body { margin:0;padding:0;font-family:sans-serif;color:#363636;background:url("../_img/sitebg.png") no-repeat left top; }
.nav {position: relative;display: flex;justify-content: center;align-items: center;flex-direction: row;height: 100px;width: 100%;border-bottom: 2px solid rgba(170, 169, 169, 0.8);}
a {text-decoration:none; font-weight:600; color:#f89d44; }
.content { display:flex; justify-content:center; align-items:center; width:100vw; height:100vh; }
.under { display:block; text-align:center; max-width:300px; line-height:130%;  }
@media only screen and (max-width: 720px) {
    .content { flex-direction:column; }
    .under { width:90vw; margin:20px auto; }
}