CSS being ignored

Hi _ not sure if this is theme specific (twenty seventeen) or a general issue… I’m making small amendments via Simple Custom CSS – and for a while they work. Then they stop working and I cannot find out why. Seems like they are being over ridden by , perhaps, the original code?

Guidance appreciated

/* Page Title*/
{

.page .panel-content .entry-title,
.page-title,
body.page:not(.twentyseventeen-front-page)
.entry-title {
color: #222;
font-size: 30px!important;
font-weight: 800;
letter-spacing: 0.14em;
text-transform:none! important;
line-height: 1.30;

}