#apresentacao {
  background-color: #fffbd6;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  overflow: hidden;
  transition: 1.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform: scale(1);
}

#apresentacao.fade-out {
  transform: scale(8);
  transform-origin: 50% 35%;
  opacity: 0;
}


#envelope-container {
  position: relative;
  width: min(92vw, 720px);
  aspect-ratio: 1280 / 900;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
}

#envelope-front-wrapper {
  position: absolute;
  inset: 0;
  z-index: 20;
  pointer-events: none;
}

#envelope-front-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#envelope-flap {
  position: absolute;
  left: 0;
  right: 0;
  z-index: 30;
  top: 0;
  height: 55%;
  transform-origin: top center;
  transform-style: preserve-3d;
  perspective: 1200px;
  transform: none;
  transition: transform 1s ease-in-out;
}

#envelope-flap.open {
  transform: rotateX(-175deg);
}

#envelope-flap-inner-wrapper {
  position: relative;
  width: 100%;
  height: 100%;
}

#envelope-flap-outer-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
}

#envelope-flap-outer-svg {
  width: 100%;
  height: 100%;
}

#wax-seal {
  position: absolute;
  left: 50%;
  bottom: 0;

  width: min(20vw, 140px);

  filter: drop-shadow(0 8px 16px rgba(0, 0, 0, 0.45));
  animation: pulse-seal 2s infinite ease-in-out;
  cursor: pointer;
  transition: opacity 0.5s ease-out;
}

#envelope-flap.open #wax-seal {
  opacity: 0;
  pointer-events: none;
}

@keyframes pulse-seal {
  0%,
  100% {
    transform: translate(-50%, 50%) scale(1) rotate(-0.00539236deg);
  }
  50% {
    transform: translate(-50%, 50%) scale(1.2) rotate(-0.00539236deg);
  }
}

#envelope-flap-inner-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  transform: rotateX(180deg);
}

#envelope-flap-inner-svg {
  background-color: red;
  width: 100%;
  height: 100%;
}

#monogram-bottom {
  position: absolute;
  left: 50%;
  bottom: 8%;
  width: min(12vw, 90px);
  opacity: 0.85;
  z-index: 25;
  transform: translateX(-50%);
}


#open-instruction {
  transition: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}
#open-instruction.fade-out {
  opacity: 0;
}