:root {
      --bg-color: #ffffff;
      --sidebar-bg: #f0f4f9;
      --text-primary: #1f1f1f;
      --text-secondary: #444746;
      --input-bg: #f0f4f9;
      --user-msg-bg: #f0f4f9;
      --hover-color: #e1e5ea;
      --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      --accent-color: #1a73e8;
      --border-radius-md: 16px;
    }

    * { margin: 0; padding: 0; box-sizing: border-box; }
    html { height: 100%; }
    body {
      font-family: var(--font-family);
      background-color: var(--bg-color);
      color: var(--text-primary); display: flex; height: 100%; height: 100dvh;
      overflow: hidden; width: 100%;
    }

    /* 侧边栏 */
    .sidebar { width: 280px; background-color: var(--sidebar-bg); padding: 16px 12px; display: flex; flex-direction: column; transition: width 0.3s ease; flex-shrink: 0; z-index: 10;}
    .menu-btn { width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; font-size: 20px; }
    .menu-btn:hover { background-color: var(--hover-color); }
    .new-chat-btn { margin-top: 24px; display: inline-flex; align-items: center; gap: 12px; padding: 12px 16px; background-color: var(--hover-color); border-radius: 50px; cursor: pointer; font-weight: 500; font-size: 14px; transition: background 0.2s; width: fit-content; }
    .new-chat-btn:hover { background-color: #d3d7dc; }
    .recent-section { margin-top: 32px; flex-grow: 1; overflow-y: auto; }
    .recent-title { font-size: 14px; color: var(--text-secondary); margin-bottom: 12px; padding-left: 12px; }
    .recent-item { padding: 10px 12px; border-radius: 8px; cursor: pointer; font-size: 14px; display: flex; align-items: center; gap: 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .recent-item:hover { background-color: var(--hover-color); }

    /* 主体内容区 */
    .main-content { flex-grow: 1; display: flex; flex-direction: column; position: relative; min-height: 0; min-width: 0; background-color: var(--bg-color);}
    header { padding: 16px 24px; display: flex; justify-content: space-between; align-items: center; font-size: 22px; flex-shrink: 0;}
    header .title { display: flex; align-items: center; gap: 8px; cursor: pointer; color: var(--text-secondary); }
    
    /* 彩虹头像 */
    .user-avatar {
      width: 32px; height: 32px; border-radius: 50%; color: white; display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: bold; border: 2px solid transparent;
      background: linear-gradient(#1a73e8, #1a73e8) padding-box, conic-gradient(#4285f4, #9b72cb, #d96570, #f4b400, #34a853, #4285f4) border-box; cursor: pointer;
    }

    /* 核心布局：工作区 */
    .workspace { display: flex; flex: 1; overflow: hidden; position: relative; width: 100%; height: 100%; }

    /* 左侧聊天区 */
    .chat-section { flex: 1; display: flex; flex-direction: column; position: relative; min-width: 400px; }

    .chat-container { flex-grow: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column; align-items: center; scroll-behavior: smooth; }
    .chat-content { width: 100%; max-width: 800px; display: flex; flex-direction: column; gap: 24px; padding-bottom: 120px; }
    
    /* 欢迎语与快捷按钮 */
    .greeting { margin-top: 40px; margin-bottom: 40px; display: flex; flex-direction: column; align-items: flex-start; width: 100%; max-width: 800px; }
    .greeting h1 { font-size: 56px; font-weight: 500; background: -webkit-linear-gradient(16deg, #4b90ff, #ff5546); -webkit-background-clip: text; -webkit-text-fill-color: transparent; margin-bottom: 10px; }
    .greeting p { font-size: 56px; color: #c4c7c5; font-weight: 500; line-height: 1.1; margin-bottom: 40px; }
    .suggestion-chips { display: none; gap: 12px; flex-wrap: wrap; }
    .chip { padding: 12px 16px; border-radius: 24px; border: 1px solid #e0e0e0; font-size: 14px; color: var(--text-secondary); cursor: pointer; transition: all 0.2s; background: var(--bg-color); white-space: nowrap; display: flex; align-items: center; gap: 8px; }
    .chip:hover { background-color: var(--hover-color); border-color: transparent; }

