/*：本代码只用作演示,不是源码。源码下载链接: http://www.bootstrapmb.com/item/4118(此说明不在下载的源码里，只用在演示页面里)*/.custom-file-container {    box-sizing: border-box;    position: relative;    display: block;}.custom-file-container__custom-file {    box-sizing: border-box;    position: relative;    display: inline-block;    width: 100%;    height: calc(2.25rem + 2px);    margin-bottom: 0;    margin-top: 5px;}.custom-file-container__custom-file:hover {    cursor: pointer;}.custom-file-container__custom-file__custom-file-input {    box-sizing: border-box;    min-width: 14rem;    max-width: 100%;    height: calc(2.25rem + 2px);    margin: 0;    opacity: 0;}.custom-file-container__custom-file__custom-file-control {    box-sizing: border-box;    position: absolute;    top: 0;    right: 0;    left: 0;    z-index: 5;    height: calc(2.25rem + 2px);    padding: .5rem .75rem;    overflow: hidden;    line-height: 1.5;    color: #515365;    user-select: none;    background-color: #fff;    background-clip: padding-box;    border: 1px solid #6156ce;    border-radius: .25rem;}.custom-file-container__custom-file__custom-file-control:empty::after {    box-sizing: border-box;    content: "Choose file...";}.custom-file-container__custom-file__custom-file-control::before {    box-sizing: border-box;    position: absolute;    top: 0;    right: 0;    z-index: 6;    display: block;    height: calc(2.25rem + 2px);    padding: .5rem .75rem;    line-height: 1.25;    color: #fff;    background-color: #6156ce;    border-left: 1px solid #6156ce;}.custom-file-container__custom-file__custom-file-control::before {    box-sizing: border-box;    content: "Browse";}.custom-file-container__image-preview {    box-sizing: border-box;    transition: all 0.6s ease;    margin-top: 20px;    margin-bottom: 40px;    height: 250px;    width: 100%;    border-radius: 4px;    background-size: contain;    background-position: center center;    background-repeat: no-repeat;}label {    margin-bottom: 14px;    color: #e95f2b;}/*：本代码只用作演示,不是源码。源码下载链接: http://www.bootstrapmb.com/item/4118(此说明不在下载的源码里，只用在演示页面里)*/