.menu { width: 70px; position: fixed; left: 20px; top: 20px; }
.menu img { width: 65px; padding-bottom: 10px; }

section { min-height: 100vh; padding: 20px 20px 20px 120px; color: black; font-size: 20px; font-weight: bold; }
#s1 a, #s2 a { text-decoration: none; background-color: white; color: red; margin-left: 10px; margin-right: 10px; padding-left: 10px; padding-right: 10px; }

#s1 { background: url('bg1.png') repeat; }
#s2 { background: url('bg2.png') repeat; color: white; }
#s3 { background: url('bg3.png') repeat; }
#s4 { background: url('bg4.png') repeat; color: white; }
#s5 { background: url('bg5.png') repeat; }
#s6 { background: url('bg6.png') repeat; color: white; }
#s7 { background: url('bg7.png') repeat; }

img { max-width: 100%; }
ul { list-style: none; padding-left: 0px; }
ul li::before { content: '\2713'; }

.div-width { max-width: 600px; }
.big { font-size: 32px; }
.livros img { width: 20%; }