treehouse/static/css/main.css

/* Color scheme. */

:root {
    /* naturally */
    --liquidex-brand-blue: #058ef0;
    /* but also: */
    --liquidex-brand-red: #eb134a;
    --liquidex-brand-yellow: #ffc31f;
    --liquidex-brand-green: #06ca4a;

    --text-color-light: #55423e;
    --link-color-light: #004ec8;
    --link-color-visited-light: #6c2380;

    --background-color: rgb(255, 253, 246);
    --background-color-tooltip: rgb(226, 223, 214);
    --text-color: #55423e;
    --link-color: #004ec8;
    --link-color-visited: #6c2380;

    --shaded-background: rgba(0, 0, 0, 5%);
    --border-1: rgba(0, 0, 0, 15%);
    --border-2: rgba(0, 0, 0, 30%);
    --hover: rgba(0, 0, 0, 15%);

    /* Hack to enable theme-matching scrollbars in <pre> */
    --shaded-against-background: #f2f0ea;
    --shaded-against-background-twice: #e6e4de;
}

@media (prefers-color-scheme: dark) {
    :root {
        --background-color: rgb(30, 40, 53);
        --background-color-tooltip: rgb(23, 31, 41);
        --text-color: #d7cdbf;
        --link-color: #93cce8;
        --link-color-visited: #f7afde;

        --shaded-background: #f7e5df0c;
        --border-0: #f7e5df1a;
        --border-1: #f7e5df26;
        --border-1-and-a-half: #f7e5df3a;
        --border-2: #f7e5df4d;

        --shaded-against-background: #29313e;
        --shaded-against-background-twice: #333a46;
    }
}

/* Article-style layout. Center everything and give it a maximum width */

body {
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;

    display: flex;
    flex-direction: column;
}

main {
    padding: 0 16px;
}

@media screen and (max-width: 480px) {
    main {
        padding: 0 8px;
    }
}

/* Choose more pretty colors than vanilla HTML */

body {
    background-color: var(--background-color);
    color: var(--text-color);

    scrollbar-color: var(--background-color);
    scrollbar-width: auto;
    scrollbar-gutter: stable;
}

body::selection {
    /* Even though this color doesn't yield the most readable text, browsers  */
    background-color: var(--liquidex-brand-blue);
}

/* Set up typography */

@font-face {
    font-family: 'RecVar';
    src: url('../font/Recursive_VF_1.085.woff2');
}

@font-face {
    font-family: 'RecVarMono';
    src: url('../font/Recursive_VF_1.085.woff2');
    font-variation-settings: "MONO" 1.0;
}


body,
pre,
code,
kbd {
    font-family: 'RecVar', sans-serif;
    font-size: 14px;
    line-height: 1.5;
}

:root {
    --recursive-mono: 0.0;
    --recursive-casl: 1.0;
    --recursive-wght: 400;
    --recursive-slnt: 0.0;
    --recursive-crsv: 0.5;

    --recursive-simplified-f: "ss03";
    --recursive-simplified-g: "ss04";
    --recursive-simplified-l: "ss05";
    --recursive-simplified-r: "ss06";
    --recursive-no-serif-L-Z: "ss08";
}

*,
*:before,
*:after {
    font-variation-settings:
        "MONO" var(--recursive-mono),
        "CASL" var(--recursive-casl),
        "wght" var(--recursive-wght),
        "slnt" var(--recursive-slnt),
        "CRSV" var(--recursive-crsv);

    font-feature-settings:
        var(--recursive-simplified-f),
        var(--recursive-simplified-g),
        var(--recursive-simplified-l),
        var(--recursive-simplified-r),
        var(--recursive-no-serif-L-Z);
}

h1 {
    --recursive-slnt: 0.0;
    --recursive-casl: 0.0;
    --recursive-wght: 900;

    font-size: 3.5rem;
    font-feature-settings: var(--recursive-simplified-r) 0;
}

h2 {
    --recursive-slnt: 0.0;
    --recursive-casl: 0.5;
    --recursive-wght: 800;

