diff --git a/web/app/controllers/contests.php b/web/app/controllers/contests.php
index 02cd3c8..029ef6b 100644
--- a/web/app/controllers/contests.php
+++ b/web/app/controllers/contests.php
@@ -5,14 +5,24 @@
 		become403Page(UOJLocale::get('need login'));
 	}
 
+	if (!isset($_COOKIE['bootstrap4'])) {
+		$REQUIRE_LIB['bootstrap5'] = '';
+	}
+
 	$upcoming_contest_name = null;
 	$upcoming_contest_href = null;
 	$rest_second = 1000000;
 	function echoContest($contest) {
-		global $myUser, $upcoming_contest_name, $upcoming_contest_href, $rest_second;
+		global $myUser, $upcoming_contest_name, $upcoming_contest_href, $rest_second, $REQUIRE_LIB;
+
+		$a_class = ' ';
+
+		if (isset($REQUIRE_LIB['bootstrap5'])) {
+			$a_class = ' class="text-decoration-none" ';
+		}
 		
 		$contest_name_link = <<<EOD
-<a href="/contest/{$contest['id']}">{$contest['name']}</a>
+<a $a_class href="/contest/{$contest['id']}">{$contest['name']}</a>
 EOD;
 		genMoreContestInfo($contest);
 		if ($contest['cur_progress'] == CONTEST_NOT_STARTED) {
@@ -23,18 +33,18 @@ EOD;
 				$rest_second = $cur_rest_second;
 			}
 			if ($myUser != null && hasRegistered($myUser, $contest)) {
-				$contest_name_link .= '<sup><a style="color:green">'.UOJLocale::get('contests::registered').'</a></sup>';
+				$contest_name_link .= '<sup><a '.$a_class.' style="color:green">'.UOJLocale::get('contests::registered').'</a></sup>';
 			} else {
-				$contest_name_link .= '<sup><a style="color:red" href="/contest/'.$contest['id'].'/register">'.UOJLocale::get('contests::register').'</a></sup>';
+				$contest_name_link .= '<sup><a '.$a_class.' style="color:red" href="/contest/'.$contest['id'].'/register">'.UOJLocale::get('contests::register').'</a></sup>';
 			}
 		} elseif ($contest['cur_progress'] == CONTEST_IN_PROGRESS) {
-			$contest_name_link .= '<sup><a style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::in progress').'</a></sup>';
+			$contest_name_link .= '<sup><a '.$a_class.' style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::in progress').'</a></sup>';
 		} elseif ($contest['cur_progress'] == CONTEST_PENDING_FINAL_TEST) {
-			$contest_name_link .= '<sup><a style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::pending final test').'</a></sup>';
+			$contest_name_link .= '<sup><a '.$a_class.' style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::pending final test').'</a></sup>';
 		} elseif ($contest['cur_progress'] == CONTEST_TESTING) {
-			$contest_name_link .= '<sup><a style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::final testing').'</a></sup>';
+			$contest_name_link .= '<sup><a '.$a_class.' style="color:blue" href="/contest/'.$contest['id'].'">'.UOJLocale::get('contests::final testing').'</a></sup>';
 		} elseif ($contest['cur_progress'] == CONTEST_FINISHED) {
-			$contest_name_link .= '<sup><a style="color:grey" href="/contest/'.$contest['id'].'/standings">'.UOJLocale::get('contests::ended').'</a></sup>';
+			$contest_name_link .= '<sup><a '.$a_class.'style="color:grey" href="/contest/'.$contest['id'].'/standings">'.UOJLocale::get('contests::ended').'</a></sup>';
 		}
 		