    /* 聊天气泡 */
    .message-row { display: flex; gap: 16px; width: 100%; }
    .message-row.user { justify-content: flex-end; }
    .message-avatar { width: 32px; height: 32px; border-radius: 50%; flex-shrink: 0; display: flex; align-items: center; justify-content: center; }
    .message-avatar.img-avatar { background: none; border-radius: 0; }
    .message-avatar.img-avatar img { width: 100%; height: 100%; object-fit: contain; }
    .message-bubble { max-width: 80%; padding: 12px 16px; font-size: 16px; line-height: 1.6; white-space: pre-wrap; word-break: break-word; }
    .message-row.user .message-bubble { background-color: var(--user-msg-bg); border-radius: 24px 8px 24px 24px; }
    .message-row.ai .message-bubble { border-radius: 8px 24px 24px 24px; padding: 4px 16px 12px 0; }

    /* 右侧 Artifact 面板 */
    .artifact-panel { width: 0; min-width: 0; margin: 0; background: #ffffff; border-radius: 16px; border: none; display: flex; flex-direction: column; transition: all 0.3s cubic-bezier(0.2, 0, 0, 1); overflow: hidden; box-shadow: 0 8px 24px rgba(0,0,0,0.05); opacity: 0; visibility: hidden; z-index: 20; }
    .artifact-panel.active { width: 50%; min-width: 550px; margin: 0 16px 16px 0; border: 1px solid #e0e0e0; opacity: 1; visibility: visible; }
    .artifact-header { padding: 12px 16px; border-bottom: 1px solid #e0e0e0; display: flex; justify-content: space-between; align-items: center; background: #ffffff; flex-shrink: 0; }
    .artifact-title { font-weight: 600; font-size: 14px; display: flex; align-items: center; gap: 8px; color: var(--text-primary);}
    .artifact-tabs { display: flex; background: #f0f4f9; border-radius: 8px; padding: 4px; }
    .artifact-tab { padding: 6px 16px; font-size: 13px; border-radius: 6px; cursor: pointer; font-weight: 500; color: #444746; transition: background 0.2s;}
    .artifact-tab.active { background: #ffffff; color: #1f1f1f; box-shadow: 0 1px 2px rgba(0,0,0,0.1); }
    .artifact-actions { display: flex; gap: 8px; align-items: center; }
    .artifact-action-btn { background: none; border: none; cursor: pointer; padding: 8px; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: var(--text-secondary); transition: 0.2s;}
    .artifact-action-btn:hover { background: #f0f4f9; color: var(--text-primary);}
    .artifact-content { flex-grow: 1; position: relative; overflow: hidden; background: #f8f9fa;}
    .artifact-code, .artifact-preview { position: absolute; top: 0; left: 0; right: 0; bottom: 0; display: none; overflow: auto; }
    .artifact-code.active, .artifact-preview.active { display: block; }
    .artifact-code pre { margin: 0; padding: 20px; font-family: Consolas, monospace; font-size: 13px; color: #1f1f1f; white-space: pre-wrap; word-break: break-all;}
    .artifact-preview iframe { width: 100%; height: 100%; border: none; background: #ffffff;}

    /* 编程代码框样式 */
    .code-block-container { background-color: #1e1e1e; color: #d4d4d4; border-radius: 8px; font-family: 'Courier New', Consolas, monospace; font-size: 14px; margin: 16px 0; overflow: hidden; box-shadow: 0 4px 6px rgba(0,0,0,0.1); }
    .code-header { background-color: #2d2d2d; color: #a0a0a0; padding: 8px 16px; font-size: 12px; display: flex; justify-content: space-between; align-items: center; user-select: none; }
    .copy-btn { cursor: pointer; transition: color 0.2s; }
    .copy-btn:hover { color: #ffffff; }
    .code-body { padding: 16px; overflow-x: auto; white-space: pre; margin: 0; display: block; }

