body {
    font-family: sans-serif;
    /* 背景画像にrgbaオーバーレイで明るさ調節を追加 */
    background: linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), url("仕事にできない背景.png");
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    line-height: 1.6;
    max-width: 800px;
    margin: auto;
    padding: 20px;
}
h1 { color: #2c3e50; }
.section-box { border-left: 4px solid #3498db; padding-left: 15px; margin: 20px 0; }