/* ============================================================
   FLUXION — RESPONSIVE BREAKPOINTS
   ============================================================ */

/* ==========================================
   LARGE DESKTOP (≤ 1440px)
   ========================================== */
@media (max-width: 1440px) {
  .readings-grid { grid-template-columns: repeat(3, 1fr); }
  .cards-grid-6  { grid-template-columns: repeat(3, 1fr); }
}

/* ==========================================
   LAPTOP (≤ 1200px)
   ========================================== */
@media (max-width: 1200px) {
  /* Landing */
  .hero-inner { grid-template-columns: 1fr; max-width: 640px; }
  .hero-visual { display: none; }
  .hero-title { font-size: var(--font-size-5xl); }
  .hero-content { text-align: center; }
  .hero-desc { max-width: 100%; }
  .hero-actions { justify-content: center; }
  .hero-eyebrow { margin: 0 auto var(--space-6); }

  .stats-bar-inner { grid-template-columns: repeat(2, 1fr); gap: var(--space-6); }

  .hw-grid { grid-template-columns: 1fr; gap: var(--space-10); }
  .hw-visual { max-width: 560px; margin: 0 auto; }

  .cloud-arch { grid-template-columns: repeat(3, 1fr); }
  .arch-arrow:nth-child(4),
  .arch-arrow:nth-child(6) { display: none; }

  .footer-top { grid-template-columns: 1fr 1fr; gap: var(--space-8); }
  .footer-top > *:first-child { grid-column: 1 / -1; }

  /* Admin */
  .admin-overview-cards { grid-template-columns: repeat(2, 1fr); }
  .admin-charts-row { grid-template-columns: 1fr; }
  .health-services { grid-template-columns: 1fr; }

  /* Dashboard */
  .live-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ==========================================
   TABLET (≤ 992px)
   ========================================== */
@media (max-width: 992px) {
  /* Nav */
  .pub-nav-links { display: none; }
  .nav-hamburger { display: flex; }

  /* Sidebar becomes overlay on mobile */
  .sidebar {
    transform: translateX(-100%);
    box-shadow: var(--shadow-xl);
  }

  .sidebar.mobile-open {
    transform: translateX(0);
  }

  /* Overlay backdrop */
  .sidebar-backdrop {
    display: block;
  }

  .main-content {
    margin-left: 0 !important;
  }

  .topbar-menu-btn { display: flex; }

  /* Topbar adjustments */
  .topbar { padding: 0 var(--space-5); }
  .topbar-status { display: none; }
  .topbar-username { display: none; }

  /* Dashboard */
  .readings-grid { grid-template-columns: repeat(2, 1fr); }
  .dashboard-bottom { grid-template-columns: 1fr; }
  .live-grid { grid-template-columns: repeat(2, 1fr); }

  /* Admin */
  .meter-detail-layout { grid-template-columns: 1fr; }
  .network-header-stats { grid-template-columns: repeat(2, 1fr); }
  .critical-event-row { grid-template-columns: 1fr 1fr; }

  /* Landing */
  .ai-cards { grid-template-columns: repeat(2, 1fr); }
  .security-grid { grid-template-columns: 1fr; }

  .section { padding: var(--space-16) var(--space-5); }
  .section-alt { padding: var(--space-16) var(--space-5); }
  .section-title { font-size: var(--font-size-3xl); }

  /* Auth */
  .auth-page { grid-template-columns: 1fr; }
  .auth-panel-left { display: none; }
  .auth-panel-right { padding: var(--space-10) var(--space-6); }
  .auth-mobile-logo { display: flex; }
  .auth-top { margin-bottom: var(--space-6); }
}

/* ==========================================
   MOBILE (≤ 640px)
   ========================================== */
@media (max-width: 640px) {
  /* Typography */
  h1 { font-size: var(--font-size-4xl); }
  h2 { font-size: var(--font-size-3xl); }
  h3 { font-size: var(--font-size-2xl); }

