twitter-bootstrap - 如何将图标移动到这个社交按钮的中心？

Question

我正在尝试将 Font Awesome 图标在其圆形背景中垂直和水平移动到中心。但每次要么在左边，要么在顶部，要么在底部。
如何固定这些图标并移动到中心？

这是代码(因为它在页脚中，所以我在 CSS 中添加了额外的行):

     
    .page-footer {
      background-color:#222222;
      padding: 0 40px;
      text-align: center;
    }
    .page-footer a {
      font-size:14px;
      color:#ffffff;
    }
    
    ul.social-buttons {
      text-align: center;
      justify-content: center;
      margin-top:40px;
    }
    
    ul.social-buttons li a {
      font-size: 35px;
      line-height: 50px;
      display: block;
      width: 70px;
      height: 70px;
      -webkit-transition: all 0.3s;
      transition: all 0.3s;
      color: #222222;
      border-radius: 100%;
      outline: none;
      background-color: #ffffff;
      border:5px solid #fed136;
    }
    
    ul.social-buttons li a:active, ul.social-buttons li a:focus, ul.social-buttons li a:hover {
      background-color: #fed136;
    }

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.5.0/css/all.css" integrity="sha384-B4dIYHKNBt8Bc12p+WXckhzcICo0wtJAoU8YZTY5qE0Id1GSseTk6S+L3BlXeVIU" crossorigin="anonymous">
<div class="col-md-4">

                  <ul class="list-inline social-buttons">
                      <li class="list-inline-item">
                        <a href="#">
                          <i class=" fab fa-linkedin-in"></i>
                        </a>
                      </li>
                      <li class="list-inline-item">
                        <a href="#">
                          <i class="fab fa-google-plus-g"></i>
                        </a>
                      </li>
                      <li class="list-inline-item">
                        <a href="#">
                          <i class="fab fa-facebook-f"></i>
                        </a>
                      </li>
                      <li class="list-inline-item">
                          <a href="#">
                            <i class="fab fa-twitter"></i>
                          </a>
                        </li>
                    </ul>
      </div>

Answer 1

您可以在 i 元素上使用 vertical-align:middle。它们是 inline-block 元素，它们将在其容器内垂直对齐。无需添加特定的行高或边距等。

见下文

.page-footer {
  background-color: #222222;
  padding: 0 40px;
  text-align: center;
}

.page-footer a {
  font-size: 14px;
  color: #ffffff;
}

ul.social-buttons {
  text-align: center;
  justify-content: center;
  margin-top: 40px;
}

ul.social-buttons li a {
  font-size: 35px;
  line-height: 50px;
  display: block;
  width: 70px;
  height: 70px;
  -webkit-transition: all 0.3s;
  transition: all 0.3s;
  color: #222222;
  border-radius: 100%;
  outline: none;
  background-color: #ffffff;
  border: 5px solid #fed136;
}

ul.social-buttons li a:active,
ul.social-buttons li a:focus,
ul.social-buttons li a:hover {
  background-color: #fed136;
}

ul.social-buttons li a i {
vertical-align:middle;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet"/>
<link href="https://use.fontawesome.com/releases/v5.5.0/css/all.css" rel="stylesheet"/>
<div class="col-md-4">
  <ul class="list-inline social-buttons">
    <li class="list-inline-item">
      <a href="#">
                      <i class=" fab fa-linkedin-in"></i>
                    </a>
    </li>
    <li class="list-inline-item">
      <a href="#">
                      <i class="fab fa-google-plus-g"></i>
                    </a>
    </li>
    <li class="list-inline-item">
      <a href="#">
                      <i class="fab fa-facebook-f"></i>
                    </a>
    </li>
    <li class="list-inline-item">
      <a href="#">
                        <i class="fab fa-twitter"></i>
                      </a>
    </li>
  </ul>
</div>

另一种选择是

ul.social-buttons li a {
    display: flex;
    align-items: center;
    justify-content: center;
}