Twitter bootstrap 引导更改面包屑切割器，带基本64映像代码

我正在尝试更改引导面包屑分隔符符号。但它不起作用。我希望我能帮上忙

<nav aria-label="breadcrumb">
  <ol class="breadcrumb">
    <li class="breadcrumb-item"><a href="#">Home</a></li>
    <li class="breadcrumb-item"><a href="#">Library</a></li>
    <li class="breadcrumb-item active">Data</li>
  </ol> 
</nav>
//CSS
    $breadcrumb-divider: url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI4IiBoZWlnaHQ9IjgiPjxwYXRoIGQ9Ik0yLjUgMEwxIDEuNSAzLjUgNCAxIDYuNSAyLjUgOGw0LTQtNC00eiIgZmlsbD0iY3VycmVudENvbG9yIi8+PC9zdmc+) !important;

数据
//CSS
$breadcrumb divider:url（数据：image/svg+xml；base64，phn2zyb4bwxucz0iahr0cdovl3dy53my5vcmcvmjawmc9zdmciihdpzhropsi4iibzwlnahq9ijgipjxwyxroiq9ik0yljugmewxideunsayiljuggw0ltqtnc00eigzmlsbd0iy3vycmvudenvg9yii8+PC9zdmc）！重要的；

---

请找到代码笔eample

如果你想用CSS制作，你应该这样写：

.breadcrumb-item+.breadcrumb-item::before {
    content: url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI4IiBoZWlnaHQ9IjgiPjxwYXRoIGQ9Ik0yLjUgMEwxIDEuNSAzLjUgNCAxIDYuNSAyLjUgOGw0LTQtNC00eiIgZmlsbD0iY3VycmVudENvbG9yIi8+PC9zdmc+);
}

对于SASS，您可以使用：

$breadcrumb-divider: url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI4IiBoZWlnaHQ9IjgiPjxwYXRoIGQ9Ik0yLjUgMEwxIDEuNSAzLjUgNCAxIDYuNSAyLjUgOGw0LTQtNC00eiIgZmlsbD0iY3VycmVudENvbG9yIi8+PC9zdmc+);

---

但是在导入引导程序之前需要声明它。

必须使用预处理覆盖变量。了解LESS/SASS/other。如果不能使用预处理，则必须手动覆盖它。