/* Header styles for Green Future Project */

.gfp-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.gfp-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-3);
}

/* Branding */

.gfp-header__branding {
  display: flex;
  align-items: center;
  min-width: 0;
}

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

.gfp-header__logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 20%, #7ccf8a, #2f7d4a);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  position: relative;
}

.gfp-header__leaf {
  width: 18px;
  height: 24px;
  border-radius: 50% 0 50% 0;
  background-color: #f5f7f4;
  transform: rotate(-35deg) translateX(2px);
  box-shadow: 0 0 0 1px rgba(15, 23, 18, 0.08);
}

.gfp-header__text {
  display: flex;
  flex-direction: column;
}

.gfp-header__site-name {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--font-size-lg);
  line-height: var(--line-height-tight);
}

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

/* Navigation */

.gfp-header__nav {
  margin-left: var(--space-6);
}

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

.gfp-header__nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding-block: 0.25rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
}

.gfp-header__nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  border-radius: var(--radius-pill);
  transition: width var(--transition-normal);
}

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

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

.gfp-header__nav-item--cta .gfp-header__nav-link {
  padding-inline: var(--space-4);
  padding-block: 0.5rem;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(47, 125, 74, 0.18);
}

.gfp-header__nav-link--primary {
  background-color: var(--color-primary);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.gfp-header__nav-link--primary::after {
  display: none;
}

.gfp-header__nav-link--primary:hover,
.gfp-header__nav-link--primary:focus-visible {
  background-color: var(--color-primary-strong);
  color: #ffffff;
}

/* Mobile toggle */

.gfp-header__toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--gray-200);
  background-color: var(--color-surface-soft);
  color: var(--color-text);
  cursor: pointer;
}

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

.gfp-header__toggle-icon {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
}

.gfp-header__toggle-bar {
  width: 18px;
  height: 2px;
  border-radius: 999px;
  background-color: var(--color-text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.gfp-header__toggle-text {
  font-size: var(--font-size-sm);
}

/* Mobile nav state */

@media (max-width: 768px) {
  .gfp-header__inner {
    padding-block: var(--space-2);
  }

  .gfp-header__tagline {
    display: none;
  }

  .gfp-header__toggle {
    display: inline-flex;
  }

  .gfp-header__nav {
    position: absolute;
    inset-inline: 0;
    top: 100%;
    background-color: var(--color-surface);
    box-shadow: var(--shadow-md);
    transform-origin: top center;
  }

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

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

  .gfp-header__nav-item--cta {
    width: 100%;
  }

  .gfp-header__nav-item--cta .gfp-header__nav-link {
    width: 100%;
    justify-content: center;
    text-align: center;
  }

  /* JS-enhanced collapsible behavior */
  .js .gfp-header__nav {
    max-height: 0;
    opacity: 0;
    visibility: hidden;
    transition:
      max-height var(--transition-slow),
      opacity var(--transition-normal),
      visibility var(--transition-normal);
  }

  .js .gfp-header__nav--open {
    opacity: 1;
    visibility: visible;
    max-height: 420px;
  }

  .js .gfp-header__nav-list {
    padding-block: var(--space-3);
  }

  /* Burger to close icon animation */
  .gfp-header__toggle[aria-expanded="true"] .gfp-header__toggle-bar:nth-child(1) {
    transform: translateY(5px) rotate(45deg);
  }

  .gfp-header__toggle[aria-expanded="true"] .gfp-header__toggle-bar:nth-child(2) {
    opacity: 0;
  }

  .gfp-header__toggle[aria-expanded="true"] .gfp-header__toggle-bar:nth-child(3) {
    transform: translateY(-5px) rotate(-45deg);
  }
}

/* Medium+ screens */

@media (min-width: 769px) {
  .gfp-header__nav-list {
    gap: var(--space-5);
  }
}