* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f0f5ff 0%, #e6f7ff 100%);
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            overflow: hidden;
            position: relative;
        }
        
        /* 科技感背景元素 */
        .tech-bg {
            position: absolute;
            width: 100%;
            height: 100%;
            top: 0;
            left: 0;
            z-index: -1;
            overflow: hidden;
        }
        
        .tech-grid {
            position: absolute;
            width: 200%;
            height: 200%;
            background-image: 
                linear-gradient(rgba(100, 180, 255, 0.1) 1px, transparent 1px),
                linear-gradient(90deg, rgba(100, 180, 255, 0.1) 1px, transparent 1px);
            background-size: 40px 40px;
            transform: rotate(-15deg) translate(-25%, -25%);
            animation: gridMove 60s linear infinite;
        }
        
        .tech-circle {
            position: absolute;
            border-radius: 50%;
            border: 1px solid rgba(64, 158, 255, 0.2);
            animation: pulse 8s infinite ease-in-out;
        }
        
        .circle-1 {
            width: 300px;
            height: 300px;
            top: 10%;
            left: 15%;
            animation-delay: 0s;
        }
        
        .circle-2 {
            width: 450px;
            height: 450px;
            bottom: 5%;
            right: 10%;
            animation-delay: 2s;
        }
        
        .tech-line {
            position: absolute;
            background: linear-gradient(90deg, transparent, rgba(64, 158, 255, 0.3), transparent);
            height: 1px;
            animation: lineMove 10s infinite linear;
        }
        
        .line-1 {
            top: 25%;
            left: -10%;
            width: 30%;
            animation-delay: 0s;
        }
        
        .line-2 {
            top: 65%;
            left: -30%;
            width: 40%;
            animation-delay: 3s;
        }
        
        .container {
            background-color: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(10px);
            border-radius: 15px;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
            width: 100%;
            max-width: 450px;
            padding: 40px;
            position: relative;
            overflow: hidden;
            border: 1px solid rgba(200, 220, 255, 0.5);
            z-index: 10;
        }
        
        .container::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(230, 240, 255, 0.2) 0%, transparent 70%);
            z-index: 0;
        }
        
        .login-header {
            text-align: center;
            margin-bottom: 30px;
            position: relative;
            z-index: 1;
        }
        
        .login-header h1 {
            color: #1a2b50;
            font-size: 28px;
            margin-bottom: 10px;
            background: linear-gradient(90deg, #2c3e50, #3498db);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        
        .login-header p {
            color: #6c7a92;
            font-size: 16px;
        }
        
        .login-form {
            position: relative;
            z-index: 1;
        }
        
        .form-group {
            margin-bottom: 25px;
            position: relative;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 8px;
            color: #34495e;
            font-weight: 500;
            font-size: 14px;
        }
        
        .form-control {
            width: 100%;
            padding: 14px 15px;
            border: 1px solid #d0e0f0;
            border-radius: 8px;
            font-size: 16px;
            transition: all 0.3s ease;
            background-color: rgba(248, 249, 255, 0.5);
            color: #2c3e50;
        }
        
        .form-control:focus {
            border-color: #3498db;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
            outline: none;
            background-color: #fff;
        }
        
        /* 验证码区域样式 */
        .captcha-group {
            display: flex;
            gap: 10px;
            align-items: center;
        }
        
        .captcha-input {
            flex: 1;
        }
        
        .captcha-image {
            height: 50px;
            width: 150px;
            border-radius: 6px;
            background: linear-gradient(135deg, #e0f0ff, #c2d9ff);
            display: flex;
            align-items: center;
            justify-content: center;
            border: 1px solid #d0e0f0;
            position: relative;
            overflow: hidden;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .captcha-image:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 10px rgba(52, 152, 219, 0.2);
        }
        
        .captcha-text {
            font-size: 24px;
            font-weight: bold;
            letter-spacing: 5px;
            color: #2c3e50;
            text-shadow: 0 2px 3px rgba(0,0,0,0.1);
            user-select: none;
            position: relative;
            z-index: 2;
            font-family: monospace;
        }
        
        .captcha-refresh {
            position: absolute;
            bottom: 5px;
            right: 5px;
            background: rgba(255, 255, 255, 0.7);
            border-radius: 50%;
            width: 24px;
            height: 24px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 12px;
            color: #3498db;
            z-index: 3;
        }
        
        .captcha-pattern {
            position: absolute;
            width: 100%;
            height: 100%;
            background-image: 
                radial-gradient(circle, transparent 10%, rgba(100, 150, 255, 0.1) 10%),
                radial-gradient(circle, transparent 10%, rgba(100, 150, 255, 0.1) 10%);
            background-size: 20px 20px;
            background-position: 0 0, 10px 10px;
            opacity: 0.4;
            z-index: 1;
        }
        
        .btn {
            display: block;
            width: 100%;
            padding: 14px;
            background: linear-gradient(to right, #3498db, #2c3e50);
            border: none;
            border-radius: 8px;
            color: white;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
            position: relative;
            overflow: hidden;
        }
        
        .btn:hover {
            background: linear-gradient(to right, #2980b9, #1a2530);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(52, 152, 219, 0.4);
        }
        
        .btn:active {
            transform: translateY(0);
        }
        
        .btn::after {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: rgba(255, 255, 255, 0.1);
            transform: rotate(30deg);
            transition: all 0.6s;
        }
        
        .btn:hover::after {
            transform: rotate(30deg) translate(20%, 20%);
        }
        
        .footer {
            text-align: center;
            margin-top: 20px;
            color: #7f8c8d;
            font-size: 14px;
            position: relative;
            z-index: 1;
        }
        
        .security-info {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            margin-top: 10px;
            color: #3498db;
            font-size: 13px;
        }
        
        /* 动画效果 */
        @keyframes gridMove {
            0% { transform: rotate(-15deg) translate(-25%, -25%); }
            100% { transform: rotate(-15deg) translate(-35%, -35%); }
        }
        
        @keyframes pulse {
            0% { transform: scale(1); opacity: 0.3; }
            50% { transform: scale(1.1); opacity: 0.5; }
            100% { transform: scale(1); opacity: 0.3; }
        }
        
        @keyframes lineMove {
            0% { transform: translateX(0); }
            100% { transform: translateX(100vw); }
        }
        
        @media (max-width: 480px) {
            .container {
                padding: 30px 20px;
                margin: 0 15px;
            }
            
            .captcha-group {
                flex-direction: column;
                align-items: stretch;
            }
            
            .captcha-image {
                width: 100%;
                margin-top: 10px;
            }
        }