body{margin:0;font-family:Segoe UI;overflow:hidden;transition:.3s;}
.light{background:#eaeef5;}
.dark{background:#111;color:white;}

.boot,.login{
position:fixed;inset:0;
display:flex;justify-content:center;align-items:center;
background:#000;color:white;font-size:30px;
z-index:9999;flex-direction:column;
}

.desktop{width:100vw;height:100vh;}

.start{
position:absolute;bottom:50px;left:10px;
background:#222;color:white;padding:10px;
border-radius:12px;display:none;
}

.start div{padding:8px;cursor:pointer;}

.window{
position:absolute;top:100px;left:100px;
width:400px;background:white;
border-radius:14px;
box-shadow:0 20px 40px rgba(0,0,0,.4);
display:none;flex-direction:column;
animation:pop .2s ease;
}

.large{width:900px;height:550px;}

@keyframes pop{
from{transform:scale(.9);opacity:0;}
to{transform:scale(1);opacity:1;}
}

.header{
background:#0078ff;color:white;
padding:8px;display:flex;
justify-content:space-between;
cursor:move;border-radius:14px 14px 0 0;
}

.content{flex:1;padding:10px;display:flex;flex-direction:column;}

.calc-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:5px;}

textarea{flex:1;}

.browser-bar{display:flex;gap:5px;}
iframe{flex:1;border:none;}

.taskbar{
position:fixed;bottom:0;left:0;right:0;
height:40px;background:#111;color:white;
display:flex;align-items:center;padding:0 10px;
}