/* ==========================================================================
   Glass cards — shared base for the calculator card and the feature cards:
   glass background, hover shine, conic glow border, 3D tilt surface.
   ========================================================================== */

.card {
  position: relative;
  border-radius: var(--radius-xl);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: blur(20px) saturate(140%);
  box-shadow: var(--shadow-soft);
  transform-style: preserve-3d;
  perspective: 1000px;
  overflow: hidden;
  transition: box-shadow 0.4s var(--ease-out), border-color 0.4s var(--ease-out);
}

.card:hover {
  border-color: rgba(255, 255, 255, 0.24);
  box-shadow: var(--shadow-strong);
}

.card__shine {
  position: absolute;
  inset: 0;
  background: radial-gradient(circle 220px at var(--mx, 50%) var(--my, 0%), rgba(255, 255, 255, 0.16), transparent 70%);
  opacity: 0;
  transition: opacity 0.4s var(--ease-out);
  pointer-events: none;
}

.card:hover .card__shine {
  opacity: 1;
}

.card__glow {
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: conic-gradient(from 180deg at var(--mx, 50%) var(--my, 50%), var(--violet), transparent 30%, var(--pink), transparent 60%, var(--cyan), transparent 90%);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.4s var(--ease-out);
  pointer-events: none;
}

.card:hover .card__glow {
  opacity: 0.65;
}