/* Web approximation of a liquid glass navigation surface.
   Layered light and moving lens, not Apple's native refraction renderer. */
body.desktop-responsive .topbar {
  --nav-ink: #f4f7fb;
  --nav-muted: #d6e0e9;
  --nav-hover: rgb(255 255 255 / 8%);
  --nav-active: rgb(255 255 255 / 13%);
  --nav-accent: #d8e8ff;
  --nav-rim-top: rgb(255 255 255 / 66%);
  --nav-rim-side: rgb(208 231 255 / 12%);
  --nav-rim-bottom: rgb(199 223 249 / 34%);
  --nav-lens-fill: rgb(226 239 255 / 13%);
  --nav-lens-light: rgb(255 255 255 / 24%);
  --nav-lens-edge: rgb(255 255 255 / 45%);
  --glass-x: 50%;
  --glass-y: 0px;
  top: 16px;
  left: 24px;
  right: 24px;
  width: min(1120px, calc(100% - 48px));
  margin-inline: auto;
  min-height: 64px;
  padding: 8px 12px 8px 26px;
  grid-template-columns: minmax(180px, 1fr) auto;
  gap: 32px;
  color: var(--nav-ink);
  border: 0;
  border-radius: 999px;
  background: linear-gradient(180deg, rgb(255 255 255 / 9%), transparent 46%, rgb(188 219 250 / 3%)), rgb(17 29 43 / 68%);
  box-shadow: inset 0 2px 3px rgb(255 255 255 / 10%),
    inset 0 -2px 4px rgb(2 14 31 / 15%), 0 3px 6px rgb(1 9 20 / 8%), 0 12px 32px rgb(1 9 20 / 12%);
  -webkit-backdrop-filter: blur(16px) saturate(155%);
  backdrop-filter: blur(16px) saturate(155%);
  transition: background-color 320ms ease, color 320ms ease, box-shadow 320ms ease;
}

body.desktop-responsive .topbar.is-solid {
  --nav-ink: #1d2939;
  --nav-muted: #23374c;
  --nav-hover: rgb(40 61 85 / 5%);
  --nav-active: #e8eff9;
  --nav-accent: #244e85;
  --nav-rim-top: rgb(255 255 255 / 100%);
  --nav-rim-side: rgb(255 255 255 / 28%);
  --nav-rim-bottom: rgb(105 143 184 / 30%);
  --nav-lens-fill: rgb(226 237 251 / 65%);
  --nav-lens-light: rgb(255 255 255 / 89%);
  --nav-lens-edge: rgb(255 255 255 / 95%);
  background: linear-gradient(180deg, rgb(255 255 255 / 54%), rgb(255 255 255 / 8%) 48%, rgb(218 232 250 / 14%)), rgb(245 250 255 / 65%);
  box-shadow: inset 0 2px 3px rgb(255 255 255 / 75%),
    inset 0 -2px 4px rgb(103 146 196 / 9%), 0 3px 6px rgb(33 58 90 / 5%), 0 12px 32px rgb(33 58 90 / 9%);
}

/* The curved rim carries the glass thickness without distorting the text. */
body.desktop-responsive .topbar::before {
  content: "";
  position: absolute;
  z-index: 0;
  inset: 0;
  padding: 1.25px;
  border-radius: inherit;
  background: linear-gradient(165deg, var(--nav-rim-top), var(--nav-rim-side) 27%, var(--nav-rim-side) 65%, var(--nav-rim-bottom));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  pointer-events: none;
}
body.desktop-responsive .topbar::after {
  content: "";
  position: absolute;
  z-index: 0;
  inset: 1px;
  border-radius: inherit;
  background: radial-gradient(210px 85px at var(--glass-x) var(--glass-y), rgb(255 255 255 / 25%), transparent 76%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 420ms ease;
}
body.desktop-responsive .topbar.is-lit::after { opacity: 1; }
body.desktop-responsive .topbar > :is(.brand, .nav-links) {
  position: relative;
  z-index: 1;
}

body.desktop-responsive .topbar .brand {
  gap: 3px;
  border-radius: 6px;
  color: var(--nav-ink);
  text-decoration: none;
}
body.desktop-responsive .topbar .brand strong {
  font-size: 17px;
  font-weight: 650;
  letter-spacing: -.02em;
  line-height: 1.25;
}
body.desktop-responsive .topbar .brand span {
  color: var(--nav-muted);
  opacity: 1;
  font-size: 10px;
  letter-spacing: .03em;
  line-height: 1.3;
}

