:root {
  color-scheme: light dark;
  --bg: light-dark(white, black);
  --fg: light-dark(black, white);
  --padding: min(2svi, 1rem);
  font-size: 16px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-weight: normal;
  user-select: none;
}

body {
  margin: 0;
  width: 100svw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  background: var(--bg);
}

#highlighter {
  display: none;
}

.cards {
  width: 100svi;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: auto;
  gap: var(--padding);
  list-style: none;

  overflow-x: auto;
  scroll-behavior: smooth;
  overscroll-behavior-x: contain;
  scrollbar-width: none;
  scroll-snap-type: x mandatory;
  padding: var(--padding) 50svi;
  scroll-padding: var(--padding);
  container-type: inline-size scroll-state;
  inline-size: 1024px;
  max-inline-size: 100vw;
  anchor-name: --carousel;
  scroll-marker-group: after;

  &:focus-visible {
    outline-color: var(--fg);
  }

  &::scroll-button(*) {
    position: fixed;
    position-anchor: --carousel;

    inline-size: 44px;
    line-height: 1;
    font-family: "system-ui";
    font-size: 1.5rem;
    display: flex;
    place-items: center;
    place-content: center;
    aspect-ratio: 1;
    background: var(--bg);
    color: var(--fg);
    border: 1px solid light-dark(hsl(0 0 0 / 0.4), hsl(0 0 100% / 0.4));
    border-radius: 9999px;
    transition: opacity 100ms ease-in-out, background 100ms ease-in-out,
      color 100ms ease-in-out;
    opacity: 0;
  }

  &:hover::scroll-button(*),
  &:has(:focus-visible)::scroll-button(*) {
    opacity: 1;
  }

  &::scroll-button(*):not(:disabled):hover {
    background: var(--fg);
    color: var(--bg);
    cursor: pointer;
    border-color: var(--fg);
  }

  &:hover::scroll-button(*):disabled {
    opacity: 0.3;
  }

  &::scroll-button(*):focus-visible {
    outline: 2px solid var(--fg);
    outline-offset: 2px;
    opacity: 1;
  }

  &::scroll-button(right) {
    position-area: inline-end center;
    content: "→" / "Next";
    translate: calc(-100% - var(--padding)) 0;
  }

  &::scroll-button(left) {
    position-area: inline-start center;
    content: "←" / "Previous";
    translate: calc(100% + var(--padding)) 0;
  }

  &::scroll-marker-group {
    position: fixed;
    position-anchor: --carousel;
    position-area: block-end;
    margin: var(--padding);
    animation: slide-in-up 800ms cubic-bezier(0.2, 0.25, 0, 1) forwards;

    display: grid;
    grid-auto-columns: auto;
    grid-auto-flow: column;
    gap: 0.5rem;
  }
}

.card {
  animation: slide-in-up 800ms cubic-bezier(0.2, 0.25, 0, 1) forwards;
  container-type: inline-size scroll-state;
  container-name: card;
  scroll-snap-align: center;
  scroll-snap-stop: always;
  height: calc(100svb - (9 * var(--padding)));
  aspect-ratio: 650 / 975;
  display: flex;
  justify-content: center;

  &::scroll-marker {
    content: "" / attr(data-label);
    aspect-ratio: 1;
    width: 0.5rem;
    border-radius: 999px;
    transition: opacity 200ms ease-in-out, background 200ms ease-in-out,
      scale 400ms cubic-bezier(0.2, 0.25, 0, 1);
    border: 1px solid var(--fg);
    scale: 0.75;
  }

  &::scroll-marker:focus-visible {
    outline: 2px solid var(--fg);
    outline-offset: 2px;
  }

  &::scroll-marker:target-current {
    background: var(--fg);
    border-color: var(--fg);
    scale: 1;
  }
}

