.site-header{
  position: sticky;
  top:0;
  z-index:100;
  background: rgba(7,18,33,.72);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner{
  display:flex;
  align-items:center;
  gap:14px;
  padding:14px 0;
}
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  min-width: 260px;
}
.brand-mark{
  width:42px;
  height:42px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(255,255,255,.22), rgba(255,255,255,.06));
  box-shadow: var(--shadow);
  display:grid;
  place-items:center;
  font-weight:800;
  letter-spacing:.06em;
  font-size:12px;
}
.brand-name{ display:block; font-weight:800; letter-spacing:.02em; font-size:14px; }
.brand-sub{ display:block; color:var(--muted); font-size:11px; margin-top:2px; }

.nav{
  display:flex;
  gap:16px;
  align-items:center;
  flex: 1;
  justify-content:center;
}
.nav-link{
  opacity:.82;
  font-weight:600;
  font-size:13px;
  padding:10px 8px;
  border-radius:12px;
  transition: background .2s var(--ease), opacity .2s var(--ease), transform .2s var(--ease);
}
.nav-link:hover{
  opacity:1;
  background: rgba(255,255,255,.06);
  transform: translateY(-1px);
}
.nav-link.is-active{
  opacity:1;
  background: rgba(38,198,218,.12);
  outline: 1px solid rgba(38,198,218,.22);
}

.header-actions{
  display:flex;
  gap:12px;
  align-items:center;
}
.menu-btn{
  display:none; /* responsive phase later */
}

.section{
  padding: 70px 0;
}
.section-alt{
  background: linear-gradient(180deg, rgba(255,255,255,.05), rgba(255,255,255,0));
  border-top: 1px solid rgba(255,255,255,.06);
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.section-head{
  display:flex;
  align-items:flex-end;
  justify-content:space-between;
  gap:16px;
  margin-bottom: 22px;
}
.section-head h2{ font-size:28px; }
.section-head p{ color:var(--muted); max-width: 62ch; }

.split{
  display:grid;
  grid-template-columns: 1.1fr .9fr;
  gap:18px;
  align-items:stretch;
}

.footer{
  padding: 28px 0;
  border-top: 1px solid var(--line);
  background: rgba(0,0,0,.10);
}
.footer-inner{
  display:flex;
  align-items:flex-start;
  }