#reading-position-indicator
{
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 5px;

    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;

    border: none;
    background-color: transparent;
    color: red;
    z-index: 99999;
}

#reading-position-indicator::-webkit-progress-bar
{
    background-color: transparent;
}

#reading-position-indicator::-webkit-progress-value
{
    background-color: red;
}

#reading-position-indicator::-moz-progress-bar
{
    background-color: red;
}

.progress-container
{
    width: 100%;
    background-color: transparent;
    position: fixed;
    top: 0;
    left: 0;
    height: 5px;
    display: block;
}

.progress-bar
{
    background-color: red;
    width: 0%;
    display: block;
    height: inherit;
}

#reading-position-indicator.single::-webkit-progress-value
{
    background-color: transparent;
    background-image: -webkit-linear-gradient(left, transparent, red);
}

#reading-position-indicator.single::-moz-progress-bar
{
    background-color: transparent;
    background-image: -moz-linear-gradient(left, transparent, red);
}

#reading-position-indicator.multiple::-webkit-progress-value
{
    background-image: -webkit-linear-gradient( -45deg, transparent 33%, rgba(0, 0, 0, .1) 33%, rgba(0,0, 0, .1) 66%, transparent 66%), -webkit-linear-gradient(left, green, red);
}

#reading-position-indicator.multiple::-moz-progress-bar
{
    background-image: -moz-linear-gradient(-45deg, transparent 33%, rgba(0, 0, 0, .1) 33%, rgba(0,0, 0, .1) 66%, transparent 66%), -moz-linear-gradient(left, green, red);
}