This is the 1609th most frequent German word.
schlicht
Plain; simple.
In this sentence, 'schlicht' is used as an adjective describing the design, connoting simplicity paired with an appealing aesthetic.
Das Design ist sehr schlicht und elegant.
The design is very simple and elegant.
Here, 'schlicht' describes the manner of dressing, emphasizing plainness or lack of ornamentation.
Er kleidete sich stets schlicht, aber sauber.
He always dressed plainly but neatly.
In this usage, 'schlicht' refers to the nature of the celebration, indicating minimalism or modesty in its execution.