 		$last_hour = round($contest['last_min'] / 60, 2);
@@ -42,17 +52,28 @@ EOD;
 		$click_zan_block = getClickZanBlock('C', $contest['id'], $contest['zan']);
 		echo '<tr>';
 		echo '<td>', $contest_name_link, '</td>';
-		echo '<td>', '<a href="'.HTML::timeanddate_url($contest['start_time'], array('duration' => $contest['last_min'])).'">'.$contest['start_time_str'].'</a>', '</td>';
+		echo '<td>', '<a'.$a_class.'href="'.HTML::timeanddate_url($contest['start_time'], array('duration' => $contest['last_min'])).'">'.$contest['start_time_str'].'</a>', '</td>';
 		echo '<td>', UOJLocale::get('hours', $last_hour), '</td>';
-		echo '<td>', '<a href="/contest/'.$contest['id'].'/registrants"><span class="glyphicon glyphicon-user"></span> &times;'.$contest['player_num'].'</a>', '</td>';
+		echo '<td>', '<a'.$a_class.'href="/contest/'.$contest['id'].'/registrants"><span class="glyphicon glyphicon-user"></span> &times;'.$contest['player_num'].'</a>', '</td>';
 		echo '<td>', '<div class="text-left">'.$click_zan_block.'</div>', '</td>';
 		echo '</tr>';
 	}
 	?>
 <?php echoUOJPageHeader(UOJLocale::get('contests')) ?>
+<?php
+if (isSuperUser($myUser)) {
+	if (isset($REQUIRE_LIB['bootstrap5'])) {
+		echo '<div class="text-end">';
+	} else {
+		echo '<div class="text-right">';
+	}
+	echo '<a href="/contest/new" class="btn btn-primary">'.UOJLocale::get('contests::add new contest').'</a>';
+	echo '</div>';
+}
+	?>
 <h4><?= UOJLocale::get('contests::current or upcoming contests') ?></h4>
 <?php
-		$table_header = '';
+			$table_header = '';
 	$table_header .= '<tr>';
 	$table_header .= '<th>'.UOJLocale::get('contests::contest name').'</th>';
 	$table_header .= '<th style="width:15em;">'.UOJLocale::get('contests::start time').'</th>';
@@ -60,16 +81,22 @@ EOD;
 	$table_header .= '<th style="width:100px;">'.UOJLocale::get('contests::the number of registrants').'</th>';
 	$table_header .= '<th style="width:180px;">'.UOJLocale::get('appraisal').'</th>';
 	$table_header .= '</tr>';
+
+	$table_config = array('page_len' => 40);
+	if (isset($REQUIRE_LIB['bootstrap5'])) {
+		$table_config['div_classes'] = array('card', 'mb-3');
+		$table_config['table_classes'] = array('table', 'uoj-table', 'mb-0');
+	}
 	echoLongTable(array('*'), 'contests', "status != 'finished'", 'order by start_time desc, id desc', $table_header,
 		echoContest,
-		array('page_len' => 40)
+		$table_config
 	);
 
 	if ($rest_second <= 86400) {
 		$notification = json_encode($upcoming_contest_name . " 已经开始了。是否要跳转到比赛页面？");
 		echo <<<EOD
 <div class="text-center bot-buffer-lg">
-<div class="text-warning">$upcoming_contest_name 倒计时</div>
+<div class="text-secondary">$upcoming_contest_name 倒计时</div>
 <div id="contest-countdown"></div>
 <script type="text/javascript">
 $('#contest-countdown').countdown($rest_second, function() {
@@ -85,18 +112,9 @@ EOD;
 
 <h4><?= UOJLocale::get('contests::ended contests') ?></h4>
 <?php
-		echoLongTable(array('*'), 'contests', "status = 'finished'", 'order by start_time desc, id desc', $table_header,
-			echoContest,
-			array('page_len' => 40,
-				'print_after_table' => function() {
-					global $myUser;
-					if (isSuperUser($myUser)) {
-						echo '<div class="text-right">';
-						echo '<a href="/contest/new" class="btn btn-primary">'.UOJLocale::get('contests::add new contest').'</a>';
-						echo '</div>';
-					}
-				}
-			)
-		);
+	echoLongTable(array('*'), 'contests', "status = 'finished'", 'order by start_time desc, id desc', $table_header,
+		echoContest,
+		$table_config
+	);
 	?>
 <?php echoUOJPageFooter() ?>