    font-size: 2rem;
}

h3 {
    --recursive-slnt: 0.0;
    --recursive-casl: 0.5;
    --recursive-wght: 700;

    font-size: 1.5rem;
}

h4 {
    --recursive-slnt: 0.0;
    --recursive-casl: 0.5;
    --recursive-wght: 700;

    font-size: 1rem;
}

pre,
code,
kbd,
th-literate-program {
    --recursive-mono: 1.0;
    --recursive-casl: 0.0;
    --recursive-slnt: 0.0;
    --recursive-wght: 450;
}

b,
strong {
    --recursive-wght: 700;
}

i,
em {
    --recursive-slnt: -16.0;
    font-style: normal;
}

/* Lay out elements a bit more compactly */

p,
pre {
    margin: 0 0;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    margin: 4px 0;
}

/* Lay out elements a little less compactly (actually just have some blank space past the end) */

body {
    padding-bottom: 10rem;
}

/* Make code examples a little prettier by giving them visual separation from the rest of the page */

code,
th-literate-program {
    padding: 3px 4px;
    background-color: var(--shaded-background);
    border-radius: 4px;
}

th-literate-program,
th-literate-output {
    display: block;
}

kbd {
    padding: 3px 6px;
    border: 1px solid var(--border-1);
    border-radius: 6px;
}

pre,
th-literate-program {
    padding: 8px 12px;
    margin: 12px 0;
    background-color: var(--shaded-against-background);
    border-radius: 8px;

    transition: background-color var(--transition-duration);
}

@media (prefers-color-scheme: light) {

    pre,
    th-literate-program {
        background-color: transparent;
        border: 1px solid var(--border-1);
    }
}


@media (prefers-color-scheme: dark) {
    .tree summary:hover {

        & pre,
        & th-literate-program:not([data-mode="output"]) {
            background-color: var(--shaded-against-background-twice);
        }
    }
}

pre>code,
th-literate-program>code {
    padding: 0;
    background: none;
    border-radius: 0px;
}

th-literate-program {
    white-space: pre;
}

/* And don't let code examples fly off and overflow the window */

pre,
th-literate-program {
    min-width: 0;
    width: auto;
    overflow: auto;
}

/* Also don't let images get out of hand */

img {
    max-width: 100%;
}

/* Also regarding images - make them look a bit more pretty by default */

img.pic {
    border-radius: 6px;
    margin: 8px 0;
}

/* Image hints for tweaking rendering */
img {
    &[src*='+pixel'] {
        image-rendering: pixelated;
        border-radius: 0;
    }

    /* TODO: These could be autogenerated! */

    &[src*='+width72'] {
        width: 72px;
        height: auto;
    }

    &[src*='+width160'] {
        width: 160px;
        height: auto;
    }

    &[src*='+width640'] {
        width: 640px;
        height: auto;
    }

    &[src*='+width752'] {
        width: 752px;
        height: auto;
    }

    /* Resources for use in JavaScript. */
    &.resource {
        display: none;
    }
}

/* Fix the default blue and ugly purple links normally have */

a {
    color: var(--link-color);
}

a:visited {
    color: var(--link-color-visited);
}

/* Make blockquotes a bit prettier */

blockquote {
    margin: 0;
    padding: 4px 12px;
    margin: 4px 0;
    border-left: 4px solid var(--border-1);
}

/* And tables. */

table {
    margin: 8px 0;
}

table,
th,
td {
    border: 1px solid var(--border-2);
    border-collapse: collapse;
    padding: 4px 10px;
}

th {
    background-color: var(--shaded-background);

    --recursive-wght: 700;
    --recursive-casl: 0.5;
}

/* Horizontal rules */

hr {
    width: 100%;
    border: none;
    border-top: 1px solid var(--border-1);
    margin-top: 2em;
    margin-bottom: 2em;
}

