html {
    min-width: 551px;
    margin: auto;
}

body {
    background-color: black;
    color: whitesmoke;
    height: 1000px;
    font-size: 1em;
}

h1 {
    display: flex;
    justify-content: center;
    font-size: 1.9rem;
    font-family: 'serif';
    flex-direction: column;
    align-items: center;
    padding-top: 100px;
    padding-bottom: 100px;
}

h2 {
    display: flex;
    justify-content: center;
    font-size: 6rem;
    font-family: 'serif';
    flex-direction: column;
    align-items: center;
}

h3 {
    display: flex;
    justify-content: center;
    font-size: 3rem;
    font-family: 'serif';
    flex-direction: column;
    align-items: center;
    padding-top: 100px;
    padding-bottom: 100px;
}

li {
    font-size: 1.8rem;
    display: flex;
    justify-content: center;
    line-height: 3rem;
}

@media (min-width: 0) and (max-width: 550px){
    div {flex-direction: column;}
    html {min-width: 420px;}
    h1 {text-align: center; font-size: 1.8rem;}
    h2 {font-size: 4.6rem;}
    h3 {font-size: 2.4rem; text-align: center;}
    img { height: 150px; width: 320px;}
    p, h4, li {font-size: 1.6rem; text-align: center;}
    header {display: block;}
    ul > li {text-align: left;}
    a {font-size: 0.9rem;}
    .firstH1 {font-size: 3.3rem; font-style: italic;} 
    .longP {margin: 14px 8px 0 8px;}
    .secondH1 {font-size: 1.7rem;}
}