.topbar{
  position: sticky; top:0; z-index:100;
  width:100%;
  padding: .55rem .9rem;
  display:flex; align-items:center; justify-content:space-between; gap:.6rem;
  background: linear-gradient(135deg,#071225 0%,#0b2b5f 38%,#0e65c0 72%,#27a8ff 100%);
  border-bottom-left-radius:18px; border-bottom-right-radius:18px;
  box-shadow: 0 10px 24px rgba(0,0,0,.55), 0 0 18px rgba(56,189,248,.45);
  overflow:hidden;
}

.logo-circle{
  width:40px; height:40px; border-radius:50%; flex-shrink:0;
  background-image:url("/icons/logo-master.png");
  background-size:cover; background-position:center; background-repeat:no-repeat;
  box-shadow: 0 0 10px rgba(37,99,235,.8), 0 0 18px rgba(56,189,248,.6);
  color:transparent;
}

.title-block{ display:flex; flex-direction:column; line-height:1.05; min-width:0; }
.main-title{ font-size:1.02rem; font-weight:800; letter-spacing:.04em; color:#f9fafb; }
.sub-title{ font-size:.74rem; color:#dbeafe; opacity:.95; }

.topbar-right{ display:flex; align-items:center; gap:.5rem; margin-left:auto; flex-wrap:wrap; }

.theme-switch{ display:flex; gap:.28rem; }
.theme-dot{
  width:22px; height:22px; border-radius:999px;
  border:1px solid rgba(148,163,184,.85);
  background:rgba(15,23,42,.9); color:#e5e7eb; font-size:.65rem;
  display:flex; align-items:center; justify-content:center; padding:0; cursor:pointer;
  box-shadow:0 0 6px rgba(15,23,42,.9); transition:transform .12s ease;
}
.theme-dot:hover{ transform:scale(1.06); }
.theme-dot-active{ border-color:#facc15; box-shadow:0 0 10px rgba(250,204,21,.9),0 0 14px rgba(56,189,248,.55); }

.btn-primary, .btn-secondary{
  padding:.32rem .85rem; font-size:.78rem; border-radius:999px; font-weight:700; cursor:pointer;
  white-space:nowrap; line-height:1;
}
.btn-primary{
  border:1px solid #22c55e;
  background:radial-gradient(circle at 30% 30%,#22c55e,#16a34a);
  color:#f9fafb;
  box-shadow:0 4px 10px rgba(22,163,74,.5),0 0 8px rgba(22,163,74,.6);
}
.btn-primary:disabled{ opacity:.6; cursor:default; }
.btn-secondary{
  border:1px solid #bfdbfe;
  background:rgba(15,23,42,.25);
  color:#e0f2fe;
  box-shadow:0 3px 10px rgba(15,23,42,.6);
}
.btn-secondary:hover{ background:rgba(15,23,42,.45); }

@media (max-width:640px){
  .topbar{ padding:.5rem .7rem; border-bottom-left-radius:16px; border-bottom-right-radius:16px; }
  .main-title{ font-size:1rem; }
  .sub-title{ font-size:.7rem; }
  .topbar-right{ width:100%; justify-content:flex-start; gap:.45rem; }
}