/* Style the noscript box a little more prettily. */

.noscript {
    padding: 16px;
    background-color: #fde748;
    color: var(--text-color-light);
    border: 1px solid #6c581c;
    border-radius: 8px;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.noscript p {
    margin-top: 0;
    margin-bottom: 16px;
}

.noscript p:last-child {
    margin-bottom: 0;
}

.noscript a {
    color: var(--link-color-light);
}

.noscript a:visited {
    color: var(--link-color-visited-light);
}

/* also, webkit. */
#webkit-makes-me-go-insane {
    display: none;
}

/* Style the navigation bar. */

nav {
    display: flex;
    align-items: center;
}

nav .nav-page {
    display: flex;
    flex-grow: 1;
    flex-direction: column;
}

/* Give the logo on the top some nicer looks */
nav .logo {
    width: 48px;
    height: 48px;
    padding: 16px;
    display: block;
    opacity: 100%;
    color: var(--text-color);
}

/* Style page titles */
h1.page-title {
    --recursive-wght: 800;
    margin-top: 0;
    margin-bottom: 0;
    margin-left: 32px;
    font-size: 1.25rem;

    & a {
        color: var(--text-color);
        text-decoration: none;

        &:hover {
            text-decoration: underline;
        }
    }
}

@media (hover: none) {
    h1.page-title a {
        text-decoration: underline;
    }
}

/* Style the `new` link on the homepage */
a[data-cast~="new"] {
    flex-shrink: 0;
    color: var(--text-color);
    opacity: 50%;

    margin-right: 16px;

    &.has-news {
        opacity: 100%;
        text-decoration: none;

        & .new-text {
            text-decoration: underline;
        }
    }

    & .badge {
        margin-left: 8px;
        text-decoration: none;
    }
}

/* Style new badges */
span.badge {
    --recursive-wght: 800;
    --recursive-slnt: 0;
    --recursive-mono: 1.0;
    --recursive-casl: 0;

    border-radius: 999px;
    padding: 2px 6px;
    font-size: 0.9em;

    &.red {
        color: white;
        background-color: #d01243;
    }

    &.blue {
        color: white;
        background-color: #058ef0;
    }

    &.before-content {
        margin-right: 6px;
    }
}

/* Style the footer */
footer {
    margin-top: 4rem;
    text-align: right;
    opacity: 40%;

    & #footer-icon {
        color: var(--text-color);
        padding-right: 24px;
    }
}

/* Style emojis to be readable */

img[data-cast~="emoji"] {
    max-width: 1.5em;
    max-height: 1.5em;
    vertical-align: bottom;
    object-fit: contain;
}

/* And also style emoji tooltips. */

th-emoji-tooltip {
    display: flex;
    flex-direction: column;
    align-items: center;

    position: fixed;
    transform: translateX(-50%) translateY(-10%) scale(0.8);
    width: max-content;
    z-index: 100;

    background-color: var(--background-color-tooltip);
    padding: 8px;
    margin-top: 8px;
    border-radius: 6px;

    transition:
        opacity var(--transition-duration) cubic-bezier(0.22, 1, 0.36, 1),
        filter var(--transition-duration) cubic-bezier(0.22, 1, 0.36, 1),
        transform var(--transition-duration) cubic-bezier(0.22, 1, 0.36, 1);
    opacity: 0%;
    filter: blur(3px);
    pointer-events: none;
}

th-emoji-tooltip.transitioned-in {
    opacity: 100%;
    filter: blur(0px);
    transform: translateX(-50%) scale(1.0);
}

th-emoji-tooltip img {
    display: block;
    max-width: 64px;
    max-height: 64px;
}

th-emoji-tooltip p {
    --recursive-wght: 550;
    color: var(--text-color);
    font-size: 0.9em;
    margin: 0;
    padding-top: 6px;
    line-height: 1;
}

/* Funny joke */

@keyframes hello-there {
    0% {
        opacity: 0%;
    }

    70% {
        opacity: 0%;
    }

    100% {
        opacity: 70%;
    }
}

.oops-you-seem-to-have-gotten-stuck {
    margin-top: 16px;
    display: none;
    position: absolute;
    opacity: 0%;
}

