body {
    margin: 0;
    padding: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(to bottom, #1a1a2e, #16213e);
    font-family: 'Arial', sans-serif;
    color: white;
    overflow: hidden;
}

#background-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

#game-container {
    text-align: center;
    z-index: 1;
}

#main-menu, #game-screen, #win-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.hidden {
    display: none !important;
}

h1 {
    font-size: 48px;
    text-shadow: 0 0 10px #00f;
    margin-bottom: 40px;
}

button {
    padding: 15px 30px;
    margin: 10px;
    font-size: 18px;
    background: linear-gradient(to right, #00f, #0ff);
    border: none;
    border-radius: 10px;
    color: white;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

button:hover {
    transform: scale(1.1);
    box-shadow: 0 0 10px #0ff;
}

#mute-btn, #mute-btn-game, #mute-btn-win {
    background: linear-gradient(to right, #ff4444, #ff8888);
}

#mute-btn.muted, #mute-btn-game.muted, #mute-btn-win.muted {
    background: linear-gradient(to right, #888, #ccc);
}

#stats {
    display: flex;
    gap: 20px;
    font-size: 20px;
    margin-bottom: 20px;
    align-items: center;
}

#game-board {
    display: grid;
    gap: 10px;
}

.card {
    width: 100px;
    height: 100px;
    background-color: #333;
    border-radius: 10px;
    cursor: pointer;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.5s;
    box-shadow: 0 0 5px #0ff;
}

.card.flipped {
    transform: rotateY(180deg);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-front {
    background: linear-gradient(to bottom, #fff, #aaa);
    font-size: 24px;
    transform: rotateY(180deg);
    box-shadow: inset 0 0 10px #0ff;
}

.card-back {
    background: url('https://via.placeholder.com/100?text=🌌') center/cover;
}

#win-screen {
    position: absolute;
    background: rgba(0, 0, 0, 0.8);
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 20px #0ff;
}

#particle-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 2;
}