  /* Landing */
  .hero { padding: calc(var(--topbar-height) + var(--space-10)) var(--space-5) var(--space-10); }
  .hero-title { font-size: var(--font-size-4xl); }
  .hero-tagline { font-size: var(--font-size-lg); }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; justify-content: center; }

  .section-header { margin-bottom: var(--space-10); }
  .section-subtitle { font-size: var(--font-size-base); }

  .stats-bar-inner { grid-template-columns: repeat(2, 1fr); }
  .stats-bar-value { font-size: var(--font-size-3xl); }

  .ai-cards { grid-template-columns: 1fr; }

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

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

  .footer-top { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: var(--space-3); text-align: center; }

  .pub-nav { padding: 0 var(--space-4); }

  /* Auth */
  .auth-panel-right { padding: var(--space-8) var(--space-5); }

  /* Dashboard */
  .readings-grid { grid-template-columns: 1fr 1fr; }
  .page-content { padding: var(--space-5); }
  .topbar { padding: 0 var(--space-4); }
  .page-header-top { flex-direction: column; align-items: flex-start; }
  .page-actions { width: 100%; }

  .welcome-banner { padding: var(--space-6); }
  .welcome-name { font-size: var(--font-size-2xl); }
  .welcome-right { display: none; }

  .live-grid { grid-template-columns: 1fr 1fr; }
  .live-reading-value { font-size: 36px; }

  .control-relay-card { padding: var(--space-6); }
  .relay-status-icon { width: 80px; height: 80px; font-size: 32px; }
  .relay-title { font-size: var(--font-size-2xl); }

  /* Admin */
  .admin-overview-cards { grid-template-columns: 1fr 1fr; }
  .network-header-stats { grid-template-columns: 1fr 1fr; }
  .critical-event-row { grid-template-columns: 1fr; }

  /* Tables — horizontal scroll */
  .table-wrapper { -webkit-overflow-scrolling: touch; }

  /* Toast container on mobile */
  #toast-container {
    top: auto;
    bottom: var(--space-4);
    right: var(--space-4);
    left: var(--space-4);
    max-width: none;
  }

  /* Modal on mobile */
  .modal-backdrop { padding: var(--space-4); align-items: flex-end; }
  .modal { max-height: 95vh; border-radius: 0 !important; }

  /* Cards grid */
  .cards-grid-6,
  .cards-grid-4,
  .cards-grid-3,
  .cards-grid-2 { grid-template-columns: 1fr 1fr; }
}

/* ==========================================
   SMALL MOBILE (≤ 400px)
   ========================================== */
@media (max-width: 400px) {
  .readings-grid { grid-template-columns: 1fr 1fr; }
  .live-grid { grid-template-columns: 1fr; }
  .admin-overview-cards { grid-template-columns: 1fr; }
  .network-header-stats { grid-template-columns: 1fr 1fr; }
  .cards-grid-6,
  .cards-grid-4,
  .cards-grid-3,
  .cards-grid-2 { grid-template-columns: 1fr; }
  .demo-readings { grid-template-columns: 1fr 1fr 1fr; }
  .stats-bar-inner { grid-template-columns: 1fr 1fr; }

  .topbar-right .topbar-user { display: none; }
}

/* ==========================================
   SIDEBAR OVERLAY BACKDROP
   ========================================== */
.sidebar-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--bg-overlay);
  z-index: calc(var(--z-sidebar) - 1);
  backdrop-filter: blur(2px);
}

.sidebar-backdrop.visible {
  display: block;
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ==========================================
   PRINT
   ========================================== */
@media print {
  .sidebar, .topbar, #toast-container, .modal-backdrop { display: none !important; }
  .main-content { margin-left: 0 !important; }
  .page-content { padding: 0; }
  body { background: white; color: black; }
  .card { box-shadow: none; border: 1px solid #ccc; }
}