.kh-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: radial-gradient(circle at top left, #fff7cc 0, #ffffff 40%, #fdf4ff 100%);
  border-bottom: 1px solid var(--color-border-subtle);
  box-shadow: var(--shadow-xs);
}

.kh-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
  gap: var(--space-3);
}

.kh-header__brand {
  display: flex;
  align-items: center;
  min-width: 0;
}

.kh-header__logo-link {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
}

.kh-header__logo-mark {
  position: relative;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 1.1rem;
  background: linear-gradient(135deg, #fff7cc, #ffe7f3, #e6f9ff);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.kh-header__logo-dot {
  position: absolute;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 999px;
  opacity: 0.9;
}

.kh-header__logo-dot--yellow {
  background: var(--color-primary);
  top: 0.4rem;
  left: 0.5rem;
}

.kh-header__logo-dot--blue {
  background: var(--color-accent-blue);
  bottom: 0.45rem;
  right: 0.55rem;
}

.kh-header__logo-dot--pink {
  background: var(--color-accent-pink);
  top: 0.8rem;
  right: 0.9rem;
}

.kh-header__brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.kh-header__site-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: 0.02em;
  color: var(--color-text);
}

.kh-header__tagline {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.kh-header__nav {
  flex: 1 1 auto;
}

.kh-header__nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
}

.kh-header__nav-item--highlight .kh-header__nav-link {
  padding-inline: 0.95rem;
  padding-block: 0.5rem;
  border-radius: var(--radius-pill);
  background: rgba(255, 184, 28, 0.12);
}

.kh-header__nav-link {
  position: relative;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-700);
  padding-block: 0.35rem;
}

.kh-header__nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -0.25rem;
  height: 0.16rem;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-accent-pink), var(--color-accent-blue));
  transform-origin: left;
  transform: scaleX(0);
  transition: transform var(--transition-normal);
}

.kh-header__nav-link:hover::after,
.kh-header__nav-link:focus-visible::after {
  transform: scaleX(1);
}

.kh-header__nav-link--cta {
  font-weight: 600;
  color: var(--color-text);
}

.kh-header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.kh-header__icon-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 999px;
  background: #ffffff;
  border: 1px solid var(--color-border-subtle);
  color: var(--color-gray-700);
  box-shadow: var(--shadow-xs);
  font-size: 1rem;
  transition: background-color var(--transition-normal), box-shadow var(--transition-normal), transform var(--transition-fast), color var(--transition-normal);
}

.kh-header__icon-link:hover {
  background: var(--color-primary-soft);
  color: var(--color-primary-contrast);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.kh-header__icon-link:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 3px;
}

.kh-header__toggle {
  display: none;
  position: relative;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 999px;
  background: #ffffff;
  border: 1px solid var(--color-border-subtle);
  box-shadow: var(--shadow-xs);
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  cursor: pointer;
}

.kh-header__toggle-bar {
  display: block;
  width: 1.25rem;
  height: 2px;
  border-radius: 999px;
  background: var(--color-gray-800);
  transition: transform var(--transition-normal), opacity var(--transition-normal), translate var(--transition-normal);
}

.kh-header__toggle-bar + .kh-header__toggle-bar {
  margin-top: 0.22rem;
}

.kh-header__toggle:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 3px;
}

.kh-header__toggle--open .kh-header__toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.kh-header__toggle--open .kh-header__toggle-bar:nth-child(2) {
  opacity: 0;
}

.kh-header__toggle--open .kh-header__toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

@media (max-width: 767.98px) {
  .kh-header__inner {
    padding-block: var(--space-2);
  }

  .kh-header__tagline {
    display: none;
  }

  .kh-header__toggle {
    display: inline-flex;
    flex-direction: column;
  }

  .kh-header__nav {
    position: fixed;
    inset-inline: 0;
    top: 3.75rem;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border-subtle);
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
  }

  .kh-header__nav-list {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-4);
    gap: 0.5rem;
  }

  .kh-header__nav-link {
    width: 100%;
    padding-block: 0.6rem;
    font-size: var(--font-size-base);
  }

  .kh-header__nav-link::after {
    bottom: 0;
  }

  .kh-header__nav--open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .kh-header__actions {
    gap: 0.4rem;
  }
}

@media (min-width: 768px) {
  .kh-header__nav {
    margin-inline: var(--space-4);
  }
}

@media (min-width: 1024px) {
  .kh-header__inner {
    padding-block: var(--space-3);
  }

  .kh-header__site-name {
    font-size: 1.35rem;
  }

  .kh-header__nav-list {
    gap: 1.75rem;
  }
}

.kh-header--no-scroll {
  overflow: hidden;
}

.kh-header__nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.2);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
  z-index: 35;
}

.kh-header__nav-overlay--visible {
  opacity: 1;
  pointer-events: auto;
}