悬停时可折叠图标/内容颜色更改

Question

我正在处理“可折叠”内容（常见问题解答下拉菜单）。在预先单击的“按钮”上，我有一个“加号”图标（按下按钮后图标变为“负号”图标）。我想要的是当按钮悬停在预单击按钮“加号”图标上时改变颜色（即变成白色）。我不确定如何修改 CSS 以在悬停时更改图标。

我试过了：

.collapsible:after, .hover{
  color: $light;
}

但这只会扭转问题...在此先感谢您！代码如下。

var coll = document.getElementsByClassName("collapsible");
var i;

for (i = 0; i < coll.length; i++) {
  coll[i].addEventListener("click", function() {
    this.classList.toggle("active");
    var content = this.nextElementSibling;
    if (content.style.display === "block") {
      content.style.display = "none";
    } else {
      content.style.display = "block";
    }
  });
}

/* TARGET ICON */
.collapsible:after {
  content: '\02795'; /* Unicode character for "plus" sign (+) */
  color: black;
  font-weight: bold;
  float: right;
  margin-left: 5px;
}

.active:after {
  content: "\2796"; /* Unicode character for "minus" sign (-) */
  color: white;
}

/* Style the button that is used to open and close the collapsible content */
.collapsible {
  background-color: white;
  color: black;
  cursor: pointer;
  padding: 10px 18px;
  width: 100%;
  border: solid;
  border-width: thin;
  border-radius: 5px;
  margin-bottom: 5px;
  text-align: left;
  outline: none;
  font-size: 24px;
}

/* Add a background color to the button if it is clicked on (add the .active class with JS), and when you move the mouse over it (hover) */
.active, .collapsible:hover {
  background-color: black;
  color: white;
}

/* Style the collapsible content. Note: hidden by default */
.content-faq {
  padding: 0px 22px;
  border-radius: 5px;
  margin-bottom: 15px;
  margin-top: -6px;
  max-height: 0;
  transition: max-height 0.2s ease-out;
  background-color: #f1f1f1;
}

<button class="collapsible">Some Question</button>
  <div class="content-faq">
    <p>Some Answer</p>
  </div>

Answer 1

使用.collapsible:hover::after选择hover上使用::after创建的内容

由于灰色是您使用的符号，它是继承的，因此将其更改为简单的+ -，仅用于演示以显示效果。
您可以使用任何符号，但不能继承颜色

var coll = document.getElementsByClassName("collapsible");
var i;

for (i = 0; i < coll.length; i++) {
  coll[i].addEventListener("click", function() {
    this.classList.toggle("active");
    var content = this.nextElementSibling;
    if (content.style.display === "block") {
      content.style.display = "none";
    } else {
      content.style.display = "block";
    }
  });
}

/* TARGET ICON */

.collapsible::after {
  content: '+';
  /* Unicode character for "plus" sign (+) */
  color: black;
  font-weight: bold;
  float: right;
  margin-left: 5px;
}

.active:after {
  content: "\2212";
  /* Unicode character for "minus" sign (-) */
  color: white;
}


/* Style the button that is used to open and close the collapsible content */

.collapsible {
  background-color: white;
  color: black;
  cursor: pointer;
  padding: 10px 18px;
  width: 100%;
  border: solid;
  border-width: thin;
  border-radius: 5px;
  margin-bottom: 5px;
  text-align: left;
  outline: none;
  font-size: 24px;
}


/* Add a background color to the button if it is clicked on (add the .active class with JS), and when you move the mouse over it (hover) */

.active,
.collapsible:hover {
  background-color: black;
  color: white;
}




/* Style the collapsible content. Note: hidden by default */

.content-faq {
  padding: 0px 22px;
  border-radius: 5px;
  margin-bottom: 15px;
  margin-top: -6px;
  max-height: 0;
  transition: max-height 0.2s ease-out;
  background-color: #f1f1f1;
}

.collapsible:hover::after {
  color: white;  
}

<button class="collapsible">Some Question</button>
<div class="content-faq">
  <p>Some Answer</p>
</div>