    /* 底部输入区 */
    .input-wrapper { position: absolute; bottom: 0; left: 0; right: 0; padding: 20px; background: linear-gradient(to top, rgba(255,255,255,1) 60%, rgba(255,255,255,0)); display: flex; justify-content: center; z-index: 100;}
    .input-box { width: 100%; max-width: 820px; background-color: var(--input-bg); border-radius: 32px; padding: 8px 16px; display: flex; align-items: flex-end; gap: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.1); position: relative; flex-wrap: wrap; }
    .input-box input[type="text"] { flex-grow: 1; border: none; background: transparent; padding: 14px 0 14px 8px; font-size: 16px; outline: none; color: var(--text-primary); }
    .input-box input[type="text"]::placeholder { color: #72777a; }
    .icon-btn { width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; border: none; background: transparent; font-size: 18px; color: var(--text-secondary); margin-bottom: 4px; transition: background 0.2s; flex-shrink: 0; position: relative; z-index: 105;}
    .icon-btn:hover { background-color: rgba(0,0,0,0.05); }
    .send-btn { color: #1a73e8; display: none; }

    .loading-spinner { display: inline-block; width: 20px; height: 20px; border: 3px solid rgba(26, 115, 232, 0.2); border-radius: 50%; border-top-color: #1a73e8; animation: spin 1s ease-in-out infinite; margin-top: 5px; }
    @keyframes spin { to { transform: rotate(360deg); } }

    /* Canvas 量子模拟器样式 */
    .simulator-card { background: #ffffff; border: 1px solid #e0e0e0; border-radius: 12px; padding: 16px; margin: 16px 0; box-shadow: 0 4px 12px rgba(0,0,0,0.05); width: 100%; max-width: 600px; }
    .simulator-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
    .simulator-title { font-weight: bold; font-size: 15px; color: #1f1f1f; display: flex; align-items: center; gap: 8px;}
    .simulator-title svg { fill: #1a73e8; width: 20px; height: 20px; }
    .canvas-container { width: 100%; height: 200px; background: #000; border-radius: 8px; overflow: hidden; position: relative; }
    canvas { width: 100%; height: 100%; display: block; }
    .observe-toggle { display: flex; align-items: center; gap: 8px; font-size: 14px; color: #444746; cursor: pointer;}
    .toggle-track { width: 36px; height: 20px; background: #b1b5ba; border-radius: 10px; position: relative; transition: 0.3s; }
    .toggle-track::after { content: ''; position: absolute; top: 2px; left: 2px; width: 16px; height: 16px; background: white; border-radius: 50%; transition: 0.3s; }
    .observe-toggle.active .toggle-track { background: #1a73e8; }
    .observe-toggle.active .toggle-track::after { transform: translateX(16px); }

    /* 菜单弹窗 */
    .overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; z-index: 90; display: none; }
    .overlay.active { display: block; }
    .model-selector-btn { display: flex; align-items: center; gap: 2px; padding: 8px 12px; margin-bottom: 6px; border-radius: 16px; font-size: 14px; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: background 0.2s; position: relative; z-index: 105; }
    .model-selector-btn:hover { background-color: rgba(0,0,0,0.05); color: var(--text-primary); }
    .gemini-dropdown { position: absolute; bottom: calc(100% + 12px); background: var(--bg-color); border-radius: var(--border-radius-md); box-shadow: 0 4px 16px rgba(0,0,0,0.1); border: 1px solid #e0e0e0; opacity: 0; visibility: hidden; pointer-events: none; transform: translateY(10px); transition: all 0.2s cubic-bezier(0.2, 0, 0, 1); z-index: 200; overflow: hidden; display: block !important; }
    .gemini-dropdown.active { opacity: 1; visibility: visible; pointer-events: auto; transform: translateY(0); }
    .model-menu { right: 50px; width: 120px; }
    .menu-item { padding: 12px 16px; font-size: 14px; cursor: pointer; display: flex; align-items: center; justify-content: space-between; }
    .menu-item:hover { background-color: var(--hover-color); }
    .menu-item.active { color: var(--accent-color); font-weight: 500; }
    .menu-item.active::after { content: "✓"; font-weight: bold; }
    .tools-panel { position: absolute; bottom: calc(100% + 12px); background: var(--bg-color); border-radius: var(--border-radius-md); box-shadow: 0 8px 24px rgba(0,0,0,0.15); border: 1px solid #e0e0e0; padding: 8px 0; opacity: 0; visibility: hidden; pointer-events: none; transform: translateY(10px) scale(0.95); transform-origin: bottom left; transition: all 0.2s cubic-bezier(0.2, 0, 0, 1); z-index: 200; display: block !important; }
    .tools-panel.active { opacity: 1; visibility: visible; pointer-events: auto; transform: translateY(0) scale(1); }
    .tool-item { display: flex; align-items: center; gap: 12px; padding: 12px 16px; font-size: 14px; color: var(--text-primary); cursor: pointer; }
    .tool-item:hover { background-color: var(--hover-color); }
    .tool-item svg { width: 20px; height: 20px; color: var(--text-secondary); fill: currentColor;}
    .tool-badge { margin-left: auto; background: linear-gradient(90deg, #4285f4, #9b72cb); color: white; font-size: 10px; font-weight: bold; padding: 2px 6px; border-radius: 8px; }
    .tool-section-title { font-size: 12px; font-weight: 600; color: var(--text-secondary); padding: 16px 16px 8px 16px; text-transform: uppercase; letter-spacing: 0.5px; }
    .tool-divider { height: 1px; background-color: #e0e0e0; margin: 4px 0; }
    .toggle-switch { position: relative; width: 36px; height: 20px; margin-left: auto; background-color: #b1b5ba; border-radius: 10px; transition: 0.3s; }
    .toggle-switch::after { content: ''; position: absolute; top: 2px; left: 2px; width: 16px; height: 16px; background: white; border-radius: 50%; transition: 0.3s; box-shadow: 0 1px 2px rgba(0,0,0,0.2); }
    .tool-item.toggled .toggle-switch { background-color: var(--accent-color); }
    .tool-item.toggled .toggle-switch::after { transform: translateX(16px); }

