body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f6;
    color: #333;
    margin: 0;
    padding: 20px;
}
header {
    text-align: center;
    border-bottom: 2px solid #e0e0e0;
    padding-bottom: 20px;
    margin-bottom: 20px;
}
h1 {
    color: #0056b3;
}
main {
    max-width: 1000px;
    margin: 0 auto;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}
.controls {
    margin-bottom: 20px;
}
#refresh-btn {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
}
#refresh-btn:hover {
    background-color: #0056b3;
}
#loading {
    text-align: center;
    font-size: 18px;
    color: #555;
    padding: 20px;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    border: 1px solid #ddd;
    padding: 12px;
    text-align: left;
    vertical-align: middle;
}
th {
    background-color: #f9f9f9;
}
button {
    cursor: pointer;
    padding: 8px 12px;
    border: none;
    border-radius: 4px;
    margin-right: 5px;
}
.btn-sync {
    background-color: #28a745;
    color: white;
}
.btn-sync:hover {
    background-color: #218838;
}
.btn-link {
    background-color: #17a2b8;
    color: white;
}
.btn-link:hover {
    background-color: #138496;
}
.btn-sync:disabled {
    background-color: #aaa;
    cursor: not-allowed;
}
.status-synced {
    color: #28a745;
    font-weight: bold;
}
.status-not-synced {
    color: #dc3545;
    font-weight: bold;
}