/* --------------------------------------------------------
   Day 12 — 3D Card Deck / Celestial Arcana
   -------------------------------------------------------- */

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

:root {
  /* Typography */
  --font-display: 'Cinzel Decorative', serif;
  --font-body: 'Cormorant Garamond', serif;

  /* Palette */
  --bg: #0a0a0f;
  --bg-surface: #14141f;
  --text: #e8e4df;
  --text-muted: #6a6570;
  --accent: #c9a96e;
  --border: rgba(201, 169, 110, 0.15);

  /* Card dimensions */
  --card-w: 300px;
  --card-h: 420px;
  --card-radius: 16px;

  /* Easing */
  --ease-out-expo: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-shuffle: cubic-bezier(0.55, 0, 0.1, 1);
  --ease-flip: cubic-bezier(0.4, 0, 0.2, 1);
}

html,
body {
  height: 100%;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.app {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* -- Grain overlay + vignette -- */

body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 180px;
}

body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9998;
  pointer-events: none;
  background: radial-gradient(ellipse at center, transparent 40%, rgba(0, 0, 0, 0.55));
}

/* -- Corner label -- */

.corner-label {
  position: fixed;
  top: 1.5rem;
  right: 1.8rem;
  font-family: var(--font-display);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--accent);
  opacity: 0.5;
  z-index: 10;
  text-transform: uppercase;
}

/* -- Header -- */

.deck-header {
  text-align: center;
  margin-top: 6vh;
  margin-bottom: 2rem;
  z-index: 2;
}

.deck-header h1 {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
  text-shadow: 0 0 40px rgba(201, 169, 110, 0.25);
}

.deck-subtitle {
  font-family: var(--font-body);
  font-style: italic;
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
  letter-spacing: 0.04em;
}

/* -- 3D Stage -- */

.deck-stage {
  perspective: 1200px;
  perspective-origin: 50% 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 55vh;
  width: 100%;
  z-index: 2;
}

.deck {
  position: relative;
  width: var(--card-w);
  height: var(--card-h);
  transform-style: preserve-3d;
}

.deck::after {
  content: '';
  position: absolute;
  bottom: -30px;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 60px;
  background: radial-gradient(ellipse, rgba(201, 169, 110, 0.12) 0%, transparent 70%);
  pointer-events: none;
  filter: blur(10px);
}

/* -- Controls -- */

.controls {
  display: flex;
  gap: 1rem;
  z-index: 2;
}

.controls__btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 0.65rem 2rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.controls__btn:hover {
  background: rgba(201, 169, 110, 0.08);
  border-color: var(--accent);
  box-shadow: 0 0 24px rgba(201, 169, 110, 0.12);
}

.controls__btn--active {
  background: rgba(201, 169, 110, 0.14);
  border-color: var(--accent);
  box-shadow: 0 0 30px rgba(201, 169, 110, 0.18);
}

/* -- Cards -- */

.card {
  position: absolute;
  width: var(--card-w);
  height: var(--card-h);
  cursor: pointer;
  transform-origin: center center;
  will-change: transform;
}

.card__inner {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
}

.card__face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--card-radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2.2rem 1.6rem;
  text-align: center;
}

/* -- Front face -- */

.card__front {
  background: linear-gradient(135deg, var(--card-from), var(--card-to));
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow:
    0 4px 30px rgba(0, 0, 0, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.18);
}

.card__front::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.14) 0%,
    transparent 45%
  );
  pointer-events: none;
}

/* Ornamental border frame */
.card__ornament {
  position: absolute;
  inset: 10px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: calc(var(--card-radius) - 6px);
  pointer-events: none;
}

.card__ornament::before,
.card__ornament::after {
  content: '';
  position: absolute;
  width: 14px;
  height: 14px;
  border-color: rgba(255, 255, 255, 0.35);
  border-style: solid;
}

.card__ornament::before {
  top: -1px;
  left: -1px;
  border-width: 2px 0 0 2px;
  border-radius: 4px 0 0 0;
}

.card__ornament::after {
  bottom: -1px;
  right: -1px;
  border-width: 0 2px 2px 0;
  border-radius: 0 0 4px 0;
}

.card__number {
  font-family: var(--font-display);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  opacity: 0.65;
  color: #fff;
  margin-bottom: 0.8rem;
}

