:root {
    --primary-color: #4a6baf;
    --secondary-color: #f5f7fa;
    --text-color: #333333;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    background-color: #f8f9fa;
    padding-bottom: 50px;
}

.header {
    background-color: white;
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 30px;
}

.branding {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo {
    max-width: 200px;
    max-height: 60px;
    object-fit: contain;
}

.balance-container {
    background-color: var(--secondary-color);
    padding: 10px 15px;
    border-radius: 5px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.card {
    border: none;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    margin-bottom: 20px;
}

.card-header {
    background-color: var(--primary-color);
    color: white;
    border-radius: 10px 10px 0 0 !important;
}

.message-info, .recipient-info {
    font-size: 0.9rem;
    color: #666;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: #3a5a9f;
    border-color: #3a5a9f;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.toast {
    margin-bottom: 20px;
}

.footer {
    padding: 20px 0;
    color: #666;
    font-size: 0.9rem;
}

.message-preview {
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: 5px;
    white-space: pre-wrap;
}

@media (max-width: 768px) {
    .branding {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    
    .logo {
        max-width: 150px;
    }
    
    .header .col-md-4 {
        margin-bottom: 10px;
    }
}