```css
body {
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

#calendar {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    padding: 20px;
}

.card {
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.fc-toolbar-title {
    font-size: 1.2rem !important;
}

.fc-button-primary {
    background-color: #4285f4 !important;
    border-color: #4285f4 !important;
}

[data-lang="fa"] {
    direction: rtl;
    text-align: right;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.fc-direction-rtl .fc-toolbar > * > :not(:first-child) {
    margin-right: 0.75em;
}
```