added style for unique event case

assets/sass/_theme/blocks/events.sass

 .block-agenda
     &--grid .events
-        @include grid(2, md)
+        &:not(.unique)
+            @include grid(2, md)
+        &.unique .event
+            flex-direction: row
+            grid-gap: $grid-gutter
+            .media
+                width: col(4, 8)
+            &-content
+                flex: 1
+                .more
+                    @include icon("arrow-right", after)
+                    margin-top: $spacing1
+                    &::after
+                        margin-left: half($spacing0)
+            @include media-breakpoint-up(desktop)
+                &-dates
+                    font-size: $h3-size-desktop
+                    line-height: $h3-line-height
+                    font-weight: $h3-weight
+                    margin-bottom: $spacing2
+                &-content h2
+                    font-size: $h2-size-desktop
+                    line-height: $h2-line-height
+                    font-weight: $h2-weight
+            @include media-breakpoint-down(desktop)
+                grid-gap: $grid-gutter-sm
+                .media:empty
+                    display: none
         .event
             display: flex
             flex-direction: column
             position: relative
+            @include media-breakpoint-down(desktop)
+                + .event 
+                    margin-top: $spacing1
             .media
                 order: -1
                 img
@@ -28,6 +58,12 @@
                 margin-top: $spacing0
 
 .block-agenda--grid 
+    @include in-page-with-sidebar
+        .events.unique .event .media:empty
+            display: none
     @include in-page-without-sidebar
-        .events
-            @include grid(3, desktop)
\ No newline at end of file
+        .events:not(.unique)
+            @include grid(3, desktop)
+            .unique
+        .events.unique .event-content
+            position: relative
\ No newline at end of file

layouts/partials/blocks/templates/agenda.html

 {{- $template := .block.template -}}
 {{- $position := .block.position -}}
 {{- $title := .block.title -}}
+{{- $isUnique := false -}}
 {{- $class := "block block-agenda" -}}
 {{- $layout_class := "block-agenda--list" -}}
 {{- with .block.data -}}
@@ -26,13 +27,18 @@
             {{ end -}}
           </div>
         {{ end -}}
-        <div class="events">
+        {{ $rangeLength := len .events }}
+        {{ if eq $rangeLength 1 }}
+          {{ $isUnique = true }}
+        {{ end }}
+        <div class="events{{ if eq $rangeLength 1 }} unique{{ end}} ">
           {{ range .events }}
             {{ $event := site.GetPage .file }}
             {{ with $event }}
                 {{ partial "events/event" (dict 
                   "event" .
                    "layout" $layout
+                   "isUnique" $isUnique
                 ) }}
             {{ end }}
           {{ end }}

layouts/partials/events/event.html

 {{ $event := .event }}
 {{ $layout := "list" }}
 {{ $layout = .layout }}
+{{ $isUnique := .isUnique }}
 {{- $direction := "" -}}
 {{ $heading := .heading | default "h2" }}
 {{ $heading_tag := (dict 
@@ -24,35 +25,52 @@
       <a href="{{ .Permalink }}" title="{{ safeHTML (i18n "commons.more_aria" (dict "Title" $title)) }}" itemprop="name">{{ $title }}</a>
     {{ $heading_tag.close }}
 
-    {{ if and (site.Params.events.index.show_description) (eq $layout "list") }}
-      {{- if (partial "GetTextFromHTML" .Params.summary) -}}
-        <p itemprop="description">
-          {{ if site.Params.events.index.truncate_description }}
-            {{ partial "GetTruncateContent" ( dict 
-              "text" .Params.summary
-              "length" site.Params.events.index.truncate_description
-              ) }}
-          {{ else }}
-            {{ partial "PrepareText" .Params.summary }}
+    {{ if eq $isUnique true }}
+      <div class="event-dates" itemprop="startDate" content="{{- if .Params.dates.from.day -}}{{ .Params.dates.from.day }}{{- end -}} {{- if .Params.dates.from.hour -}}{{ .Params.dates.from.hour }}{{- end -}}">
+        {{ .Params.dates.computed.short }}
+        <div class="event-time">
+          {{ if .Params.dates.from.hour }}
+            <span>{{ .Params.dates.from.hour }}</span>
+          {{ end }}
+          {{ if .Params.dates.to.hour }}
+            <span> {{ .Params.dates.to.hour }}</span>
           {{ end }}
-        </p>
+        </div>
+      </div>
+
+      {{ if site.Params.events.index.show_description }}
+        {{- if (partial "GetTextFromHTML" .Params.summary) -}}
+          <p itemprop="description">
+            {{ if site.Params.events.index.truncate_description }}
+              {{ partial "GetTruncateContent" ( dict 
+                "text" .Params.summary
+                "length" site.Params.events.index.truncate_description
+                ) }}
+            {{ else }}
+              {{ partial "PrepareText" .Params.summary }}
+            {{ end }}
+          </p>
+        {{- end -}}
       {{- end -}}
-    {{- end -}}
+  
+      <p class="more meta" aria-hidden="true">{{- i18n "commons.more" -}}</p>
+  {{ end }}
   </div>
 
-  <div class="event-dates" itemprop="startDate" content="{{- if .Params.dates.from.day -}}{{ .Params.dates.from.day }}{{- end -}} {{- if .Params.dates.from.hour -}}{{ .Params.dates.from.hour }}{{- end -}}">
-    {{ .Params.dates.computed.short }}
-    <div class="event-time">
-      {{ if .Params.dates.from.hour }}
-        <span>{{ .Params.dates.from.hour }}</span>
-      {{ end }}
-      {{ if .Params.dates.to.hour }}
-        <span> {{ .Params.dates.to.hour }}</span>
-      {{ end }}
+  {{ if eq $isUnique false }}
+    <div class="event-dates" itemprop="startDate" content="{{- if .Params.dates.from.day -}}{{ .Params.dates.from.day }}{{- end -}} {{- if .Params.dates.from.hour -}}{{ .Params.dates.from.hour }}{{- end -}}">
+      {{ .Params.dates.computed.short }}
+      <div class="event-time">
+        {{ if .Params.dates.from.hour }}
+          <span>{{ .Params.dates.from.hour }}</span>
+        {{ end }}
+        {{ if .Params.dates.to.hour }}
+          <span> {{ .Params.dates.to.hour }}</span>
+        {{ end }}
+      </div>
     </div>
-  </div>
 
-  {{ if and (site.Params.events.index.show_description) (eq $layout "grid") }}
+    {{ if and (site.Params.events.index.show_description) (eq $layout "grid") }}
       {{- if (partial "GetTextFromHTML" .Params.summary) -}}
         <div class="event-description">
           <p itemprop="description">
@@ -68,6 +86,7 @@
         </div>
       {{- end -}}
     {{- end -}}
+  {{ end }}
 
   <div class="media">
     {{- if .Params.image -}}