.qs-site-header{position:fixed;top:0;left:0;right:0;height:var(--nav-height);z-index:40;background:radial-gradient(circle at top,#22c55e1f 0,transparent 55%),rgba(9,9,11,0.98);backdrop-filter:blur(16px);border-bottom:1px solid var(--color-border-subtle)}.qs-site-header-inner{height:var(--nav-height);display:flex;align-items:center;justify-content:space-between;gap:var(--space-6)}.qs-logo{display:flex;align-items:center;gap:var(--space-3);color:var(--color-text)}.qs-logo-mark{width:28px;height:28px;display:flex;align-items:center;justify-content:center;border-radius:0;border:1px solid var(--color-accent-primary);background:radial-gradient(circle at center,rgba(34,197,94,0.28) 0,transparent 60%);box-shadow:var(--shadow-glow-accent);font-family:var(--font-mono);font-size:0.7rem;letter-spacing:0.08em;text-transform:uppercase;color:var(--color-accent-primary)}.qs-logo-text{display:flex;flex-direction:column}.qs-logo-title{font-family:var(--font-sans);font-size:var(--font-size-sm);font-weight:600;letter-spacing:0.18em;text-transform:uppercase;line-height:1}.qs-logo-subtitle{font-family:var(--font-mono);font-size:var(--font-size-xs);color:var(--color-text-muted);letter-spacing:0.14em;text-transform:uppercase;margin-top:2px}.qs-primary-nav{display:flex;align-items:center}.qs-primary-nav-list{display:flex;align-items:center;gap:var(--space-6)}.qs-primary-nav-link{font-size:var(--font-size-xs);letter-spacing:0.16em;text-transform:uppercase;color:var(--color-text-muted);position:relative;padding-bottom:0.25rem;transition:color var(--transition-medium)}.qs-primary-nav-link::after{content:"";position:absolute;left:0;bottom:0;width:0;height:1px;background:linear-gradient(90deg,var(--color-accent-primary),var(--color-accent-warning));transition:width var(--transition-medium)}.qs-primary-nav-link:hover,.qs-primary-nav-link:focus-visible{color:var(--color-text)}.qs-primary-nav-link:hover::after,.qs-primary-nav-link:focus-visible::after{width:100%}.qs-primary-nav-cta{padding:0.5rem 1rem;border:1px solid #4ade80;background:linear-gradient(135deg,#22c55e,#16a34a);color:#020617!important;box-shadow:var(--shadow-glow-accent);display:inline-flex;align-items:center;gap:var(--space-2)}.qs-primary-nav-cta::after{display:none}.qs-primary-nav-cta:hover,.qs-primary-nav-cta:focus-visible{filter:brightness(1.08);transform:translateY(-1px)}.qs-nav-toggle{display:none;align-items:center;justify-content:center;width:40px;height:40px;border-radius:0;border:1px solid var(--color-border-strong);background-color:var(--color-surface-elevated);padding:0;gap:4px}.qs-nav-toggle-bar{width:18px;height:2px;background-color:var(--color-neutral-100);transition:transform var(--transition-fast),opacity var(--transition-fast),background-color var(--transition-fast);transform-origin:center}.qs-nav-toggle:focus-visible{outline:2px solid var(--color-accent-warning);outline-offset:3px}.qs-nav-toggle[aria-expanded="true"] .qs-nav-toggle-bar:first-child{transform:translateY(4px) rotate(45deg)}.qs-nav-toggle[aria-expanded="true"] .qs-nav-toggle-bar:last-child{transform:translateY(-4px) rotate(-45deg)}@media (max-width:960px){.qs-nav-toggle{display:flex}.qs-primary-nav{position:absolute;top:var(--nav-height);right:0;left:0;transform:translateY(-4px);background:radial-gradient(circle at top,#22c55e10 0,transparent 55%),var(--color-bg);border-bottom:1px solid var(--color-border-subtle);max-height:0;overflow:hidden;opacity:0;visibility:hidden;transition:max-height var(--transition-medium),opacity var(--transition-medium),visibility var(--transition-medium)}.qs-primary-nav-list{flex-direction:column;align-items:flex-start;padding:var(--space-4) var(--space-4) var(--space-5);gap:var(--space-4)}.qs-primary-nav-link,.qs-primary-nav-cta{font-size:var(--font-size-sm)}.qs-primary-nav-open{max-height:320px;opacity:1;visibility:visible}.qs-primary-nav-cta{width:100%;justify-content:center}}@media (max-width:480px){.qs-site-header-inner{gap:var(--space-3)}.qs-logo-subtitle{display:none}}

/* checklist: hamburger X */
.qs-nav-toggle {
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
}
.qs-nav-toggle .nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-neutral-100);
  transform-origin: center;
  transition: transform 0.2s ease, opacity 0.2s ease;
}
.qs-nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.qs-nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}
.qs-nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (max-width: 960px) {
  .qs-primary-nav-open {
    max-height: calc(100vh - var(--nav-height));
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .qs-primary-nav-item {
    width: 100%;
  }
  .qs-primary-nav-link {
    display: flex;
    align-items: center;
    min-height: 44px;
    width: 100%;
  }
}