:root {
    /* pre-defined colors */
    --pdt-grey-950: hsl(0deg, 0%, 95%);
    --pdt-grey-750: hsl(0deg, 0%, 75%);
    --pdt-grey-400: hsl(0deg, 0%, 40%);
    --pdt-grey-250: hsl(0deg, 0%, 25%);
    --pdt-grey-150: hsl(0deg, 0%, 15%);
    --pdt-grey-100: hsl(0deg, 0%, 10%);
    --pdt-primary-850: hsl(205deg, 100%, 85%);
    --pdt-primary-800: hsl(205deg, 100%, 80%);
    --pdt-primary-700: hsl(205deg, 100%, 70%);
    --pdt-secondary-850: hsl(250deg, 100%, 85%);
}

/* adjust admonition block spacing. this allows for a background on
 * admonition blocks that doesn't make the elements look to tightly
 * spaced.
 */
div.admonitionblock {
    border-radius: 3px;
    margin: 1.5em 0;
    padding: 0.5em 10% 0.5em 0.5em;
}

div.admonitionblock td.icon {
    padding-right: 0.5em;
}

div.admonitionblock td.icon > img {
    box-sizing: border-box;
    padding: 0.15em;
}

/* Fine-tune headings a bit */
h4 {
  font-size: 1.1em;
}
h5 {
  font-size: 1.05em;
}
h6 {
  font-size: 1.0em;
}

/* Support for heading anchor links */
h3 {
    border-bottom: unset;
}

h3 > span {
    display: inline-block;
    border-bottom: 2px solid silver;
}

a.headerlink {
    color: var(--pdt-grey-750);
    padding: 0 4px;
    text-decoration: none;
    visibility: hidden;
}

/* add it as an pseudo-element, so that it does not show up in the ToC */
a.headerlink::after {
    content: '\00b6';
    text-decoration: none;
}

h1:hover > a.headerlink,
h2:hover > a.headerlink,
h3:hover > a.headerlink,
h4:hover > a.headerlink,
h5:hover > a.headerlink,
h6:hover > a.headerlink {
  visibility: visible;
}

/* Dark mode theme */
@media screen and (prefers-color-scheme: dark) {
    :root {
        color-scheme: dark;
        --pdt-body-background: var(--pdt-grey-150);
        --pdt-text: var(--pdt-grey-950);
        --pdt-headline: var(--pdt-primary-800);
        --pdt-link: var(--pdt-primary-700);
        --pdt-link-visited: var(--pdt-secondary-850);
        --pdt-highlighted-text: var(--pdt-primary-850);
        --pdt-background-sidebar: var(--pdt-grey-100);
        --pdt-background-listings: var(--pdt-grey-100);
        --pdt-border: var(--pdt-grey-400);
        --pdt-border-alt: var(--pdt-grey-250);
        --pdt-table-border: var(--pdt-grey-400);
        --pdt-background-admonition: var(--pdt-grey-250);
    }

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

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

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

    /* style headlines, titles etc. */
    h1,
    h2,
    h3,
    h4,
    h5,
    h6,
    thead,
    #author,
    #toctitle,
    div.title,
    td.hdlist1,
    caption.title,
    p.tableblock.header {
        color: var(--pdt-headline);
    }

    h1,
    h2,
    h3,
    #footer {
        border-color: var(--pdt-border);
    }

    /* formatted colored text */
    dt,
    em,
    pre,
    code,
    strong,
    .monospaced {
        color: var(--pdt-highlighted-text);
    }

    /* style the table of contents sidebar */
    div #toc {
        color: var(--pdt-text);
        background-color: var(--pdt-background-sidebar);
        border-color: var(--pdt-border-alt);
    }

    div #toc a:link,
    div #toc a:visited {
        color: var(--pdt-text);
    }

    /* reduce the brigthness of images a bit and make it reversable
     * through hovering over them.
     */
    .image > img {
        filter: brightness(90%);
    }

    .image > img:hover {
        filter: none;
    }

    /* tables */
    th.tableblock,
    td.tableblock,
    table.tableblock {
        border-color: var(--pdt-table-border);
    }

    div.quoteblock,
    div.verseblock {
        color: var(--pdt-text);
        border-color: var(--pdt-border);
    }

    /* listings (e.g. code snippet blocks) */
    div.listingblock > div.content {
        background-color: var(--pdt-background-listings);
        border-color: var(--pdt-border-alt);
    }

    /* admonition blocks (e.g. notes, warnings etc.) */
    div.admonitionblock {
        color: var(--pdt-text);
        background-color: var(--pdt-background-admonition);
    }

    div.admonitionblock td.content {
        border-color: var(--pdt-border);
    }

    /* makes the admonition icons appear a bit more consistent, by
     * adding a white background the shadows in the icons look
     * "correct"
     */
    div.admonitionblock td.icon > img {
        background-color: white;
        border-radius: 100%;
        filter: brightness(95%);
    }

    /* invert the logo */
    #header > h1 > .image > img {
        filter: invert(100%) hue-rotate(180deg) brightness(90%);
    }

    /* fixes the black text on unorderd lists */
    ul > li > * {
        color: var(--pdt-text);
    }
}