:root{
  --bg:#fff0f6;
  --pink-1:#ffd9e8;
  --pink-2:#ffb3d1;
  --accent:#ff80ab;
  --text:#333;
}

*{box-sizing:border-box}
body{
  margin:0;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  background: linear-gradient(180deg, #fff0f6 0%, #fff6fa 100%);
  color:var(--text);
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:20px;
}

.container{
  width:100%;
  max-width:980px;
  text-align:center;
}

h1{ color:var(--accent); margin:6px 0 2px }
p{ margin:6px 0 14px; opacity:0.9 }

.controls{
  display:flex;
  gap:12px;
  align-items:center;
  justify-content:center;
  flex-wrap:wrap;
  margin-bottom:12px;
}

.difs{ display:flex; gap:8px }
.dif-btn{
  background:transparent;
  border:2px solid var(--pink-2);
  padding:8px 12px;
  border-radius:10px;
  cursor:pointer;
  color:var(--accent);
  font-weight:600;
  transition:all .15s;
}
.dif-btn.active, .dif-btn:hover{
  background:var(--pink-1);
  transform:translateY(-3px);
}

.start{ 
  background:var(--accent);
  color:white;
  border:none;
  padding:10px 16px;
  border-radius:12px;
  cursor:pointer;
  font-weight:700;
  box-shadow:0 6px 14px rgba(255,128,171,0.18);
}

.info{
  display:flex;
  gap:20px;
  justify-content:center;
  margin:16px 0 22px;
  font-size:18px;
  font-weight:600;
}

/* Tablero - grid responsive */
.tablero{
  display:grid;
  justify-content:center;
  gap:14px;
  padding:12px;
}

/* Card flip layout */
.carta{
  width:110px;
  height:110px;
  perspective:900px;
}
.carta-inner{
  width:100%;
  height:100%;
  position:relative;
  transform-style:preserve-3d;
  transition: transform .5s;
  cursor:pointer;
  border-radius:12px;
}
.carta.volteada .carta-inner{ transform:rotateY(180deg) }

.carta-face{
  position:absolute;
  inset:0;
  display:flex;
  align-items:center;
  justify-content:center;
  backface-visibility:hidden;
  border-radius:12px;
  font-size:20px;
  font-weight:700;
  box-shadow:0 6px 12px rgba(0,0,0,0.12);
}

/* back (visible antes de voltear) */
.carta-back{
  background: linear-gradient(180deg,var(--pink-1),var(--pink-2));
  color:#7a1537;
}

/* front (visible al voltearse) */
.carta-front{
  background: #fff;
  transform:rotateY(180deg);
  color:var(--accent);
  padding:6px;
  text-align:center;
}

/* popup */
.popup{
  position:fixed;
  inset:0;
  display:flex;
  justify-content:center;
  align-items:center;
  background:rgba(0,0,0,0.4);
  z-index:40;
}
.popup-contenido{
  background:#fff;
  padding:22px;
  border-radius:14px;
  width:90%;
  max-width:360px;
  text-align:center;
}
.popup-actions{ margin-top:12px }
.popup button{ padding:8px 12px; border-radius:10px; border:none; background:var(--accent); color:white; cursor:pointer; font-weight:700; }

/* oculto */
.oculto{ display:none; }

.tablero{
  display: grid;
  justify-content: center;
  gap: 14px;
  padding: 12px;
  /* La nueva línea mágica: */
  grid-template-columns: repeat(var(--cols, 4), 1fr);
}

.carta{
  /* Ancho y alto automáticos para que se ajusten al grid */
  width: 100%;
  aspect-ratio: 1 / 1; /* Mantiene la carta cuadrada */
  perspective: 900px;
}