body{
    margin:0;
    font-family:Arial,sans-serif;
    background:#111827;
    color:#fff;
}

header{
    background:#1f2937;
    padding:15px;
    text-align:center;
}

nav{
    display:flex;
    overflow-x:auto;
    background:#0f172a;
}

nav button{
    flex:1;
    min-width:120px;
    padding:15px;
    background:none;
    border:none;
    color:white;
    font-size:15px;
    cursor:pointer;
}

nav button:hover{
    background:#2563eb;
}

main{
    padding:20px;
}

.card{
    background:#1f2937;
    border-radius:10px;
    padding:20px;
    margin-bottom:20px;
}

.page{
    display:none;
}

#dashboard{
    display:block;
  }