.annotation {
    margin: 30px;
    text-align: right;
}

.back {
    display: flex;
    flex-wrap: wrap;
    -webkit-box-pack: start;
    justify-content: flex-start;
    padding-left: 10px;
}

.back-btn {
    display: block;
    background: #efefef;
    width: calc(50% - 10px);
    padding: 10px;
    margin: 0 10px 50px 0;
    color: #808080;
    font-size: 2rem;
    line-height: 2;
    border: #808080 1px solid;
    border-radius: 10px;
    text-align: center;
    text-decoration: none;
}

.bunner {
    margin: 30px 0 80px;
}

.bunner a {
    display: block;
}