:root {
    --header-colour: #00000031;
    --main-colour: #393e41;
    --footer-colour: #00000031;
    --text-colour: #f6f7eb;
    --text-accent-colour: #e94f37;
    --button-border-colour: var(--text-accent-colour);
    --button-border-highlight-colour: #f7b3a9;

    --header-size: 50px;
    --tab-transition-time: 250ms; /* Must be in ms for JS parsing */
}



html, body {
    width: 100%;
    height: 100%;
    margin: 0;
}

body {
    color: var(--text-colour);
    font-family: sans-serif;
    display: flex;
    flex-flow: column;
    background-color: var(--main-colour);
}



header, main, footer {
    width: 100%;
}

header {
    position: fixed;
    top: 0;
    background-color: var(--header-colour);
}

/* Required to set the width and height of the header, as `fixed` elements can't have their size set. */
header > div {
    width: 100vw;
    height: var(--header-size);
    backdrop-filter: blur(10px);
}

header > div > * {
    height: var(--header-size);
}

main {
    flex: 1 1 auto;
    margin-top: var(--header-size);
    text-align: center;
    background-color: var(--main-colour);
}

main > article {
    display: unset;
    transition: filter var(--tab-transition-time), opacity var(--tab-transition-time);
}

.hiddenTab {
    filter: blur(10px);
    opacity: 0;
}

footer {
    flex: 0 1 auto;
    display: flex;
    padding: 20px 0 20px 0;
    background-color: var(--footer-colour);
}

footer > div {
    width: 50%;
    height: fit-content;
    margin: auto 0 auto 0;
    text-align: center;
}

footer > div > * {
    margin: 0 auto 0 auto;
}



#tab-pics {
    display: flex;
    flex-wrap: wrap;
}

#tab-pics > * {
    margin: 10px;
    flex: 1 1 auto;
    max-width: 50vw;
    max-height: 50vh;
    object-fit: scale-down;
}



button {
    display: inline-flex;
    padding: 5px;
    border: none;
    border-bottom: 2px solid var(--text-accent-colour);
    background-color: #212425;
    color: var(--text-colour);
    align-items: center;
    cursor: pointer;
    transition: border-bottom-color 0.5s;
}

button > img {
    filter: invert();
    margin-right: 5px;
}

button:hover, .buttonHighlight {
    border-bottom-color: var(--button-border-highlight-colour);
}



.textHighlight {
    color: var(--text-accent-colour);
}

/* Used to make text appear to the right of an image */
.imgRightText {
    display: flex;
    width: fit-content;
}

.imgRightText > img {
    height: 100%;
    margin-right: 5px;
}

.imgRightText > p {
    margin: auto;
}