*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

body{
    background:#0f172a;
    color:#fff;
    font-family:Arial,Helvetica,sans-serif;
}

a{
    color:inherit;
    text-decoration:none;
}

.layout{
    display:flex;
    min-height:100vh;
}

.sidebar{
    width:260px;
    background:#111827;
    padding:25px;
}

.sidebar h2{
    margin-bottom:35px;
    font-size:28px;
}

.sidebar ul{
    list-style:none;
}

.sidebar li{
    margin-bottom:8px;
}

.sidebar li a{
    display:block;
    padding:14px;
    border-radius:10px;
}

.sidebar li a:hover{
    background:#1e293b;
}

.active a{
    background:#2563eb;
}

.content{
    flex:1;
    padding:35px;
}

.topbar{
    margin-bottom:30px;
}

.dashboard{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(260px,1fr));
    gap:20px;
}

.card{
    background:#1e293b;
    padding:25px;
    border-radius:15px;
    box-shadow:0 10px 25px rgba(0,0,0,.25);
}

.card h2{
    margin-bottom:15px;
    font-size:18px;
}

.card p{
    font-size:28px;
    font-weight:bold;
}

.card small{
    color:#94a3b8;
}

.online{
    color:#22c55e;
}

.offline{
    color:#ef4444;
}

.controls{
    margin-top:35px;
    display:flex;
    gap:15px;
}

button{
    background:#2563eb;
    color:white;
    border:none;
    border-radius:10px;
    padding:14px 28px;
    cursor:pointer;
    font-size:16px;
    transition:.2s;
}

button:hover{
    background:#1d4ed8;
}