/* @mentions autocomplete (only allowed dropdown-style UI; see consistency.md) */
        #mentions-dropdown-container.mentions-dropdown {
            width: 20rem;
            max-width: min(20rem, calc(100vw - 1rem));
            max-height: 18rem;
            overflow-y: auto;
            overflow-x: hidden;
            padding: 0.25rem;
            border-radius: var(--radius-xl, 0.75rem);
            border: 1px solid rgba(255, 255, 255, 0.1);
            background: rgba(var(--theme-r), var(--theme-g), var(--theme-b), calc(var(--glass-opacity) * 0.35));
            backdrop-filter: blur(var(--glass-blur)) saturate(180%);
            -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
            box-shadow: 0 16px 40px -12px rgba(0, 0, 0, 0.55);
            box-sizing: border-box;
        }
        .mentions-dropdown-item {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 0.625rem 0.75rem;
            cursor: pointer;
            border-radius: 0.5rem;
            transition: background-color 0.15s ease;
            background-color: transparent;
            min-width: 0;
        }
        .mentions-dropdown-item.mentions-dropdown-item-active {
            background-color: rgba(255, 255, 255, 0.08);
        }
        .mentions-dropdown-name {
            color: rgba(255, 255, 255, 0.92);
            font-size: 0.875rem;
            font-weight: 600;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
            min-width: 0;
            flex: 1;
        }
        /* Tailwind preflight uses img { max-width: 100% } — pin size so avatars never fill the menu width */
        #mentions-dropdown-container.mentions-dropdown .mentions-dropdown-avatar {
            width: 36px !important;
            height: 36px !important;
            max-width: 36px !important;
            max-height: 36px !important;
            border-radius: 9999px;
            object-fit: cover;
            border: 1px solid rgba(255, 255, 255, 0.12);
            flex-shrink: 0;
        }