/* Header styles for GTT Adam Karpiński */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(16px);
  background: linear-gradient(to bottom, rgba(3,7,18,0.9), rgba(3,7,18,0.82));
  border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
  gap: var(--space-4);
}

.header-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  background: radial-gradient(circle at 20% 20%, rgba(59,130,246,0.7), transparent 55%),
              radial-gradient(circle at 80% 80%, rgba(8,47,73,0.9), transparent 55%),
              #020617;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
}

.brand-mark__icon {
  width: 22px;
  height: 22px;
  border-radius: 999px;
  border: 1px solid rgba(191, 219, 254, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.brand-mark__dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #22c55e;
  box-shadow: 0 0 12px rgba(34,197,94,0.8);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--gray-50);
}

.brand-subtitle {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* Navigation */

.primary-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  padding-block: 0.25rem;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.02rem;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, #1d4ed8, #22c55e);
  transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--gray-50);
}

.nav-link:hover::after,
.nav-link:focus-visible::after {
  width: 100%;
}

.nav-item--cta .nav-link--cta {
  padding-inline: 0.9rem;
  padding-block: 0.35rem;
  border-radius: var(--radius-full);
  border: 1px solid rgba(59,130,246,0.8);
  background: radial-gradient(circle at top left, rgba(37,99,235,0.3), transparent 60%);
  color: #e5e7eb;
}

.nav-item--cta .nav-link--cta:hover,
.nav-item--cta .nav-link--cta:focus-visible {
  background: radial-gradient(circle at top left, rgba(37,99,235,0.5), transparent 60%);
  border-color: #1d4ed8;
}

/* Mobile navigation */

.nav-toggle {
  position: relative;
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.22rem;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 999px;
  border: 1px solid rgba(148,163,184,0.6);
  background: rgba(15,23,42,0.9);
  cursor: pointer;
  padding: 0.4rem;
  color: var(--gray-100);
}

.nav-toggle__bar {
  width: 100%;
  height: 2px;
  border-radius: 999px;
  background-color: currentColor;
  transition: transform var(--transition-base), opacity var(--transition-base), translate var(--transition-base);
}

.nav-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

/* Closed state handled by default; open state via .is-open on header */

.site-header.is-menu-open .nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.site-header.is-menu-open .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.site-header.is-menu-open .nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Layout: desktop vs mobile */

@media (max-width: 767px) {
  .primary-nav {
    position: fixed;
    inset-inline: 0;
    top: 3.4rem;
    background: radial-gradient(circle at top, rgba(37,99,235,0.28), transparent 65%),
                rgba(3,7,18,0.98);
    border-bottom: 1px solid rgba(148,163,184,0.35);
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-base), opacity var(--transition-base);
  }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-4) var(--space-4) var(--space-5);
    gap: var(--space-3);
  }

  .site-header.is-menu-open .primary-nav {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }
}

@media (max-width: 480px) {
  .brand-subtitle {
    display: none;
  }
}