diff --git a/jcal/src/Calendar.scss b/jcal/src/Calendar.scss
index 7fc4f2d..29a73f0 100644
--- a/jcal/src/Calendar.scss
+++ b/jcal/src/Calendar.scss
@@ -168,21 +168,22 @@
 }
 
 @media (pointer: coarse), (hover: none) {
-    .DayDetail-gregorian abbr {
+    .DayDetail abbr {
         position: relative;
         display: inline-flex;
         justify-content: center;
-        text-decoration: underline dashed;
 
         &:focus::after {
             content: attr(title);
             position: absolute;
             top: 90%;
+            left: 0;
             color: #000;
             background-color: #fff;
             border: 1px solid;
             width: fit-content;
             padding: 3px;
+            z-index: 20;
         }
     }
 }
diff --git a/jcal/src/Calendar.tsx b/jcal/src/Calendar.tsx
index dccf3fd..70b5f41 100644
--- a/jcal/src/Calendar.tsx
+++ b/jcal/src/Calendar.tsx
@@ -21,17 +21,17 @@ function WeekdayName({name}: { name: string }): JSX.Element {
 function DayDetail({jdn}: { jdn: number }): JSX.Element {
     const lc = jdnLongCount(jdn);
     return <div className="DayDetail">
-        <div className="DayDetail-jdn"><abbr title="Julian day number">JD</abbr> {jdn}</div>
+        <div className="DayDetail-jdn"><abbr title="Julian day number" tabIndex={0}>JD</abbr> {jdn}</div>
         <div className="DayDetail-gregorian">
-            <abbr title="Gregorian date">G.</abbr>{' '}
+            <abbr title="Gregorian date" tabIndex={0}>G.</abbr>{' '}
             {formatJG(jdnGregorian(jdn))}
         </div>
         {lc && <div className="DayDetail-lc">
-          <abbr title="Mesoamerican long count date">LC</abbr>{' '}
+          <abbr title="Mesoamerican long count date" tabIndex={0}>LC</abbr>{' '}
             {lc.join('.\u200b')}
         </div>}
         {jdn >= frStartJD && jdn <= frEndJD && <div className="DayDetail-fr">
-          <abbr title="French Republican Calendar">FR</abbr>{' '}
+          <abbr title="French Republican Calendar" tabIndex={0}>FR</abbr>{' '}
             {frDateFormat(jdnFrench(jdn))}
         </div>}
     </div>;