.site-header{position:sticky;top:0;z-index:50;background:var(--color-surface-bg);border-bottom:var(--border-default)}
.header-inner{display:flex;align-items:center;justify-content:space-between;min-height:72px}
.brand{display:flex;align-items:center;gap:0.6rem}
.brand-mark{height:44px;width:auto}
.brand-text{font-family:var(--font-heading);font-weight:700;font-size:1rem}
.nav{display:flex}
.nav-list{display:flex;align-items:center;gap:1.5rem;list-style:none}
.nav a{font-size:var(--text-sm);letter-spacing:0.05em;text-transform:uppercase}
.nav a:hover{color:var(--color-text-primary)}
.nav-toggle{display:none;flex-direction:column;justify-content:center;gap:4px;padding:0.5rem}
.nav-toggle-line{width:24px;height:2px;background:var(--color-text-primary)}
.nav-open .nav{position:fixed;inset:0;background:var(--color-surface-bg);padding:5rem 1rem;overflow:auto}
.nav-open .nav-list{flex-direction:column;align-items:flex-start;gap:1rem}
@media (max-width:900px){
  .nav{display:none}
  .nav-toggle{display:flex; z-index: 1000;}
  .nav-open .nav{display:block}
  .brand-mark{height:34px}
  .brand-text{font-size:0.9rem}
}