/* MD3 设计系统变量 */
        :root {
            --md-primary: #6750A4;
            --md-surface: #FAFAFA;
            --md-surface-tint: #F5F3FF;
            --md-on-surface: #1D1B20;
            --md-on-surface-variant: #6B6B6B;
            --md-error: #B3261E;
            --md-outline: #E0E0E0;
            --md-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
            --md-shadow-elevated: 0 2px 6px rgba(0,0,0,0.15), 0 1px 4px rgba(0,0,0,0.12);
            --md-success: #4CAF50;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
            background-color: var(--md-surface);
            color: var(--md-on-surface);
            line-height: 1.5;
        }

        /* 顶部导航栏 - MD3 Top App Bar */
        .top-navigation-bar {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            height: 64px;
            background: var(--md-surface);
            display: flex;
            align-items: center;
            padding: 0 16px;
            box-shadow: 0 1px 3px rgba(0,0,0,0.1);
            z-index: 1000;
        }

        .nav-back-btn {
            width: 40px;
            height: 40px;
            border: none;
            background: none;
            border-radius: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--md-primary);
            cursor: pointer;
            transition: background-color 0.2s;
            margin-right: 16px;
        }

        .nav-back-btn:hover {
            background-color: rgba(103, 80, 164, 0.08);
        }

        .nav-title {
            font-size: 22px;
            font-weight: 500;
            color: var(--md-on-surface);
            flex: 1;
        }

        .container {
            max-width: 500px;
            margin: 80px auto 100px;
            padding: 0 16px;
        }

        /* 用户资产卡片 - MD3 Elevated Card */
        .user-asset-card {
            background: linear-gradient(135deg, #F5F3FF, #FAFAFA);
            border-radius: 12px;
            padding: 20px;
            margin-bottom: 24px;
            box-shadow: var(--md-shadow-elevated);
            display: flex;
            align-items: center;
            gap: 16px;
        }

        .asset-icon {
            width: 48px;
            height: 48px;
            background: var(--md-primary);
            border-radius: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
        }

        .asset-info {
            flex: 1;
        }

        .asset-label {
            font-size: 14px;
            color: var(--md-on-surface-variant);
            margin-bottom: 4px;
        }

        .asset-value {
            font-size: 24px;
            font-weight: 600;
            color: var(--md-on-surface);
        }

        /* 表单卡片组 */
        .form-section {
            display: flex;
            flex-direction: column;
            gap: 16px;
            margin-bottom: 24px;
        }

        .form-card {
            background: white;
            border-radius: 12px;
            padding: 20px;
            box-shadow: var(--md-shadow);
            border: 1px solid var(--md-outline);
        }

        .form-header {
            display: flex;
            align-items: center;
            gap: 12px;
            margin-bottom: 16px;
        }

        .form-icon {
            width: 24px;
            height: 24px;
            color: var(--md-primary);
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .form-title {
            font-size: 16px;
            font-weight: 500;
            color: var(--md-on-surface);
        }

        /* MD3 Outlined TextField 样式 */
        .md-textfield {
            position: relative;
            margin-bottom: 8px;
        }

        .md-textfield-input {
            width: 100%;
            height: 56px;
            padding: 16px;
            border: 2px solid var(--md-outline);
            border-radius: 4px;
            background: white;
            font-size: 16px;
            transition: all 0.2s;
            outline: none;
        }

        .md-textfield-input:focus {
            border-color: var(--md-primary);
        }

        .md-textfield-label {
            position: absolute;
            left: 16px;
            top: 50%;
            transform: translateY(-50%);
            background: white;
            padding: 0 4px;
            color: var(--md-on-surface-variant);
            transition: all 0.2s;
            pointer-events: none;
        }

        .md-textfield-input:focus + .md-textfield-label,
        .md-textfield-input:not(:placeholder-shown) + .md-textfield-label {
            top: 0;
            font-size: 12px;
            color: var(--md-primary);
        }

        .md-textfield-supporting {
            font-size: 12px;
            color: var(--md-on-surface-variant);
            margin-top: 4px;
            padding: 0 16px;
        }

        .textfield-with-unit {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .textfield-unit {
            color: var(--md-primary);
            font-weight: 500;
            white-space: nowrap;
        }

        /* 额度限制双输入框 */
        .limit-fields {
            display: flex;
            gap: 12px;
        }

        .limit-field {
            flex: 1;
        }

        .field-divider {
            width: 1px;
            background: var(--md-outline);
            margin: 8px 0;
        }

        /* 汇率提示横幅 */
        .exchange-banner {
            background: var(--md-surface-tint);
            border-radius: 8px;
            padding: 12px 16px;
            text-align: center;
            margin-bottom: 24px;
            color: var(--md-primary);
            font-weight: 500;
        }

        /* 收款方式卡片 */
        .payment-card {
            background: white;
            border-radius: 12px;
            padding: 20px;
            margin-bottom: 24px;
            border: 1px solid var(--md-outline);
            cursor: pointer;
            transition: all 0.2s;
        }

        .payment-card:hover {
            border-color: var(--md-primary);
        }

        .payment-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 12px;
        }

        .payment-type {
            display: flex;
            align-items: center;
            gap: 12px;
            flex: 1;
        }

        .payment-icon {
            width: 24px;
            height: 24px;
            border-radius: 4px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 14px;
            font-weight: 600;
        }

        .payment-icon.wechat {
            background: #07C160;
        }

        .payment-icon.alipay {
            background: #1677FF;
        }

        .payment-manage {
            color: var(--md-primary);
            display: flex;
            align-items: center;
            gap: 4px;
            font-weight: 500;
        }

        .payment-info {
            color: var(--md-on-surface-variant);
            font-size: 14px;
        }

        /* 底部操作按钮 */
        .bottom-action {
            position: fixed;
            bottom: 24px;
            left: 16px;
            right: 16px;
            max-width: 500px;
            margin: 0 auto;
        }

        .md-elevated-button {
            width: 100%;
            height: 48px;
            background: var(--md-primary);
            color: white;
            border: none;
            border-radius: 24px;
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.2s;
            box-shadow: var(--md-shadow-elevated);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        .md-elevated-button:hover:not(:disabled) {
            background: #56408B;
            transform: translateY(-1px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        }

        .md-elevated-button:disabled {
            background: #D1C4E9;
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        .loading-spinner {
            width: 20px;
            height: 20px;
            border: 2px solid transparent;
            border-top: 2px solid white;
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        /* 数字滚动动画 */
        @keyframes countUp {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .counting {
            animation: countUp 0.8s ease-out;
        }

        /* 保存成功动画 */
        .success-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(103, 80, 164, 0.95);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            z-index: 10000;
            opacity: 0;
            transition: opacity 0.3s ease;
        }

        .success-icon {
            width: 80px;
            height: 80px;
            background: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 20px;
            transform: scale(0);
            transition: transform 0.3s ease;
        }

        .success-checkmark {
            width: 40px;
            height: 40px;
            border: 4px solid var(--md-success);
            border-left: none;
            border-top: none;
            transform: rotate(45deg) scale(0);
            margin-top: -8px;
            transition: transform 0.3s ease 0.1s;
        }

        .success-text {
            color: white;
            font-size: 18px;
            font-weight: 500;
            opacity: 0;
            transform: translateY(20px);
            transition: all 0.3s ease 0.2s;
        }

        /* 响应式设计 */
        @media (max-width: 359px) {
            .container {
                padding: 0 12px;
            }
            
            .form-card {
                padding: 16px;
            }
        }

        @media (min-width: 768px) {
            .container {
                margin: 80px auto 100px;
            }
        }