@layer components {
  :root {
    --nav-height: 72px;
    --nav-height-scrolled: 64px;
    --nav-bg: rgba(255, 252, 248, 0.7);
    --nav-bg-scrolled: rgba(255, 252, 248, 0.85);
    --nav-border: 1px solid transparent;
    --nav-border-scrolled: 1px solid var(--color-border);
    --nav-backdrop: blur(20px) saturate(180%);
    --nav-transition: 250ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  }

  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--nav-height);
    transition: height var(--nav-transition), background var(--nav-transition), box-shadow var(--nav-transition);
  }

  .site-header.is-scrolled {
    height: var(--nav-height-scrolled);
    background: var(--nav-bg-scrolled);
    backdrop-filter: var(--nav-backdrop);
    -webkit-backdrop-filter: var(--nav-backdrop);
    border-bottom: var(--nav-border-scrolled);
    box-shadow:
      0 1px 2px rgba(0, 0, 0, 0.03),
      0 4px 8px rgba(0, 0, 0, 0.02);
  }

  .nav {
    width: 100%;
    height: 100%;
  }

  .nav__container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-6);
  }

  .nav__logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--color-text-primary);
    font-family: var(--font-display);
    font-size: var(--text-xl);
    font-weight: 500;
    letter-spacing: var(--tracking-tight);
    transition: opacity 200ms ease;
  }

  .nav__logo:hover {
    opacity: 0.8;
  }

  .nav__logo:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
    border-radius: 4px;
  }

  .nav__menu {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    list-style: none;
    margin: 0;
    padding: 0;
  }

  .nav__link {
    display: block;
    padding: var(--space-2) var(--space-1);
    font-family: var(--font-ui);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    text-decoration: none;
    position: relative;
    transition: color 200ms ease;
  }

  .nav__link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--color-text-primary);
    transform: translateX(-50%);
    transition: width 250ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border-radius: 1px;
  }

  .nav__link:hover {
    color: var(--color-text-primary);
  }

  .nav__link:hover::after {
    width: 100%;
  }

  .nav__link:focus-visible {
    outline: none;
    color: var(--color-text-primary);
  }

  .nav__link:focus-visible::after {
    width: 100%;
  }

  .nav__link--cta {
    padding: var(--space-2) var(--space-4);
    border-radius: var(--btn-radius);
    background: var(--color-text-primary);
    color: var(--color-bg-primary);
  }

  .nav__link--cta::after {
    display: none;
  }

  .nav__link--cta:hover {
    background: var(--color-text-primary);
    color: var(--color-bg-primary);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }

  .nav__toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    padding: 0;
    transition: background 200ms ease;
  }

  .nav__toggle:hover {
    background: var(--color-surface-hover);
  }

  .nav__toggle:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
  }

  .nav__toggle-icon {
    position: relative;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: 1px;
    transition: background 200ms ease;
  }

  .nav__toggle-icon::before,
  .nav__toggle-icon::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--color-text-primary);
    border-radius: 1px;
    transition: transform 250ms cubic-bezier(0.25, 0.46, 0.45, 0.94), top 200ms ease, bottom 200ms ease;
  }

  .nav__toggle-icon::before {
    top: -7px;
  }

  .nav__toggle-icon::after {
    bottom: -7px;
  }

  .nav__toggle[aria-expanded="true"] .nav__toggle-icon {
    background: transparent;
  }

  .nav__toggle[aria-expanded="true"] .nav__toggle-icon::before {
    top: 0;
    transform: rotate(45deg);
  }

  .nav__toggle[aria-expanded="true"] .nav__toggle-icon::after {
    bottom: 0;
    transform: rotate(-45deg);
  }

  @media (max-width: 900px) {
    .nav__toggle {
      display: flex;
    }

    .nav__menu {
      position: fixed;
      top: var(--nav-height);
      left: 0;
      right: 0;
      flex-direction: column;
      align-items: stretch;
      gap: 0;
      padding: var(--space-4) var(--space-6);
      background: var(--nav-bg-scrolled);
      backdrop-filter: var(--nav-backdrop);
      -webkit-backdrop-filter: var(--nav-backdrop);
      border-bottom: 1px solid var(--color-border);
      box-shadow:
        0 8px 24px rgba(0, 0, 0, 0.08),
        0 16px 48px rgba(0, 0, 0, 0.04);
      transform: translateY(-100%);
      opacity: 0;
      visibility: hidden;
      transition:
        transform 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94),
        opacity 200ms ease,
        visibility 0ms 300ms;
    }

    .nav__menu.is-open {
      transform: translateY(0);
      opacity: 1;
      visibility: visible;
      transition:
        transform 300ms cubic-bezier(0.25, 0.46, 0.45, 0.94),
        opacity 200ms ease,
        visibility 0ms;
    }

    .nav__link {
      padding: var(--space-3) var(--space-4);
      font-size: var(--text-base);
      border-radius: var(--radius-md);
    }

    .nav__link:hover {
      background: var(--color-surface-hover);
    }

    .nav__link::after {
      display: none;
    }

    .nav__link--cta {
      margin-top: var(--space-2);
      text-align: center;
    }
  }
}