body {
    margin: 0;
    overflow: hidden;
    font-family: 'Arial', sans-serif;
    background: #000;
    color: #fff;
}

#canvas-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 1;
}

/* 霓虹背景动画 */
.neon-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    /* 深邃宇宙背景，中心蓝紫色星云 */
    background: 
        radial-gradient(circle at 50% 50%, rgba(76, 0, 255, 0.2) 0%, transparent 40%),
        radial-gradient(circle at 40% 40%, rgba(0, 200, 255, 0.15) 0%, transparent 35%),
        radial-gradient(ellipse at center, #0b1026 0%, #000000 100%);
    overflow: hidden;
}

#ui-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2;
    text-align: center;
    pointer-events: none; /* 让点击穿透到 canvas */
}

.title {
    margin-top: 20px;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 0 0 10px #fff, 0 0 20px #ff00de, 0 0 30px #ff00de;
    letter-spacing: 2px;
}

.left-controls {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 20px;
    pointer-events: auto;
}

.bottom-controls {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 20px;
    pointer-events: auto;
}

button {
    background: rgba(0, 0, 0, 0.6);
    border: 2px solid #00ffd5;
    color: #00ffd5;
    padding: 10px 20px;
    font-size: 1.1rem;
    cursor: pointer;
    border-radius: 25px;
    transition: all 0.3s ease;
    text-transform: uppercase;
    box-shadow: 0 0 10px rgba(0, 255, 213, 0.3);
}

button:hover, button.active {
    background: #00ffd5;
    color: #000;
    box-shadow: 0 0 20px rgba(0, 255, 213, 0.8);
}

#message {
    margin-top: 20px;
    font-size: 2rem;
    color: #ffd700;
    text-shadow: 0 0 10px #ff0000;
    transition: opacity 0.5s;
}

.hidden {
    opacity: 0;
    pointer-events: none;
}