/* 引入一种好看的系统字体 */
body { 
    margin: 0; 
    overflow: hidden; 
    background-color: #1a1a1a; 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
canvas { 
    display: block; 
}

/* 🌟 高级毛玻璃渐变遮罩层 */
#blocker {
    position: absolute; 
    top: 0; left: 0;
    width: 100vw; 
    height: 100vh;
    background: radial-gradient(circle, rgba(0,0,0,0.5) 0%, rgba(0,0,0,0.85) 100%);
    backdrop-filter: blur(8px); /* 毛玻璃模糊效果 */
    display: flex; 
    justify-content: center; 
    align-items: center;
    z-index: 10; 
    cursor: pointer;
}

/* 菜单面板排版 */
#instructions {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 50px 60px;
    border-radius: 20px;
    text-align: center; 
    color: white; 
    pointer-events: none; 
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    animation: fadeIn 1s ease-out;
}

#instructions h1 {
    margin: 0 0 10px 0;
    font-size: 32px;
    letter-spacing: 2px;
    font-weight: 600;
}

.click-to-start {
    color: #ffcc00;
    font-size: 18px;
    margin-bottom: 40px;
    animation: pulse 2s infinite;
}

/* 按键说明网格 */
.controls-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px 30px;
    text-align: left;
    margin-bottom: 30px;
    color: #ccc;
}

.control-item span {
    display: inline-block;
    background: rgba(255,255,255,0.2);
    padding: 4px 10px;
    border-radius: 6px;
    font-weight: bold;
    color: #fff;
    min-width: 50px;
    text-align: center;
    margin-right: 10px;
    font-size: 14px;
}

.divider {
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    margin: 20px 0;
}

/* 🌟 提示文字样式：带点发光和特殊颜色 */
.hint {
    font-size: 15px;
    color: #ffebcc;
    font-style: italic;
    opacity: 0.9;
    text-shadow: 0 0 8px rgba(255, 204, 0, 0.4);
}

/* 🌟 极简圆圈准星 (取代原来的丑陋加号) */
#crosshair {
    position: absolute;
    top: 50%; 
    left: 50%;
    transform: translate(-50%, -50%);
    width: 6px;
    height: 6px;
    border: 1.5px solid rgba(255, 255, 255, 0.8);
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.2);
    pointer-events: none; 
    z-index: 5;
    box-shadow: 0 0 4px rgba(0,0,0,0.5);
}

/* 视角切换按钮：半透明磨砂风格 */
#modeBtn {
    position: absolute; 
    top: 25px; 
    right: 25px;
    padding: 10px 20px; 
    font-size: 14px; 
    cursor: pointer;
    z-index: 999; 
    border-radius: 30px; 
    border: 1px solid rgba(255,255,255,0.2);
    background: rgba(0, 0, 0, 0.4); 
    backdrop-filter: blur(5px);
    color: #fff; 
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

#modeBtn:hover { 
    background: rgba(255, 255, 255, 0.1); 
    border-color: #ffcc00;
    color: #ffcc00;
}

/* 简单的呼吸动画 */
@keyframes pulse {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}