/* SHELL */
.memory-shell {
  position: relative;
  z-index: 1;
  /* max-width: 900px; */
  max-width: 600px;
  width: 100%;
  padding: 24px;
  margin: auto;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-orb {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: conic-gradient(from 180deg, var(--accent), var(--accent-secondary), var(--accent));
  box-shadow: var(--shadow-neon);
}

.logo-text {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--accent), #00ccff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.stats {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.btn-restart {
  margin-left: 12px;
  padding: 6px 14px;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  background: linear-gradient(135deg, var(--accent), var(--accent-secondary));
  color: #050712;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  box-shadow: var(--shadow-neon);
}

/* PANEL */
.memory-panel {
  background: var(--panel);
  border-radius: var(--radius-lg);
  padding: 18px;
  border: 1px solid rgba(0,246,255,0.25);
  box-shadow: 0 0 20px rgba(0,246,255,0.15);
}

/* GRID */
.grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(60px, 1fr));
  gap: 12px;
}

@media (max-width: 520px) {
  .grid {
    grid-template-columns: repeat(4, minmax(50px, 1fr));
  }
}

/* CARD */
.card {
  position: relative;
  width: 100%;
  padding-top: 100%; /* square */
  perspective: 800px;
  cursor: pointer;
}

.card-inner {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  transform-style: preserve-3d;
  transition: transform 0.4s ease;
}

.card.flipped .card-inner,
.card.matched .card-inner {
  transform: rotateY(180deg);
}

/* FRONT (face down) */
.card-front,
.card-back {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  backface-visibility: hidden;
}

/* BACKGROUND FRONT */
.card-front {
  background: linear-gradient(145deg, #050712, #0b1020);
  border: 1px solid rgba(0,246,255,0.35);
  box-shadow: 0 0 14px rgba(0,246,255,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-front::before {
  content: "";
  width: 60%;
  height: 60%;
  border-radius: 50%;
  background:
    radial-gradient(circle at 30% 20%, rgba(255,255,255,0.4), transparent 60%),
    conic-gradient(from 180deg, var(--accent), var(--accent-secondary), var(--accent));
  opacity: 0.9;
}

/* BACK (face up) */
.card-back {
  transform: rotateY(180deg);
  background: radial-gradient(circle at top, rgba(0,246,255,0.18), #050712);
  border: 1px solid rgba(0,246,255,0.4);
  box-shadow: 0 0 18px rgba(0,246,255,0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Different colors per symbol (optional subtle) */
.card-back[data-symbol="Q"] { color: var(--accent); }
.card-back[data-symbol="X"] { color: var(--accent-secondary); }
.card-back[data-symbol="★"] { color: #ffd966; }
.card-back[data-symbol="∞"] { color: #9b8cff; }
.card-back[data-symbol="?"] { color: #ff9fbf; }
.card-back[data-symbol="✓"] { color: #7dffb3; }
.card-back[data-symbol="⚡"] { color: #ffe066; }
.card-back[data-symbol="◎"] { color: #8be9ff; }

/* DISABLED STATE */
.card.matched {
  cursor: default;
  opacity: 0.9;
}