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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            background: url("/static/images/background.jpg") center/cover no-repeat;
            position: relative;
            padding: 20px;
        }

        body::before {
            content: '';
            position: fixed;
            top: 0; left: 0; right: 0; bottom: 0;
            background: rgba(0, 0, 0, 0.25);
            z-index: 0;
        }

        .register-card {
            position: relative;
            z-index: 1;
            width: 460px;
            max-height: 90vh;
            overflow-y: auto;
            padding: 35px 40px 30px;
            background: rgba(255, 255, 255, 0.01);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-radius: 20px;
            border: 1px solid rgba(255, 255, 255, 0.2);
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
            text-align: center;
        }

        .register-card .logo {
            font-size: 26px;
            font-weight: bold;
            color: #fff;
            letter-spacing: 3px;
            margin-bottom: 6px;
            text-shadow: 0 2px 4px rgba(0,0,0,0.2);
        }

        .register-card .subtitle {
            font-size: 12px;
            color: rgba(255, 255, 255, 0.7);
            letter-spacing: 2px;
            margin-bottom: 8px;
        }

        .register-card .slogan {
            font-size: 13px;
            color: #ff6b6b;
            margin-bottom: 25px;
            text-shadow: 0 1px 2px rgba(0,0,0,0.2);
        }

        .form-group {
            margin-bottom: 14px;
            text-align: left;
        }

        .form-group label {
            display: block;
            font-size: 13px;
            color: rgba(255, 255, 255, 0.85);
            margin-bottom: 6px;
        }

        .form-group input {
            width: 100%;
            padding: 11px 14px;
            border: 1px solid rgba(255, 255, 255, 0.25);
            border-radius: 10px;
            background: rgba(255, 255, 255, 0.02);
            color: #fff;
            font-size: 14px;
            outline: none;
            transition: all 0.3s;
        }

        .form-group input::placeholder {
            color: rgba(255, 255, 255, 0.5);
        }

        .form-group input:focus {
            border-color: rgba(255, 255, 255, 0.5);
            background: rgba(255, 255, 255, 0.15);
            box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.1);
        }

        .form-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
        }

        .register-btn {
            width: 100%;
            padding: 13px;
            margin-top: 10px;
            border: none;
            border-radius: 10px;
            background: linear-gradient(135deg, #ff4444, #cc0000);
            color: #fff;
            font-size: 15px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            letter-spacing: 2px;
        }

        .register-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 20px rgba(255, 68, 68, 0.4);
        }

        .register-links {
            margin-top: 18px;
            font-size: 13px;
            color: rgba(255, 255, 255, 0.7);
        }

        .register-links a {
            color: #ff6b6b;
            text-decoration: none;
            transition: color 0.3s;
        }

        .register-links a:hover {
            color: #fff;
        }

        .alert {
            display: none;
            padding: 10px 14px;
            border-radius: 8px;
            margin-bottom: 15px;
            font-size: 13px;
            text-align: left;
        }

        .alert-error {
            background: rgba(255, 77, 79, 0.2);
            color: #ffccc7;
            border: 1px solid rgba(255, 77, 79, 0.3);
        }

        .alert-success {
            background: rgba(82, 196, 26, 0.2);
            color: #d9f7be;
            border: 1px solid rgba(82, 196, 26, 0.3);
        }

        @media (max-width: 520px) {
            .register-card { width: 100%; padding: 25px 20px; }
            .form-row { grid-template-columns: 1fr; }
        }