body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: #f4f6f8;
    margin: 0;
    padding: 0;
    color: #333;
}

.container {
    max-width: 900px;
    margin: 50px auto;
    background: white;
    padding: 40px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
}

h1 {
    font-size: 32px;
    border-bottom: 3px solid #222;
    padding-bottom: 10px;
    margin-bottom: 20px;
}

h2 {
    margin-top: 30px;
    color: #222;
}

p {
    line-height: 1.8;
}

ul {
    line-height: 1.8;
}

.footer {
    margin-top: 40px;
    text-align: center;
    color: #888;
}

/* エイプリルフール警告 */
.aprilfool-box {
    background: linear-gradient(135deg, #ff4d4d, #ff0000);
    color: white;
    font-size: 24px;
    font-weight: bold;
    text-align: center;
    padding: 25px;
    margin-bottom: 30px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(255,0,0,0.5);
    animation: pulse 1.5s infinite;
}

/* 点滅アニメーション */
@keyframes pulse {
    0% {
        transform: scale(1);
        box-shadow: 0 0 15px rgba(255,0,0,0.5);
    }
    50% {
        transform: scale(1.02);
        box-shadow: 0 0 30px rgba(255,0,0,0.8);
    }
    100% {
        transform: scale(1);
        box-shadow: 0 0 15px rgba(255,0,0,0.5);
    }
}