body {
color: #000;
background: url(https://images.cnblogs.com/cnblogs_com/rentu/1491357/o_191125113517e98a9116fdfaaf5185ef6fe3815494eef11f7aeb.jpg
)  fixed;
background-size: cover;
font-family: "Helvetica Neue",Helvetica,Verdana,Arial,sans-serif;
font-size: 12px;
opacity: 0.6;
min-height: 95%;

  background-repeat:no-repeat;

}
h1{font-size:20px;}
h2{font-size:14px;}
.list{font-size:14px;}