/* header.css -- Fixed header */

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-h);
  z-index: 100;
  background: var(--c-bg);
  border-bottom: 1px solid var(--c-border);
  transition: border-color var(--dur) var(--ease);
}

.header--scrolled {
  border-bottom-color: var(--c-accent);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--s-24);
}

.header__brand {
  display: flex;
  align-items: center;
  gap: var(--s-12);
  text-decoration: none;
}

.header__wordmark {
  font-family: var(--f-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--c-text);
  text-decoration: none;
}

.header__age-badge {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--s-4);
}

.header__nav-main {
  display: flex;
  align-items: center;
  gap: var(--s-4);
}

.header__nav-utility {
  display: flex;
  align-items: center;
  gap: var(--s-4);
  margin-left: var(--s-16);
  padding-left: var(--s-16);
  border-left: 1px solid var(--c-border);
}

.header__link {
  font-family: var(--f-body);
  font-weight: 500;
  font-size: 0.8125rem;
  color: var(--c-text-dim);
  text-decoration: none;
  padding: var(--s-8) var(--s-12);
  border-radius: var(--r-sm);
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.header__link:hover,
.header__link--active {
  color: var(--c-text);
}

.header__link--active {
  color: var(--c-accent);
}

/* Hamburger */
.header__hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.header__hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--c-text);
  border-radius: 1px;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.header__hamburger--open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.header__hamburger--open span:nth-child(2) {
  opacity: 0;
}

.header__hamburger--open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile menu */
.header__mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0;
  width: 100%;
  height: calc(100vh - var(--header-h));
  background: var(--c-bg);
  border-top: 1px solid var(--c-border);
  padding: var(--s-24);
  overflow-y: auto;
  z-index: 99;
}

.header__mobile-menu--open {
  display: block;
}

.header__mobile-link {
  display: block;
  font-family: var(--f-body);
  font-weight: 500;
  font-size: 1rem;
  color: var(--c-text-dim);
  text-decoration: none;
  padding: var(--s-12) 0;
  border-bottom: 1px solid var(--c-border);
  transition: color var(--dur) var(--ease);
}

.header__mobile-link:hover {
  color: var(--c-accent);
}

/* Spacer for fixed header */
.header-spacer {
  height: var(--header-h);
}