:root {
  --switch-bg: rgba(255, 255, 255, 0.86);
  --switch-ink: #101010;
  --switch-active: #101010;
  --switch-active-ink: #fff;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body { margin: 0; }

a { color: inherit; }

button, a { -webkit-tap-highlight-color: transparent; }

::selection { background: var(--selection, #b9ffdf); color: #101010; }

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.75rem 1rem;
  background: #fff;
  color: #111;
  transform: translateY(-150%);
  transition: transform 180ms ease;
}

.skip-link:focus { transform: translateY(0); }

.concept-switcher {
  position: fixed;
  z-index: 900;
  right: 1rem;
  bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.38rem;
  border: 1px solid rgba(20, 20, 20, 0.14);
  border-radius: 999px;
  background: var(--switch-bg);
  color: var(--switch-ink);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.14);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.concept-switcher > span {
  padding: 0 0.55rem 0 0.65rem;
  opacity: 0.58;
}

.concept-switcher a {
  display: grid;
  min-width: 2.1rem;
  min-height: 2.1rem;
  place-items: center;
  border-radius: 999px;
  text-decoration: none;
}

.concept-switcher a:hover,
.concept-switcher a:focus-visible,
.concept-switcher a[aria-current="page"] {
  outline: none;
  background: var(--switch-active);
  color: var(--switch-active-ink);
}

.scroll-progress {
  position: fixed;
  z-index: 950;
  top: 0;
  left: 0;
  width: calc(var(--scroll-progress, 0) * 100%);
  height: 3px;
  background: var(--progress-color, currentColor);
  pointer-events: none;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(2rem);
  transition: opacity 650ms ease, transform 800ms cubic-bezier(.2,.75,.2,1);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 680px) {
  .concept-switcher {
    right: 50%;
    bottom: 0.65rem;
    transform: translateX(50%);
  }

  .concept-switcher > span { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
}