[For 1.6] ModNotice Plus 1.5.5

[lexy]

where exactly add this code which template??

.modnotice {
    background: #ADCBE7;
    padding: 8px;
    margin: auto auto;
    border: 1px solid #0F5C8E;
    color: #000000;
    font-size: 12px;
}