@media (max-width: 767px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .mobile-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 1rem;
    background: #212121;
    border-bottom: 1px solid #2a2a2a;
    z-index: 20;
  }

  .mobile-title {
    font-family: 'Press Start 2P', monospace;
    font-size: 0.5rem;
    color: #fff;
  }

  .menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 10px;
    background: transparent;
    border: none;
    cursor: pointer;
  }

  .menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: #fff;
    transition: transform 0.2s, opacity 0.2s;
  }

  .menu-toggle[aria-expanded='true'] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .menu-toggle[aria-expanded='true'] span:nth-child(2) {
    opacity: 0;
  }

  .menu-toggle[aria-expanded='true'] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: min(280px, 85vw);
    height: 100dvh;
    z-index: 30;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    padding-top: 3.5rem;
  }

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

  .sidebar-brand {
    display: none;
  }

  .drawer-overlay {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 25;
    pointer-events: auto;
  }

  .drawer-overlay[hidden] {
    display: none;
  }

  .content-panel {
    padding: 0.75rem;
  }

  .content-panel-inner {
    padding: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .nav-item,
  .btn,
  .menu-toggle span,
  .sidebar {
    transition: none;
  }
}