update

src/App.js

@@ -479,11 +479,14 @@ const SingleRow = ({ parsedSequence, rowStart, rowEnd, setHoveredInfo, rowId, in
   // Calculate dimensions and tick interval
   const width = rowSequence.length * sep; // 10 pixels per character
   let height = 70 + featureBlocks.length * 20;
-  const approxNumTicks = Math.ceil(width / 60); // One tick every 60 pixels
+// if rowStart is more than 5 digits, then we need more spacing
+  const spacing = rowStart > 10000 ? 60 : 40;
+  const approxNumTicks = Math.ceil(width / spacing); // One tick every 60 pixels
   let tickInterval = Math.ceil(rowSequence.length / approxNumTicks);
   const options = [5, 10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000, 200000, 500000, 1000000, 2000000, 5000000, 10000000];
-  // find nearest option to tickInterval
-  tickInterval = options.reduce((prev, curr) => (Math.abs(curr - tickInterval) < Math.abs(prev - tickInterval) ? curr : prev));
+  // find option just larger than tickInterval
+
+  tickInterval  = options.find((option) => option >= tickInterval);
   const modulus = rowStart % tickInterval;
   const numTicks = Math.floor((rowEnd - rowStart) / tickInterval) + 1;