body {
    margin: 0;
    overflow: hidden;
    background-color: #000;
    font-family: 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}

canvas {
    display: block;
}

/* フィルムグレイン・ノイズエフェクト */
body::after {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 999;
    opacity: 0.05;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
}

#ui-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

#start-screen {
    position: absolute;
    width: 100%;
    height: 100%;
    background: #000;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    z-index: 100;
    pointer-events: auto;
}

#start-button {
    padding: 15px 40px;
    font-size: 1.2rem;
    background: #600;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin-top: 20px;
}

#message {
    position: absolute;
    bottom: 25%;
    width: 100%;
    color: #f00;
    font-size: 1.2rem;
    text-align: center;
    opacity: 0;
    transition: opacity 0.5s;
    text-shadow: 0 0 10px #f00;
    pointer-events: none;
}

/* バーチャルジョイスティック */
#joystick-zone {
    position: absolute;
    bottom: 40px;
    left: 40px;
    width: 100px;
    height: 100px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    pointer-events: auto;
    border: 2px solid rgba(255,255,255,0.2);
}

#joystick-stick {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

/* 射撃ボタン */
#shoot-button {
    position: absolute;
    bottom: 50px;
    right: 50px;
    width: 80px;
    height: 80px;
    background: rgba(200, 0, 0, 0.3);
    border: 3px solid rgba(255, 255, 255, 0.4);
    border-radius: 50%;
    pointer-events: auto;
    display: flex;
    justify-content: center;
    align-items: center;
}

#shoot-button:active {
    background: rgba(255, 0, 0, 0.6);
    transform: scale(0.95);
}

#shoot-button::after {
    content: "HIT";
    color: white;
    font-weight: bold;
    font-size: 14px;
    opacity: 0.6;
}

#crosshair {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 6px;
    height: 6px;
    background: rgba(255,255,255,0.5);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}