.bar {
  position: fixed;
  z-index: 50;
  inset: 0 0 auto 0;
  border-bottom: 1px solid transparent;
  transition: background-color 0.25s, border-color 0.25s;
}

.solid {
  background: var(--topbar-bg);
  border-bottom-color: var(--line);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.inner {
  width: var(--shell);
  height: 68px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  text-decoration: none;
  font: 700 18px/1 var(--font-head);
  letter-spacing: -0.03em;
}

.nav {
  display: flex;
  gap: 28px;
  margin-right: 10px;
  font-size: 15px;
  font-weight: 500;
}

.nav a {
  padding: 6px 0;
  text-decoration: none;
  background: linear-gradient(currentColor, currentColor) left bottom / 0 1.5px no-repeat;
  transition: background-size 0.25s;
}

.nav a:hover {
  background-size: 100% 1.5px;
}

.nav a[aria-current='page'] {
  font-weight: 700;
  background-size: 100% 2px;
}

.seg {
  display: flex;
  padding: 3px;
  border-radius: var(--radius-control);
  box-shadow: inset 0 0 0 1px var(--line);
}

.seg button {
  padding: 6px 10px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--muted);
  font: 600 13px/1.2 var(--font-body);
  letter-spacing: 0.02em;
  cursor: pointer;
}

.seg button[aria-pressed='true'] {
  background: var(--ink);
  color: var(--paper);
}

.toggle {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 0;
  border-radius: var(--radius-control);
  background: transparent;
  color: var(--ink);
  box-shadow: inset 0 0 0 1px var(--line);
  cursor: pointer;
  transition: box-shadow 0.2s;
}

.toggle:hover {
  box-shadow: inset 0 0 0 1.5px var(--ink);
}

.toggle svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Second row: anchors for the sections of this page. */
.subwrap {
  width: var(--shell);
  margin: 0 auto;
}

.sub {
  display: flex;
  gap: 22px;
  height: 34px;
  align-items: flex-start;
  font-size: 14px;
  color: var(--muted);
}

.sub a {
  text-decoration: none;
  transition: color 0.2s;
}

.sub a:hover {
  color: var(--ink);
}

@media (max-width: 860px) {
  .nav,
  .subwrap {
    display: none;
  }
}