.hero-block {
    position: relative;
    width: 100%;
    background-position: center;
}
.hero-block::after {
    content: "";
    display: block;
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    margin: auto;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,.3);
}
.hero-block .container {
    position: relative;
    z-index: 1;
    text-align: center;
}
.hero-title {
    padding-bottom: 24px;
}
.hero-subtitle {
    max-width: 680px;
    margin: auto;
}