    /* 购买引导弹窗样式 */
    .paywall-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background-color: rgba(255, 255, 255, 0.8); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); z-index: 2000; display: none; align-items: center; justify-content: center; opacity: 0; transition: opacity 0.3s ease; }
    .paywall-overlay.is-visible { display: flex !important; opacity: 1; }
    .paywall-modal { background: var(--bg-color); width: 90%; max-width: 750px; border-radius: var(--border-radius-md); box-shadow: 0 12px 40px rgba(0,0,0,0.12); padding: 40px; text-align: left; border: 1px solid #e0e0e0; transform: translateY(20px); transition: transform 0.3s cubic-bezier(0.2, 0, 0, 1); max-height: 90vh; overflow-y: auto; }
    .paywall-overlay.is-visible .paywall-modal { transform: translateY(0); }
    .paywall-icon { margin-bottom: 20px; text-align: center; }
    .paywall-title { font-size: 26px; font-weight: 600; color: var(--text-primary); margin-bottom: 12px; text-align: center; }
    .paywall-desc { font-size: 15px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 30px; text-align: center; max-width: 650px; margin-left: auto; margin-right: auto; }
    .premium-features-title { font-size: 18px; font-weight: bold; color: var(--text-primary); margin-bottom: 16px; }
    .features-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 40px; }
    .feature-category { font-size: 15px; font-weight: bold; color: var(--text-primary); margin: 16px 0 12px 0; }
    .feature-category:first-child { margin-top: 0; }
    .feature-item { display: flex; align-items: flex-start; font-size: 14px; color: var(--text-primary); margin-bottom: 14px; line-height: 1.5; }
    .feature-check { width: 16px; height: 16px; margin-right: 6px; margin-top: 2px; flex-shrink: 0; color: var(--text-primary); }
    .feature-icon { width: 20px; height: 20px; margin-right: 10px; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-size: 16px; }
    .feature-text { flex: 1; }
    .paywall-actions { display: flex; flex-direction: column; gap: 8px; margin-top: 24px; align-items: center;}
    .paywall-btn { padding: 12px 24px; border-radius: 50px; font-size: 15px; font-weight: 500; cursor: pointer; border: none; transition: background 0.2s; width: 100%; max-width: 400px; }
    .paywall-btn.primary { background-color: var(--accent-color); color: white; }
    .paywall-btn.primary:hover { background-color: #1557b0; }
    .paywall-btn.secondary { background-color: transparent; color: var(--text-secondary); }
    .paywall-btn.secondary:hover { background-color: var(--hover-color); }

