/* BK Scroll To Top — fixed button, theme-variable aware with fallbacks */
.bkst-top{
  position:fixed;
  right:clamp(16px,3vw,28px);
  bottom:clamp(16px,3vw,28px);
  z-index:9999;
  width:46px;height:46px;
  display:inline-flex;align-items:center;justify-content:center;
  background:var(--color-primary,#0F172A);
  color:#fff;
  border:1px solid transparent;
  border-radius:50%;
  cursor:pointer;
  box-shadow:0 4px 14px rgba(0,0,0,.25);
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity .25s ease,transform .25s ease,background .2s ease;
  padding:0;
}
.bkst-top.is-show{opacity:1;visibility:visible;transform:none}
.bkst-top:hover{background:var(--color-primary-soft,#1E293B)}
.bkst-top:focus-visible{outline:2px solid var(--color-accent,#0EA5E9);outline-offset:2px}
.bkst-top[hidden]{display:none}
@media (prefers-reduced-motion:reduce){
  .bkst-top{transition:none}
}
@media print{.bkst-top{display:none}}