$module: ".event-line-box";

#{$module} {

    &__content {

        &:after {

            content: "";
            display: block;
            width: 100%;
            height: 1px;
            background: rgba(0, 0, 0, 0.5);

            @include margin(1 0 2 0);

            @include mq($until: sm) {
                @include margin(1 0 1 0);
            }

        }

    }

    &__month {

        @include font-size(l);
        @include line-height(1);
        @include typeface(serif);
        font-weight: weight(heavy);

        @include mq($until: sm) {
            display: none;
        }

    }

    &__image {

        width: 100%;
        height: auto;

    }

    &__tags {

        margin-bottom: 5px;

    }

    &__title {

        @include font-size(xxl);
        @include line-height(1.25);
        @include typeface(sans-serif);
        font-weight: weight(bold);

        margin-top: 0;
        @include margin-bottom(1);

    }

    &__desc {

        @include font-size(m);
        @include line-height(1);
        @include typeface(serif);
        font-weight: weight(light);

    }

}

$module: ".event-line-box";

#{$module} {

    &__content {

        &:after {

            content: "";
            display: block;
            width: 100%;
            height: 1px;
            background: rgba(0, 0, 0, 0.25);

            @include margin(1 0 2 0);

            @include mq($until: sm) {
                @include margin(1 0 1 0);
            }

        }

    }

    &__month {

        @include font-size(l);
        @include line-height(1);
        @include typeface(serif);
        font-weight: weight(heavy);

        @include mq($until: sm) {
            display: none;
        }

    }

    &__image {

        width: 100%;
        height: auto;

    }

    &__tags {

        margin-bottom: 5px;

    }

    &__title {

        @include font-size(xxl);
        @include line-height(1.25);
        @include typeface(sans-serif);
        font-weight: weight(bold);

        margin-top: 0;
        @include margin-bottom(1);

    }

    &__desc {

        @include font-size(m);
        @include line-height(1);
        @include typeface(serif);
        font-weight: weight(light);

    }

}

Change the opacity on the event line box
Change the opacity on the event line box