body.desktop-responsive .topbar .nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 0;
  font-size: 13px;
  isolation: isolate;
}
body.desktop-responsive .topbar .nav-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 21px;
  border-radius: 999px;
  color: var(--nav-muted);
  font-weight: 500;
  line-height: 1.2;
  white-space: nowrap;
  text-decoration: none;
  opacity: 1;
  z-index: 1;
  -webkit-tap-highlight-color: transparent;
  transition: background-color 220ms ease, color 220ms ease, transform 180ms ease !important;
}
body.desktop-responsive .topbar .nav-links a::after { content: none; }
body.desktop-responsive .topbar .nav-links a.active {
  background: var(--nav-active);
  color: var(--nav-accent);
}
body.desktop-responsive .topbar .nav-lens {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: var(--lens-width, 94px);
  border-radius: 999px;
  z-index: 0;
  pointer-events: none;
  opacity: 0;
  transform: translate3d(var(--lens-x, 0px), 0, 0);
  background: linear-gradient(165deg, var(--nav-lens-light), transparent 52%), var(--nav-lens-fill);
  box-shadow: inset 0 1px 1px var(--nav-lens-edge), inset 0 -1px 2px rgb(80 117 160 / 16%),
    0 2px 4px rgb(22 53 88 / 9%);
  transition: transform 480ms cubic-bezier(.22, 1, .36, 1), width 360ms cubic-bezier(.22, 1, .36, 1), opacity 180ms ease;
}
body.desktop-responsive .topbar .nav-lens.is-visible { opacity: 1; }
body.desktop-responsive .topbar .nav-lens.is-pressed {
  transform: translate3d(var(--lens-x, 0px), 0, 0) scale(.96, .93);
}
body.desktop-responsive .topbar .nav-links.has-lens a.active,
body.desktop-responsive .topbar .nav-links.has-lens a:hover,
body.desktop-responsive .topbar .nav-links.has-lens a.active:hover { background: transparent; }
@media (hover: hover) {
  body.desktop-responsive .topbar .nav-links a:hover {
    background: var(--nav-hover);
    color: var(--nav-ink);
  }
  body.desktop-responsive .topbar .nav-links a.active:hover { background: var(--nav-active); }
}
body.desktop-responsive .topbar .nav-links a:active { transform: scale(.96); }
body.desktop-responsive .topbar :is(a:focus-visible) {
  outline: 2px solid var(--nav-accent) !important;
  outline-offset: 3px;
}

body.desktop-responsive .viewport-section { scroll-margin-top: 104px; }

@media (max-width: 800px) {
  body.desktop-responsive .topbar {
    top: 12px;
    left: 16px;
    right: 16px;
    width: calc(100% - 32px);
    min-height: 60px;
    gap: 12px;
    padding-left: 22px;
  }
  body.desktop-responsive .topbar .nav-links a { padding-inline: 14px; }
}
@media (max-width: 540px) {
  body.desktop-responsive .topbar {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 12px;
    border-radius: 22px;
  }
  body.desktop-responsive .topbar .brand {
    flex-direction: row;
    align-items: baseline;
    gap: 8px;
    padding-left: 10px;
  }
  body.desktop-responsive .topbar .nav-links { justify-content: space-between; }
  body.desktop-responsive .topbar .nav-links a { padding-inline: 12px; }
  body.desktop-responsive .viewport-section { scroll-margin-top: 128px; }
}
@supports not (backdrop-filter: blur(1px)) {
  body.desktop-responsive .topbar { background: #1b2633; }
  body.desktop-responsive .topbar.is-solid { background: #f8faff; }
}
@media (prefers-reduced-transparency: reduce) {
  body.desktop-responsive .topbar { background: #1b2633; backdrop-filter: none; -webkit-backdrop-filter: none; }
  body.desktop-responsive .topbar.is-solid { background: #f8faff; }
  body.desktop-responsive .topbar::after { display: none; }
  body.desktop-responsive .topbar .nav-lens { background: #354b65; }
  body.desktop-responsive .topbar.is-solid .nav-lens { background: #e8eff9; }
}
@media (prefers-reduced-motion: reduce) {
  body.desktop-responsive .topbar,
  body.desktop-responsive .topbar::after,
  body.desktop-responsive .topbar .nav-lens,
  body.desktop-responsive .topbar .nav-links a { transition: none !important; }
  body.desktop-responsive .topbar .nav-links a:active { transform: none; }
  body.desktop-responsive .topbar .nav-lens.is-pressed { transform: translate3d(var(--lens-x, 0px), 0, 0); }
  body.desktop-responsive .topbar::after { display: none; }
}