.header {
    padding: 5px 10px;
    background-color: #00FFFF;
    border-bottom: 1px solid;
}

body {
    margin: 0;
    font-family: "MS ゴシック", system-ui;
}

h3 {
    border-bottom: 2px solid;
}

h4, h2 {
    border-left: 5px solid;
    padding-left: 8px;
}

.content {
    margin: 16px;
}

a {
    color: #0000FF;
    font-weight: bold;
}

a:hover{
    color: #ff0000;
    font-weight: bold;
}

img {
    width: 400px;
    display: block;
    height: auto;
    border-radius: 10px;
}

.footer {
    padding: 10px 10px;
    text-align: center;
    background-color: #666666;
    color: white;
}