:root {
    --blue: #3182ce;
    --indigo: #5a67d8;
    --darkindigo: #434190;
    --green: #38a169;
    --red: #e53e3e;
    --yellow: #ecc94b;
    --black: #1a202c;
    --gray: #4a5568;
    --mediumgray: #e2e8f0;
    --lightgray: #f7fafc;
}

/* default style */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
    color: var(--black);
}

svg {
    fill: var(--black);
}

.main-container {
    max-width: 80rem;
    margin: auto;
}

/* links */

a:hover {
    color: var(--darkindigo);
    text-decoration: underline;
}

a:hover svg {
    fill: var(--darkindigo);
}

/* titles */
.main-title {
    line-height: 1;
    font-weight: 300;
    font-size: 1.875rem;
    margin-bottom: 1.5rem;
}

/* utilities */
.fill-green {
    fill: var(--green);
}

.fill-red {
    fill: var(--red);
}

.fill-yellow {
    fill: var(--yellow);
}

.fill-gray {
    fill: var(--gray);
}

.text-center {
    text-align: center;
}

.vertical-middle {
    vertical-align: middle;
}

.margin-auto {
    margin: auto;
}

.inline {
    display: inline;
}

.hidden {
    display: none;
}

/* media queries */
@media (min-width: 48rem) {
    .md-inline {
        display: inline;
    }
}