    /* =======================================================
       支付聚合弹窗与视觉营销样式
       ======================================================= */
    .payment-modal-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background-color: rgba(0, 0, 0, 0.6); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); z-index: 4000; display: none; overflow-y: auto; align-items: center; justify-content: center; padding: 20px; }
    .payment-modal-overlay.is-visible { display: flex !important; }

    .pricing-container { background: #ffffff; border-radius: 20px; padding: 50px 40px; margin: auto; max-width: 1100px; width: 100%; box-shadow: 0 10px 30px rgba(0,0,0,0.05); position: relative; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; }

    .pricing-close-btn { position: absolute; top: 20px; right: 20px; background: #f3f4f6; color: #6b7280; width: 32px; height: 32px; border-radius: 50%; display: flex; align-items: center; justify-content: center; text-decoration: none; font-size: 20px; font-weight: bold; transition: all 0.2s; border: none; cursor: pointer; z-index: 100;}
    .pricing-close-btn:hover { background: #e5e7eb; color: #374151; text-decoration: none; }

    /* 顶部紧迫感提示 */
    .promo-banner { background: #fff5f5; border: 1px solid #feb2b2; color: #c53030; padding: 10px; border-radius: 12px; margin-bottom: 20px; text-align: center; font-weight: bold; font-size: 14px; animation: pulse 2s infinite; margin-top: 40px;}
    @keyframes pulse { 0% { transform: scale(1); } 50% { transform: scale(1.01); } 100% { transform: scale(1); } }
    
    /* 模拟悬浮购买记录 (桌面端) */
    .purchase-ticker { 
        position: absolute; top: 30px; left: 40px; /* 悬浮定位 */
        background: rgba(248, 250, 252, 0.95); backdrop-filter: blur(8px);
        border-radius: 50px; padding: 0 20px; 
        height: 36px; overflow: hidden; 
        border: 1px solid rgba(226, 232, 240, 0.8); z-index: 90;
        box-shadow: 0 4px 15px rgba(0,0,0,0.08);
        max-width: 400px;
    }
    .ticker-content { transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1); }
    .ticker-item { 
        height: 36px; line-height: 36px; font-size: 13px; color: #475569; font-weight: 500;
        white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: block;
    }

    .page-title { text-align: left; color: #4A6BFF; font-size: 30px; font-weight: 900; margin-bottom: 12px; letter-spacing: 1px; }
    .page-subtitle { text-align: left; color: #4b5563; font-size: 15px; margin-bottom: 25px; line-height: 1.6; }
    
    .cs-btn-wrapper { text-align: left; margin-bottom: 40px; }
    .cs-btn { background: #F0F4FF; color: #4A6BFF; border: none; padding: 8px 20px; border-radius: 20px; font-size: 14px; font-weight: 500; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; transition: opacity 0.2s; }
    .cs-btn:hover { opacity: 0.8; }

    .cards-wrapper { display: flex; flex-wrap: wrap; gap: 24px; justify-content: center; align-items: stretch; }

    .plan-card { flex: 1; min-width: 280px; max-width: 330px; border-radius: 16px; padding: 40px 24px 30px 24px; position: relative; display: flex; flex-direction: column; transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease; cursor: pointer; border: 2px solid transparent; }
    .plan-card.selected-card { transform: translateY(-5px) scale(1.03) !important; z-index: 20; }
    
    /* 金牌推荐标签样式 */
    .card-pro .recommend-label { position: absolute; top: -14px; left: 50%; transform: translateX(-50%); background: #1a73e8; color: white; padding: 4px 14px; border-radius: 50px; font-size: 12px; font-weight: bold; white-space: nowrap; box-shadow: 0 4px 10px rgba(26, 115, 232, 0.3); z-index: 30; }

    .plan-tag { position: absolute; top: -1px; right: -1px; padding: 6px 16px; font-size: 12px; font-weight: bold; border-bottom-left-radius: 12px; border-top-right-radius: 16px; }
    .plan-title { font-size: 15px; line-height: 1.6; margin-bottom: 25px; height: 48px; }
    .plan-price { font-size: 52px; font-weight: 900; margin-bottom: 5px; display: flex; align-items: baseline; flex-wrap: wrap; gap: 4px; }
    .plan-price .currency { font-size: 24px; margin-right: 0; font-weight: normal; }
    .plan-price .unit { font-size: 16px; font-weight: normal; margin-left: 0; color:#6b7280; }
    
