.site-header{
  position:sticky;
  top:0;
  z-index:1000;
  background:var(--color-surface-primary);
  border-bottom:1px solid var(--color-border-default);
}
.header-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  min-height:72px;
  gap:var(--space-4);
}
.brand{
  display:flex;
  align-items:center;
  gap:var(--space-2);
  text-decoration:none;
}
.brand-mark{
  height:36px;
  width:auto;
}
.brand-text{
  font-family:var(--font-body);
  font-size:0.9rem;
  letter-spacing:0.12em;
}
.nav{
  display:flex;
}
.nav-list{
  display:flex;
  gap:var(--space-4);
  margin:0;
  padding:0;
}
.nav-list li{margin:0;padding:0;}
.nav-list a{
  font-size:0.85rem;
  text-transform:uppercase;
  letter-spacing:0.08em;
  position:relative;
}
.nav-list a::after{
  content:"";
  position:absolute;
  left:0;
  bottom:-4px;
  width:0;
  height:2px;
  background:var(--color-accent-primary);
  transition:width .2s ease;
}
.nav-list a:hover::after{width:100%;}
.nav-toggle{
  display:none;
}
@media(max-width:900px){
  .nav-toggle{
    display:flex;
  }
  .nav-toggle span {
    width: 15px;
    height: 2px;
    background: #000;
  }
  .nav{
    position:fixed;
    top:72px;
    right:0;
    width:280px;
    height:calc(100vh - 72px);
    background:var(--color-surface-elevated);
    border-left:1px solid var(--color-border-default);
    transform:translateX(100%);
    transition:transform .25s ease;
    padding:var(--space-4);
  }
  .nav.open{transform:translateX(0);}
  .nav-list{
    flex-direction:column;
    gap:var(--space-3);
  }
}