Old-era (Phase II) file referenced from bioblitz, Valdes and other old viz **/
+
 :root {
   --imerss-map-width: 500px;
   --imerss-eco-colour: #DEE0B0;
diff --git a/src/client/css/xetthecum.css b/src/client/css/xetthecum.css
index 80f7dacf..cbe6a0d2 100644
--- a/src/client/css/xetthecum.css
+++ b/src/client/css/xetthecum.css
@@ -88,6 +88,7 @@ body {
 
 .imerss-container {
     margin: 1.5rem 0.5rem 0.5rem 0.5rem;
+    flex-direction: row;
 }
 
 .imerss-map-holder {
@@ -233,6 +234,8 @@ body {
 
 .imerss-map {
     height: 450px;
+    min-width: 480px;
+    min-height: 320px;
 }
 
 .imerss-tabs {
@@ -287,6 +290,8 @@ body {
 
 .imerss-checklist-holder {
     padding: 1em 1.4em;
+    /** Override definition which ended up in imerss-viz.css of 0.5em 1.2em in May 2024 */
+    margin: 0;
 }
 
 .checklist-hulq-name {
@@ -433,6 +438,11 @@ body {
     width: auto;
 }
 
+/** Override core definition from May 2024 onwards - make sure images are flush in row in Xetthecum **/
+.taxonDisplay-image-holder {
+    padding-left: 0;
+}
+
 .taxonDisplay-wikipediaSummary {
     display: block;
     margin-left: 2.5rem;