bootloader.css

#bootloader, #bootloader * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

#bootloader {
    position: fixed;
    left: 0;
    top: 0;

    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;

    width: 100vw;
    height: 100vh;
    padding: 50px;

    font-family: monospace;
    font-size: 12px;

    background-color: rgba(255, 255, 255, 1);
    opacity: 1;
    transition: opacity ease-out 0.4s, background-color ease-out 0.2s;
}

#bootloader .progress-container {
    min-width: 100px;
    max-width: 400px;
    width: 100%;
    height: 8px;

    margin: 1em;
    padding: 1px;
    overflow: hidden;

    background-color: #EEE;
    border: 1px solid #AAA;
}

#bootloader .progress-container > .progress {
    height: 100%;
    width: 0;
    background-color: #AAA;
    transition: width ease-out 0.4s;
}

#bootloader .error {
    color: #F32;
}