main.css

* {
    margin: 0;
    padding: 0;
    text-decoration: none;
    box-sizing: border-box;
    font-family: sans-serif;
    scroll-behavior: smooth;
    outline: none;
}

@media (min-height:800px) and (min-width:1200px){
    * {
        font-size: 1.5rem;
    }
}

body {
    background-color: #e3e3e3;
}

a:hover {
    cursor: pointer;
}

.burger {
    left: 1rem;
    top: 1rem;
    width: 1.5rem;
    height: .7rem;
    position: fixed;
    z-index: 2;
    cursor: pointer;
}

.burger span {
    display: block;
    background-color: #262626;
    height: 20%;
    margin-bottom: 20%;
}

.burger span.last {
    display: block;
    background-color: #262626;
    height: 20%;
    margin-bottom: 0;
}

nav {
    position: fixed;
    height: 80%;
    width: 45%;
    opacity: 0;
    transition: .2s ease;
}

nav.active {
    opacity: 1;
}

nav::before {
    content: '';
    display: inline-block;
    width: 0;
    height: 100%;
    vertical-align: middle;
}

nav ul {
    width: 80%;
    display: inline-block;
    vertical-align: middle;
}

nav ul li {
    display: block;
    text-transform: uppercase;
    line-height: 2.5;
    font-size: .8rem;
    padding-left: 30%;
    font-weight: 800;
    color: #262626;
    cursor: pointer;
    letter-spacing: 2px;
}

main {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    overflow: auto;
    transition: .3s ease;
}

main article {
    height: calc(100vh + 8rem);
    display: flex;
    flex-direction: column;
    justify-content: center;
    background-color: #fafafa;
    color: #262626;
    padding: 4rem;
    border-bottom: 8rem solid #e3e3e3;

}

main article:last-child {
    height: 100vh;
    border-bottom: none;
}

@media screen and (orientation:portrait) {
    article {
        padding: 4rem 1rem;
    }
}

@media screen and (orientation:landscape) and (max-width:900px) {
    artile {
        padding: 0 4rem;
    }
}

main a, main a:visited {
    color: teal;
    font-weight: bold;
}

main p {
    padding-bottom: 1em;
}

main h1 {
    margin: 0 0 .7em;
}

main ul li {
    margin: 0 0 .5em 1em;
}

nav.active + main {
    cursor: pointer;
}

@media screen and (orientation:portrait) {
    nav.active + main {
        transform: translateX(35%) scale(.8);
        box-shadow: 0 0 30px 5px rgba(38, 38, 38, .3);
    }
}

@media screen and (orientation:landscape) {
    nav.active + main {
        transform: translateX(20%) scale(.8);
        box-shadow: 0 0 30px 5px rgba(38, 38, 38, .3);
    }
}