* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: #07080b; }
body { min-height: 100dvh; overflow: hidden; }
.page { position: relative; width: 100vw; height: 100dvh; background: #07080b; }
.background {
  position: absolute;
  inset: 0;
  background-image: url('assets/background.png');
  background-repeat: no-repeat;
  background-position: center center;
  background-size: cover;
  animation: reveal 900ms ease-out both;
}
.background::after {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  box-shadow: inset 0 0 130px rgba(0,0,0,.30);
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}
@keyframes reveal {
  from { opacity: 0; transform: scale(1.015); }
  to { opacity: 1; transform: scale(1); }
}
@media (max-aspect-ratio: 4/5) {
  body { overflow-y: auto; }
  .page { min-height: 100dvh; height: auto; display: grid; place-items: center; }
  .background {
    position: relative;
    width: 100vw;
    height: 100dvh;
    min-height: 640px;
    background-size: contain;
    background-color: #07080b;
  }
}
@media (prefers-reduced-motion: reduce) {
  .background { animation: none; }
}

.back-portal {
  position: absolute;
  z-index: 10;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 24px;
  border: 1px solid rgba(220,177,94,.75);
  border-radius: 999px;
  background: rgba(7,8,11,.72);
  color: #e2bd73;
  font: 600 13px/1 Arial, sans-serif;
  letter-spacing: .12em;
  text-decoration: none;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background .2s ease, color .2s ease, transform .2s ease, box-shadow .2s ease;
}
.back-portal:hover {
  background: #d8ad5b;
  color: #090a0d;
  transform: translateX(-50%) translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,0,0,.35);
}
@media (max-width: 600px) {
  .back-portal { bottom: 22px; min-height: 42px; padding: 0 18px; font-size: 11px; }
}