.icon-burger { background-image: url('png/burger.png'); background-repeat: no-repeat; }

.icon-next { background-image: url('png/next.png'); background-repeat: no-repeat; }

.icon-pdf { background-image: url('png/pdf.png'); background-repeat: no-repeat; }

.icon-prev { background-image: url('png/prev.png'); background-repeat: no-repeat; }

.icon-up { background-image: url('png/up.png'); background-repeat: no-repeat; }