Close button关闭按钮
A generic close button for dismissing content like modals and alerts.一个通用的关闭按钮，用于关闭模态和警报等内容。
Example例子
Provide an option to dismiss or close a component with 提供使用.btn-close. .btn-close关闭或关闭组件的选项。Default styling is limited, but highly customizable. 默认样式是有限的，但高度可自定义。Modify the Sass variables to replace the default 修改Sass变量以替换默认background-image. background-image。Be sure to include text for screen readers确保包括屏幕阅读器的文本, as we’ve done with ，正如我们对aria-label.aria-label所做的那样。
<button type="button" class="btn-close" aria-label="Close"></button>Disabled state禁用状态
Disabled close buttons change their 禁用的关闭按钮更改其opacity. opacity。We’ve also applied 我们还应用了pointer-events: none and user-select: none to preventing hover and active states from triggering.pointer-events: none和user-select: none来防止触发悬停和活动状态。
<button type="button" class="btn-close" disabled aria-label="Close"></button>White variant白色变体
Change the default 使用.btn-close to be white with the .btn-close-white class. .btn-close-white类将默认的.btn-close更改为白色。This class uses the 此类使用filter property to invert the background-image.filter属性反转background-image。
<button type="button" class="btn-close btn-close-white" aria-label="Close"></button>
<button type="button" class="btn-close btn-close-white" disabled aria-label="Close"></button>Sass
Variables变量
$btn-close-width: 1em;
$btn-close-height: $btn-close-width;
$btn-close-padding-x: .25em;
$btn-close-padding-y: $btn-close-padding-x;
$btn-close-color: $black;
$btn-close-bg: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$btn-close-color}'><path d='M.293.293a1 1 0 011.414 0L8 6.586 14.293.293a1 1 0 111.414 1.414L9.414 8l6.293 6.293a1 1 0 01-1.414 1.414L8 9.414l-6.293 6.293a1 1 0 01-1.414-1.414L6.586 8 .293 1.707a1 1 0 010-1.414z'/></svg>");
$btn-close-focus-shadow: $input-btn-focus-box-shadow;
$btn-close-opacity: .5;
$btn-close-hover-opacity: .75;
$btn-close-focus-opacity: 1;
$btn-close-disabled-opacity: .25;
$btn-close-white-filter: invert(1) grayscale(100%) brightness(200%);