*{
    box-sizing: border-box;
}

html, body {
    margin: 0;
    font-family:Arial, Helvetica, sans-serif;
    color: #fff;
    background-color: #333;
    overflow: hidden;
}

.landing {
    position: relative;
    background-image: url(images/black.jpg);
    background-position: center;
    background-size: cover;
    height: 100vh;
}

.landing-inner {
    position: absolute; /*so it covers the entire space*/
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.7);
    text-align: center;
    padding-top: 40px;
}

.landing p{
    font-size: 20px;
}

.landing h1{
    font-size: 50px;
}

.countdown {
    font-size: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.countdown div{
    padding: 20px;
    border: 1px solid #fff;
    border-radius: 10px;
    margin: 5px;
    opacity: 0.7;
    background: #000;
}

.countdown div:first-child{
    background: #17a2b8;
}

.countdown span{
    display: block;
    font-size: 25px;
}

@media (max-width:600px) {
    img{
        width: 45%;
    }
    .landing h1{
        font-size: 40px;
    }
    .countdown div{
        font-size: 30px;
        flex-direction: column;
    }
    .countdown div{
        display: none;
    }
    .countdown div:first-child{
        display: block;
        width: 80%;
        padding: 10px;
    }
}

@media (max-width:350px) {
    img{
        width: 65%;
    }
     img {
        padding-top: 20px;
    }
}

@media (max-height: 600px) {
    img {
        width: 30%;
    }

    .landing p{
        display: none;
    }
}

@media (max-height: 450px) {
    .landing h1{
        display: none;
    }

    img {
        padding-bottom: 30px;
    }
}