@media (max-width: 680px) {

  /* Header */
  .art-header { padding: 10px 0; }
  .art-header-inner { padding: 0 12px; gap: 8px; justify-content: flex-start; }
  .art-back-btn { font-size: 0; gap: 0; padding: 6px; flex-shrink: 0; }
  .art-back-btn svg { width: 16px; height: 16px; }
  .art-brand { position: absolute; left: 50%; transform: translateX(-50%); pointer-events: none; white-space: nowrap; gap: 6px; }
  .art-brand-logo { width: 26px; height: 26px; }
  .art-brand-title { font-size: 14px; letter-spacing: 0.5px; white-space: nowrap; }
  .art-brand-sub { display: none; }
  .art-header-right { display: none; }

  /* Body column layout */
  .cab-body {
    display: flex;
    flex-direction: column;
    min-height: calc(100vh - 50px);
    overflow-x: hidden;
  }

  /* Sidebar as horizontal bar */
  .cab-sidebar {
    position: static;
    left: auto;
    top: auto;
    transform: none;
    width: calc(100% - 24px);
    margin: 10px 12px 0;
    border-radius: 14px;
    border: 1.5px solid #ccc8c2;
    padding: 8px 10px;
    flex-direction: row;
    justify-content: center;
    gap: 4px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.07);
    background: #fff;
    overflow-x: auto;
    scrollbar-width: none;
    transition: none;
    flex-shrink: 0;
    z-index: 10;
  }
  .cab-sidebar::-webkit-scrollbar { display: none; }
  .cab-nav-btn { flex: 0 0 auto; padding: 8px; }
  .cab-nav-btn .cab-nav-icon svg, .cab-nav-btn .cab-nav-icon .ti { width: 18px; height: 18px; font-size: 18px; }

  .cab-hover-island { display: none; }

  /* Main */
  .art-main { padding: 20px 12px 64px; max-width: 100%; }
  .art-page-title-wrap { margin-bottom: 12px; }
  .art-page-title { font-size: 22px; margin-bottom: 4px; }
  .art-page-subtitle { font-size: 13px; }

  /* Add button */
  .art-add-wrap { margin-bottom: 20px; }
  .art-add-btn { padding: 12px 24px; font-size: 13px; width: 100%; justify-content: center; }

  /* Grid single column */
  .art-grid { grid-template-columns: 1fr; gap: 14px; width: 100%; max-width: 100%; min-width: 0; overflow: hidden; }
  .art-main { overflow-x: hidden; min-width: 0; max-width: 100vw; box-sizing: border-box; }
  html, body { overflow-x: hidden; max-width: 100vw; }

  /* Card */
  .art-card { min-width: 0; max-width: calc(100vw - 24px); width: calc(100vw - 24px); overflow: hidden; box-sizing: border-box; margin: 0 auto; }
  .art-card-media-photo, .art-card-media-video { max-width: 100%; overflow: hidden; width: 100%; }
  .art-card-media-photo img, .art-card-media-video video { max-width: 100%; width: 100%; display: block; }
  .art-card-body { padding: 14px 14px 10px; min-width: 0; max-width: 100%; overflow: hidden; }
  .art-card-footer { padding: 8px 14px 12px; }
  .art-card-admin { padding: 4px 14px 8px; }
  .art-card-title {
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
    min-width: 0;
    display: block;
  }
  .art-card-media-photo { min-height: 160px; max-height: 260px; }

  /* Compose fullscreen */
  .art-compose-overlay { padding: 0; align-items: stretch; justify-content: stretch; }
  .art-compose-wrap { max-width: 100%; padding: 0; gap: 0; height: 100%; }
  .art-compose-modal {
    max-height: 100%;
    height: 100%;
    border-radius: 0;
    transform: none;
    transition: none;
  }
  .art-compose-overlay.active .art-compose-modal { transform: none; }
  .art-compose-left { min-height: 0; }
  .art-compose-editor { min-height: 200px; font-size: 16px; padding: 16px; }
  .art-compose-title-input { font-size: 16px; padding: 14px 16px 12px; }

  /* Compose actions */
  .art-compose-actions { padding: 8px 12px; gap: 8px; }

  /* Toolbar toggle button */
  .art-toolbar-toggle {
    display: flex;
    align-items: center; gap: 5px;
    background: var(--pink-soft); border: 1.5px solid var(--pink); border-radius: 8px;
    padding: 7px 14px; font-family: 'Montserrat', sans-serif; font-size: 12px; font-weight: 700;
    color: var(--pink-deep); cursor: pointer; transition: background .2s;
    flex-shrink: 0;
  }
  .art-toolbar-toggle:hover { background: #f5c8c3; }

  /* Right panel hidden, shown as overlay */
  .art-compose-right { display: none; }
  .art-compose-right.mobile-open {
    display: flex;
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    max-height: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,.5);
    z-index: 320;
    padding: 16px;
    opacity: 1;
    transform: none;
    border: none;
    border-radius: 0;
    box-shadow: none;
    overflow-y: auto;
  }
  .art-compose-right.mobile-open .art-toolbar {
    flex-direction: column;
    width: 100%;
    max-width: 320px;
    background: #fff;
    border-radius: 16px;
    padding: 16px;
    box-shadow: 0 12px 40px rgba(0,0,0,.2);
    gap: 6px;
    align-items: stretch;
  }
  .art-compose-right.mobile-open .art-tb-row { justify-content: center; flex-wrap: wrap; }
  .art-compose-right.mobile-open .art-tb-sep { width: 80%; height: 1px; margin: 4px auto; }
  .art-compose-right.mobile-open .art-cancel-btn { margin: 8px auto 0; width: 100%; max-width: 320px; background: #fff; border-radius: 12px; padding: 12px; font-size: 14px; font-weight: 600; }

  .art-compose-actions { padding: 8px 12px; padding-bottom: 56px; }
  .art-compose-media-preview { padding: 8px 12px; }

  /* Read fullscreen */
  .art-read-modal {
    width: 100%;
    max-width: 100%;
    max-height: 100%;
    height: 100%;
    border-radius: 0;
    margin: 0;
    transform: none;
    transition: none;
  }
  .art-read-overlay.active .art-read-modal { transform: none; }
  .art-read-body { padding: 48px 16px 24px; font-size: 14px; }
  .art-read-content { font-size: 14px; line-height: 1.75; }

  /* Photo modal */
  .art-photo-modal-img { max-width: 95vw; max-height: 85vh; }
  .art-photo-modal-inner { max-width: 95vw; max-height: 95vh; }

  /* Misc */
  .art-card-readmore { font-size: 11px; padding: 4px 10px; }
}