/* 基础样式重置 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Microsoft YaHei', sans-serif;
        }

        /* 动态背景 */
        body {
            background: linear-gradient(-45deg, #e53935, #c62828, #b71c1c, #880e4f);
            background-size: 400% 400%;
            animation: gradientBG 15s ease infinite;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow: hidden;
        }

        /* 粒子效果 */
        .bg-particles {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            overflow: hidden;
            z-index: -1;
        }

        .particle {
            position: absolute;
            width: 6px;
            height: 6px;
            background: rgba(255, 255, 255, 0.3);
            border-radius: 50%;
            animation: float 10s infinite linear;
        }

        /* 主要容器 */
        .container {
            background: rgba(255, 255, 255, 0.95);
            border-radius: 20px;
            padding: 80px 60px;
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
            text-align: center;
            max-width: 800px;
            width: 85%;
            backdrop-filter: blur(10px);
            animation: fadeInUp 0.8s ease;
        }

        /* 标题 */
        h1 {
            color: #b71c1c;
            font-size: 3em;
            margin-bottom: 50px;
            font-weight: 700;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
            animation: pulse 2s infinite;
        }

        /* 按钮容器 */
        .buttons {
            display: flex;
            gap: 40px;
            justify-content: center;
            flex-wrap: wrap;
        }

        /* 登录按钮 */
        .login-btn {
            background: linear-gradient(135deg, #e53935 0%, #c62828 100%);
            color: white;
            border: none;
            padding: 18px 40px;
            font-size: 1.3em;
            border-radius: 50px;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(229, 57, 53, 0.3);
            min-width: 180px;
            font-weight: 600;
        }

        .login-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(229, 57, 53, 0.4);
            background: linear-gradient(135deg, #d32f2f 0%, #b71c1c 100%);
        }

        /* 模态窗口 */
        .modal {
            display: none;
            position: fixed;
            z-index: 1000;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.5);
            backdrop-filter: blur(5px);
            animation: fadeIn 0.3s ease;
        }

        .modal-content {
            background-color: white;
            margin: 5% auto;
            padding: 40px;
            border-radius: 15px;
            width: 90%;
            max-width: 400px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
            animation: slideIn 0.4s ease;
        }

        .close {
            color: #aaa;
            float: right;
            font-size: 28px;
            font-weight: bold;
            cursor: pointer;
            transition: color 0.3s ease;
        }

        .close:hover {
            color: #b71c1c;
        }

        /* 表单样式 */
        .form-group {
            margin-bottom: 25px;
            text-align: left;
        }

        .form-group label {
            display: block;
            color: #333;
            margin-bottom: 8px;
            font-weight: 600;
            font-size: 1.1em;
        }

        .form-group input {
            width: 100%;
            padding: 15px;
            border: 2px solid #e0e0e0;
            border-radius: 10px;
            font-size: 1em;
            transition: border-color 0.3s ease;
        }

        .form-group input:focus {
            outline: none;
            border-color: #e53935;
            box-shadow: 0 0 0 3px rgba(229, 57, 53, 0.1);
        }

        .submit-btn {
            width: 100%;
            background: linear-gradient(135deg, #e53935 0%, #c62828 100%);
            color: white;
            border: none;
            padding: 15px;
            font-size: 1.2em;
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-weight: 600;
            margin-top: 10px;
        }

        .submit-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(229, 57, 53, 0.3);
        }

        /* 动画效果 */
        @keyframes gradientBG {
            0% { background-position: 0% 50%; }
            50% { background-position: 100% 50%; }
            100% { background-position: 0% 50%; }
        }

        @keyframes float {
            0% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
            10% { opacity: 1; }
            90% { opacity: 1; }
            100% { transform: translateY(-100px) rotate(360deg); opacity: 0; }
        }

        @keyframes fadeInUp {
            from { opacity: 0; transform: translateY(30px); }
            to { opacity: 1; transform: translateY(0); }
        }

        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.02); }
            100% { transform: scale(1); }
        }

        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }

        @keyframes slideIn {
            from { opacity: 0; transform: translateY(-50px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            .container {
                padding: 40px 20px;
            }
            
            h1 {
                font-size: 2em;
            }
            
            .buttons {
                gap: 20px;
            }
            
            .login-btn {
                padding: 15px 30px;
                font-size: 1.1em;
                min-width: 150px;
            }
        }