/* ===== 公告栏主体（默认隐藏）===== */
        .announcement {
            position: fixed;
            bottom: 20px;
            right: 20px;
            width: 320px;
            background: #fff;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
            overflow: hidden;
            z-index: 9999;
            opacity: 0;
            transform: translateX(110%) translateY(10px);
            transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
        }

        .announcement.active {
            opacity: 1;
            transform: translateX(0) translateY(0);
        }

        /* 标题栏（固定置顶）*/
        .announcement-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 12px 16px;
            background: #0066cc;
            color: white;
            font-weight: bold;
            position: sticky;
            top: 0;
            z-index: 1;
        }

        .close-btn {
            background: none;
            border: none;
            color: white;
            font-size: 18px;
            cursor: pointer;
            transition: transform 0.2s;
        }
        .close-btn:hover {
            transform: scale(1.2);
        }

        /* 内容区域（支持滚动）*/
        .announcement-content {
            max-height: 200px;
            padding: 16px;
            overflow-y: auto;
            line-height: 1.6;
            color: #333;
        }

        /* 滚动条美化 */
        .announcement-content::-webkit-scrollbar {
            width: 6px;
        }
        .announcement-content::-webkit-scrollbar-thumb {
            background: #ccc;
            border-radius: 3px;
        }

        /* ===== 折叠按钮（右下角小方块）===== */
        .announcement-toggle {
            position: fixed;
            bottom: 120px;
            right: 16px;
            width: 52px;
            height: 48px;
            background: #0066cc;
            color: white;
            border: none;
            border-radius: 6px;
            font-weight: bold;
            font-size: 14px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 2px 6px rgba(0,0,0,0.15);
            z-index: 9998;
            opacity: 0;
            transform: scale(0.8);
            transition: all 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
        }

        .announcement-toggle.show {
            opacity: 1;
            transform: scale(1);
        }

        .announcement-toggle:hover {
            transform: scale(1.05);
        }

        /* 防止按钮被遮挡：公告栏展开时隐藏折叠按钮 */
        .announcement.active + .announcement-toggle {
            display: none;
        }

        /* 响应式适配（小屏微调）*/
        @media (max-width: 480px) {
            .announcement {
                width: 90vw;
                max-width: 320px;
            }
        }