ungetestet, aus dem Kopf:
.footer {
position: fixed;
height: 50px;
}
.content {
min-height: calc(100% - 50px);
}
.sidebar {
min-height: 100%;
}
position: fixed;
height: 50px;
}
.content {
min-height: calc(100% - 50px);
}
.sidebar {
min-height: 100%;
}