    .price-compare { font-size: 13px; color: #ef4444; font-weight: bold; margin-bottom: 15px; display: block; width: 100%; text-align: left;}
    .price-compare span { text-decoration: line-through; color: #9ca3af; font-weight: normal; margin-right: 6px;}
    
    .plan-features { list-style: none; padding: 0; margin: 0 0 40px 0; flex-grow: 1; }
    .plan-features li { display: flex; align-items: flex-start; gap: 10px; font-size: 13px; margin-bottom: 18px; line-height: 1.5; }
    .plan-features li svg { flex-shrink: 0; width: 18px; height: 18px; margin-top: 1px; }

    .plan-btn { width: 100%; padding: 14px; border-radius: 8px; font-size: 16px; font-weight: bold; border: none; cursor: pointer; transition: all 0.2s; margin-top: auto; }
    .plan-btn:hover { opacity: 0.9; transform: translateY(-1px); }

    .card-basic { order: 3; border: 2px solid #e5e7eb; background: #fff; }
    .card-basic.selected-card { border-color: #1a73e8 !important; box-shadow: 0 0 0 4px rgba(26, 115, 232, 0.15), 0 10px 30px rgba(0,0,0,0.1) !important; }
    .card-basic .plan-title { color: #111; font-weight: 600; }
    .card-basic .plan-price { color: #111; }
    .card-basic .plan-features li { color: #374151; }
    .card-basic .plan-features li svg { color: #10b981; }
    .card-basic .plan-btn { background: #f3f4f6; color: #111; }

    .card-pro { order: 1; border: 2px solid #1a73e8 !important; background: #fff; box-shadow: 0 10px 25px rgba(26, 115, 232, 0.15) !important; animation: border-glow 3s infinite; z-index: 10; }
    @keyframes border-glow { 0% { border-color: #1a73e8; box-shadow: 0 0 5px rgba(26, 115, 232, 0.2); } 50% { border-color: #4285f4; box-shadow: 0 0 20px rgba(26, 115, 232, 0.5); } 100% { border-color: #1a73e8; box-shadow: 0 0 5px rgba(26, 115, 232, 0.2); } }
    .card-pro .plan-tag { background: #2563EB; color: #fff; }
    .card-pro .plan-title { color: #111; font-weight: 600; }
    .card-pro .plan-price { color: #111; }
    .card-pro .plan-features li { color: #374151; }
    .card-pro .plan-features li svg { color: #10b981; }
    .card-pro .plan-btn { background: #2563EB; color: #fff; }

    .card-premium { order: 2; background: #262626; border: 2px solid #262626; }
    .card-premium.selected-card { border-color: #F59E0B !important; box-shadow: 0 0 0 4px rgba(245, 158, 11, 0.15), 0 10px 30px rgba(0,0,0,0.1) !important; }
    .card-premium .plan-tag { background: #F59E0B; color: #111; }
    .card-premium .plan-title { color: #fff; font-weight: 600; }
    .card-premium .plan-price { color: #fff; }
    .card-premium .plan-price .unit { color: #9ca3af; }
    .card-premium .plan-features li { color: #e5e7eb; }
    .card-premium .plan-features li svg { color: #F59E0B; }
    .card-premium .plan-btn { background: #F59E0B; color: #111; }

    .payment-section { margin-top: 50px; padding-top: 30px; border-top: 1px dashed #e5e7eb; }
    #captcha { max-width: 320px; margin: 15px auto; border-radius: 8px; border: 1px solid #eee; }

    /* ==========================================================
       移动端响应式修改 (解决裁切、层叠与悬浮排版问题)
       ========================================================== */
    @media (max-width: 1024px) {
      .artifact-panel.active { position: absolute; right:0; top:0; bottom:0; width: 100%; min-width: 100%; margin: 0; border-radius: 0; border: none; z-index: 200;}
    }

