.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.login-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    padding: 40px;
    width: 100%;
    max-width: 400px;
    animation: slideUp 0.6s ease-out;
}

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

.login-header {
    text-align: center;
    margin-bottom: 32px;
}

.login-header h1 {
    color: #2d3748;
    font-size: 28px;
    font-weight: 700;
    margin: 0 0 8px 0;
}

.login-header p {
    color: #718096;
    font-size: 14px;
    margin: 0;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    color: #2d3748;
    font-weight: 600;
    font-size: 14px;
}

.form-group input {
    padding: 12px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.2s ease;
    background: #f7fafc;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
    background: white;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-group input:disabled {
    background: #f1f5f9;
    color: #94a3b8;
    cursor: not-allowed;
}

.error-message {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: #fed7d7;
    border: 1px solid #feb2b2;
    border-radius: 8px;
    color: #c53030;
    font-size: 14px;
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.error-icon {
    font-size: 16px;
}

.login-button {
    padding: 14px 24px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 8px;
}

.login-button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
}

.login-button:active:not(:disabled) {
    transform: translateY(0);
}

.login-button:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.loading-spinner {
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top: 2px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.login-footer {
    margin-top: 32px;
    text-align: center;
}

.login-footer p {
    color: #718096;
    font-size: 14px;
    margin: 0 0 16px 0;
}

.system-info small {
    color: #a0aec0;
    font-size: 12px;
}

/* 반응형 디자인 */
@media (max-width: 480px) {
    .login-container {
        padding: 16px;
    }
    
    .login-card {
        padding: 24px;
    }
    
    .login-header h1 {
        font-size: 24px;
    }
}

/* 다크모드 지원 */
@media (prefers-color-scheme: dark) {
    .login-card {
        background: #1a202c;
        color: white;
    }
    
    .login-header h1 {
        color: white;
    }
    
    .login-header p {
        color: #a0aec0;
    }
    
    .form-group label {
        color: #e2e8f0;
    }
    
    .form-group input {
        background: #2d3748;
        border-color: #4a5568;
        color: white;
    }
    
    .form-group input:focus {
        background: #2d3748;
        border-color: #667eea;
    }
}