.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 1.5rem;
  padding: 1.1rem clamp(1.25rem, 4vw, 3rem);
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: transform 0.55s var(--ease), border-color 0.4s, background-color 0.4s;
}
.site-header.is-scrolled { border-bottom-color: var(--line); }
.site-header.is-tucked { transform: translateY(-100%); }
.header-phone { color: var(--ink-dim); font-size: 0.72rem; letter-spacing: 0.04em; text-decoration: none; white-space: nowrap; }
.header-phone:hover { color: var(--ink); }
.header-store-link {
  display: inline-flex;
  align-items: center;
  padding: 0.55em 0.8em;
  color: var(--ink);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-decoration: none;
  text-transform: uppercase;
  white-space: nowrap;
  border: 1px solid var(--line);
  border-radius: 0.25rem;
}
.header-store-link:hover {
  color: var(--ink);
  background: var(--bg-raise);
  border-color: var(--ink-dim);
}
.logo {
  display: inline-flex; align-items: center; gap: 0.55rem;
  grid-column: 1;
  justify-self: start;
  color: var(--ink); text-decoration: none;
  font-family: var(--grotesk); font-weight: 600;
  letter-spacing: 0.34em; font-size: 0.95rem;
}
.logo-mark { display: block; width: 1.35rem; height: 1.35rem; object-fit: contain; }
.site-nav {
  grid-column: 2;
  display: flex;
  justify-self: center;
  gap: clamp(1rem, 3vw, 2.4rem);
}
.site-nav a {
  position: relative;
  color: var(--ink-dim); text-decoration: none;
  font-size: 0.78rem; letter-spacing: 0.16em; text-transform: uppercase;
  transition: color 0.3s;
}
.site-nav a::after {
  content: "";
  position: absolute; left: 0; bottom: -5px;
  width: 100%; height: 1px;
  background: var(--ink);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.45s var(--ease);
}
.site-nav a:hover { color: var(--ink); }
.site-nav a:hover::after { transform: scaleX(1); transform-origin: left; }

.header-actions {
  grid-column: 3;
  display: flex;
  align-items: center;
  justify-self: end;
  gap: 0.9rem;
}
.theme-toggle {
  display: inline-grid; place-items: center;
  width: 2.45rem; height: 2.45rem;
  padding: 0;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink-faint);
  cursor: pointer;
  flex: none;
  transition: color 0.35s var(--ease), background-color 0.35s var(--ease), border-color 0.35s var(--ease), transform 0.35s var(--ease);
}
.theme-toggle:hover { color: var(--ink); border-color: var(--ink-dim); transform: translateY(-2px); }
.theme-toggle[data-theme-mode="light"],
.theme-toggle[data-theme-mode="dark"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--bg);
}
.theme-glyph {
  position: relative;
  display: grid; place-items: center;
  width: 1.05rem; height: 1.05rem;
}
.theme-glyph svg {
  grid-area: 1 / 1;
  width: 1.05rem; height: 1.05rem;
  opacity: 0;
  transform: scale(0.65) rotate(-8deg);
  transition: opacity 0.35s var(--ease), transform 0.45s var(--ease);
}
.theme-toggle[data-theme-mode="system"] .icon-system,
.theme-toggle[data-theme-mode="light"] .icon-sun,
.theme-toggle[data-theme-mode="dark"] .icon-moon {
  opacity: 1;
  transform: scale(1) rotate(0);
}
.theme-toggle:active { transform: scale(0.94); }