* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #f5f2eb;
  --dot: #d4d0c8;
  --card-bg: #fffef9;
  --card-border: #d4d0c8;
  --card-shadow1: rgba(0,0,0,0.06);
  --card-shadow2: rgba(0,0,0,0.05);
  --rule-line: #c8d4e0;
  --red-margin: #e8b4b8;
  --text-primary: #2a2a2a;
  --text-secondary: #6b6b6b;
  --text-hint: #bbb;
  --drop-shadow: rgba(0,0,0,0.04);
  --toggle-bg: #e0ddd6;
  --toggle-fg: #6b6b6b;
  --card-pad-y: 16px;
  --content-indent: 16px;
  --line-h: clamp(26px, 2.5vw, 32px);
  --margin-line-left: clamp(24px, 3vw, 40px);
  --dot-size: clamp(24px, 2.5vw, 32px);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #141418;
    --dot: #2a2a30;
    --card-bg: #1c1c22;
    --card-border: #2a2a32;
    --card-shadow1: rgba(0,0,0,0.2);
    --card-shadow2: rgba(0,0,0,0.3);
    --rule-line: #2a2a32;
    --red-margin: #4a2a2e;
    --text-primary: #e0ddd6;
    --text-secondary: #8a8a94;
    --text-hint: #555;
    --drop-shadow: rgba(0,0,0,0.15);
    --toggle-bg: #2a2a32;
    --toggle-fg: #8a8a94;
  }
}

[data-theme="dark"] {
  --bg: #141418;
  --dot: #2a2a30;
  --card-bg: #1c1c22;
  --card-border: #2a2a32;
  --card-shadow1: rgba(0,0,0,0.2);
  --card-shadow2: rgba(0,0,0,0.3);
  --rule-line: #2a2a32;
  --red-margin: #4a2a2e;
  --text-primary: #e0ddd6;
  --text-secondary: #8a8a94;
  --text-hint: #555;
  --drop-shadow: rgba(0,0,0,0.15);
  --toggle-bg: #2a2a32;
  --toggle-fg: #8a8a94;
}

body {
  background-color: var(--bg);
  width: 100%;
  height: 100dvh;
  overflow: hidden;
  background-image: radial-gradient(circle, var(--dot) 0.8px, transparent 0.8px);
  background-size: var(--dot-size) var(--dot-size);
  transition: background-color 0.3s ease;
  font-family: 'Caveat', cursive;
}

.card {
  position: absolute;
  perspective: 800px;
  cursor: grab;
  -webkit-user-select: none;
  user-select: none;
}

.card--dragging {
  cursor: grabbing;
  z-index: 100;
}

.card:focus-visible {
  outline: 2px solid var(--text-secondary);
  outline-offset: 4px;
  border-radius: 6px;
}

.card__inner {
  width: clamp(280px, 28vw, 420px);
  aspect-ratio: 420 / 300;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.5s ease;
}

.card--art .card__inner {
  width: clamp(200px, 19vw, 280px);
  aspect-ratio: 280 / 200;
}

.card__inner--flipped {
  transform: rotateY(180deg);
}

.card__face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 6px;
  padding: 16px 16px 16px calc(var(--margin-line-left) + var(--content-indent));
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  box-shadow:
    0 1px 3px var(--card-shadow1),
    0 8px 24px var(--card-shadow2),
    6px 8px 16px var(--drop-shadow);
  background-image:
    linear-gradient(transparent calc(var(--line-h) - 1px), var(--rule-line) calc(var(--line-h) - 1px), var(--rule-line) var(--line-h), transparent var(--line-h));
  background-size: 100% var(--line-h);
  background-position: 0 calc(var(--card-pad-y) - 4px);
  transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
}

.card__face::before {
  content: '';
  position: absolute;
  left: var(--margin-line-left);
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--red-margin);
  opacity: 0.6;
}

.card__front {
  display: flex;
  flex-direction: column;
  gap: clamp(2px, 0.3vw, 4px);
}

.card__front--note {
  justify-content: center;
  padding-top: 32px;
}

.card__back {
  transform: rotateY(180deg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: clamp(6px, 0.8vw, 10px);
  padding-left: calc(var(--margin-line-left) + var(--content-indent));
}

.card__back nav {
  display: flex;
  flex-direction: column;
  gap: clamp(6px, 0.8vw, 10px);
}

.card__name {
  font-size: clamp(1.2rem, 1.8vw, 1.6rem);
  font-weight: 600;
  color: var(--text-primary);
  line-height: var(--line-h);
}

.card__tagline {
  font-size: clamp(1.25rem, 1.4vw, 1.4rem);
  color: var(--text-secondary);
  line-height: var(--line-h);
}

