:root {
    --brand-color: #f7f8fa;
    --font-color: #f7f8fa;
    --font-size: 1.3rem;
    --mono: "Oxygen mono", monospace;
    --sans: Oxygen, sans-serif;
}
.theme-blue {
    --bg-color: #0378A6;
    --link-color: #e310cb;
    --link-color-hover: #ff17e4;
    --answer-color: #F2CB05;
    --icon-color: #D9A404;
    --icon-color-hover: #d3bb72;
    --brand-color: #f7f8fa;
    --font-color: #f7f8fa;
    --gradient-color-left: rgba(14, 0, 14, 0);
    --gradient-color-right: rgba(134, 251, 251, 1);
}
.theme-dark {
    --bg-color: #171321;
    --link-color: #e310cb;
    --link-color-hover: #ff17e4;
    --answer-color: #86fbfb;
    --icon-color: #86fbfb;
    --icon-color-hover: #e310cb;
    --brand-color: #f7f8fa;
    --font-color: #f7f8fa;
    --gradient-color-left: rgba(255, 23, 288, 1);
    --gradient-color-right: rgba(134, 251, 251, 1);
}
/* border box model: https://css-tricks.com/box-sizing/ */
html {
    box-sizing: border-box;
}
*,
*::before,
*::after {
    box-sizing: inherit;
}

body {
    height: 100%;
    padding: 0;
    margin: 0;
    font-family: var(--sans);
    background-color: var(--bg-color);
    color: var(--font-color);
    font-size: var(--font-size);
}
h1,
h2,
h3 {
    font-family: var(--mono);
    margin: 0;
}
a {
    color: var(--link-color);
}
a:hover {
    color: var(--link-color-hover);
    text-decoration: none;
}

.gradient-bar {
    background: linear-gradient(90deg, var(--gradient-color-left) 0%, var(--gradient-color-right) 100%);
    height: 2px;
}

#main {
    height: 100%;
    padding: 6rem 1rem 10rem 1rem;
    max-width: 550px;
    margin: 0 auto;
    margin-bottom: -100px;
    overflow: scroll;
}
#main p {
    font-size: 1rem;
    line-height: 1.5;
}

#main .question {
    font-family: var(--mono);
    font-size: 2rem;
}
.question span {
    font-family: var(--sans);
    font-size: 6rem;
    color: var(--answer-color);
    display: block;
    font-weight: 300;   
}
#main h2 {
    font-size: 2rem;
}

footer {
    height: 100px;
    margin-top: -100px;
}
nav {
    font-family: var(--mono);
    font-size: 80%;
    padding: 1rem
}

nav h1 a {
    font-family: var(--sans);
}

nav ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-flow: row wrap;
    justify-content: center;
    align-items: center;
    gap: 2rem;
}
nav li:first-child {
    flex-basis: 100%;
    text-align: center;
}
nav [class*="fa-"]{
    font-size: 150%;
    color: var(--icon-color);
}
nav h1 [class*="fa-"]{
    font-size: 90%;
    color: var(--icon-color);
}
nav [class=brand] {
    color: var(--brand-color);
    display: block;
}
 nav a:hover,
 nav [class*="fa-"]:hover {
    color: var(--icon-color-hover);
 }

 @media (min-width: 850px) {
    #main {
        max-width: 750px;
    }
    nav {
        max-width: 1200px;
        margin: 0 auto;
    }
    nav li:first-child {
        flex-basis: auto;
        text-align: left;
        margin-right: auto;
    }
 }