css怎么取消边框

element {
  border: 0;
}

element {
  border-top-width: 0;
  border-right-width: 0;
  border-bottom-width: 0;
  border-left-width: 0;
}

element {
  border-style: none;
}

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>CSS 取消边框示例</title>
  <style>
    .button {
      padding: 10px 20px;
      background-color: #007bff;
      color: white;
      border: 2px solid #007bff;
      border-radius: 5px;
    }

    .button.no-border {
      border: 0;
    }
  </style>
</head>
<body>
  <button class="button">默认按钮</button>
  <button class="button no-border">无边框按钮</button>
</body>
</html>