.logo-bg {
  /* переменные */
  --center-offset: -50%;
  --logo-scale: 0.8; /*уменьшить: 0.6, 0.4, 0.2 | увеличить: 1.1, 1.5, 2.0*/

  position: fixed;
  top: 50%;
  left: calc(50% + var(--sidebar-width) / 2);

  width: max-content;
  height: max-content;

  transform: translate(var(--center-offset), var(--center-offset))
    scale(var(--logo-scale));
  z-index: 0;
  pointer-events: none;

  opacity: 1;
  animation: logo-spin 12s linear infinite;
  overflow: hidden;
  border-radius: 50%;

  /* Позволяет браузеру правильно обрабатывать вложенные 3D-трансформации */
  transform-style: preserve-3d;
}

.logo-bg img {
  display: block;
  filter: contrast(1.6) brightness(1.1) saturate(1.2)
    drop-shadow(0 0 35px rgba(255, 255, 255, 0.15));

  animation: spin 10s linear infinite;
  transform-origin: center;
}

@keyframes logo-spin {
  from {
    transform: translate(var(--center-offset), var(--center-offset))
      scale(var(--logo-scale)) rotateY(0deg);
  }
  to {
    transform: translate(var(--center-offset), var(--center-offset))
      scale(var(--logo-scale)) rotateY(360deg);
  }
}

/* лёгкий световой слой */
.logo-bg::after {
  content: "";
  position: absolute;
  inset: 0;

  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.12) 0%,
    rgba(255, 255, 255, 0.05) 40%,
    rgba(0, 0, 0, 0) 70%
  );

  mix-blend-mode: screen;
}

/* Неоновый контур */
.logo-bg::before {
  content: "";
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  background: conic-gradient(
    #50dd73 0deg,
    #00c9ff 90deg,
    transparent 120deg,
    transparent 180deg,
    #50dd73 200deg,
    #00c9ff 270deg,
    transparent 300deg,
    transparent 360deg
  );
  animation: neon-orbit 2s linear infinite;
  filter: blur(3px);
  z-index: -1;
}

@keyframes neon-orbit {
  to {
    transform: rotate(360deg);
  }
}