.site-header{
  position:sticky;
  top:0;
  z-index:1000;
  background:var(--color-surface-bg);
  border-bottom:1px solid var(--color-surface-border);
}
.site-header__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  min-height:64px;
}
.site-header__brand{
  display:flex;
  align-items:center;
  gap:0.5rem;
}
.site-header__logo-mark img{
  height:48px;
  width:auto;
}
.site-header__brand-text{
  font-family:var(--font-heading);
  font-size:1rem;
}
.site-header__toggle{
  display:none;
  width:44px;
  height:44px;
  align-items:center;
  justify-content:center;
}
.site-header__toggle-lines,
.site-header__toggle-lines::before,
.site-header__toggle-lines::after{
  content:"";
  display:block;
  width:20px;
  height:2px;
  background:var(--color-text-primary);
  position:relative;
}
.site-header__toggle-lines::before{top:-6px;position:absolute;}
.site-header__toggle-lines::after{top:6px;position:absolute;}
.site-header__nav{
  display:flex;
  align-items:center;
  gap:1.5rem;
}
.site-header__menu{
  display:flex;
  gap:1.5rem;
}
.site-header__menu li{margin:0;padding:0;}
.site-header__menu a{
  font-size:0.95rem;
}
@media (max-width:900px){
  .site-header__toggle{display:flex;}
  .site-header__nav{
    position:fixed;
    top:0;
    right:0;
    height:100vh;
    width:80%;
    max-width:320px;
    background:var(--color-surface-card);
    flex-direction:column;
    padding:2rem;
    transform:translateX(100%);
    transition:transform 0.3s ease;
    overflow-y:auto;
  }
  .site-header__nav.is-open{
    transform:translateX(0);
  }
  .site-header__menu{
    flex-direction:column;
    gap:1.5rem;
  }
}