.file-upload-wrapper {
    position: relative;
    overflow: hidden;
    display: inline-block;
}

.file-upload-wrapper input[type=file] {
    font-size: 100px;
    position: absolute;
    left: 0;
    top: 0;
    opacity: 0;
}

.file-upload-wrapper .btn-upload {
    border: 1px solid #ccc;
    display: inline-block;
    padding: 6px 12px;
    cursor: pointer;
}