CSS立体标签实现

    <style>
        .tag { background-color: #de3f33; position: relative; text-align: center; color: #fff; line-height: 40px; width: 150px; margin: 100px auto; }
            .tag:before { content: ''; width: 0; height: 0; border-bottom: 5px solid #b23838; border-left: 5px solid transparent; position: absolute; top: -5px; left: 0; }
    </style>

   <div class="tag">最佳答案</div>