body {
    margin: 0;
    padding: 0;
}

.t-center {
    text-align: center;
}

.container {
    width: 100%;
    max-width: 1680px;
    margin: 0 auto;
}

a.back {
    margin-top: 20px;
    color: #000;
    border-bottom: 1px solid #000;
    padding-bottom: 3px;
    text-decoration: none;
    display: inline-block;
}

.line {
    width: 100%;
    height: 1px;
    background-color: #000;
}

.headnav {
    text-align: center;
}

.headnav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.headnav ul li {
    margin: 10px 0;
}

.headnav ul li a {
    text-decoration: none;
    color: #000;
}

.headnav ul li a:hover {
    color: red;
}