diff --git a/index.html b/index.html
index 7d15776..11691f9 100644
--- a/index.html
+++ b/index.html
@@ -9,11 +9,11 @@
         <link rel="stylesheet" href="site/style.css">
     </head>
     <body>
-        <label id="input_label" for="tags">Organism 1: </label><input class="rounded" id="tags" value="Homo sapiens">
+        <label id="input_label" for="tags"><span class="bold-text">Organism 1:</span> </label><input class="rounded" id="tags" value="Homo sapiens">
         &emsp;
-        <label id="input_label" for="tags2">Organism 2: </label><input class="rounded" id="tags2" value="Danio rerio">
+        <label id="input_label" for="tags2"><span class="bold-text">Organism 2:</span> </label><input class="rounded" id="tags2" value="Danio rerio">
         <br><br>
-        NCBI Gene IDs of Organism 1:<br>
+        <span class="bold-text">NCBI Gene IDs of Organism 1:</span><br>
         <textarea id="inputText" rows="10" cols="30">
 1639
 1643
@@ -22,7 +22,7 @@
         <br>
         <button class="rounded-button" id="submitButton">Search</button>
         <br><br>
-        Orthologous gene relations between two organisms:
+        <span class="bold-text">Orthologous gene relations between two organisms:</span>
         <table border="1" id="resultsTable">
         </table>
         <br>
diff --git a/site/style.css b/site/style.css
index 9ee1007..352d398 100644
--- a/site/style.css
+++ b/site/style.css
@@ -9,6 +9,11 @@ h1, h2, h3, h4, h5, h6 {
     color: #191970; /* ミッドナイトブルー */
 }
 
+.bold-text {
+    font-weight: bold; /* 太字 */
+    color: #191970;    /* ミッドナイトブルー */
+}
+
 /* テーブルのスタイル */
 table {
     width: 100%;           /* テーブルの幅を最大に */
