/* Global variables */
:root {
    --card-ratio: 55 / 85;
    --card-width: 420px;
    --card-height: calc(var(--card-width) * var(--card-ratio));
    --corner-size: 12px;
    --icon-size: 80px;
    --colour-bg: #333;
    --colour-card-bg: #302f34;
    --colour-gold: #d4cd96;
}

/* CSS Styles */
*,
*:before,
*:after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    align-items: center;
    background: linear-gradient(135deg, lighten(var(--colour-bg), 5), var(--colour-bg));
    background-color: var(--colour-bg);
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 24px;
    overscroll-behavior: none;
    scrollbar-width: none;
}

body::-webkit-scrollbar {
    display: none;
}

a {
    color: inherit;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.card {
    color: var(--colour-gold);
    font-family: 'Fira Sans', sans-serif;
    height: 100%;
    left: 0;
    position: absolute;
    top: 0;
    transform-origin: 100% 50%;
    transform-style: preserve-3d;
    width: 100%;
    -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
    transition: transform .6s cubic-bezier(.49, .23, .58, .49);
}

.card.flipped {
    transform: translateX(-100%) rotateY(-180deg);
}

.card-front,
.card-back {
    backface-visibility: hidden;
    background: repeating-linear-gradient(135deg,
        rgba(darken(var(--colour-card-bg), 50), .3),
        transparent 1px,
        rgba(darken(var(--colour-card-bg), 50), .3) 2px
    );
    background-size: 3px 3px;
    background-color: var(--colour-card-bg);
    border-radius: 1px;
    box-shadow: 0px -6px 8px 0px rgba(0, 0, 0, .1),
        0px 6px 8px 0px rgba(0, 0, 0, .1),
        6px 0px 8px 0px rgba(0, 0, 0, .1),
        -6px 0px 8px 0px rgba(0, 0, 0, .1);
    cursor: pointer;
    height: 100%;
    left: 0;
    padding: 5%;
    position: absolute;
    top: 0;
    width: 100%;
}

.card-back {
    transform: rotateY(180deg);
}

.card-back .layer {
    background: repeating-linear-gradient(135deg,
        rgba(darken(var(--colour-gold), 50), .3),
        transparent 1px,
        rgba(darken(var(--colour-gold), 50), .3) 2px
    );
    background-size: 3px 3px;
    background-color: var(--colour-gold);
    color: var(--colour-card-bg);
    height: 100%;
    position: relative;
    width: 100%;
}

.card-back .layer:after {
    background: linear-gradient(135deg, rgba(0, 0, 0, .2), transparent);
    content: '';
    display: block;
    height: 100%;
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;
}

.card-back .top,
.card-back .bottom {
    left: 8%;
    position: absolute;
    z-index: 1;
}

.card-back .top {
    top: 12%;
}

.card-back .bottom {
    bottom: 12%;
}

.card-back h2,
.card-back h3,
.card-back h4 {
    font-weight: 400;
    margin: 2px 0;
}

.card-back h2 {
    font-size: 18px;
    font-weight: 500;
    text-transform: uppercase;
}

.card-back h3 {
    font-size: 16px;
}

.card-back h4 {
    font-size: 16px;
    font-style: italic;
}

.card-front .layer {
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    height: 100%;
    justify-content: center;
    position: relative;
    width: 100%;
}

.card-front h1 {
    font-size: 32px;
    font-weight: 400;
    letter-spacing: -2px;
    margin: 0 auto;
    padding: 6px 18px 4px;
    text-align: center;
}

.card-front .corner {
    backface-visibility: hidden;
    border-right: 2px solid var(--colour-gold);
    border-top: 2px solid var(--colour-gold);
    height: var(--corner-size);
    position: absolute;
    width: var(--corner-size);
}

.card-front .corner:nth-of-type(1) {
    right: 0;
    top: 0;
}

.card-front .corner:nth-of-type(2) {
    left: 0;
    top: 0;
    transform: rotateZ(-90deg);
}

.card-front .corner:nth-of-type(3) {
    bottom: 0;
    left: 0;
    transform: rotateZ(180deg);
}

.card-front .corner:nth-of-type(4) {
    bottom: 0;
    right: 0;
    transform: rotateZ(90deg);
}

.card-wrapper {
    height: var(--card-height);
    max-width: var(--card-width);
    perspective: 600px;
    position: relative;
    width: 100%;
    transition: transform 1s;
}