@media (max-width: 767px) {
  body { font-size: 16px; }
  .main-header { padding: 0 12px; }
  .header-logo span { font-size: 18px; }
  .header-right { gap: 6px; }
  .header-center { display: none; }
  .online-members-popover {
    right: -6px;
    min-width: 180px;
    grid-template-columns: 1fr;
  }
  .online-member-stack-avatar {
    width: 28px;
    height: 28px;
  }
  .my-page-btn { padding: 2px 2px 2px 0; gap: 6px; }
  .header-avatar { width: 34px; height: 34px; flex-basis: 34px; }
  .profile-menu-caret { width: 12px; height: 12px; }
  .profile-menu-caret svg { width: 12px; height: 12px; }
  .my-page-label { display: none; }
  .shell { display: block; }
  .sidebar { display: none; }
  .content { padding: 16px; padding-bottom: 88px; }
  .bottom-nav {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(54px, 1fr));
    gap: 4px;
    padding: 8px;
    background: var(--panel);
    border-top: 1px solid var(--line);
    box-shadow: 0 -1px 4px rgba(60,64,67,0.10);
    z-index: 100;
  }
  .bottom-nav a {
    text-align: center;
    padding: 8px 4px;
    border-radius: 8px;
    font-size: 12px;
    color: var(--muted);
  }
  .bottom-nav a.active {
    background: rgba(26, 115, 232, 0.12);
    color: var(--accent);
    font-weight: 700;
  }
  .bottom-nav a.active .bottom-nav-label,
  .bottom-nav a.active .bottom-nav-icon {
    color: var(--accent) !important;
  }
  .bottom-nav > * {
    display: flex;
    min-width: 0;
    justify-self: stretch;
    align-self: stretch;
  }
  .bottom-nav .bottom-nav-entry,
  .bottom-nav .bottom-nav-profile-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    width: 100%;
    min-width: 0;
    min-height: 56px;
    height: 56px;
    padding: 8px 4px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    color: var(--muted);
    text-align: center;
    text-decoration: none;
    background: transparent !important;
    box-shadow: none !important;
  }
  .bottom-nav .bottom-nav-link,
  .bottom-nav .bottom-nav-profile-item {
    flex: 1 1 0;
  }
  .bottom-nav .bottom-nav-icon,
  .bottom-nav .bottom-nav-profile-avatar {
    width: 22px;
    height: 22px;
    flex: 0 0 22px;
  }
  .bottom-nav .bottom-nav-profile-btn {
    all: unset;
    box-sizing: border-box;
    cursor: pointer;
    transition: background-color 0.18s ease, color 0.18s ease;
  }
  .bottom-nav .bottom-nav-profile-btn:active {
    transform: none;
  }
  .bottom-nav .bottom-nav-profile-avatar {
    border-radius: 50%;
    object-fit: cover;
    border: 1.25px solid #fff;
    box-shadow: 0 0 0 1px rgba(17, 24, 39, 0.06);
  }
  .bottom-nav .bottom-nav-profile-item .bottom-nav-profile-btn {
    background: transparent !important;
    color: var(--muted) !important;
  }
  .bottom-nav .bottom-nav-profile-item.is-open .bottom-nav-entry,
  .bottom-nav .bottom-nav-profile-item.is-open .bottom-nav-profile-btn {
    background: rgba(26, 115, 232, 0.12) !important;
    color: var(--accent) !important;
    font-weight: 700;
  }
  .bottom-nav .bottom-nav-profile-item.is-open .bottom-nav-label {
    color: var(--accent) !important;
  }
  .profile-menu--bottom-nav > #my-page-btn {
    display: none !important;
  }
  .dash-profile-area { padding: 24px 12px 16px; }
  .dash-avatar { width: 72px; height: 72px; }
  .dash-user-name { font-size: 18px; }
  .dash-chips { gap: 6px; }
  .dash-chip { font-size: 13px; padding: 6px 12px; }

  /* フォトグリッド: モバイルでは2列に */
  .photo-grid { columns: 2; }
  .grid { grid-template-columns: 1fr; }
}