.envelope-gate {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: var(--color-bg);
  z-index: 10;
  cursor: pointer;
  transition: opacity 0.6s ease;
}

.envelope-gate.is-open {
  pointer-events: none;
  opacity: 0;
}

.envelope {
  position: relative;
  width: 16rem;
  height: 11rem;
  perspective: 60rem;
}

.envelope-body {
  position: absolute;
  inset: 0;
  background: var(--color-panel-alt);
  border: 1px solid var(--color-accent);
  border-radius: 0.25rem;
}

.envelope-card {
  position: absolute;
  left: 10%;
  right: 10%;
  bottom: 8%;
  height: 70%;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-accent);
  border-radius: 0.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: translateY(0) scale(0.9);
  transition: transform 0.7s ease 0.3s;
}

.envelope-flap {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5.5rem;
  background: var(--color-accent-3);
  clip-path: polygon(0 0, 100% 0, 50% 100%);
  transform-origin: top center;
  transition: transform 0.7s ease;
}

.envelope.is-open .envelope-flap {
  transform: rotateX(180deg);
}

.envelope.is-open .envelope-card {
  transform: translateY(-6rem) scale(1.1);
}

.envelope-hint {
  font-size: 0.85rem;
  color: var(--color-accent-2);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}