header,
section {
    position: relative;
}

.header-image {
    width: 100%;
    height: 100%;
    object-fit: cover !important;
}

.header-overlay {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    bottom: auto;
    left: auto;
    right: auto;
}

.header-overlay-diagonal {
    background: rgba(0,0,0,.75);
    color: #ffffff;
}

.header-small {
    height: 250px;
}

.header-large {
    height: 500px;
}

.section-image {
    width: 100%;
    height: 250px;
    object-fit: cover !important;
}

.section-image-background {
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    height:250px;
}

.section-image-thumbnail {
    height: 150px;
}

/* sm */
@media (min-width: 576px) {

    .header-small {
        height: 250px;
    }

    .header-large {
        height: 400px;
    }
}

/* md */
@media (min-width: 768px) {

    .section-image-background {
        height: auto;
    }

}

/* lg */
@media (min-width: 992px) {

    .header-small {
        height: 300px;
    }

    .header-large {
        height: 600px;
    }

    .header-overlay-diagonal {
        background: -webkit-linear-gradient(30deg, rgba(0,0,0,.75) 50%, transparent 50.1%);
    }
}

/* xl */
@media (min-width: 1200px) {

}