body {
 margin: 0;
 padding: 0;
 width: 100%;
 height: 100%;
}
.wrap {
position: fixed;
 width: 100%;
 height: 100%;
 background: url("/static/images/background.jpg");
 background-size: cover;
     display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    text-shadow: 5px 1px 20px black;
}

.top {
 display: flex;
 align-items: center;
 justify-content: center;
 flex-wrap: wrap;
 padding-top: 80px;
 color: #fff;
 text-align: center;
}

.top .logo {
 font-size: 20px;
 margin-bottom: 20px;
 width: 100%;
}

.top .tip {
 font-size: 60px;
}

.bottom {
 position: fixed;
 width: 100%;
 bottom: 20px;
 margin-bottom: 20px;
 color: #fff;
 font-size: 16px;
 color: #fff;
 display: flex;
 justify-content: center;
}
.middle {
 font-size: 3vh;
 color: #fff;
 text-align: center;
    text-indent: 2em;
    height: 50%;
}
a:link {
 color: #fff;
 text-decoration: none;
}
a:visited {
 text-decoration: none;
 color: #fff;
}

a:hover {
 text-decoration: underline;
 color: #ccc;
}