*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial,Helvetica,sans-serif;
}

body{
    background:linear-gradient(135deg,#6a11cb,#2575fc);
    min-height:100vh;
    display:flex;
    justify-content:center;
    align-items:center;
}

.container{
    width:95%;
    max-width:700px;
    background:#fff;
    border-radius:25px;
    padding:25px;
    text-align:center;
    box-shadow:0 10px 30px rgba(0,0,0,.3);
}

h1{
    color:#2575fc;
    margin-bottom:10px;
}

.top-bar{
    display:flex;
    justify-content:space-between;
    margin:20px 0;
    font-size:20px;
    font-weight:bold;
}

#grid{
    display:grid;
    grid-template-columns:repeat(8,1fr);
    gap:6px;
    margin:25px auto;
}

.cell{
    background:#f3f3f3;
    border-radius:8px;
    height:45px;
    display:flex;
    justify-content:center;
    align-items:center;
    font-size:26px;
    font-weight:bold;
    cursor:pointer;
    user-select:none;
    transition:.2s;
}

.cell:hover{
    background:#2575fc;
    color:white;
}

#message{
    min-height:35px;
    font-size:22px;
    font-weight:bold;
    color:#2575fc;
    margin-top:15px;
}

#startBtn{
    margin-top:20px;
    padding:15px 35px;
    border:none;
    border-radius:50px;
    background:linear-gradient(45deg,cyan,magenta);
    font-size:18px;
    font-weight:bold;
    cursor:pointer;
}