/* First image (Logo. Full height) */
.bgimg-1 {
    background-image: url('/w3images/parallax1.jpg');
    min-height: 100%;
}

/* Second image (Portfolio) */
.bgimg-2 {
    background-image: url("/w3images/parallax2.jpg");
    min-height: 400px;
}

/* Third image (Contact) */
.bgimg-3 {
    background-image: url("/w3images/parallax3.jpg");
    min-height: 400px;
}

https://w3schools.com/w3images/parallax1.jpg

file:///w3images/parallax1.jpg

/* First image (Logo. Full height) */
.bgimg-1 {
    background-image: url('https://w3schools.com/w3images/parallax1.jpg');
    min-height: 100%;
}

/* Second image (Portfolio) */
.bgimg-2 {
    background-image: url("https://w3schools.com/w3images/parallax2.jpg");
    min-height: 400px;
}

/* Third image (Contact) */
.bgimg-3 {
    background-image: url("https://w3schools.com/w3images/parallax3.jpg");
    min-height: 400px;
}