```html

YAKUP OS - Milli İşletim Sistemi Prototipi

body {
font-family: 'Inter', sans-serif;
background: radial-gradient(circle at center, #0f172a , #020617 );
overflow: hidden;
user-select: none;
}
.window {
backdrop-filter: blur(16px);
background-color: rgba(15, 23, 42, 0.85);
border: 1px solid rgba(255, 255, 255, 0.1);
box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);