/* =========================
   Header / Navigation
   ========================= */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(18px);
  background: rgba(10,12,18,.45);
}
:root[data-theme="light"] .site-header{
  background: rgba(247,248,255,.72);
}

.header-content{
  height: 74px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 16px;
}

.brand{
  display:flex;
  align-items:center;
  gap: 10px;
}
.brand-mark{
  width: 38px;
  height: 38px;
  display:grid;
  place-items:center;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,.04));
  box-shadow: 0 14px 40px rgba(0,0,0,.22);
}
.brand-name{
  font-weight: 900;
  letter-spacing: .2px;
}

.header-actions{
  display:flex;
  align-items:center;
  gap: 10px;
}

.icon-btn{
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display:grid;
  place-items:center;
  cursor:pointer;
  transition: transform .16s ease, background .16s ease;
}
.icon-btn:hover{ transform: translateY(-1px); background: rgba(255,255,255,.10); }

.mobile-menu-toggle{
  display:none;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  width: 42px;
  height: 42px;
  border-radius: 14px;
  cursor:pointer;
  padding: 8px;
}

.main-nav ul{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  align-items:center;
  gap: 14px;
}
.main-nav a{
  color: var(--muted);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 12px;
  border-radius: 999px;
  transition: background .16s ease, color .16s ease;
}
.main-nav a:hover{
  background: rgba(255,255,255,.06);
  color: var(--text);
}
.main-nav a.active{
  color: var(--text);
  background: rgba(124,92,255,.22);
  border: 1px solid rgba(124,92,255,.28);
}
.main-nav a.btn-pill{
  color: var(--text);
}

@media (max-width: 920px){
  .mobile-menu-toggle{ display:block; }
  .main-nav{
    position: absolute;
    top: 74px;
    left: 20px;
    right: 20px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(10,12,18,.72);
    backdrop-filter: blur(18px);
    box-shadow: var(--shadow);
    padding: 12px;
    transform-origin: top;
    transform: scale(.98);
    opacity: 0;
    pointer-events: none;
    transition: opacity .18s ease, transform .18s ease;
  }
  :root[data-theme="light"] .main-nav{
    background: rgba(247,248,255,.92);
  }
  .main-nav.active{
    opacity: 1;
    transform: scale(1);
    pointer-events: auto;
  }
  .main-nav ul{
    flex-direction:column;
    align-items:stretch;
    gap: 8px;
  }
  .main-nav a{
    border-radius: 16px;
    padding: 12px 12px;
    background: rgba(255,255,255,.04);
  }
}