.card-wrapper {
  --card-padding: min(7cqw, 2rem);
  background: linear-gradient(
    to bottom,
    light-dark(hsl(0 0 100%), hsl(0 0 0)) 0%,
    light-dark(hsl(0 0 0 / 0), hsl(0 0 100% / 0.1)) 100%
  );
  position: relative;
  height: 100%;
  aspect-ratio: 650 / 975;
  overflow: clip;
  border-radius: 0.5rem;
  display: flex;
  flex-direction: column;
  justify-content: end;
  gap: 0.5rem;
  color-scheme: light;
  box-shadow: inset 0 0 0 1px light-dark(hsl(0 0 0 / 0.1), hsl(0 0 100% / 0.1));
  opacity: 0.6;
  scale: 0.95;
  transition: opacity 300ms cubic-bezier(0.2, 0.25, 0, 1),
    scale 300ms cubic-bezier(0.2, 0.25, 0, 1);
  container-type: inline-size;
  container-name: card-wrapper;

  *:not(img) {
    position: relative;
    z-index: 1;
    font-size: 0.75rem;
    line-height: 1rem;
    margin: 0;
  }

  .texts {
    z-index: 3;
    color: var(--fg);
    background: linear-gradient(
      to bottom,
      transparent 0%,
      light-dark(hsl(0 0 100% / 0.9), hsl(0 0 0 / 0.9)) 90%
    );
    display: flex;
    flex-direction: column;
    padding: 25% var(--card-padding) var(--card-padding);
  }

  .actor,
  h2,
  p {
    font-size: max(1rem, 4cqi);
    line-height: 1.1em;
    transition: opacity 300ms cubic-bezier(0.2, 0.25, 0, 1),
      translate 300ms cubic-bezier(0.2, 0.25, 0, 1);
    opacity: 0;
  }

  .actor {
    font-size: max(0.8rem, 4cqi);
    font-style: italic;
    font-family: Georgia, "Times New Roman", Times, serif;
    translate: 0 1rem;
    margin-bottom: 0.25rem;
  }

  h2 {
    font-size: max(1.1rem, 8cqi);
    line-height: 1em;
    text-wrap: pretty;
    display: flex;
    flex-direction: column-reverse;
    gap: 0.25rem;
    align-items: baseline;
    translate: 0 1.5rem;
  }

  p {
    font-size: max(0.8rem, 4cqi);
    text-wrap: balance;
    margin-top: 0.5rem;
    translate: 0 2rem;
  }

  &.card-empire {
    color-scheme: dark;
  }

  img {
    position: absolute;
    inset: 0;
    z-index: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: bottom;
    filter: grayscale(1) blur(5px);
    translate: 0 calc(var(--padding) * 2);
    transition: filter 600ms cubic-bezier(0.2, 0.25, 0, 1) 100ms,
      translate 700ms cubic-bezier(0.37, 0, 0, 0.98);
  }

  .symbol {
    width: min(3rem, 15cqmin);
    aspect-ratio: 1 / 1;
    background: url(images/alliance.svg) center center no-repeat;
    background-size: contain;
    position: absolute;
    top: var(--card-padding);
    left: var(--card-padding);
    z-index: 4;
    rotate: -20deg;
    scale: 0.8;
    transition: opacity 300ms cubic-bezier(0.2, 0.25, 0, 1),
      rotate 300ms cubic-bezier(0.2, 0.25, 0, 1),
      scale 300ms cubic-bezier(0.2, 0.25, 0, 1);
    opacity: 0;

    .card-empire & {
      background-image: url(images/empire.svg);
    }
  }
}

@container card-wrapper (max-width: 160px) {
  .card-wrapper .texts {
    opacity: 0;
  }
}

@container card scroll-state(snapped: x) {
  .card-wrapper {
    opacity: 1;
    scale: 1;
    transition-duration: 800ms;

    img {
      filter: grayscale(0);
      translate: 0 0;
    }

    .symbol {
      rotate: 0deg;
      scale: 1;
    }

    .symbol,
    h2,
    .actor,
    p {
      opacity: 1;
      translate: 0 0;
      transition-duration: 800ms;
      transition-delay: 200ms;
    }
    .actor {
      opacity: 0.75;
    }
  }
}

@keyframes slide-in-up {
  from {
    opacity: 0;
    translate: 0 2rem;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
}
CSS-only Carousel
