.image .btn-group {
    margin-top: 10px;
}
img {
    max-width: 100%; /* This rule is very important, please do not ignore this! */
}
.img-container, .img-preview {
    width: 100%;
    text-align: center;
}
.img-preview {
    float: left;
    margin-right: 10px;
    margin-bottom: 10px;
    overflow: hidden;
}
.preview-lg {
    width: 263px;
    height: 148px;
}

.btn-file {
    position: relative;
    overflow: hidden;
}
.btn-file input[type=file] {
    position: absolute;
    top: 0;
    right: 0;
    min-width: 100%;
    min-height: 100%;
    font-size: 100px;
    text-align: right;
    filter: alpha(opacity=0);
    opacity: 0;
    outline: none;
    background: white;
    cursor: inherit;
    display: block;
}