.img {
    max-width: 300px;
    margin: 30px auto;
}
.top-ttl {
    align-items: center;
}
.top-ttl p {
    margin-bottom: 40px;
}
.top-ttl h2, .top-ttl p {
    text-align: center;
}
.back-btn {
    display: flex;
    width: 100%;
    max-width: 360px;
    height: 70px;
    color: #fff;
    justify-content: center;
    align-items: center;
    background-color: #4ca535;
    margin: 0 auto;
}
header {
    background: url(../img/contact/header.jpg) no-repeat center / cover;
}