*{
    margin: 0;
    padding: 0;
}

/* 01. style slider and move it to the background position */
.slider{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: lightblue;
    z-index: -1;
}

/* 02. style nav bar */
nav{
    display: grid;
    grid-template-columns: 10% 1fr 1fr 10%;
    min-height: 8vh;
    align-items: center;
}

.logo{
    grid-column: 2/3;
}

.menu{
    justify-self: end;
}

/* 03. resize the bigger intro image, important to know! */
section{
    display: flex;
    height: 90vh;
    justify-content: center;
    align-items: center;

    /* to show the container, which we use to resize bigger image */
    /* background-color: gray; */
}

.intro{
    /* to show the intro container */
    /* height: 60%;
    width: 80%; */

    height: 95%;
    width: 100%;

    /* for contrast, Nr.05, it is very important! */
    position: relative;
}

.intro img{
    width: 100%;
    height: 100%;
    object-fit: cover;

}

/* 04. adjust headline text */
.headline{
    position: absolute;
    top: 40%;
    left: 50%;
    font-size: 4em;
    color: #fff;

    /* to adjust the text itself again to the center area, could use: */
    /* transform: translate(-50%, -50%);  */
}

/* 05. generate and add contrast to the image, use position absolute, good for
       very bright pictures */

.intro::after{
    content: "";
    background: black;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0.15;
}

/* 06. but we want the headline to be obvious and strong */
.headline{
    z-index: 2;
}