如何均匀按钮

Question

我有四个下拉按钮，如下所示：

我试着勾勒出按钮，我注意到它们甚至没有。

我无法使它们均匀，我尝试使用display: inline-block;，但这似乎无法解决问题。难道我做错了什么？还是我缺少一些代码？或者甚至可能是因为JavaScript？

这是我的代码：

function myFunction() {
  var dropdowns = document.getElementsByClassName("dropdown-content");
  var i;
  
  for (i = 0; i < dropdowns.length; i++) {
    var openDropdown = dropdowns[i];
    if (openDropdown.classList.contains('show')) {
      openDropdown.classList.remove('show');
    }
  }
	
  this.event.target.nextElementSibling.classList.toggle("show");
}

// Close the dropdown menu if the user clicks outside of it
window.onclick = function (event) {
  if (!event.target.matches('.dropbtn')) {
    var dropdowns = document.getElementsByClassName("dropdown-content");
    var i;
    
    for (i = 0; i < dropdowns.length; i++) {
      var openDropdown = dropdowns[i];
      if (openDropdown.classList.contains('show')) {
        openDropdown.classList.remove('show');
      }
    }
  }
}

/* Dropdown Button */
.dropbtn {
  background-color: #4CAF50;
  color: white;
  border: none;
  cursor: pointer;
  width: 180px;
  height: 50px;
  text-align: center;
  line-height: 1.1em;
  font-size: 1.1em;
  font-family: Questrial;
}

/* Dropdown button on hover & focus */
.dropbtn:hover,
.dropbtn:focus {
  background-color: #3e8e41;
}

/* 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;
  font-family: Questrial;
}

/* Links inside the dropdown */
.dropdown-content a {
  color: black;
  padding: 5px 16px;
  text-decoration: none;
  display: block;
}

/* Change color of dropdown links on hover */
.dropdown-content a:hover {
  background-color: #3B3B3B;
  color: #fff;
}

/* Show the dropdown menu (use JS to add this class to the .dropdown-content container when the user clicks on the dropdown button) */
.show {
  display: block;
}

<div class="dropdown">
  <button onclick="myFunction()" class="dropbtn">Add Equipment</button>
  <div class="dropdown-content">
    <a href="registeravrorups.php">Add AVR / UPS</a>
    <a href="registercpu.php">Add CPU</a>
  </div>
</div>
<div class="dropdown">
  <button onclick="myFunction()" class="dropbtn">Add Spare Equipment</button>
  <div class="dropdown-content">
    <a href="registeravrorupsspare.php">Add Spare AVR / UPS</a>
    <a href="registercpuspare.php">Add Spare CPU</a>
  </div>
</div>
<br>
<div class="dropdown">
  <button onclick="myFunction()" class="dropbtn">Deployed Equipment</button>
  <div class="dropdown-content">
    <a href="viewavrorups.php">Deployed AVR / UPS</a>
    <a href="viewcpu.php">Deployed CPU</a>
  </div>
</div>
<div class="dropdown">
  <button onclick="myFunction()" class="dropbtn">Spare Equipment</button>
  <div class="dropdown-content">
    <a href="registeravrorupsspare.php">View Spare AVR / UPS</a>
    <a href="viewcpuspare.php">View Spare CPU</a>
  </div>
</div>