Shian/src/sass/components/_header.scss

.site-header {
    position: fixed;
    z-index: 10;
    height: 4rem;
    width: 100vw;
    overflow: hidden;
    @include transition;
    &.enabled {
        height: 100vh;
        width: 100vw;
    }

    &__background {
        z-index: -1;
        width: 100vw;
        height: 100vh;
        position: absolute;
        @include transition;
        @include bg-283-yuika;

        opacity: 0%;
        top: -23vh;
        &--yuriko {
            @include bg-765-yuriko;
        }
        &--enabled {
            opacity: 100%;
            top: 0;
        }
    }
    &__overlay {
        opacity: 50%;
        background-color: $black;
    }

    &__inner {
        z-index: 1;
        width: 100%;
        height: 100%;
        @include transition;
    }

    &.enabled &__inner {
       background: rgba(0,0,0,0.5);
    }
    &.detached &__inner {
       background: rgba(0,0,0,0.5);
    }
}

.header {
    display: flex;
    flex-direction: column;
    @include transition;
    &__top {
        display: flex;
        flex-direction: row;
    }

    &__title {
        flex-grow: 1;
        @include transition;
        a {
            display: flex;
            flex-direction: row;
            align-items: center;
            @include py(1rem);
            color: $white;
            font-size: $text-lg;
            padding-left: 1rem;
            height: 100%;
        }
        &:hover {
            background-color: $theme-blue;
        }
    }

    &__nav-button {
        width: 4rem;
        height: 4rem;
        position: relative;
        cursor: pointer;
        padding: 0.5rem;
        text-align: center;
        white-space: nowrap;
        @include transition;
        &:hover {
            background-color: $theme-blue;
        }
    }
    &__icon {
        width: 3rem;
        height: 3rem;
        color: $white;
        @include px(0.50rem);
        @include py(0.75rem);
    }
}