/* ==========================================================================
   Small screens — sticky top bar with a separate navigation drawer
   ========================================================================== */

@media (max-width: 840px) {
  #app { display: block; }
  .mobile-topbar {
    position: sticky;
    top: 0;
    z-index: 120;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    align-items: center;
    gap: 0.85rem;
    width: 100%;
    padding: 0.7rem 1.1rem;
    background: rgba(246, 240, 225, 0.94);
    border-bottom: 1px solid var(--hairline);
    backdrop-filter: blur(8px);
  }
  .mobile-brand { display: none; }
  .mobile-nav {
    display: flex;
    grid-column: 2;
    grid-row: 1;
    flex-direction: row;
    gap: 1rem;
    min-width: 0;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    scrollbar-width: none;
  }
  .mobile-nav::-webkit-scrollbar { display: none; }
  .mobile-nav button {
    flex: 0 0 auto;
    border-left: none;
    border-bottom: 2px solid transparent;
    padding: 0.4rem 0;
    white-space: nowrap;
  }
  .mobile-nav button.active { border-left: none; border-bottom-color: var(--pink); }
  .side-toggle {
    position: static;
    width: auto;
    min-width: 2.75rem;
    min-height: 2.75rem;
    padding: 0.5rem;
    border: none;
    background: transparent;
    font-family: var(--sans);
    font-size: 1.4rem;
    box-shadow: none;
  }
  .side-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(58, 53, 44, 0.4);
    z-index: 125;
  }
  .side, body.side-collapsed .side {
    position: fixed;
    top: 0;
    left: 0;
    width: min(19rem, 85vw);
    height: 100vh;
    height: 100dvh;
    padding: 4.5rem 1.5rem max(1.5rem, env(safe-area-inset-bottom));
    background: var(--paper);
    border-right: 1px solid var(--hairline);
    z-index: 130;
    transform: translateX(-100%);
    visibility: hidden;
    overscroll-behavior: contain;
  }
  body.mobile-menu-open { overflow: hidden; }
  body.mobile-menu-open .side {
    transform: translateX(0);
    visibility: visible;
    box-shadow: 4px 0 24px rgba(58, 53, 44, 0.15);
  }
  .side-close {
    display: block;
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    width: 2.75rem;
    height: 2.75rem;
    border: 1px solid var(--hairline);
    border-radius: 2px;
    background: transparent;
    color: var(--sage-deep);
    font-size: 1.5rem;
    cursor: pointer;
  }
  .main-nav button { min-height: 2.75rem; }
  .logout-btn { min-height: 2.75rem; }
  .side-logo { width: 4.5rem; margin-bottom: 1.5rem; }
  .side-foot { margin-top: auto; padding-top: 1.5rem; }
  .side-swallow { width: 7rem; }
  main { padding: 2.6rem 1.15rem 3.5rem; }
  .section { scroll-margin-top: 5rem; }
  .letter p { font-size: 1.1rem; }
  .wall-row { grid-template-columns: 1fr; gap: 1.6rem; }
  .venue-legend { grid-template-columns: 1fr; }
  .venue-inline { display: none; }
  .venue-link-desktop { display: none; }
  .venue-link-mobile { display: inline; }
  .fort-page { padding: calc(4rem + env(safe-area-inset-top)) 1rem 3rem; }
  .wall-row .artwork:nth-child(even) { margin-top: 0; }
  .catalog { padding: 0.8rem; }
  .catalog-panel { max-height: calc(100vh - 1.6rem); max-height: calc(100dvh - 1.6rem); border-radius: 1.25rem; }
  .catalog-scroll { padding: 3.5rem 1.25rem 1.25rem; }
  .catalog-art { max-width: 17rem; margin: 0 auto; }
  .login-logo-text { font-size: 1.1rem; }
  .login-logo-mark { width: 5.2rem; }
  .code-row { flex-direction: column; }
  #login-btn { width: 100%; padding: 0.95rem; }
  .site-footer { padding: 2.2rem 1.15rem 2.6rem; }
}

@media (max-width: 840px) and (prefers-reduced-motion: reduce) {
  .side, body.side-collapsed .side { transition: none; }
}