* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 20px;
    margin: 0;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: auto;
    background: #fff;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

h1 {
    color: #333;
    text-align: center;
    margin-bottom: 30px;
    font-size: 2.2em;
    font-weight: 300;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #555;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

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

.form-group small {
    display: block;
    margin-top: 5px;
    color: #666;
    font-size: 14px;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    cursor: pointer;
    margin-bottom: 0;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin-right: 8px;
}

.form-actions {
    display: flex;
    gap: 15px;
    margin-top: 30px;
}

.btn-primary {
    background-color: #007cba;
    color: white;
}

.btn-primary:hover {
    background-color: #005a87;
}

.btn-primary:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #545b62;
}

.btn-secondary:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.btn-danger {
    background-color: #dc3545;
    color: white;
    padding: 12px 24px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
}

.btn-danger:hover {
    background-color: #c82333;
}

.btn-danger:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

/* Contact List Styles */
#contactsContainer {
    margin-top: 30px;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 4px;
    border: 1px solid #dee2e6;
}

#contactsHeader {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid #dee2e6;
}

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

.pagination-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.contacts-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 4px;
    overflow: hidden;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.contacts-table th,
.contacts-table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #dee2e6;
}

.contacts-table th {
    background-color: #f8f9fa;
    font-weight: bold;
    color: #495057;
}

.contacts-table tr:hover {
    background-color: #f8f9fa;
}

.contacts-table th:first-child,
.contacts-table td:first-child {
    width: 40px;
    text-align: center;
}

.contact-checkbox {
    cursor: pointer;
}

#progressContainer {
    margin-top: 30px;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 4px;
    border: 1px solid #dee2e6;
}

#progressStats {
    margin-bottom: 15px;
    font-weight: bold;
    color: #495057;
}

#progressStats span {
    margin-right: 15px;
}

#progressBar {
    width: 100%;
    height: 20px;
    background-color: #e9ecef;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 15px;
}

#progressFill {
    height: 100%;
    background-color: #28a745;
    width: 0%;
    transition: width 0.3s ease;
}

#logContainer {
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    margin-bottom: 15px;
}

#logOutput {
    margin: 0;
    padding: 10px;
    background-color: #f8f9fa;
    font-family: 'Courier New', monospace;
    font-size: 12px;
    white-space: pre-wrap;
    word-wrap: break-word;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        padding: 20px;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    #progressStats {
        flex-direction: column;
        gap: 10px;
    }
    
    h1 {
        font-size: 1.8em;
    }
}

/* Loading animation */
@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.btn-primary:disabled {
    animation: pulse 1.5s infinite;
}