transbeam/static/transbeam.css

input[type="file"] {
    display: none;
}

button, .fake_button {
    font-size: 18px;
    font-family: sans-serif;
    color: #000;
    background-color: #ccc;
    border: 1px solid #bbb;
    border-radius: 4px;
    padding: 6px 12px;
    cursor: pointer;
}

button:hover, .fake_button:hover {
    background-color: #aaa;
}

button:disabled, button:disabled:hover, .fake_button:disabled, .fake_button:disabled:hover {
    color: #aaa;
    background-color: #eee;
    border-color: #ddd;
}