:root {
            --primary-color: #6366f1;
            --secondary-color: #8b5cf6;
            --accent-color: #f59e0b;
            --success-color: #10b981;
            --danger-color: #ef4444;
            --dark-color: #1e293b;
            --light-color: #f8fafc;
            --border-radius: 16px;
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        body {
            font-family: "Noto Sans Thai", sans-serif;
            font-weight: 400;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0;
            padding: 20px;
        }

        .auth-container {
            width: 100%;
            max-width: 420px;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-radius: var(--border-radius);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            padding: 3rem;
            transition: var(--transition);
            animation: fadeInUp 0.5s ease-out;
        }

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

        .auth-container:hover {
            transform: translateY(-5px);
            box-shadow: 0 25px 30px -5px rgba(0, 0, 0, 0.15), 0 15px 15px -5px rgba(0, 0, 0, 0.08);
        }

        .auth-container h2 {
            font-size: 2rem;
            font-weight: 700;
            color: var(--dark-color);
            text-align: center;
            margin-bottom: 2rem;
            position: relative;
        }

        .auth-container h2::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 50px;
            height: 4px;
            background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
            border-radius: 2px;
        }

        .logo-icon {
            font-size: 3rem;
            color: var(--primary-color);
            text-align: center;
            display: block;
            margin-bottom: 1rem;
            animation: pulse 2s infinite;
        }

        @keyframes pulse {
            0% {
                transform: scale(1);
            }
            50% {
                transform: scale(1.05);
            }
            100% {
                transform: scale(1);
            }
        }

        .form-group {
            margin-bottom: 1.5rem;
        }

        .form-label {
            color: var(--dark-color);
            font-weight: 500;
            margin-bottom: 0.5rem;
        }

        .form-control {
            border: 2px solid #e2e8f0;
            border-radius: 10px;
            padding: 0.75rem 1rem;
            transition: var(--transition);
            font-size: 1rem;
        }

        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 0.2rem rgba(99, 102, 241, 0.25);
            transform: translateY(-2px);
        }

        .form-check {
            margin-bottom: 1.5rem;
        }

        .form-check-input {
            width: 1.25rem;
            height: 1.25rem;
            border: 2px solid #e2e8f0;
            transition: var(--transition);
        }

        .form-check-input:checked {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }

        .form-check-label {
            margin-left: 0.5rem;
            color: var(--dark-color);
            font-weight: 500;
        }

        .btn {
            border-radius: 10px;
            padding: 0.75rem 1.5rem;
            font-weight: 600;
            transition: var(--transition);
            border: none;
            font-size: 1rem;
            text-transform: uppercase;
            letter-spacing: 0.5px;
            position: relative;
            overflow: hidden;
        }

        .btn::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: rgba(255, 255, 255, 0.2);
            transition: left 0.5s;
        }

        .btn:hover::before {
            left: 100%;
        }

        .btn-primary {
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            width: 100%;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
        }

        .btn-primary:active {
            transform: translateY(0);
        }

        .register-link {
            text-align: center;
            margin-top: 1.5rem;
            padding-top: 1.5rem;
            border-top: 1px solid #e2e8f0;
        }

        .register-link p {
            color: #64748b;
            margin-bottom: 0.5rem;
        }

        .register-link a {
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 600;
            transition: var(--transition);
        }

        .register-link a:hover {
            color: var(--secondary-color);
            text-decoration: underline;
        }

        .alert {
            border: none;
            border-radius: 10px;
            padding: 1rem;
            font-weight: 500;
            margin-bottom: 1.5rem;
            animation: slideDown 0.3s ease-out;
        }

        @keyframes slideDown {
            from {
                opacity: 0;
                transform: translateY(-20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .alert-success {
            background: #d1fae5;
            color: #065f46;
        }

        .alert-danger {
            background: #fee2e2;
            color: #991b1b;
        }

        .alert-warning {
            background: #fef3c7;
            color: #92400e;
        }

        .disabled-link {
            color: #9ca3af !important;
            cursor: not-allowed !important;
            text-decoration: none !important;
            pointer-events: none;
        }

        /* Responsive Design */
        @media (max-width: 480px) {
            .auth-container {
                padding: 2rem 1.5rem;
            }

            .auth-container h2 {
                font-size: 1.5rem;
            }

            .logo-icon {
                font-size: 2.5rem;
            }
        }

        /* Background Animation */
        .bg-animation {
            position: fixed;
            width: 100%;
            height: 100%;
            top: 0;
            left: 0;
            z-index: -1;
            opacity: 0.1;
        }

        .bg-animation span {
            position: absolute;
            display: block;
            width: 20px;
            height: 20px;
            background: rgba(255, 255, 255, 0.5);
            animation: move 25s linear infinite;
            bottom: -150px;
        }

        .bg-animation span:nth-child(1) {
            left: 25%;
            width: 80px;
            height: 80px;
            animation-delay: 0s;
        }

        .bg-animation span:nth-child(2) {
            left: 10%;
            width: 20px;
            height: 20px;
            animation-delay: 2s;
            animation-duration: 12s;
        }

        .bg-animation span:nth-child(3) {
            left: 70%;
            width: 20px;
            height: 20px;
            animation-delay: 4s;
        }

        .bg-animation span:nth-child(4) {
            left: 40%;
            width: 60px;
            height: 60px;
            animation-delay: 0s;
            animation-duration: 18s;
        }

        .bg-animation span:nth-child(5) {
            left: 65%;
            width: 20px;
            height: 20px;
            animation-delay: 0s;
        }

        .bg-animation span:nth-child(6) {
            left: 75%;
            width: 110px;
            height: 110px;
            animation-delay: 3s;
        }

        .bg-animation span:nth-child(7) {
            left: 35%;
            width: 150px;
            height: 150px;
            animation-delay: 7s;
        }

        .bg-animation span:nth-child(8) {
            left: 50%;
            width: 25px;
            height: 25px;
            animation-delay: 15s;
            animation-duration: 45s;
        }

        .bg-animation span:nth-child(9) {
            left: 20%;
            width: 15px;
            height: 15px;
            animation-delay: 2s;
            animation-duration: 35s;
        }

        .bg-animation span:nth-child(10) {
            left: 85%;
            width: 150px;
            height: 150px;
            animation-delay: 0s;
            animation-duration: 11s;
        }

        @keyframes move {
            0% {
                transform: translateY(0) rotate(0deg);
                opacity: 1;
                border-radius: 0;
            }
            100% {
                transform: translateY(-1000px) rotate(720deg);
                opacity: 0;
                border-radius: 50%;
            }
        }