index.css

@import url("https://necolas.github.io/normalize.css/8.0.0/normalize.css");

/*! HTML5 Boilerplate v6.1.0 | MIT License | https://html5boilerplate.com/ */

/*
 * What follows is the result of much research on cross-browser styling.
 * Credit left inline and big thanks to Nicolas Gallagher, Jonathan Neal,
 * Kroc Camen, and the H5BP dev community and team.
 */

/* ==========================================================================
   Base styles: opinionated defaults
   ========================================================================== */

html {
    color: #222;
    font-size: 1em;
    line-height: 1.4;
}

/*
 * Remove text-shadow in selection highlight:
 * https://twitter.com/miketaylr/status/12228805301
 *
 * Vendor-prefixed and regular ::selection selectors cannot be combined:
 * https://stackoverflow.com/a/16982510/7133471
 *
 * Customize the background color to match your design.
 */

::-moz-selection {
    background: #b3d4fc;
    text-shadow: none;
}

::selection {
    background: #b3d4fc;
    text-shadow: none;
}

/*
 * A better looking default horizontal rule
 */

hr {
    display: block;
    height: 1px;
    border: 0;
    border-top: 1px solid #ccc;
    margin: 1em 0;
    padding: 0;
}

/*
 * Remove the gap between audio, canvas, iframes,
 * images, videos and the bottom of their containers:
 * https://github.com/h5bp/html5-boilerplate/issues/440
 */

audio,
canvas,
iframe,
img,
svg,
video {
    vertical-align: middle;
}

/*
 * Remove default fieldset styles.
 */

fieldset {
    border: 0;
    margin: 0;
    padding: 0;
}

/*
 * Allow only vertical resizing of textareas.
 */

textarea {
    resize: vertical;
}

/* ==========================================================================
   Author's custom styles
   ========================================================================== */

/*
 * Defaults
 */

html, body {
    border: none;
    height: 100%;
    padding: 0;
    width: 100%;
}

/*
 * Style
 */

body {
  background-attachment: fixed;
  background-image: url("index/noise-texture.png"), linear-gradient(to bottom, lightslategray, #2e3436);
  background-repeat: repeat;
  font-family: sans-serif;
  text-align: center;
}

header, footer {
  padding: 1em;
}

main {
  border-image: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.75), rgba(0, 0, 0, 0)) 1;
  border-width: 0.1em 0;
  border-style: solid;
  display: inline-block;
  margin: auto;
  max-width: 80%;
  padding: 0.5em;
}

main > a {
  border-radius: 0.5em;
  display: inline-block;
  margin: 0.5em;
  max-height: 10em;
  max-width: 10em;
  overflow: hidden;
  vertical-align: middle;
}

main > a > img {
  height: 100%;
  width: 100%;
}


/* ==========================================================================
   Print styles.
   Inlined to avoid the additional HTTP request:
   https://www.phpied.com/delay-loading-your-print-css/
   ========================================================================== */

@media print {
    *,
    *:before,
    *:after {
        background: transparent !important;
        color: #000 !important; /* Black prints faster */
        -webkit-box-shadow: none !important;
        box-shadow: none !important;
        text-shadow: none !important;
    }

    a,
    a:visited {
        text-decoration: underline;
    }

    a[href]:after {
        content: " (" attr(href) ")";
    }

    abbr[title]:after {
        content: " (" attr(title) ")";
    }

    /*
     * Don't show links that are fragment identifiers,
     * or use the `javascript:` pseudo protocol
     */

    a[href^="#"]:after,
    a[href^="javascript:"]:after {
        content: "";
    }

    pre {
        white-space: pre-wrap !important;
    }
    pre,
    blockquote {
        border: 1px solid #999;
        page-break-inside: avoid;
    }

    /*
     * Printing Tables:
     * http://css-discuss.incutio.com/wiki/Printing_Tables
     */

    thead {
        display: table-header-group;
    }

    tr,
    img {
        page-break-inside: avoid;
    }

    p,
    h2,
    h3 {
        orphans: 3;
        widows: 3;
    }

    h2,
    h3 {
        page-break-after: avoid;
    }
}