在悬停时从Bootstrap Carousel链接中删除文本修饰

Question

在悬停模式下，我无法删除字幕链接中的下划线装饰。我正在使用Bootstrap Carousel。也许有人可以帮忙？提前致谢。这是我的html和css代码：

<!-- Wrapper for Slides -->
        <div class="carousel-inner" role="listbox">
          <div class="item active" id="image">
            <img src="images/1.png" class="img-responsive" alt="1">
            <div class="carousel-caption" id="caption_1"> <a href="1.html">
              <h1><span>1</span></h1></a>
            </div>
          </div>
          <div class="item" id="image">
            <img src="images/2.png" class="img-responsive" alt="2">
            <div class="carousel-caption" id="caption_2"> <a href="2.html">
              <h1><span>2</span></h1></a>
            </div>  
          </div>
        </div>


a h1 span {
text-decoration: none;
color: white;
margin-left: auto;
margin-right: auto;
margin-bottom: 10px;
font-family: Roboto;
font-size: 28px;
font-weight: bold;
text-transform: uppercase;
background-color: #337EC0;
opacity: 0.75;
padding: 5px;
-webkit-transition-duration: 0.4s; /* Safari */
transition-duration: 0.4s;

}

a h1 span:hover {
color: white;
text-decoration: none;
background-color: #337EC0;
opacity: 0.95;

}