@keyframes bookColorWave{0%{background-position:0% 50%}50%{background-position:100% 50%}to{background-position:0% 50%}}.book-wave-background{position:relative;z-index:-1;top:0;left:0;width:100%;height:100%;background:linear-gradient(-45deg,#c62828,#2e7d32,#1565c0,#f9a825,#6a1b9a,#212121);background-size:400% 400%;animation:bookColorWave 30s ease infinite;filter:blur(0px);opacity:.7}