Further style changes

site/public/index.html

@@ -22,7 +22,7 @@
 
   <div class="container-fluid p-5 my-5 border">
     <div class="row justify-content-center p-3">
-      <div class="col-sm-6"
+      <div class="col-sm-6 text-center"
         <form action="search.php" method="POST">
           <input type="text" name="search" placeholder="search for a patent record">
           <input type="submit" value="search">
@@ -31,27 +31,27 @@
     </div>
 
     <div class="row p-3">
-      <div class="col">
+      <div class="col text-center">
         <a href="./random.php">show a random record</a>
       </div>
 
-      <div class="col">
+      <div class="col text-center">
         <a href="./compare.php">compare two random records</a>
       </div>
     </div>
 
     <div class="row p-3">
-      <div class="col">
+      <div class="col text-center">
         <a href="./titles.php">ten random titles</a>
       </div>
 
-      <div class="col">
+      <div class="col text-center">
         <a href="./abstracts.php">ten random abstracts</a>
       </div>
     </div>
 
     <div class="row p-3">
-      <div class="col">
+      <div class="col text-center">
         <form action="search.php" method="POST">
           <input type="hidden" name="search" value="leak">
           <button type="submit" class="btn-link">
@@ -60,7 +60,7 @@
         </form>
       </div>
 
-      <div class="col">
+      <div class="col text-center">
         <form action="search.php" method="POST">
           <input type="hidden" name="search" value="secret">
           <button type="submit" class="btn-link">