<form id="search-form"  class="636319a64d6c4 search-box-form" action="/index.php" method="get" target="_blank"> 

      <input class="636319a64d6c5 search-input"  name="keyword" type="text" placeholder="输入关键字... 回车" required>

<input type="hidden" name="c" value="search">

      <input type="hidden" name="s" value="pb">

    </form>