/* =========================================================================
   RESPONSIVE BREAKPOINTS SYSTEM (320px to 1920px)
   ========================================================================= */

/* Mobile Hamburger Menu Toggle Button */
.mobile-hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--ink-heading);
  cursor: pointer;
  padding: 8px;
  border-radius: var(--radius-sm);
}

.mobile-hamburger:hover {
  background: var(--surface-muted);
}

.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 45;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

/* 1200px & Above (Large Desktop / 1440px / 1920px) */
@media (min-width: 1200px) {
  .app-shell {
    grid-template-columns: 310px 1fr;
  }
}

/* 1024px to 1199px (Standard Desktop / Laptop) */
@media (max-width: 1024px) {
  .dashboard-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  main.content {
    padding: 28px 32px 100px;
  }
}

/* 768px to 1023px (Tablet Responsive) */
@media (max-width: 900px) {
  .mobile-hamburger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .app-shell {
    grid-template-columns: 1fr;
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: 300px;
    height: 100vh;
    z-index: 50;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 10px 0 30px rgba(0, 0, 0, 0.3);
  }

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

  .user-profile-badge span {
    display: none;
  }

  .progress-strip {
    padding: 12px 20px;
  }
}

/* 600px to 767px (Small Tablet & Large Mobile) */
@media (max-width: 640px) {
  .grid2, .grid3 {
    grid-template-columns: 1fr;
  }

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

  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .topbar-actions {
    width: 100%;
    justify-content: space-between;
  }

  .topbar-actions .btn {
    flex: 1;
  }

  main.content {
    padding: 20px 16px 90px;
  }

  .card {
    padding: 20px 16px;
  }

  .preview-shell {
    padding: 12px;
  }

  #docPreview {
    padding: 24px 18px;
    font-size: 11.5px;
  }

  .doc-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .doc-row .doc-tag {
    margin-bottom: 4px;
  }

  .progress-strip .stepbtns {
    width: 100%;
    justify-content: space-between;
  }

  .progress-strip .stepbtns .btn {
    flex: 1;
  }
}

/* 320px to 480px (Ultra Compact Mobile Screens: 320, 360, 375, 390, 412, 425, 480) */
@media (max-width: 480px) {
  .app-header {
    padding: 0 14px;
  }

  .brand-badge {
    display: none;
  }

  .brand-logo {
    height: 34px;
  }

  .btn {
    padding: 8px 12px;
    font-size: 12px;
  }

  .topbar h2 {
    font-size: 24px;
  }
}