.header {
  background-color: var(--color-primary-dark);
  position: -webkit-sticky;
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* Logo */
.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-white);
  letter-spacing: -0.02em;
}

.header__logo img,
.header__logo svg {
  height: 32px;
  width: auto;
}

/* Navigation */
.header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
/* flex-gap fallback for older Safari */
.header__nav > * + * { margin-left: var(--space-1); }

.nav-item {
  position: relative;
}

.nav-item__link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-white);
  background: none;
  border: none;
  border-radius: var(--border-radius);
  transition: color var(--transition-fast), background-color var(--transition-fast);
  cursor: pointer;
  letter-spacing: 0.01em;
}

.nav-item__link:hover,
.nav-item--active .nav-item__link {
  color: var(--color-accent-orange);
  background-color: rgba(255, 255, 255, 0.12);
}

.nav-item__arrow {
  width: 12px;
  height: 12px;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-item__arrow,
.nav-item:focus-within .nav-item__arrow,
.nav-item--desktop-open .nav-item__arrow {
  transform: rotate(180deg);
}

/* Dropdown */
.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 230px;
  padding: var(--space-2);
  background-color: var(--color-primary-dark);
  border-radius: var(--border-radius);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--transition-fast), visibility var(--transition-fast), transform var(--transition-fast);
  z-index: var(--z-dropdown);
  margin-top: var(--space-2);
}

.nav-item:hover .nav-dropdown,
.nav-item:focus-within .nav-dropdown,
.nav-item--desktop-open .nav-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-dropdown__link {
  display: block;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: rgba(255, 255, 255, 0.9);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
}

.nav-dropdown__link:hover {
  background-color: rgba(255, 255, 255, 0.12);
  color: var(--color-accent-orange);
}

/* ── Mega-Menu (4-column dropdown for "Learn") ── */
.mega-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  display: grid;
  gap: var(--space-6);
  padding: var(--space-6) var(--space-8);
  background-color: var(--color-primary-dark);
  border-radius: var(--border-radius-lg, var(--border-radius));
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.12);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast), transform var(--transition-fast);
  z-index: var(--z-dropdown);
  margin-top: var(--space-2);
  min-width: 520px;
}

/* Dynamic column count based on data attribute */
.mega-menu[data-columns="1"] { grid-template-columns: 1fr; min-width: 220px; }
.mega-menu[data-columns="2"] { grid-template-columns: repeat(2, 1fr); min-width: 400px; }
.mega-menu[data-columns="3"] { grid-template-columns: repeat(3, 1fr); min-width: 560px; }
.mega-menu[data-columns="4"] { grid-template-columns: repeat(4, 1fr); min-width: 700px; }

.nav-item--mega:hover .mega-menu,
.nav-item--mega:focus-within .mega-menu,
.nav-item--mega.nav-item--desktop-open .mega-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.mega-menu__column {
  min-width: 0;
}

.mega-menu__heading {
  font-size: 0.7rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-accent-orange);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 var(--space-3) 0;
  padding: 0 var(--space-3);
}

.mega-menu__link {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: rgba(255, 255, 255, 0.9);
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
}

.mega-menu__link:hover {
  background-color: rgba(255, 255, 255, 0.12);
  color: var(--color-accent-orange);
}

/* Header CTA */
.header__cta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-left: var(--space-4);
}
/* flex-gap fallback for older Safari */
.header__cta > * + * { margin-left: var(--space-3); }

/* Secondary "Log In" text link — sits beside Get Started button */
.header__login-link {
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.8125rem;
  text-decoration: none;
  transition: color 0.15s ease;
  white-space: nowrap;
}
.header__login-link:hover {
  color: var(--color-white);
  text-decoration: underline;
}

/* Ghost button — transparent on dark header, clear white text */
.btn--ghost {
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: var(--color-white);
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  line-height: 1;
  white-space: nowrap;
}

.btn--ghost:hover {
  background-color: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.5);
  color: var(--color-accent-orange);
}

/* User avatar button */
.header__user-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--border-radius-full);
  border: 2px solid rgba(255, 255, 255, 0.3);
  background-color: var(--color-accent-orange);
  color: var(--color-white);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.header__user-btn:hover {
  border-color: var(--color-white);
  background-color: var(--color-accent-orange-hover);
  transform: translateY(-1px);
}

.header__user-initials {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  line-height: 1;
  text-transform: uppercase;
}

/* Mobile toggle */
.header__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  color: var(--color-white);
}

.header__toggle svg {
  width: 24px;
  height: 24px;
}

/* Mobile navigation */
@media (max-width: 1024px) {
  .header__toggle {
    display: block;
  }

  .header__nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background-color: var(--color-primary-dark);
    flex-direction: column;
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    gap: var(--space-1);
  }

  .header__nav--open {
    display: flex;
  }

  .nav-item {
    width: 100%;
  }

  .nav-item__link {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--font-size-base);
  }

  .nav-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    background-color: rgba(255, 255, 255, 0.05);
    margin-top: 0;
    padding-left: var(--space-4);
    display: none;
  }

  .nav-item--mobile-open .nav-dropdown {
    display: block;
  }

  /* Mega-menu mobile: stack columns as accordion sections */
  .mega-menu {
    position: static;
    display: none;
    grid-template-columns: 1fr;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    background-color: rgba(255, 255, 255, 0.05);
    margin-top: 0;
    padding: var(--space-3) var(--space-4);
    min-width: 0;
    gap: var(--space-4);
  }

  .mega-menu[data-columns="1"],
  .mega-menu[data-columns="2"],
  .mega-menu[data-columns="3"],
  .mega-menu[data-columns="4"] {
    grid-template-columns: 1fr;
    min-width: 0;
  }

  .nav-item--mobile-open .mega-menu {
    display: grid;
  }

  /* Override desktop hover/focus-within rules that leak transform: translateX(-50%) into mobile */
  .nav-item--mega:hover .mega-menu,
  .nav-item--mega:focus-within .mega-menu,
  .nav-item--mega.nav-item--desktop-open .mega-menu {
    position: static;
    transform: none;
    box-shadow: none;
    border: none;
  }

  .mega-menu__heading {
    padding: var(--space-2) 0;
    margin-bottom: var(--space-2);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

  .mega-menu__link {
    padding: var(--space-2) var(--space-2);
  }

  .nav-dropdown__link {
    color: rgba(255, 255, 255, 0.9);
  }

  .nav-dropdown__link:hover {
    background-color: rgba(255, 255, 255, 0.12);
    color: var(--color-accent-orange);
  }

  .header__cta {
    margin-left: 0;
    margin-top: var(--space-4);
    width: 100%;
    flex-direction: column;
  }

  .header__cta .btn {
    width: 100%;
  }

  .header__cta .header__user-btn {
    width: 36px;
    align-self: flex-start;
  }
  /* flex-gap fallback: switch to vertical margin on mobile */
  .header__nav > * + * { margin-left: 0; margin-top: var(--space-1); }
  .header__cta > * + * { margin-left: 0; margin-top: var(--space-3); }
}