.tech-back-top {
  position: fixed;
  right: 48px;
  bottom: 44px;
  z-index: 120;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  padding: 0;
  overflow: visible;
  border: 1px solid rgba(48, 213, 255, 0.35);
  border-radius: 50%;
  color: #dffaff;
  background: radial-gradient(circle at 50% 35%, rgba(34, 76, 101, 0.96), rgba(6, 12, 20, 0.98) 66%);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.34), inset 0 0 12px rgba(48, 213, 255, 0.08);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 160ms ease, transform 220ms ease, border-color 220ms ease, box-shadow 220ms ease;
}

.tech-back-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.tech-back-top__orbit {
  position: absolute;
  inset: 3px;
  border: 1px solid rgba(48, 213, 255, 0.18);
  border-radius: 50%;
  transition: inset 260ms ease, border-color 260ms ease, transform 600ms ease;
}

.tech-back-top__orbit::before,
.tech-back-top__orbit::after {
  position: absolute;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  content: "";
  background: #7af1ff;
  box-shadow: 0 0 7px #30d5ff;
}

.tech-back-top__orbit::before {
  top: 2px;
  left: 5px;
}

.tech-back-top__orbit::after {
  right: 4px;
  bottom: 3px;
}

.tech-back-top__rocket {
  position: relative;
  width: 10px;
  height: 19px;
  border: 1px solid rgba(223, 250, 255, 0.9);
  border-radius: 52% 52% 35% 35%;
  background: linear-gradient(90deg, #78dff1, #f1fdff 52%, #65b8df);
  box-shadow: 0 0 8px rgba(48, 213, 255, 0.34);
  transition: transform 260ms cubic-bezier(.2, .8, .2, 1), box-shadow 260ms ease;
}

.tech-back-top__rocket::before,
.tech-back-top__rocket::after {
  position: absolute;
  bottom: 1px;
  width: 5px;
  height: 8px;
  content: "";
  background: #2386b4;
}

.tech-back-top__rocket::before {
  left: -5px;
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
}

.tech-back-top__rocket::after {
  right: -5px;
  clip-path: polygon(0 0, 100% 100%, 0 100%);
}

.tech-back-top__window {
  position: absolute;
  top: 5px;
  left: 50%;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #07111d;
  box-shadow: 0 0 0 1px #62eaff, 0 0 5px #30d5ff;
  transform: translateX(-50%);
}

.tech-back-top__flame {
  position: absolute;
  top: 19px;
  left: 50%;
  width: 4px;
  height: 6px;
  border-radius: 0 0 60% 60%;
  background: linear-gradient(#fff, #30d5ff 45%, rgba(155, 140, 255, 0));
  filter: drop-shadow(0 2px 3px #30d5ff);
  opacity: 0.62;
  transform: translateX(-50%) scaleY(0.65);
  transform-origin: top;
  transition: opacity 220ms ease, transform 220ms ease;
}

.tech-back-top:hover,
.tech-back-top:focus-visible {
  border-color: rgba(122, 241, 255, 0.9);
  outline: none;
  box-shadow: 0 0 0 4px rgba(48, 213, 255, 0.08), 0 0 24px rgba(48, 213, 255, 0.38), inset 0 0 15px rgba(48, 213, 255, 0.14);
  transform: translateY(-2px);
}

.tech-back-top:hover .tech-back-top__orbit,
.tech-back-top:focus-visible .tech-back-top__orbit {
  inset: -5px;
  border-color: rgba(48, 213, 255, 0.52);
  border-style: dashed;
  transform: rotate(120deg);
}

.tech-back-top:hover .tech-back-top__rocket,
.tech-back-top:focus-visible .tech-back-top__rocket {
  box-shadow: 0 0 14px rgba(122, 241, 255, 0.8);
  transform: translateY(-3px);
}

.tech-back-top:hover .tech-back-top__flame,
.tech-back-top:focus-visible .tech-back-top__flame {
  opacity: 1;
  transform: translateX(-50%) scaleY(1.25);
  animation: tech-rocket-flame 260ms ease-in-out infinite alternate;
}

@keyframes tech-rocket-flame {
  from { transform: translateX(-50%) scaleY(0.9); }
  to { transform: translateX(-50%) scaleY(1.35); }
}

@media (max-width: 680px) {
  .tech-back-top {
    right: 24px;
    bottom: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .tech-back-top:hover .tech-back-top__flame,
  .tech-back-top:focus-visible .tech-back-top__flame {
    animation: none;
  }
}