/* 戻るボタンの配置 */
a[href="../../index.html"] {
    position: fixed;
    right: 20px;
    bottom: 20px;
    background-color: #ffffff;
    padding: 10px 20px;
    border-radius: 5px;
    text-decoration: none;
    color: #333;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: background-color 0.3s;
}

a[href="../../index.html"]:hover {
    background-color: #ddd;
}
body, html {
    margin: 0;
    padding: 0;
    overflow: hidden;
}
h1{
    text-align: center;
}
.glass-frame {
    position: relative;
    width: 500px;
    height: 500px;
    margin: 50px auto;
    padding: 10px; /* 内側の余白 */
    border-radius: 15px;
    background: rgba(255, 255, 255, 0.2); /* 透明な白 */
    box-shadow: 0 4px 10px rgba(255, 255, 255, 0.3), 0 0 20px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(10px); /* 背景をぼかす */
    border: 2px solid rgba(255, 255, 255, 0.4);
}
canvas {
    display: block;
    width: 500px;
    height: 500px;
    border-radius: 10px;
    margin: 0 auto;
    background-image: url(../images/underwater.jpg);
}

@keyframes rippleEffect {
    0% { transform: scale(1); filter: blur(0px); }
    50% { transform: scale(1.002); filter: blur(1px); }
    100% { transform: scale(1); filter: blur(0px); }
}

.ripple-animation {
    animation: rippleEffect 0.2s ease-out;
}