#index\:treehouse>details:not([open])>summary .oops-you-seem-to-have-gotten-stuck {
    display: inline;
    animation: 4s hello-there forwards;
}

/* Literate programming support */

:root {
    --error-color: #d94141;
}

@media (prefers-color-scheme: dark) {
    :root {
        --error-color: #e39393;
    }
}

th-literate-program[data-mode="input"] {
    /* Override the cursor with an I-beam, because the editor captures clicks and does not bubble
       them back up to the caller */
    cursor: text;
}

th-literate-program[data-mode="output"] {
    padding: 0;
    background: none;
    border: none;
    border-radius: 0;

    & iframe,
    & img.placeholder-image {
        border-style: none;
        border-radius: 4px;
        display: block;
    }

    & img.placeholder-image.js {
        transition: opacity var(--transition-duration);
    }

    & iframe,
    & img.placeholder-image.loading {
        opacity: 50%;
    }

    & iframe.loaded {
        opacity: 100%;
    }

    /* The inner iframe is hidden until something requests display. */
    & iframe.hidden {
        display: none;
    }

    & pre>code {
        display: block;
    }

    & pre.error {
        color: var(--error-color);
        position: relative;

        &:empty {
            display: none;
        }

        &::after {
            content: 'Error';

            padding: 8px;

            position: absolute;
            right: 0;
            top: 0;

            color: var(--text-color);
            opacity: 50%;
        }
    }

    & pre.console,
    & pre.placeholder-console {
        position: relative;
        margin-top: 0;
        margin-bottom: 0;

        &:empty {
            display: none;
        }

        &::after {
            content: 'Console';

            padding: 8px;

            position: absolute;
            right: 0;
            top: 0;

            color: var(--text-color);
            opacity: 50%;
        }
    }
}

/* Syntax highlighting */

:root {
    --syntax-comment: #9b8580;
    --syntax-identifier: var(--text-color);
    --syntax-keyword1: #e15e2b;
    --syntax-keyword2: #199aca;
    --syntax-operator: #e3755b;
    --syntax-function: #d57b07;
    --syntax-literal: #a64fb3;
    --syntax-string: #79ac3b;
    --syntax-punct: #a28680;
}

@media (prefers-color-scheme: dark) {
    :root {
        --syntax-comment: #aca8a4;
        --syntax-identifier: var(--text-color);
        --syntax-keyword1: #ffb06a;
        --syntax-keyword2: #8ad4f9;
        --syntax-operator: #ec9f8d;
        --syntax-function: #fbd283;
        --syntax-literal: #e9b9f0;
        --syntax-string: #b0dd7a;
        --syntax-punct: #9d9a96;
    }
}

.th-syntax-highlighting span {
    &.comment {
        --recursive-slnt: -16.0;
        color: var(--syntax-comment);
    }

    &.identifier {
        color: var(--syntax-identifier);
    }

    &.keyword1 {
        color: var(--syntax-keyword1);
    }

    &.keyword2 {
        color: var(--syntax-keyword2);
    }

    &.operator {
        color: var(--syntax-operator);
    }

    &.function {
        color: var(--syntax-function);
    }

    &.literal {
        color: var(--syntax-literal);
    }

    &.string {
        color: var(--syntax-string);
    }

    &.punct {
        color: var(--syntax-punct);
    }

}

.th-syntax-highlighting {
    & .export {
        text-decoration: underline dotted;
        cursor: help;
        text-decoration-color: transparent;
        transition: text-decoration-color var(--transition-duration);
    }

    &:hover,
    &:focus {
        & .export {
            text-decoration-color: var(--syntax-keyword1);
        }
    }
}

/* Style settings sections */

section[data-cast~="settings"] {
    /* Don't display settings when JavaScript is disabled.
       JS overrides this value on the element itself. */
    display: none;
}