/* Scroll-top button styles reused from main.css */
:root {
  --border: rgba(15, 23, 42, 0.08);
  --fg: #0F172A;
  --shadow-md: 0 4px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.12);
  --transition: 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}

.scroll-top {
  position: fixed;
  right: 1.5rem;
  bottom: calc(1.5rem + env(safe-area-inset-bottom));
  width: 64px;
  height: 64px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.95);
  color: var(--fg);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  box-shadow: var(--shadow-md);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition), box-shadow var(--transition);
  z-index: 110;
}

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

.scroll-top:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.scroll-top:active {
  transform: translateY(0);
}