/* Header styles for Tree Plant Initiative */

.tpi-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: rgba(245, 247, 244, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border-subtle);
}

.tpi-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-3);
  padding-bottom: var(--space-3);
  gap: var(--space-4);
}

.tpi-header__brand {
  display: flex;
  align-items: center;
  min-width: 0;
}

.tpi-header__logo-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
}

.tpi-header__logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 20%, #58a96f 0, #2e7d4f 40%, #205a39 100%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.tpi-header__logo-mark .fa-tree {
  font-size: 1.2rem;
}

.tpi-header__text-group {
  display: flex;
  flex-direction: column;
}

.tpi-header__site-name {
  font-weight: 700;
  font-size: var(--font-size-lg);
  letter-spacing: -0.01em;
}

.tpi-header__tagline {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* Navigation */

.tpi-header__nav {
  display: flex;
  align-items: center;
}

.tpi-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.tpi-header__nav-link {
  position: relative;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  padding: 0.25rem 0;
}

.tpi-header__nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -0.2rem;
  height: 2px;
  border-radius: var(--radius-full);
  background: linear-gradient(90deg, var(--color-primary) 0%, #58a96f 100%);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--transition-normal);
}

.tpi-header__nav-link:hover,
.tpi-header__nav-link:focus-visible {
  color: var(--color-primary-dark);
}

.tpi-header__nav-link:hover::after,
.tpi-header__nav-link:focus-visible::after {
  transform: scaleX(1);
}

.tpi-header__nav-item--primary .tpi-header__nav-link--cta {
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  background-color: var(--color-primary);
  color: #ffffff;
  box-shadow: var(--shadow-xs);
}

.tpi-header__nav-item--primary .tpi-header__nav-link--cta::after {
  display: none;
}

.tpi-header__nav-item--primary .tpi-header__nav-link--cta:hover,
.tpi-header__nav-item--primary .tpi-header__nav-link--cta:focus-visible {
  background-color: var(--color-primary-dark);
}

/* Mobile menu toggle */

.tpi-header__menu-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 0.35rem 0.8rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border-subtle);
  background-color: #ffffff;
  color: var(--color-text);
}

.tpi-header__menu-toggle-box {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
}

.tpi-header__menu-toggle-bar {
  width: 18px;
  height: 2px;
  border-radius: 999px;
  background-color: var(--color-text);
  transition: transform var(--transition-normal), opacity var(--transition-normal), background-color var(--transition-normal);
}

.tpi-header__menu-toggle-text {
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

/* Open state animation */

.tpi-header--menu-open .tpi-header__menu-toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.tpi-header--menu-open .tpi-header__menu-toggle-bar:nth-child(2) {
  opacity: 0;
}

.tpi-header--menu-open .tpi-header__menu-toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Responsive behavior */

@media (max-width: 768px) {
  .tpi-header__inner {
    padding-top: var(--space-2);
    padding-bottom: var(--space-2);
  }

  .tpi-header__menu-toggle {
    display: inline-flex;
  }

  .tpi-header__nav {
    position: absolute;
    inset-inline: 0;
    top: 100%;
    background-color: rgba(245, 247, 244, 0.98);
    border-bottom: 1px solid var(--color-border-subtle);
    box-shadow: var(--shadow-md);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transform: translateY(-4px);
    transition: max-height var(--transition-slow), opacity var(--transition-normal), transform var(--transition-normal);
  }

  .tpi-header__nav-list {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-3) var(--space-4) var(--space-4);
    gap: var(--space-2);
  }

  .tpi-header__nav-link {
    font-size: var(--font-size-md);
  }

  .tpi-header--menu-open .tpi-header__nav {
    max-height: 420px;
    opacity: 1;
    transform: translateY(0);
  }
}

@media (min-width: 769px) {
  .tpi-header__nav-item--primary .tpi-header__nav-link--cta {
    margin-left: var(--space-2);
  }
}

/* Reduced motion: fall back to simpler behavior */

@media (prefers-reduced-motion: reduce) {
  .tpi-header__nav {
    transition: none;
  }

  .tpi-header__menu-toggle-bar {
    transition: none;
  }
}