.page-content {
            text-align: center;
            color: #6b7280;
            font-size: 20px;
            padding: 2rem;
        }
        .page-content h1 {
            font-size: 2.4rem;
            font-weight: 600;
            color: #1f2937;
            margin-bottom: 0.5rem;
        }

        /* ============================================
                   右下角悬浮按钮
        ============================================ */
        .float-btn {
            position: fixed;
            bottom: 32px;
            right: 32px;
            width: 64px;
            height: 64px;
            border-radius: 50%;
            border: none;
            background: #4f46e5;
            color: #fff;
            font-size: 30px;
            box-shadow: 0 8px 28px rgba(79, 70, 229, 0.4);
            cursor: pointer;
            transition: transform 0.25s ease, box-shadow 0.25s ease, opacity 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 999;
        }
        .float-btn:hover {
            transform: scale(1.08);
            box-shadow: 0 12px 36px rgba(79, 70, 229, 0.5);
        }
        .float-btn:active {
            transform: scale(0.94);
        }

        /* 按钮隐藏 (点击后消失) */
        .float-btn.hidden {
            opacity: 0;
            pointer-events: none;
            transform: scale(0.6);
        }

        /* ============================================
                   留言框遮罩 (全屏，但卡片在右下角)
        ============================================ */
        .message-overlay {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.30);
            backdrop-filter: blur(3px);
            -webkit-backdrop-filter: blur(3px);
            z-index: 1000;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s ease;
        }

        .message-overlay.active {
            opacity: 1;
            pointer-events: auto;
        }

        /* ============================================
                   留言卡片 — 定位在右下角，向上弹出
        ============================================ */
        .message-card {
            position: fixed;
            /* 卡片固定在右下角，位于按钮上方 */
            bottom: 100px;
            right: 32px;
            width: 420px;
            max-width: calc(100vw - 48px);
            max-height: 70vh;
            background: #ffffff;
            border-radius: 24px;
            padding: 28px 30px 32px;
            box-shadow: 0 25px 60px rgba(0, 0, 0, 0.25);
            display: flex;
            flex-direction: column;

            /* 动画：从右下角向上滑入 + 微缩放 */
            transform: translateY(30px) scale(0.94);
            opacity: 0;
            transform-origin: bottom right;
            transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1),
                        opacity 0.3s ease;
            pointer-events: none;
        }

        /* 当遮罩激活时，卡片滑入 */
        .message-overlay.active .message-card {
            transform: translateY(0) scale(1);
            opacity: 1;
            pointer-events: auto;
        }

        /* ---- 卡片头部 ---- */
        .message-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 18px;
            flex-shrink: 0;
        }
        .message-header h2 {
            font-size: 18px;
            font-weight: 600;
            color: #1f2937;
            letter-spacing: -0.01em;
        }
        .close-btn {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            border: none;
            background: #f3f4f6;
            color: #4b5563;
            font-size: 20px;
            line-height: 1;
            cursor: pointer;
            transition: background 0.2s, transform 0.15s;
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }
        .close-btn:hover {
            background: #e5e7eb;
            transform: rotate(90deg);
        }
        .close-btn:active {
            transform: rotate(90deg) scale(0.9);
        }

        /* ---- 留言框内容区 (用户可自由定制) ---- */
        .message-body {
            flex: 1;
            overflow-y: auto;
            padding-right: 4px;
        }

        /* 用户自定义内容示例 — 你可以完全替换这块 */
        .message-body .demo-placeholder {
            color: #374151;
            font-size: 18px;
            line-height: 30px;
        }
        .message-body .demo-placeholder textarea {
            width: 100%;
            min-height: 120px;
            padding: 12px 14px;
            border: 1.5px solid #d1d5db;
            border-radius: 14px;
            font-size: 0.95rem;
            font-family: inherit;
            resize: vertical;
            transition: border-color 0.2s;
            background: #fafafa;
            color: #1f2937;
        }
        .message-body .demo-placeholder textarea:focus {
            outline: none;
            border-color: #4f46e5;
            background: #ffffff;
            box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.08);
        }
        .message-body .demo-placeholder .hint {
            margin-top: 10px;
            font-size: 0.85rem;
            color: #9ca3af;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .message-body .demo-placeholder .hint svg {
            width: 18px;
            height: 18px;
            fill: none;
            stroke: #9ca3af;
            stroke-width: 2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        /* 底部操作按钮 */
        .message-footer {
            margin-top: 18px;
            display: flex;
            justify-content: flex-end;
            gap: 10px;
            flex-shrink: 0;
        }
        .message-footer .btn-send {
            padding: 10px 28px;
            border: none;
            border-radius: 40px;
            background: #4f46e5;
            color: #fff;
            font-weight: 500;
            font-size: 0.95rem;
            cursor: pointer;
            transition: background 0.2s, transform 0.15s;
            box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3);
        }
        .message-footer .btn-send:hover {
            background: #4338ca;
        }
        .message-footer .btn-send:active {
            transform: scale(0.96);
        }
        .message-footer .btn-cancel {
            padding: 10px 20px;
            border: none;
            border-radius: 40px;
            background: transparent;
            color: #6b7280;
            font-weight: 500;
            font-size: 0.95rem;
            cursor: pointer;
            transition: background 0.2s;
        }
        .message-footer .btn-cancel:hover {
            background: #f3f4f6;
        }

        /* ===== 响应式小调整 ===== */
        @media (max-width: 480px) {
            .float-btn {
                width: 56px;
                height: 56px;
                font-size: 26px;
                bottom: 20px;
                right: 20px;
            }
            .message-card {
                right: 16px;
                bottom: 84px;
                padding: 22px 18px 24px;
                max-width: calc(100vw - 32px);
            }
            .message-header h2 {
                font-size: 1.1rem;
            }
        }