/* Navigation follows the brand homepage; product content keeps its own styles. */
.site-header {
  --paper: #fffdf8;
  --ink: #2f2924;
  --red: #7a302c;
  --line: rgba(47, 41, 36, 0.16);
  --header-height: 84px;
  --page-pad: clamp(24px, 5vw, 80px);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  text-rendering: optimizeLegibility;
}


.site-header {
  position: fixed;
  z-index: 150;
  top: 0;
  left: 0;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  width: 100%;
  height: var(--header-height);
  padding: 0 var(--page-pad);
  border-bottom: 1px solid transparent;
  transition: height 320ms var(--ease), background 320ms ease, border-color 320ms ease;
}

.site-header.is-scrolled {
  height: 68px;
  border-color: var(--line);
  background: rgba(246, 240, 231, 0.9);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
}

.brand {
  justify-self: start;
}

.brand img {
  width: 132px;
  height: 56px;
  object-fit: contain;
  object-position: left center;
}

.site-nav {
  display: flex;
  gap: 34px;
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0.06em;
}

.site-nav a,
.header-link {
  position: relative;
  padding: 12px 0;
}

.header-actions {
  display: flex;
  align-items: center;
  justify-self: end;
  gap: 18px;
}

.site-header:not(.is-scrolled) .header-link {
  color: var(--paper);
  text-shadow: 0 1px 12px rgba(47, 41, 36, 0.28);
}

.site-nav a::after,
.header-link::after {
  position: absolute;
  right: 0;
  bottom: 5px;
  left: 0;
  height: 1px;
  content: "";
  background: var(--red);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 260ms var(--ease);
}

.site-nav a:hover::after,
.site-nav a:focus-visible::after,
.header-link:hover::after,
.header-link:focus-visible::after {
  transform: scaleX(1);
  transform-origin: left;
}

.header-link {
  color: var(--red);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.internal-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 18px;
  border: 1px solid rgba(122, 48, 44, 0.5);
  border-radius: 999px;
  color: var(--red);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: color 220ms ease, background 220ms ease, border-color 220ms ease, transform 220ms var(--ease);
}

.site-header:not(.is-scrolled) .internal-link {
  border-color: rgba(255, 253, 248, 0.72);
  color: var(--paper);
  background: rgba(47, 41, 36, 0.16);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.internal-link:hover,
.internal-link:focus-visible {
  border-color: var(--red);
  color: var(--paper);
  background: var(--red);
  transform: translateY(-1px);
}

@media (max-width: 1080px) {
  .site-header { grid-template-columns: 1fr auto; }
  .site-nav { display: none; }
}

@media (max-width: 820px) {
  .site-header, .site-header.is-scrolled { height: var(--header-height); }
  .brand img { width: 108px; height: 48px; }
  .header-actions {
    position: absolute;
    right: var(--page-pad);
    gap: 8px;
  }
  .header-link {
    padding: 9px 13px;
    border: 1px solid rgba(122, 48, 44, 0.22);
    border-radius: 999px;
    font-size: 12px;
  }
  .site-header:not(.is-scrolled) .header-link {
    color: var(--red);
    border-color: rgba(122, 48, 44, 0.32);
    background: rgba(255, 253, 248, 0.78);
    backdrop-filter: blur(10px);
  }
  .internal-link {
    min-height: 38px;
    padding: 0 13px;
  }
}
.site-nav a[aria-current="page"] { color: var(--red); }
@media (max-width: 600px) {
  .header-actions .header-link { display: none; }
}
.site-nav a[aria-current="page"]::after { transform: scaleX(1); }
.hero-content { padding-top: 138px; }
.directory-toolbar { top: 68px; }
.reading-progress { z-index: 160; }
.skip-link { z-index: 200; }
@media (max-width: 820px) {
  .site-header { --header-height: 72px; }
  .hero-content { padding-top: 126px; }
  .directory-toolbar { top: 72px; }
}
@media (min-width: 1800px) {
  .hero-content { padding-top: 161px; }
}
@media (max-width: 760px) {
  .hero-content { padding-top: 111px; }
  .collection-hero { height: 647px; }
}
@media (max-width: 560px) {
  .site-header { --page-pad: 22px; }
}