.nj-back-top {
  --nj-back-top-tamano: 54px;
  --nj-back-top-separacion: 24px;
  --nj-back-top-color-fondo: #e5e5e5;
  --nj-back-top-color-icono: #1c1c1c;
  --nj-back-top-color-pista: #cfcfcf;
  --nj-back-top-color-progreso: #1c1c1c;
  --nj-back-top-grosor: 3px;
  --nj-back-top-icono: 42%;
  position: fixed;
  right: var(--nj-back-top-separacion);
  bottom: var(--nj-back-top-separacion);
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px) scale(0.92);
  transition: opacity 0.35s cubic-bezier(0.22, 1, 0.36, 1), transform 0.35s cubic-bezier(0.22, 1, 0.36, 1), visibility 0.35s;
}
.nj-back-top--izquierda {
  right: auto;
  left: var(--nj-back-top-separacion);
}
.nj-back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.nj-back-top__link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--nj-back-top-tamano);
  height: var(--nj-back-top-tamano);
  border-radius: 50%;
  background: var(--nj-back-top-color-fondo);
  color: var(--nj-back-top-color-icono);
  text-decoration: none;
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}
.nj-back-top__link:hover,
.nj-back-top__link:focus-visible {
  color: var(--nj-back-top-color-icono);
  transform: scale(1.05);
}
.nj-back-top__link:focus-visible {
  outline: 2px solid var(--nj-back-top-color-progreso);
  outline-offset: 3px;
}
.nj-back-top__ring {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  fill: none;
  transform: rotate(-90deg) scale(1.1);
  pointer-events: none;
}
.nj-back-top__track,
.nj-back-top__progress {
  stroke-width: var(--nj-back-top-grosor);
}
.nj-back-top__track {
  stroke: var(--nj-back-top-color-pista);
}
.nj-back-top__progress {
  stroke: var(--nj-back-top-color-progreso);
  stroke-linecap: round;
  transition: stroke-dashoffset 0.15s linear;
}
.nj-back-top__icon {
  position: relative;
  display: block;
  width: var(--nj-back-top-icono);
  height: var(--nj-back-top-icono);
}
.nj-back-top__icon svg {
  display: block;
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}
@media (prefers-reduced-motion: reduce) {
  .nj-back-top,
  .nj-back-top__link,
  .nj-back-top__progress {
    transition: none;
  }
}