    @media (max-width: 768px) {
      .sidebar { display: none; }
      .greeting h1, .greeting p { font-size: 40px; }
      .greeting p { margin-bottom: 24px; }
      .message-bubble { max-width: 90%; }
      .suggestion-chips { display: flex; }
      .chip { font-size: 13px; padding: 10px 14px; }
      .paywall-modal { padding: 16px 12px; width: 96%; max-height: 98vh; }
      .paywall-icon { margin-bottom: 8px; }
      .paywall-icon svg { width: 36px; height: 36px; }
      .paywall-title { font-size: 18px; margin-bottom: 8px; }
      .paywall-desc { font-size: 12px; margin-bottom: 12px; line-height: 1.4; }
      
      .payment-modal-overlay { padding: 8px; align-items: center; }
      
      /* 修改为 auto 防止内容多被裁掉一半 */
      .pricing-container { padding: 16px 12px; border-radius: 16px; width: 100%; max-height: 96vh; overflow-y: auto; display: flex; flex-direction: column; }
      
      .pricing-close-btn { top: 8px; right: 8px; width: 28px; height: 28px; font-size: 18px; z-index: 100;}

      .page-title { font-size: 18px; margin-bottom: 4px; text-align: center; }
      .page-subtitle { font-size: 11px; margin-bottom: 8px; text-align: center; line-height: 1.2; display: block;}
      
      .cs-btn-wrapper { text-align: center; margin-bottom: 8px; display: block;}
      .cs-btn { padding: 4px 12px; font-size: 12px; }
      
      .card-pro .recommend-label { font-size: 9px; padding: 2px 6px; top: -8px; }
      .price-compare { font-size: 9px; margin-bottom: 4px; display: block; line-height:1.1;}
      .price-compare span { display: block; margin-right: 0;}
      
      .promo-banner { font-size: 10px; padding: 6px; margin-bottom: 8px; margin-top: 35px; /* 给悬浮横幅留出空间 */}
      
      /* 模拟悬浮购买记录 (手机端) */
      .purchase-ticker { 
          top: 10px; left: 10px; right: 45px; /* 避开关闭按钮 */
          height: 28px; padding: 0 10px; margin: 0;
          background: rgba(255, 255, 255, 0.95);
          box-shadow: 0 2px 10px rgba(0,0,0,0.1);
      }
      .ticker-item { 
          height: 28px; line-height: 28px; font-size: 10px; 
          /* 强制单行，超出省略号，避免变成两排显示不全 */
          white-space: nowrap; overflow: hidden; text-overflow: ellipsis; 
          display: block; text-align: left; /* 手机端靠左更自然 */
      }

      .cards-wrapper { flex-direction: row; flex-wrap: nowrap; overflow: visible; gap: 6px; padding-bottom: 8px; margin-bottom: 0; justify-content: space-between; align-items: stretch; }
      .cards-wrapper::-webkit-scrollbar { display: none; }

      .plan-card { flex: 1; min-width: 0; max-width: 33.33%; padding: 14px 4px 10px 4px; border-radius: 10px; display: flex; flex-direction: column; }
      .plan-card.selected-card { transform: translateY(-2px) scale(1.02) !important; z-index: 10; }
      
      .card-pro { order: 1; }
      .card-premium { order: 2; }
      .card-basic { order: 3; }
      
      .plan-tag { padding: 2px 6px; font-size: 9px; top: -1px; right: -1px; border-bottom-left-radius: 8px; border-top-right-radius: 10px; }
      .plan-title { font-size: 11px; margin-bottom: 6px; line-height: 1.2; height: auto; padding-right: 0;}
      .plan-price { font-size: 18px; margin-bottom: 4px; align-items: baseline; flex-wrap: wrap; gap: 2px;}
      .plan-price .currency { font-size: 12px; }
      .plan-price .unit { font-size: 10px; }
      
      .plan-features { display: block; margin-bottom: 8px; flex-grow: 1; }
      .plan-features li { width: 100%; font-size: 10px; margin-bottom: 4px; align-items: flex-start; gap: 2px;}
      .plan-features li svg { width: 10px; height: 10px; margin-top: 2px;}
      
      .plan-btn { padding: 6px; font-size: 12px; border-radius: 6px; margin-top: auto;}

      /* 增加 padding-bottom 防止贴底被裁切 */
      .payment-section { margin-top: 0; padding-top: 8px; padding-bottom: 16px; border-top: 1px solid #e5e7eb; flex-shrink: 0;}
      .payment-section .form-group { margin-bottom: 8px; }
      #contact_info { height: 36px; font-size: 13px; }
      
