body {
    background-color: #ffffff;
    background: url(../Pictures/abstract.jpg);
}
.box {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    width: 100%;
    height: 100%;
    position: absolute;
    right: 0;
    top: 0;
}

.top {
    font-weight: bold;
    color: #212529;
}
.top.notfound {
    font-size: 10rem;
    font-weight: 900;
}
.top.dardast {
    font-size: 2rem;
    margin-bottom: 2rem;
    word-spacing: -2px;
}

a {
    text-decoration: none;
    background-color: #212529;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    color: #ffffff;
    word-spacing: -1px;
}

@media (max-width: 576px) {
    .top.notfound {font-size: 5rem;}
    .top.dardast {font-size: 2rem;}
    a {font-size: 0.9rem;}
}