.black-btn {
    padding: 10px 16px;
    background: #000;
    color: #fff;
    font: bold 16px / 18px 'Neo Sans Pro 2', Arial, sans-serif;
    text-transform: uppercase;
    text-decoration: none;
    border: 1px solid #000;
    cursor: pointer;
    transition: background 0.3s, color 0.3s;
    position: relative;
    font-weight: 500;
    font-style: italic;

    display: flex;
    justify-content: center;
    vertical-align: middle;
    line-height: 1;
}

.black-btn:hover,
.black-btn:focus {
    background: #fff;
    color: #000;
    outline: none;
}

.black-btn:before {
    content: "/ ";
    -webkit-transition: all 0.35s ease;
    -moz-transition: all 0.35s ease;
    -o-transition: all 0.35s ease;
    transition: all 0.35s ease;
    color: #ff1a36;
    margin-right: 5px;
}





@media (min-width: 220px) {
    .black-btn {
        padding: 10px 16px;
        font-size: 10px;
    }
}

@media (min-width: 300px) {
    .black-btn {
        padding: 12px 20px;
        font-size: 14px;
    }
}

@media (min-width: 640px) {
    .black-btn {
        padding: 16px 24px;
        font-size: 16px;
    }
}


.index-about-section__buttons {
    display: flex;
    flex-flow: column;
    justify-content: center;
    align-items: center;
}

.index-about-section__buttons .black-btn {
    margin-top: 48px;
}