      /* 添加 flex-wrap 防止支付选项过多导致错乱 */
      .btn-group { display: flex !important; flex-direction: row; flex-wrap: wrap; gap: 8px; width: 100%; justify-content: center; }
      .btn-group .btn { flex: 1; border-radius: 6px !important; border: 1px solid #d1d5db !important; padding: 8px 4px !important; margin: 0 !important; float: none !important; font-size: 12px; background: #ffffff !important; color: #4b5563 !important; display: flex; align-items: center; justify-content: center; gap: 4px; box-shadow: none !important; transition: all 0.2s; }
      .btn-group .btn.active { border-color: #1a73e8 !important; background: #e8f0fe !important; color: #1a73e8 !important; font-weight: bold; }
      
      #captcha { margin: 0 auto; max-width: 100%; padding: 2px; }

      .input-wrapper { padding: 10px 4px; }
      .input-box { padding: 6px 8px; border-radius: 24px; gap: 4px; }
      .input-box input[type="text"] { font-size: 15px; padding: 12px 0 12px 4px; }
      .send-btn { width: 44px; height: 44px; margin-right: -4px; }
      .send-btn svg { width: 32px !important; height: 32px !important; fill: #1a73e8; }
    }

    /* 权限拦截提示弹窗样式 */
    .limit-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background-color: rgba(255, 255, 255, 0.8); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); z-index: 2500; display: none; align-items: center; justify-content: center; opacity: 0; transition: opacity 0.3s ease; }
    .limit-overlay.is-visible { display: flex !important; opacity: 1; }
    .limit-modal { background: var(--bg-color); width: 90%; max-width: 480px; border-radius: var(--border-radius-md); box-shadow: 0 12px 40px rgba(0,0,0,0.12); padding: 40px 30px; text-align: center; border: 1px solid #e0e0e0; transform: translateY(20px); transition: transform 0.3s cubic-bezier(0.2, 0, 0, 1); }
    .limit-overlay.is-visible .limit-modal { transform: translateY(0); }
    .limit-icon { font-size: 48px; margin-bottom: 16px; }
    .limit-title { font-size: 22px; font-weight: 600; color: var(--text-primary); margin-bottom: 12px; }
    .limit-desc { font-size: 15px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 20px; text-align: left; }
    .limit-list { text-align: left; font-size: 14px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 28px; padding-left: 0; list-style: none; }
    .limit-list li { display: flex; align-items: flex-start; gap: 8px; margin-bottom: 8px; }
    .limit-list li::before { content: "✅"; font-size: 14px; }
    .limit-btn { background-color: var(--accent-color); color: white; border: none; padding: 12px 20px; border-radius: 50px; font-size: 15px; font-weight: 500; cursor: pointer; width: 100%; transition: background 0.2s; margin-bottom: 12px; box-shadow: 0 2px 6px rgba(26,115,232,0.3); }
    .limit-btn:hover { background-color: #1557b0; }
    .limit-close { background: transparent; color: var(--text-secondary); border: none; padding: 8px; font-size: 14px; cursor: pointer; transition: color 0.2s; }
    .limit-close:hover { color: var(--text-primary); }

    /* 文件上传预览标签样式 */
    .file-preview-area { width: 100%; display: none; padding-left: 48px; margin-top: 4px; margin-bottom: 4px; animation: fadeIn 0.3s ease; }
    .file-tag { display: inline-flex; align-items: center; gap: 8px; background-color: #ffffff; border: 1px solid #d1d5db; padding: 6px 14px; border-radius: 16px; font-size: 13px; color: #1f1f1f; box-shadow: 0 1px 3px rgba(0,0,0,0.05); }
    .file-tag svg { width: 16px; height: 16px; fill: #1a73e8; }
    .remove-file-btn { background: none; border: none; font-size: 18px; color: #72777a; cursor: pointer; display: flex; align-items: center; justify-content: center; padding: 0 2px; margin-left: 4px; line-height: 1; }
    .remove-file-btn:hover { color: #ea4335; }
    @keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }
    .gemini-logo { width: 24px; height: 24px; object-fit: contain; }