Accessible HTML File Input

By being more thoughtful, we can have a file input that is beautiful but still accessible.

Disclaimer: no testing had been done via screen reader. It would be great if you can inform me if you find anything that is not accessible.

The Markup

html
<div class="file-input">
<input type="file" class="file-input--input" id="my-file-input" />
<label for="my-file-input" class="file-input--label button" tabindex="-1"
>Upload</label
>
<!-- setting for attribute of label to the id of the file input so clicking
it would simulate click on the file input -->
<!-- setting tabindex to -1 so that label will not be tab target -->
</div>

The Style

scss
.file-input {
&--input {
position: fixed;
left: -1000px; /* putting the input off the screen so that
it cannot be seen visually, but still be focusable by
screen reader / keyboard tab
using display: none or visiblity:hidden or opacity: 0
can cause some screen reader to ignore it */
top: 0;
cursor: pointer;
z-index: -1;
}
&--input:focus + &--label {
// rules for focused button
}
}
.button {
// rules to style the label like a button
}