.site-header {
  position: sticky; top: 0; z-index: 60;
  background: rgba(8,8,13,.72);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--line-soft);
}
.site-header .wrap {
  display: flex; align-items: center; gap: var(--sp-5);
  height: 68px;
}
.brand { display: flex; align-items: center; gap: .6rem; font-weight: 700; letter-spacing: -.02em; }
.brand-mark {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  background: linear-gradient(145deg, var(--accent-hi), var(--accent-low));
  display: grid; place-items: center;
  box-shadow: 0 6px 18px -8px rgba(124,92,255,.9);
}
.brand-mark svg { width: 17px; height: 17px; }
.brand span small { display: block; font-size: .68rem; color: var(--text-faint); font-weight: 500; letter-spacing: .01em; }

.site-nav { display: flex; align-items: center; gap: .25rem; margin-left: auto; }
.site-nav a {
  padding: .5rem .8rem; border-radius: var(--r-sm);
  color: var(--text-muted); font-size: var(--step--1); font-weight: 600;
  transition: color .15s, background .15s;
}
.site-nav a:hover { color: var(--text); background: var(--surface-2); }
.site-nav a.is-active { color: var(--text); background: var(--accent-ghost); }
.site-nav .btn { margin-left: .4rem; }

.nav-toggle { display: none; margin-left: auto; padding: .5rem; border-radius: var(--r-sm); color: var(--text-muted); }
.nav-toggle:hover { background: var(--surface-2); color: var(--text); }