/* ============================================================
   HEADER
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0 1.5rem;
  background: var(--paper);
  opacity: 0.92;
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-shrink: 0;
  color: var(--ink);
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  color: var(--blue);
  font-size: 1.15rem;
  font-family: var(--font-display);
  line-height: 1;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 36px;
  height: 36px;
  align-items: center;
  justify-content: center;
  color: var(--ink);
  flex-shrink: 0;
}

.header-search {
  flex: 1;
  max-width: 560px;
  margin: 0 auto;
  position: relative;
}

.header-search input {
  width: 100%;
  font-family: var(--font-serif);
  font-size: var(--step--1);
  padding: 0.55rem 0.9rem 0.55rem 2.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--paper-raised);
  color: var(--ink);
}

.header-search input::placeholder {
  color: var(--ink-faint);
  font-style: italic;
}

.header-search input:focus {
  outline: none;
  border-color: var(--blue-soft);
  background: #fff;
}

.header-search svg {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  width: 15px;
  height: 15px;
  color: var(--ink-faint);
  pointer-events: none;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  flex-shrink: 0;
  font-size: var(--step--1);
  color: var(--ink-muted);
}

.header-right a,
.icon-btn {
  color: var(--ink-muted);
  background: none;
  border: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.header-right a:hover,
.icon-btn:hover {
  color: var(--blue);
  text-decoration: none;
}

.icon-btn svg {
  width: 17px;
  height: 17px;
}

/* Search results dropdown */
.search-results {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  right: 0;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 24px rgba(32, 38, 45, 0.08);
  max-height: 60vh;
  overflow-y: auto;
  z-index: 60;
}

.search-results.hidden {
  display: none;
}

.search-results-group-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  padding: 0.6rem 0.9rem 0.2rem;
}

.search-result {
  display: block;
  padding: 0.5rem 0.9rem;
  border-top: 1px solid var(--border);
  color: var(--ink);
  font-size: var(--step--1);
}

.search-result:first-of-type {
  border-top: none;
}

.search-result:hover {
  background: var(--paper);
  text-decoration: none;
}

.search-result .part-label {
  display: block;
  color: var(--ink-faint);
  font-size: 0.72rem;
  margin-top: 0.1rem;
}

.search-empty {
  padding: 0.9rem;
  color: var(--ink-muted);
  font-size: var(--step--1);
  font-style: italic;
}

@media (max-width: 900px) {
  .menu-toggle { display: flex; }
  .header-right .header-about-label { display: none; }
}

@media (max-width: 600px) {
  .site-header { gap: 0.8rem; padding: 0 1rem; }
  .brand-name { display: none; }
}