/* ==========================================================================
   Responsive — Mobile-First Breakpoints
   ========================================================================== */

/* ---------- Mobile (base: 0–639px) ---------- */

.nav-hamburger { display: flex; }

.nav-menu {
  position: absolute;
  top: 100%;
  right: 0;
  height: calc(100vh - var(--nav-height));
  width: 280px;
  flex-direction: column;
  gap: 0;
  padding: var(--space-6);
  background: var(--color-bg-elevated);
  border-left: 1px solid var(--color-border);
  transform: translateX(100%);
  transition: transform var(--transition-base), background-color var(--transition-theme);
  z-index: var(--z-overlay);
  overflow-y: auto;
}

.nav-menu.is-open {
  transform: translateX(0);
}

.nav-overlay {
  display: block;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  height: calc(100vh - var(--nav-height));
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
  z-index: calc(var(--z-overlay) - 1);
}

.nav-overlay.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.nav-menu .nav-link {
  display: block;
  padding: var(--space-4) 0;
  font-size: var(--text-base);
  border-bottom: 1px solid var(--color-border);
}

.nav-menu .nav-link::after { display: none; }

/* Lang toggle in mobile menu */
.nav-menu .lang-toggle {
  padding: var(--space-3) 0;
  border: none;
  margin-top: var(--space-2);
}

/* Cert detail mobile */
.cert-detail-body {
  grid-template-columns: 1fr;
}

/* Hero mobile */
.hero-inner {
  grid-template-columns: 1fr;
  text-align: center;
}

.hero-content { display: contents; }
.hero-greeting { order: -2; }
.hero-image { order: -1; }

.hero-image img {
  width: 180px;
  height: 180px;
  margin: 0 auto;
}

.hero-ctas { justify-content: center; }

.hero-intro { margin-left: auto; margin-right: auto; }

/* Cards mobile */
.card-grid {
  grid-template-columns: 1fr;
}

/* About grid mobile */
.about-grid {
  grid-template-columns: 1fr;
}

/* Features mobile */
.feature-grid {
  grid-template-columns: 1fr;
}

/* Footer mobile */
.footer-inner {
  flex-direction: column;
  text-align: center;
  gap: var(--space-4);
}

/* Contact mobile */
.contact-links {
  flex-direction: column;
  align-items: center;
}

/* App detail mobile */
.app-detail-header {
  flex-direction: column;
  text-align: center;
}

/* Privacy banner mobile */
.privacy-banner {
  flex-direction: column;
  text-align: center;
}

/* ---------- Tablet (640px+) ---------- */
@media (min-width: 640px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .cert-detail-body {
    grid-template-columns: 1fr 1fr;
  }

  .hero-image img {
    width: 280px;
    height: 280px;
  }

  .contact-links {
    flex-direction: row;
  }

  .footer-inner {
    flex-direction: row;
    text-align: left;
  }

  .app-detail-header {
    flex-direction: row;
    text-align: left;
  }

  .privacy-banner {
    flex-direction: row;
    text-align: left;
  }
}

/* ---------- Desktop (1024px+) ---------- */
@media (min-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .section {
    padding: var(--space-16) 0;
  }

  .hero {
    padding: var(--space-20) 0;
  }

  .nav-hamburger { display: none; }
  .nav-overlay { display: none; }

  .nav-menu {
    position: static;
    width: auto;
    flex-direction: row;
    gap: var(--space-8);
    padding: 0;
    background: transparent;
    border: none;
    transform: none;
    overflow: visible;
  }

  .nav-menu .nav-link {
    display: inline;
    padding: var(--space-2) 0;
    font-size: var(--text-sm);
    border-bottom: none;
  }

  .nav-menu .nav-link::after { display: block; }

  .nav-menu .lang-toggle {
    padding: var(--space-1) var(--space-2);
    border: 1px solid var(--color-border);
    margin-top: 0;
  }

  .toggle-label { display: inline; }

  .nav-controls {
    margin-right: auto;
  }

  .about-grid {
    grid-template-columns: 1fr 1fr;
  }

  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ---------- Wide Desktop (1280px+) ---------- */
@media (min-width: 1280px) {
  .container {
    padding: 0 var(--space-8);
  }

  .hero-image img {
    width: 340px;
    height: 340px;
  }
}

/* ---------- Extra Wide Desktop (1536px+) ---------- */
@media (min-width: 1536px) {
  .hero-image img {
    width: 400px;
    height: 400px;
  }
}