html, body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    padding: 0;
    margin: 0;
    width: 100%;
    height: 100vh;
    background-color: white;
}

header {
    position: fixed;
    display: block;
    width: 100%;
    top: 0;
    left: 0;
    text-align: right;
}

main {
    display: block;
    margin: 0 auto;
    width: 90%;
    height: 100%;
    background-color: transparent;
}

section {
    background-color: transparent;
    padding: 32px 0;
}

h1 {
    padding: 0;
    margin: 0;
    line-height: 1.3;
    font-size: 24pt;
}

p {
    padding: 0;
    margin: 0;
    margin-top: 8px;
    line-height: 1.9;
    font-size: 16pt;
}

button {
    display: block;
    -webkit-appearance: none;
    appearance: none;
    outline: none;
    cursor: pointer;
    width: 200px;
    padding: 12px 0;
    margin: 8px auto;
    font-size: 14pt;
    font-weight: 600;
    border: none;
    border: 2px solid transparent;
    background-color: transparent;
    border-radius: 4px;
}

.theme-label {
    display: block;
    font-size: 11pt;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-right: 12px;
    margin-top: 12px;
    font-weight: bold;
    color: #3f454b;
}


.light {
    background-color: white;
}

.light h1, 
.light .theme-label {
    color: #252525;
}

.light p {
    color: #3f454b;
}

.light .theme-label output {
    color: hsla(211, 65%, 50%, 1);
}


.light button {
    border-color: hsla(211, 65%, 50%, 1);
    background-color: hsla(211, 65%, 50%, 0.1);
    color: hsla(211, 65%, 50%, 1);
}

.light button:hover, 
.light button:focus {
    background-color: hsla(211, 65%, 50%, 1);
    color: hsla(211, 65%, 50%, 0.3);
    color: white;
    -webkit-box-shadow: 0 0 12px 0 #3f454b;
    box-shadow: 0 0 12px 0 #3f454b;
}

.dark {
    background-color: #1A1C20;
}

.dark h1, 
.dark p, 
.dark .theme-label {
    color: #f1f1f1;
}

.dark button {
    border-color: #C4DFFF;
    background-color: #C4DFFF;
    color: #3f454b;
}

.dark button:hover, 
.dark button:focus {
    -webkit-box-shadow: 0 0 12px 0 #C4DFFF;
    box-shadow: 0 0 12px 0 #C4DFFF;
}

.dark .theme-label output {
    color: #C4DFFF;
}

@media screen and (min-width: 712px) {

    main {
        display: -webkit-flex;
        display: -ms-flex;
        display: flex;
        -webkit-box-pack: center;
        -ms-flex-pack: center;
        justify-content: center;
        -webkit-box-align: center;
        -ms-flex-align: center;
        align-items: center;
    }

    section {
        max-width: 912px; 
    }
}