:root {
    --r-main-font-size: 3.8vmin;
    /* By default reveal.js white theme utilize pixels. */
    --r-block-margin: 0.5em;
    --r-heading-margin: 0 0.5em 0 0;
    /* We also need to set font. */
    --r-font-family: system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans","Liberation Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";
}

/* As we are using ./reveal.js/theme/night.css we are always in dark mode. */
:root {
    --r-background-color: #111;
    --r-background-color-highlight: #333;
    --r-main-color: #ddd;
    --r-heading-color: #3bb5dc;
    --r-link-color: #3bb5dc;
    --r-link-color-hover: #6ca0e8;
    --r-selection-background-color: #98bdef;
    --r-selection-color: #fff;
    --r-important: #f11;
    --r-warning: #f5bc42;
    --r-dim-color: #aaa;
}

/* Redefine font size. */
.reveal {
    font-size: var(--r-main-font-size);
}

/* Align slides content to the left. */
.reveal .slides {
    text-align: left;
}

.reveal .border {
    border: 1px solid white;
}

/* Keep image aspect ratio. */
img {
    object-fit: contain;
}

.reveal .important {
    color: var(--r-important);
}

.reveal .small {
    font-size: 75%;
}

.reveal pre>code {
    padding: 0 1rem;
}

.reveal code, .reveal .code {
    font-family: monospace;
}

.reveal pre {
    margin: 0;
    width: 100%;
}

.reveal table {
    /* We do not need to center tables. */
    margin-left: 0
}

.reveal .dim {
    color: var(--r-dim-color);
}

/*
 * Page layout.
 */

body {
    display: flex;
    height: 100vh;
    width: 100vw;
    flex-direction: column;
    font-family: var(--r-main-font);
}

header {
    padding: 2px 5px 2px 5px;
    block-size: fit-content;
    flex-grow: 0;
    flex-shrink: 0;
}

.presentation {
    margin-bottom: 1px;
}

footer {
    padding: 0.5em;
    block-size: fit-content;
    flex-grow: 0;
    flex-shrink: 0;
    margin-top: auto;
}

section {
    /* Section is top element, it can have size of parent which is
       sized using JavaScript. */
    height: 100%;
}

/*
 * Header, images on both sides of particular size.
 */

header {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
    vertical-align: top;
}

header img {
    max-height:9vh;
    object-fit: contain;
}

/*
 * Style of header and footer.
 */

header {
    color: var(--r-main-color);
    background-color: var(--color-background-footer);
}

footer {
    color: var(--r-main-color);
    background-color: var(--color-background-footer);
    font-size: max( 2.0vmin, 0.7em) ;
    border-top: 4px solid #31809F;
}

/**
 * Fragments.
 */

.reveal .fragment.current-fragment {
    background-color: var(--r-background-color-highlight);
    color: var(--r-main-color);
}

/**
 * Content layout.
 */

.flex-column {
    display: flex;
    flex-direction: column;
}

.flex-column-fill {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.flex-column-cropp {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.flex-row {
    display: flex;
    flex-direction: row;
}

.flex-row-cropp {
    display: flex;
    flex-direction: row;
    overflow: hidden;
}

.image-container {
    overflow: hidden;
}

/* As we use image containers inside a flex box, they would span
  full with. In order to prevent that we fit the width to the width
  of the image. */
a.image-container {
    width: fit-content;
}

.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    width: 100%;
}

/* Spacing helpers. */
.reveal .my-2 {
    margin: 2rem 0;
}