*, *::before, *::after { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #f7f8fa;
  color: #1a1a1a;
}

main {
  max-width: 1100px;
  margin: 2rem auto;
  padding: 0 1rem;
}

/* ============================
   Header
   ============================ */
header {
  background: #1f2937;
  padding: 1rem 2rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  position: relative;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo-link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
}

.logo {
  display: block;
  max-height: 80px;
  width: auto;
}

/* ============================
   Footer
   ============================ */
footer {
  background: #1f2937;
  color: #d1d5db;
  padding: 1.5rem 2rem;
  margin-top: 3rem;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-logos {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 2rem;
}

.footer-logos a {
  display: inline-flex;
  align-items: center;
  opacity: 0.85;
  transition: opacity 0.15s;
}

.footer-logos a:hover {
  opacity: 1;
}

.footer-copy {
  margin: 0;
  font-size: 0.8rem;
  color: #9ca3af;
  text-align: center;
}

.footer-copy a {
  color: #9ca3af;
  text-decoration: underline;
}

.footer-copy a:hover {
  color: #e5e7eb;
}

.footer-powered {
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  text-align: center;
}

.footer-powered-label {
  font-size: 0.8rem;
  color: #9ca3af;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.footer-powered-items {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.75rem 1.25rem;   /* row gap 0.75rem, column gap 1.25rem */
}

.footer-logo {
  display: block;
  max-height: 40px;
  width: auto;
  opacity: 0.9;
  transition: opacity 0.15s;
}

.footer-logo:hover {
  opacity: 1;
}

.footer-source {
  font-size: 0.85rem;
  font-weight: 500;
  color: #d1d5db;
  letter-spacing: 0.02em;
}


/* ============================
   Accessibility
   ============================ */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- Desktop menu ---------- */
.primary-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 1.5rem;
}

.primary-nav a {
  color: #e5e7eb;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.4rem 0.2rem;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.primary-nav a:hover {
  color: #ffffff;
  border-bottom-color: #60a5fa;
}

/* Hide the hamburger on desktop */
.nav-toggle {
  display: none;
}

/* ============================
   Responsive
   ============================ */
@media (max-width: 600px) {
  header { padding: 0.75rem 1rem; }
  .logo { max-height: 40px; }

  footer { padding: 1rem; }
  .footer-logos { gap: 1rem; }
  .footer-logo { max-height: 30px; }

  .nav-toggle {
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    gap: 4px;
    width: 40px;
    height: 40px;
    padding: 0;
    background: transparent;
    border: none;
    cursor: pointer;
  }

  .nav-toggle-bar {
    display: block;
    width: 22px;
    height: 2px;
    background: #ffffff;
    border-radius: 2px;
    transition: transform 0.2s, opacity 0.2s;
  }

  /* Animate hamburger → X when open */
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
    opacity: 0;
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  /* Collapse the nav by default on mobile */
  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #1f2937;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }

  .primary-nav.open {
    max-height: 320px;   /* enough for a few menu items */
  }

  .primary-nav ul {
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 0;
  }

  .primary-nav a {
    display: block;
    padding: 0.75rem 1.25rem;
    border-bottom: none;
  }

  .primary-nav a:hover {
    background: rgba(255, 255, 255, 0.06);
  }
}