.ech-top-button{
  position: fixed;
  right: 40px;
  bottom: 80px;
  z-index: 1400;

  display: inline-flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;

  min-width: 100px;
  padding: 5px 7px;

  border: 0;
  border-radius: 5px;

  background: rgb(240,240,240);
  color: rgb(0,84,134);

  cursor: pointer;
  user-select: none;

  box-shadow:
    0 6px 14px rgba(0,0,0,0.20);

  /* default hidden */
  opacity: 0;
  visibility: hidden;
  pointer-events: none;

  transform: translateY(8px);
  transition:
    opacity 0.25s ease,
    transform 0.25s ease,
    visibility 0.25s;
}

/* sichtbar ab Scroll */
.ech-top-button.is-visible{
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

/* Fokus sichtbar */
.ech-top-button:focus{
  outline: 2px solid rgb(0,84,134);
  outline-offset: 2px;
}

/* Pfeil (SVG-frei, rein CSS) */
.ech-top-icon{
  width: 0;
  height: 0;
  border-left: 12px solid transparent;
  border-right: 12px solid transparent;
  border-bottom: 14px solid rgb(0,84,134);
}

/* Text */
.ech-top-text{
  font-size: 10px;
  line-height: 1;
  font-weight: 600;
  color: rgb(0,84,134);
}

/* Hover */
.ech-top-button:hover{
  filter: brightness(0.97);
}

/* Dark Mode */
@media (prefers-color-scheme: dark){
  .ech-top-button{
    background: rgb(60,60,60);
    color: rgb(255,255,255);
    box-shadow:
      0 6px 14px rgba(0,0,0,0.45);
  }

  .ech-top-icon{
    border-bottom-color: rgb(255,255,255);
  }

  .ech-top-text{
    color: rgb(255,255,255);
  }

  .ech-top-button:focus{
    outline-color: rgb(255,255,255);
  }
}