如何在引导程序 3 中居中对齐照片下方的文本？

我希望用户名文本在页面中间的用户照片下方居中。这是我的 html 代码，但它不起作用：

<div class="row">
    <div class="col-sm-4 col-sm-push-4">

            <ul class="list-unstyled">
                <li class="text-center">
                    <img class="img-responsive img-circle" :src="BASE_URL +'/media/avatars/' + photo">
                </li>   
                <li class="text-center">
                    <h5><strong>{{$route.params.username}}</strong></h5>
                </li>
            </ul>          
    </div> 
</div>

我也尝试过其他技巧，比如li没有，class="text-center"但它们没有按预期工作。我该如何解决？

PS 这里是我使用的完整 custom.css：

body {
    background: #fdca15;
direction: rtl;
text-align: rtl;

}



.bala{
    text-align: center;
}



.mylogo  {
    width: 150px;
    text-align: left !important;
}

.results {
    font-family: sans-serif, arial, parastoo, tahoma, sans;
}


.search-bar {
    font-family: sahel, tahoma, sans;
}

.large-text{
    padding: 20px;
}



.share-links {      
 float: left;
}

.single-joke , .profile {
    padding: 10px;
    background: #fff;
    border-radius: 5px;

}


.btn-round-lg{
border-radius: 22.5px;

}
.btn-round{
border-radius: 17px;
}
.btn-round-sm{
border-radius: 15px;
}


 a:hover{
    color: red;
     text-decoration: none;
 }

 .grey {
    color: #aeadad;
 }

 .green {
    color: #9fde86;
 }

  .red {
    color: #ff7761;
 }

 .white {
    color: #fff;
 }

 .img-circle {
    height: 50px;
    width: 50px;
 }

 .avatar-comment {
    height: 32px;
    width: 32px;
 }

.img-responsive {
  margin: auto !important;
}


 .profile-photo {
        height: 128px;
    width: 128px;

 }
 .vertical-align {
    display: flex;
    align-items: center;
}

.username {
    text-align: right;
}

/* Dropdown Button */
.dropbtn {
    background-color: #ff8e15;
    color: white;
    padding: 16px;
    font-size: 16px;
    border: none;
    cursor: pointer;
}

/* The container <div> - needed to position the dropdown content */
.dropdown {
    position: relative;
    display: inline-block;
}

/* Dropdown Content (Hidden by Default) */
.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
}

/* Links inside the dropdown */
.dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
}

/* Change color of dropdown links on hover */
.dropdown-content a:hover {background-color: #f1f1f1}

/* Show the dropdown menu on hover */
.dropdown:hover .dropdown-content {
    display: block;
}

/* Change the background color of the dropdown button when the dropdown content is shown */
.dropdown:hover .dropbtn {
    background-color: #3e8e41;
}

.joke-photo {
    max-width: "900px";
}

 .submenu:hover {
    cursor: pointer;
 }

 .photo-image {

    max-width: 800px;
 }

 .img-avatar {
    max-width: 64px;
    max-height: 64px;
 }

.img-small {

    max-width: 512px;
    max-height: 512px;

}

 ul li img {
    vertical-align: middle;
}


a {

    color: #852f01 !important;

}


a:hover {

    color: #E65100 !important;
}