.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 70px;
  padding: 1rem clamp(1rem, 5vw, 4rem);
  background: rgba(14, 19, 27, 0.86);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  line-height: 1.2;
}

.topbar-left { display: flex; align-items: center; gap: clamp(0.75rem, 2vw, 1.5rem); min-width: 0; }

.topbar .logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.01em;
  color: var(--text);
  text-decoration: none;
  flex-shrink: 0;
  transition: color 0.2s ease;
}

.topbar .logo:hover { color: #FFFFFF; }

.topbar .logo-mark {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  object-fit: contain;
  transition: transform 0.4s var(--ease);
}

.topbar .logo:hover .logo-mark { transform: rotate(-8deg) scale(1.06); }

.nav-search { margin: 0; min-width: 0; }

.nav-search input {
  width: 220px;
  max-width: 100%;
  font: inherit;
  font-size: 0.85rem;
  line-height: 1.2;
  color: var(--text);
  background-color: rgba(14, 19, 27, 0.6);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23A1A9B6' stroke-width='2.4'%3E%3Ccircle cx='10.5' cy='10.5' r='6.5'/%3E%3Cpath d='M15.5 15.5L21 21'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: 0.65rem center;
  background-size: 14px 14px;
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 0.5rem 0.7rem 0.5rem 2rem;
  outline: none;
  transition: border-color 0.2s ease, background-color 0.2s ease, width 0.3s var(--ease);
}

.nav-search input::placeholder { color: var(--muted); opacity: 0.8; }
.nav-search input:hover { border-color: var(--line-strong); }
.nav-search input:focus { border-color: var(--accent); background-color: rgba(14, 19, 27, 0.85); }
.nav-search input::-webkit-search-cancel-button { filter: invert(0.7); cursor: pointer; }

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
  font-weight: 500;
}

.nav-links a {
  position: relative;
  display: inline-block;
  padding: 0.35rem 0;
  color: var(--muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a[aria-current="page"] { color: var(--text); }

.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after,
.nav-links a[aria-current="page"]::after { transform: scaleX(1); }

.nav-mobile-toggle {
  display: none;
  font: inherit;
  font-size: 0.85rem;
  line-height: 1.2;
  background: none;
  border: 1px solid var(--line);
  border-radius: 0;
  color: var(--text);
  padding: 0.5rem 0.7rem;
  cursor: pointer;
  flex-shrink: 0;
  transition: border-color 0.2s ease;
}

.nav-mobile-toggle:hover,
.nav-mobile-toggle[aria-expanded="true"] { border-color: var(--accent); }

@media (max-width: 1240px) {
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 0;
    background: #121823;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 18px 30px -12px rgba(0, 0, 0, 0.6);
  }
  .nav-links.open { display: flex; animation: nav-drop 0.22s var(--ease); }
  .nav-links a { display: block; padding: 0.85rem clamp(1rem, 5vw, 4rem); }
  .nav-links a:hover { background: rgba(90, 169, 240, 0.06); }
  .nav-links a::after { display: none; }
  .nav-links a[aria-current="page"] { color: var(--accent); }
  .nav-mobile-toggle { display: block; }
}

@keyframes nav-drop {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 560px) {
  .topbar .logo-text { display: none; }
  .nav-search input { width: 200px; }
}

@media (max-width: 360px) {
  .nav-search input { width: 165px; font-size: 0.8rem; }
}