.flash-left-right {
    font-weight: 300;
    text-align: center;
    font-size: 20px;
    font-family: Hack, sans-serif;
    /*text-transform: uppercase;*/
    background: linear-gradient(90deg, #000, #fff, #000);
    letter-spacing: 5px;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    background-repeat: no-repeat;
    background-size: 80%;
    animation: shine 5s linear infinite;
    position: relative;
}

@keyframes shine {
    0% {
        background-position-x: -500%;
    }

    100% {
        background-position-x: 500%;
    }
}




/* 
The container box is relative so we can position stuff inside of it 
*/
.image-box {
    position: relative;
    width:100%;
    /*height:70%;*/
}

.image-box__background {
        background-position: left center;
        background-repeat: no-repeat;
        background-size: contain;
        float: none;
        width: 100%;
        height: auto;
    }

.image-box__background,
.image-box__overlay {
    position: absolute;
    top: 0px;
    right: 0;
    bottom: 0;
    left: 0;
}
/* 
The background image div sizes and positions the background itself.
It's also at the bottom-most position in our "div stack" (z-index 1)

We set the image url via a CSS custom property, that's set via the style attribute in our HTML
*/
.image-box__background {
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    /*background-image: url('https://scx1.b-cdn.net/csz/news/800/2017/theoreticala.jpg');*/
    z-index: 1
}

/* 
The overlay div is just a colored element with some opacity.
It's above the background image in our stack, so it appears to 
darken the image 
*/
.image-box__overlay {
    background: rgba(0, 0, 0, 0.5);
    z-index: 2;
}

/* 
The content div is at the top of our stack. 
We'd probably add some padding or flexbox properties here as well, 
to place the content appropriately
*/
.image-box__content {
    position: relative;
    z-index: 3;
    color: white;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* just for the demo */
/*html, body {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
}

h1 {
    font-size: 30px;
}*/
.grid-container-1Column {
    display: grid;
    grid-gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(100%, 1fr));
}



.grid-container {
    display: grid;
    grid-gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}


.grid-item {
    background-color: rgba(255, 255, 255, 0.8);
    border: 0px solid rgba(0, 0, 0, 0.8);
    padding: 10px;
    font-size: 30px;
    text-align: center;
    box-shadow: 2px 2px 4px 0 #ccc;
}
    .grid-item img {
        background-position: left center;
        background-repeat: no-repeat;
        background-size: contain;
        float: none;
        width: 100%;
        height: auto;
        transition: opacity 1s;
        /*transition: 300ms ease-in-out;*/
        /*transform: translateX(-20%);*/
    }

#main-image.hidding {
    /*-moz-transition: all 0.5s;
    -o-transition: all 0.5s;
    -webkit-transition: all 0.5s;
    transition: all 0.5s;*/
    -webkit-transform: scale(0);
    -ms-transform: scale(0);
    transform: scale(0);
    -webkit-transition: .5s ease;
    transition: all .5s ease;
}

#main-image {
    -webkit-transform: scale(1);
    -ms-transform: scale(1);
    transform: scale(1);
    -webkit-transition: .5s ease;
    transition: all .3s ease-in-out;
    /*transition: opacity 1s;*/
}

#main-image-left {
    /*position: relative;
    top:0;
    left: -100%;*/
    /* width: 100px;
    height: 100px;*/
    /*background: blue;
    -webkit-animation: slide-left 0.5s forwards;*/
    /*-webkit-animation-delay: 2s;*/
    /*animation: slide-left 0.5s forwards;*/
    /*animation-delay: .5s;*/
}

    #main-image-left.hidding {
        /*-moz-transition: all 0.5s;
    -o-transition: all 0.5s;
    -webkit-transition: all 0.5s;
    transition: all 0.5s;*/
        -webkit-transform: scale(0);
        -ms-transform: scale(0);
        transform: scale(0);
        -webkit-transition: .5s ease;
        transition:  .5s ease;
    }


@keyframes reveal {
    from {
        left: 0%;
    }

    to {
        left: 100%;
    }
}

@-webkit-keyframes moveLeft {
    0% {
        transform: translateX(100vw);
        opacity: 0;
    }

    100% {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes moveLeft {
    0% {
        transform: translateX(100vw);
        opacity: 0;
    }

    100% {
        transform: translateX(0);
        opacity: 1;
    }
}


.div-expandable {
    background: #fff;
    overflow: hidden;
    transition: all .5s ease-in-out;
    line-height: 0;
    padding: 0 1em;
    color: transparent;
}

    .div-expandable:target {
        line-height: 1.5;
        padding-top: 1em;
        padding-bottom: 1em;
        color: black;
    }

.flex-title {
    display: flex;
    align-items: flex-end;
    flex-wrap: wrap;
    border-bottom: 1px solid #ccc;
    max-width: 50vw;
    /*margin: 40px auto;*/
    padding-top: 50px;
    font-size: 21px;
}

    .flex-title > span {
        white-space: nowrap;
    }
    .flex-title .title-main {
        flex-grow: 1;
    }
    .flex-title .title-note {
        font-size: 60%;
        color: #999;
    }