.card__description {
  margin-top: 32px;
  font-size: clamp(0.95rem, 1.4vw, 1rem);
  color: var(--text-secondary);
  line-height: var(--line-h);
}

.card__link {
  font-size: clamp(1.25rem, 1.4vw, 1.4rem);
  color: var(--text-secondary);
  text-decoration: none;
  width: max-content;
  line-height: var(--line-h);
  transition: color 0.15s;
}

.card__link:hover {
  color: var(--text-primary);
}

.card__link:focus-visible,
.card__art-link:focus-visible {
  outline: 2px solid var(--text-secondary);
  outline-offset: 2px;
  border-radius: 2px;
}

.card__flip-hint {
  position: absolute;
  bottom: clamp(6px, 0.8vw, 10px);
  right: clamp(10px, 1.2vw, 16px);
  font-family: system-ui, sans-serif;
  font-size: clamp(0.5rem, 0.6vw, 0.6rem);
  color: var(--text-hint);
  letter-spacing: 0.03em;
}

.card__art-link {
  font-size: clamp(1.25rem, 1.4vw, 1.4rem);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
}

.card__art-link:hover {
  color: var(--text-primary);
}

.card--art .card__back {
  align-items: center;
}

.card--img .card__inner {
  width: clamp(120px, 12vw, 160px);
  aspect-ratio: 160 / 190;
}

.card__img-front {
  padding: clamp(8px, 1vw, 12px) clamp(8px, 1vw, 12px) clamp(24px, 2.5vw, 32px);
  background-image: none;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.card__img-front::before {
  display: none;
}

.card__img {
  width: 100%;
  flex: 1;
  object-fit: cover;
  border-radius: 3px;
  -webkit-user-drag: none;
  user-select: none;
  pointer-events: none;
}

.card__img-caption {
  font-size: clamp(0.7rem, 1.3vw, 1.1rem);
  color: var(--text-secondary);
  margin-top: clamp(4px, 0.5vw, 6px);
}

.card--img .card__back {
  align-items: center;
  justify-content: center;
  padding-left: clamp(8px, 1vw, 12px);
  padding-right: clamp(8px, 1vw, 12px);
}

.card--photo .card__inner {
  width: clamp(120px, 12vw, 160px);
  aspect-ratio: 160 / 190;
}

.card--photo .card__face {
  padding: clamp(8px, 1vw, 12px) clamp(8px, 1vw, 12px) clamp(20px, 2vw, 28px);
  background-image: none;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.card--photo .card__face::before {
  display: none;
}

.card__photo-img {
  width: 100%;
  flex: 1;
  object-fit: cover;
  border-radius: 3px;
  -webkit-user-drag: none;
  user-select: none;
  pointer-events: none;
}

.card__photo-caption {
  font-size: clamp(0.7rem, 1.3vw, 1.1rem);
  color: var(--text-secondary);
  margin-top: clamp(4px, 0.5vw, 6px);
}

.theme-toggle {
  position: fixed;
  bottom: 16px;
  right: 16px;
  z-index: 9999;
  background: var(--toggle-bg);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 6px 12px;
  cursor: pointer;
  font-family: system-ui, sans-serif;
  font-size: 0.65rem;
  color: var(--toggle-fg);
  letter-spacing: 0.03em;
  transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

.theme-toggle:hover {
  color: var(--text-primary);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--text-secondary);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 900px) {
  body {
    overflow: auto;
    height: auto;
    min-height: 100dvh;
  }

  main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px 10px;
    padding: clamp(24px, 5vw, 40px) clamp(12px, 3vw, 20px) 80px;
    max-width: 400px;
    margin: 0 auto;
  }

  .card {
    position: relative;
    cursor: default;
    justify-self: center;
  }

  .card--dragging {
    cursor: default;
  }

  /* intro card spans full width */
  .card:first-child {
    grid-column: 1 / -1;
    justify-self: center;
  }

  /* stagger rows with slight vertical offsets */
  .card:nth-child(even) {
    margin-top: 14px;
  }

  .card__inner {
    width: min(300px, calc(100vw - 48px));
    aspect-ratio: 420 / 280;
  }

  .card--art .card__inner {
    width: min(160px, 42vw);
    aspect-ratio: 280 / 200;
  }

  .card--photo .card__inner,
  .card--img .card__inner {
    width: min(150px, 42vw);
    aspect-ratio: 160 / 190;
  }
}

@media (max-width: 380px) {
  .card__inner,
  .card--art .card__inner {
    width: calc(100vw - 24px);
  }
}