body {
    font-family: "Yu Gothic", sans-serif;
    text-align: center;
    background: linear-gradient(135deg, #ffecd2, #fcb69f);
    padding: 20px;
}

h1 {
    font-size: 42px;
    margin-bottom: 20px;
    color: #333;
    text-shadow: 2px 2px #ffffffaa;
}

/* How to Play */
.how-to-play {
    background: #ffffffdd;
    padding: 20px;
    width: 450px;
    margin: 0 auto 25px;
    border-radius: 12px;
    box-shadow: 0 0 12px #aaa;
}

.how-to-play ul {
    text-align: left;
    line-height: 1.8;
}

/* Player Inputs */
.player-inputs input {
    padding: 10px;
    margin: 5px;
    border-radius: 8px;
    border: 1px solid #888;
}

.player-inputs button {
    padding: 10px 20px;
    background: #ff7f50;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.player-inputs button:hover {
    background: #ff5722;
}

/* Game Layout */
.game-container {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 20px;
}

/* Board */
.board {
    display: grid;
    grid-template-columns: repeat(3, 120px);
    grid-template-rows: repeat(3, 120px);
    gap: 10px;
}

.cell {
    background: white;
    border-radius: 12px;
    font-size: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: 0.2s;
    box-shadow: 0 0 10px #aaa;
}

.cell:hover {
    background: #ffe0b2;
}

/* Scoreboard */
.scoreboard {
    background: #ffffffdd;
    padding: 20px;
    width: 250px;
    border-radius: 12px;
    box-shadow: 0 0 12px #aaa;
}

.scoreboard button {
    width: 100%;
    padding: 12px;
    margin-top: 12px;
    border: none;
    background: #4caf50;
    color: white;
    border-radius: 8px;
    cursor: pointer;
}

.scoreboard button:hover {
    background: #388e3c;
}

#status {
    margin-top: 15px;
    font-weight: bold;
}

/* Fullscreen Popup */
.popup {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    backdrop-filter: blur(8px);
    background: rgba(0,0,0,0.4);
    display: flex;
    justify-content: center;
    align-items: center;
}

.popup-box {
    background: white;
    padding: 40px;
    width: 350px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 0 20px #444;
    animation: pop 0.3s ease-out;
}

@keyframes pop {
    from { transform: scale(0.7); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.popup-box h2 {
    font-size: 32px;
    margin-bottom: 20px;
}

.popup-box button {
    padding: 12px 20px;
    background: #2196f3;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.popup-box button:hover {
    background: #1976d2;
}

.hidden {
    display: none;
}