/* --- 底部输入区 --- */
        .input-area {
            padding: 20px 20px 40px 20px;
            display: flex;
            justify-content: center;
            background: linear-gradient(180deg, var(--gradient-fade) 0%, var(--gradient-fade-to) 40%);
        }

        .input-pill {
            display: flex;
            flex-direction: column;
            background-color: var(--bg-gray);
            border-radius: 24px;
            width: 100%;
            max-width: var(--chat-max-width);
            padding: 12px 16px;
            gap: 8px;
            position: relative;
        }

        .upload-icon {
            color: var(--text-muted);
            cursor: pointer;
            display: flex;
            align-items: center;
            padding: 4px;
            border-radius: 50%;
            transition: color 0.2s;
        }
        .upload-icon:hover { color: var(--text-main); }

        .input-pill textarea {
            width: 100%;
            background: transparent;
            border: none;
            outline: none;
            font-size: 15px;
            resize: none;
            height: 24px;
            line-height: 24px;
            max-height: 150px;
            color: var(--text-main);
            overflow-y: hidden;
            padding: 0;
        }
        .input-pill textarea::placeholder { color: var(--text-muted); opacity: 0.5; }

        .pill-bottom { display: flex; align-items: center; gap: 8px; width: 100%; min-width: 0; }
        .pill-toolrail {
            display: flex;
            align-items: center;
            gap: 8px;
            min-width: 0;
            flex: 1;
            overflow-x: auto;
            overflow-y: hidden;
            scrollbar-width: none !important;
        }
        .pill-toolrail::-webkit-scrollbar { display: none !important; }
        .model-info { color: var(--text-muted); font-size: 13px; white-space: nowrap; max-width: 220px; overflow: hidden; text-overflow: ellipsis; }
        .pill-toolrail .tool-icon-btn {
            width: 30px;
            height: 30px;
            min-width: 30px;
            padding: 0;
            border-radius: 10px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0;
            flex-shrink: 0;
        }
        .pill-toolrail .tool-icon-btn::after,
        .pill-toolrail .tool-icon-btn .web-tools-summary {
            display: none;
        }
        .tool-icon-text {
            position: absolute;
            width: 1px;
            height: 1px;
            overflow: hidden;
            clip: rect(0 0 0 0);
            white-space: nowrap;
        }
        .pill-toolrail .web-tools-info.active {
            color: #2a75e7;
            background: rgba(42, 117, 231, 0.1);
        }
        .pill-toolrail .context-clear-btn.tool-icon-btn {
            border: none;
            background: transparent;
            color: var(--text-muted);
            cursor: pointer;
        }
        .pill-toolrail .context-clear-btn.tool-icon-btn:hover {
            background: rgba(128,128,128,0.1);
            color: var(--text-main);
        }

        /* 按钮组：上传 + 发送，右侧对齐 */
        .action-group { display: flex; align-items: center; gap: 4px; margin-left: auto; flex-shrink: 0; }
        .action-btn { border: none; border-radius: 50%; display: flex; justify-content: center; align-items: center; cursor: pointer; transition: all 0.2s; }
        /* 上传按钮：透明背景，次要按钮 */
        .upload-action { background: transparent; color: var(--text-muted); width: 34px; height: 34px; }
        .upload-action:hover { color: var(--text-main); background: rgba(128,128,128,0.1); }
        /* 发送按钮：深色圆形主按钮 */
        .send-action { background-color: var(--black-btn); color: var(--text-on-dark); width: 34px; height: 34px; }
        .send-action:hover { opacity: 0.85; }
        .send-action .stop-icon { display: none; }
        .send-action .send-icon { display: block; }
        /* 响应中：切换为停止样式 */
        .send-action.responding { background-color: var(--text-muted); }
        .send-action.responding .stop-icon { display: block; }
        .send-action.responding .send-icon { display: none; }
        .send-action.responding:hover { opacity: 0.85; }
        /* 禁用状态：空内容时灰色不可点击 */
        .send-action.disabled { background-color: var(--border-color); color: var(--text-muted); cursor: not-allowed; opacity: 0.6; pointer-events: none; }

        /* --- 模式切换 --- */
        .mode-toggle-wrap { display: flex; align-items: center; gap: 0; }
        .mode-toggle-btn {
            padding: 6px 16px;
            font-size: 13px;
            border: 1px solid var(--border-color);
            background: var(--bg-surface);
            color: var(--text-muted);
            cursor: pointer;
            transition: all 0.15s;
            white-space: nowrap;
            font-weight: 400;
        }
        .mode-toggle-btn:first-child { border-radius: 8px 0 0 8px; }
        .mode-toggle-btn:last-child { border-radius: 0 8px 8px 0; }
        .mode-toggle-btn:not(:first-child):not(:last-child) { border-radius: 0; border-left: none; border-right: none; }
        .mode-toggle-btn + .mode-toggle-btn { border-left: none; }
        .mode-toggle-btn.active {
            background: var(--text-main);
            color: var(--text-on-dark);
            border-color: var(--text-main);
            font-weight: 500;
        }
        .mode-toggle-btn:hover:not(.active) { border-color: var(--text-muted); color: var(--text-main); }