@media (max-width: 768px) {
  .sidebar {
    display: none;
  }

  .main-content,
  .app-main,
  .content {
    margin-left: 0;
    width: 100%;
  }

  .inbox-shell {
    display: grid;
    grid-template-columns: 1fr;
    min-height: 100dvh;
  }

  .inbox-list {
    display: none;
  }

  .inbox-chat {
    min-height: 100dvh;
    padding-bottom: 88px;
  }

  .chat-actions {
    overflow-x: auto;
    white-space: nowrap;
  }

  .reply-box,
  .message-composer,
  .composer {
    position: sticky;
    bottom: 0;
    z-index: 20;
    background: #ffffff;
    padding: 12px;
    box-shadow: 0 -8px 24px rgba(15, 23, 42, 0.12);
  }

  .quick-reply-button,
  .reply-box button,
  .message-composer button,
  .mobile-bottom-nav a {
    min-height: 44px;
    min-width: 44px;
  }

  .mobile-bottom-nav {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 30;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 4px;
    padding: 8px;
    background: #ffffff;
    border-top: 1px solid #e5e7eb;
  }

  .mobile-bottom-nav a {
    display: grid;
    place-items: center;
    color: #1f2937;
    text-decoration: none;
    font-size: 12px;
  }

  .push-permission-banner {
    position: sticky;
    top: 0;
    z-index: 40;
  }
}