Fixed december in calendar and modernized CSS

Library/Widgets/Calendar.md

@@ -18,7 +18,7 @@ function generate_calendar(calendarID, year, month)
     year = (wantedMonth - (wantedMonth % 12)) / 12
     month = wantedMonth % 12
     if month == 0 then
-      month = 1
+      month = 12
     end
   end
 
@@ -73,12 +73,12 @@ function generate_calendar(calendarID, year, month)
               for _, e in pairs(events) do
                 local datematch = e.at.match(
                   string.format("^%d-%02d-%02d( +[0-9]+:[0-9]+)?", year, month, day))
-                if #datematch >= 2 and not datematch[2] then
+                if datematch and #datematch >= 2 and not datematch[2] then
                     cellcontent = cellcontent .. string.format(
                       [[<a href="%s"><div class="event all-day">%s</div></a>]],
                       e.ref, e.name
                   )
-                elseif #datematch >= 2 and datematch[2] then
+                elseif datematch and #datematch >= 2 and datematch[2] then
                   cellcontent = cellcontent .. string.format(
                     [[
                       <a href="%s">
@@ -166,52 +166,49 @@ end
 ```space-style
 .calendartable {
   border-collapse: collapse; 
-  /* width: 500px; */
-}
 
-.calendartable table {
+  table {
     border-color: var(--panel-border-color);
     border: 2px solid #444;
     border-collapse: collapse;
-}
     
-.calendartable th {
+    th {
       width: 14%;
       padding: 3px; 
       text-align: left;  
       background-color: var(--panel-background-color);
       color: #852624;
       border: 1px solid #aaa;
-}
+    }
     
-
-.calendartable td {
+    td {
       width: 14%;
       padding: 3px; 
       text-align: left;
       vertical-align: top;
       border: 1px solid #aaa;
-}
     
-.calendartable td.today {
+      &.today {
       background-color: #f6f3c2;
-}
+      }
+    }
+  }
   
-.calendartable a {
+  a {
     text-decoration-line: none;
     color: var(--root-color);
-}
     
-.calendartable a.mark {
+    &.mark {
       text-decoration-line: none;
       color: var(--ui-accent-text-color);
-}
+    }
+  }
   
-.calendartable span.extramarker {
+  span.extramarker {
     background-color: yellow;
-}
+  }
   
-.calendartable .event {
+  .event {
     background-color: #2ca05a;
     color: #fff;
     border-radius: 4px;
@@ -221,20 +218,20 @@ end
     white-space: normal;
     overflow-wrap: normal !important;
     word-break: normal !important;
-}
     
-.calendartable .event.all-day {
+    &.all-day {
       background-color: #852624;
-}
+    }
 
-.calendartable .event .time {
+    .time {
       font-weight: bold;
-}
+    }
+  }
   
-.calendartable .month-prev,
-.calendartable .month-next,
-.calendartable .month-now {
+  .month-prev,
+  .month-next,
+  .month-now {
     cursor: pointer;
+  }
 }
-
 ```