:root {
    --primary-color: #0056b3;
    --background-color: #f0f2f5;
    --form-background: #ffffff;
    --text-color: #333;
    --label-color: #555;
    --border-color: #d9d9d9;
    --shadow-color: rgba(0, 0, 0, 0.1);
        }

        body, html {
            height: 100%;
            margin: 0;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
            background-color: var(--background-color);
            display: flex;
            justify-content: center;
            align-items: center;
        }

        /* --- 登录框容器 --- */
        .login-wrapper {
            display: flex;
            width: 800px;
            margin: 20px;
            background: var(--form-background);
            border-radius: 12px;
            box-shadow: 0 8px 30px var(--shadow-color);
            overflow: hidden;
        }

        /* --- 左侧欢迎/品牌区域 --- */
        .login-brand {
            background-color: var(--primary-color);
            color: white;
            padding: 50px;
            width: 45%;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
        }
        
        .login-brand .logo {
            font-size: 50px;
            margin-bottom: 20px;
        }

        .login-brand h1 {
            margin: 0;
            font-size: 24px;
            font-weight: 600;
        }

        .login-brand p {
            margin-top: 10px;
            font-size: 14px;
            opacity: 0.8;
        }

        /* --- 右侧表单区域 --- */
        .login-form-container {
            padding: 50px;
            width: 55%;
            box-sizing: border-box; /* 确保内边距不会增加宽度 */
        }

        .login-form h2 {
            text-align: left;
            font-size: 28px;
            font-weight: 700;
            color: var(--text-color);
            margin-top: 0;
            margin-bottom: 15px;
        }

        /* --- 输入组 --- */
        .input-group {
            position: relative;
            margin-bottom: 10px;
        }

        .input-group .input-icon {
            position: absolute;
            left: 15px;
            top: 50%;
            transform: translateY(-50%);
            color: #aaa;
            transition: color 0.3s ease;
        }
        
        .input-field {
            width: 100%;
            padding: 14px 15px 14px 45px; /* 左侧为图标留出空间 */
            border: 1px solid var(--border-color);
            border-radius: 6px;
            font-size: 16px;
            box-sizing: border-box;
            transition: border-color 0.3s, box-shadow 0.3s;
        }

        .input-field:focus {
            outline: none;
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(0, 86, 179, 0.1);
        }

        .input-field:focus + .input-icon {
            color: var(--primary-color);
        }

        /* --- 登录按钮 --- */
        .login-button {
            width: 100%;
            padding: 14px;
            margin-top: 5px;
            background-color: var(--primary-color);
            border: none;
            border-radius: 6px;
            color: white;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.1s ease;
        }

        .login-button:hover {
            background-color: #004a99; /* 悬停时颜色加深 */
        }
        
        .login-button:active {
            transform: scale(0.99); /* 点击时轻微缩小 */
        }

        /* --- 页脚 --- */
        .footer {
            text-align: center;
            margin-top: 30px;
            font-size: 12px;
            color: #999;
        }
        
        /* --- 响应式设计 --- */
        @media (max-width: 768px) {
            .login-wrapper {
                flex-direction: column;
                max-width: 400px;
            }
            .login-brand {
                width: 100%;
                padding: 30px;
                border-radius: 12px 12px 0 0;
            }
            .login-form-container {
                width: 100%;
                padding: 30px;
            }
        }