body {
        background: linear-gradient(135deg, #2563eb 0%, #2563eb 100%);
        display: flex;
        align-items: center;
        justify-content: center;
        min-height: 100vh;
    }
    .login-container {
        width: 100%;
        max-width: 400px;
        padding: 20px;
    }
    .login-card {
        background: white;
        border-radius: 12px;
        box-shadow: 0 10px 40px rgba(0,0,0,0.2);
        padding: 40px;
    }
    .login-logo {
        text-align: center;
        margin-bottom: 30px;
    }
    .login-logo img {
        max-width: 150px;
        height: auto;
    }
    .login-logo h1 {
        font-size: 24px;
        color: #374151;
        margin-top: 15px;
    }
    .login-logo p {
        color: #6b7280;
        font-size: 14px;
        margin-top: 5px;
    }
    .login-form .form-group {
        margin-bottom: 20px;
    }
    .login-form .form-control {
        padding: 14px 16px;
        font-size: 15px;
    }
    .login-form .btn {
        width: 100%;
        padding: 14px;
        font-size: 16px;
        font-weight: 600;
    }
    .input-icon {
        position: relative;
    }
    .input-icon i {
        position: absolute;
        left: 14px;
        top: 50%;
        transform: translateY(-50%);
        color: #9ca3af;
    }
    .input-icon .form-control {
        padding-left: 42px;
    }
    /* 사원번호 기억 체크박스 */
    .remember-id {
        display: flex;
        align-items: center;
        margin-bottom: 20px;
        font-size: 14px;
        color: #6b7280;
    }
    .remember-id input[type="checkbox"] {
        width: 18px;
        height: 18px;
        margin-right: 8px;
        cursor: pointer;
    }
    .remember-id label {
        cursor: pointer;
        margin: 0;
    }
    /* 입력 유효성 스타일 */
    .form-control.is-invalid {
        border-color: #dc2626;
        background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23dc3545'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e");
        background-repeat: no-repeat;
        background-position: right 12px center;
        background-size: 20px 20px;
    }
    .form-control.is-valid {
        border-color: #059669;
    }
    .invalid-feedback {
        display: none;
        color: #dc2626;
        font-size: 12px;
        margin-top: 5px;
    }
    .form-control.is-invalid + .invalid-feedback,
    .input-icon .is-invalid ~ .invalid-feedback {
        display: block;
    }
    /* 로그인 버튼 로딩 상태 */
    .btn-loading {
        position: relative;
        pointer-events: none;
    }
    .btn-loading::after {
        content: "";
        position: absolute;
        width: 16px;
        height: 16px;
        top: 50%;
        left: 50%;
        margin-left: -8px;
        margin-top: -8px;
        border: 2px solid #fff;
        border-radius: 50%;
        border-top-color: transparent;
        animation: spin 0.8s linear infinite;
    }
    @keyframes spin {
        to { transform: rotate(360deg); }
    }

    /* 2차 인증 모달 (원본 동일) */
    .modal-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.7);
        z-index: 9999;
        align-items: center;
        justify-content: center;
    }
    .modal-overlay.active {
        display: flex;
    }
    .modal-box {
        background: white;
        border-radius: 20px;
        padding: 40px;
        max-width: 500px;
        width: 90%;
        box-shadow: 0 5px 30px rgba(0, 0, 0, 0.3);
    }
    .modal-header {
        text-align: center;
        margin-bottom: 30px;
    }
    .modal-header h2 {
        font-size: 24px;
        color: #374151;
        margin-bottom: 10px;
    }
    .modal-header p {
        color: #6b7280;
        font-size: 14px;
    }
    .verification-code-input {
        display: flex;
        justify-content: center;
        gap: 10px;
        margin: 30px 0;
    }
    .verification-code-input input {
        width: 50px;
        height: 60px;
        text-align: center;
        font-size: 24px;
        font-weight: bold;
        border: 2px solid #e5e7eb;
        border-radius: 10px;
        transition: all 0.3s;
    }
    .verification-code-input input:focus {
        border-color: #2563eb;
        outline: none;
        box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
    }
    .resend-code {
        text-align: center;
        margin: 20px 0;
        color: #6b7280;
        font-size: 14px;
    }
    .resend-code button {
        background: none;
        border: none;
        color: #2563eb;
        text-decoration: underline;
        cursor: pointer;
        font-size: 14px;
        margin-top: 10px;
    }
    .resend-code button:disabled {
        color: #9ca3af;
        cursor: not-allowed;
    }
    .timer {
        color: #dc2626;
        font-weight: bold;
    }
    .modal-actions {
        display: flex;
        gap: 10px;
        margin-top: 30px;
    }
    .modal-actions .btn {
        flex: 1;
        padding: 14px;
        border-radius: 10px;
        font-size: 16px;
        font-weight: 600;
        cursor: pointer;
        border: none;
    }
    .modal-actions .btn-secondary {
        background: #f3f4f6;
        color: #374151;
        border: 1px solid #e5e7eb;
    }
    .modal-actions .btn-primary {
        background: #2563eb;
        color: white;
    }
    /* 로그인 실패 경고 */
    .attempt-warning {
        background: #fffbeb;
        border: 1px solid #d97706;
        border-radius: 8px;
        padding: 12px;
        margin-bottom: 20px;
        text-align: center;
        display: none;
    }
    .attempt-warning.show {
        display: block;
    }
    .attempt-warning strong {
        color: #d97706;
    }
    /* 계정 잠금 모달 */
    .locked-modal .modal-box {
        border: 2px solid #dc2626;
    }