.card__icon {
  width: 52px;
  height: 52px;
  margin-bottom: 1.2rem;
}

.card__icon svg {
  width: 100%;
  height: 100%;
}

.card__title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: #fff;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  margin-bottom: 0.6rem;
}

.card__text {
  font-family: var(--font-body);
  font-style: italic;
  font-size: 0.92rem;
  line-height: 1.55;
  color: rgba(255, 255, 255, 0.82);
}

/* -- Back face -- */

.card__back {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  transform: rotateY(180deg);
  padding: 2.5rem 2rem;
  justify-content: flex-start;
  padding-top: 3.5rem;
}

.card__back-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 0.8rem;
}

.card__back-divider {
  width: 40px;
  height: 1px;
  background: var(--border);
  margin-bottom: 1.2rem;
}

.card__back-text {
  font-family: var(--font-body);
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--text);
  text-align: left;
  margin-bottom: 1.5rem;
}

.card__back-detail {
  font-family: var(--font-display);
  font-size: 0.6rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: auto;
}

/* -- Card flip -- */

.card__inner {
  transition: transform 0.6s var(--ease-flip);
}

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

/* -- Floating animation -- */

@keyframes float {
  0%, 100% { margin-top: 0; }
  50% { margin-top: -8px; }
}

.card--top {
  animation: float 3s ease-in-out infinite;
}

/* -- Fan focus state -- */

.card--fan-focus {
  filter: brightness(1.08) !important;
}

.card--fan-focus .card__front {
  box-shadow:
    0 8px 50px rgba(0, 0, 0, 0.6),
    0 0 30px rgba(201, 169, 110, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.card--fan-focus .card__ornament {
  border-color: rgba(255, 255, 255, 0.3);
}

/* -- Card hover in fan -- */

.card:hover .card__front {
  box-shadow:
    0 6px 40px rgba(0, 0, 0, 0.55),
    0 0 20px rgba(201, 169, 110, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

/* -- Card indicator -- */

.card-indicator {
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  opacity: 0.6;
  text-align: center;
  margin-top: 0.8rem;
  z-index: 2;
  transition: opacity 0.3s ease;
}

/* -- Keyboard hint -- */

.keyboard-hint {
  font-family: var(--font-body);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
  margin-top: 0.6rem;
  opacity: 0.35;
  letter-spacing: 0.03em;
  z-index: 2;
}

/* -- Responsive -- */

@media (max-width: 768px) {
  :root {
    --card-w: 240px;
    --card-h: 336px;
  }

  .deck-header { margin-top: 4vh; margin-bottom: 1.2rem; }
  .deck-stage { height: 50vh; perspective: 1000px; }
  .card__face { padding: 1.8rem 1.2rem; }
  .card__title { font-size: 1.15rem; }
  .card__text { font-size: 0.82rem; }
  .card__icon { width: 42px; height: 42px; }
  .controls { gap: 0.6rem; }
  .controls__btn { padding: 0.5rem 1.3rem; font-size: 0.68rem; }
  .card__back { padding: 2rem 1.5rem; padding-top: 2.8rem; }
  .card__back-text { font-size: 0.8rem; }
  .keyboard-hint { display: none; }
}

@media (max-width: 480px) {
  :root {
    --card-w: 210px;
    --card-h: 294px;
  }

  .deck-header h1 { font-size: 1.2rem; }
  .deck-subtitle { font-size: 0.9rem; }
  .deck-stage { perspective: 800px; height: 48vh; }
  .card__face { padding: 1.5rem 1rem; }
  .card__title { font-size: 1rem; }
  .card__text { font-size: 0.78rem; }
  .card__icon { width: 36px; height: 36px; margin-bottom: 0.8rem; }
  .card__number { font-size: 0.6rem; margin-bottom: 0.5rem; }
  .card__ornament { inset: 7px; }
  .controls { flex-wrap: wrap; justify-content: center; }
  .controls__btn { padding: 0.5rem 1rem; font-size: 0.65rem; min-height: 44px; }
}

@media (prefers-reduced-motion: reduce) {
  .card--top .card__inner,
  .card--top.card--flipped .card__inner {
    animation: none;
  }

  .card,
  .card__inner {
    transition-duration: 0.01ms !important;
  }
}