.portfolio-home-link {
  position: fixed;
  right: max(20px, env(safe-area-inset-right));
  bottom: max(20px, env(safe-area-inset-bottom));
  z-index: 10000;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border: 1px solid rgba(255,255,255,.34);
  border-radius: 999px;
  background: rgba(18,26,38,.88);
  box-shadow: 0 8px 30px rgba(0,0,0,.2);
  backdrop-filter: blur(14px);
  color: #fff;
  font: 600 13px/1.2 "Noto Sans SC", "Microsoft YaHei", sans-serif;
  letter-spacing: .04em;
  text-decoration: none;
  transition: background .2s ease, transform .2s ease;
}
.portfolio-home-link:hover { background: #253b5b; transform: translateY(-2px); }
.portfolio-home-link:focus-visible { outline: 3px solid #ff893f; outline-offset: 4px; }
@media (max-width: 600px) {
  .portfolio-home-link { right: max(12px, env(safe-area-inset-right)); bottom: max(12px, env(safe-area-inset-bottom)); padding-inline: 14px; }
}
@media (prefers-reduced-motion: reduce) { .portfolio-home-link { transition: none; } }