/* ============================================================
   HEADER — DT Malware Safe
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 247, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-xs);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: var(--space-6);
}

/* ── Logo ─────────────────────────────────────────────────── */
.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
  flex-shrink: 0;
}
.site-logo:hover { text-decoration: none; }
.logo-mark {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  transition: transform var(--dur) var(--ease);
}
.site-logo:hover .logo-mark { transform: scale(1.05); }
.logo-wordmark {
  display: flex;
  flex-direction: column;
  line-height: 1;
}
.logo-dt {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.02em;
}
.logo-suffix {
  font-family: var(--font-heading);
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ── Nav ──────────────────────────────────────────────────── */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
.nav-link {
  position: relative;
  padding: 0.375rem 0.75rem;
  font-family: var(--font-heading);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color var(--dur-fast), background var(--dur-fast);
}
.nav-link:hover {
  color: var(--text);
  background: var(--bg-alt);
  text-decoration: none;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0.75rem;
  right: 0.75rem;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
  transform: scaleX(0);
  transition: transform var(--dur) var(--ease);
}
.nav-link.active {
  color: var(--primary);
  font-weight: 600;
}
.nav-link.active::after { transform: scaleX(1); }

/* ── Header CTA ───────────────────────────────────────────── */
.header-cta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
}

/* ── Mobile Menu Button ───────────────────────────────────── */
.menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--dur-fast);
}
.menu-btn:hover { background: var(--bg-alt); }
.menu-btn span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--dur) var(--ease), opacity var(--dur-fast);
  transform-origin: center;
}
.menu-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-btn.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.menu-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Mobile Nav Panel ─────────────────────────────────────── */
.mobile-nav {
  display: none;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-4);
  border-top: 1px solid var(--border);
  background: var(--surface);
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--dur-slow) var(--ease);
}
.mobile-nav.open { max-height: 400px; }
.mobile-nav .nav-link {
  display: block;
  padding: 0.625rem 0.875rem;
  border-radius: var(--radius-sm);
}
.mobile-nav .nav-link::after { display: none; }
.mobile-nav .btn { width: 100%; justify-content: center; margin-top: var(--space-2); }

@media (max-width: 768px) {
  .menu-btn { display: flex; }
  .site-nav, .header-cta { display: none; }
  .mobile-nav { display: flex; }
}