/* ここにスタイルを追加 */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f4f4f4;
}
.container {
    width: 80%;
    margin: auto;
    overflow: hidden;
}
header {
    background: #333;
    color: #fff;
    padding-top: 30px;
    min-height: 70px;
    border-bottom: #0779e4 3px solid;
}
header h1 {
    float: left;
    margin: 0;
}
nav {
    float: right;
    margin-top: 10px;
}
nav a {
    color: #fff;
    text-decoration: none;
    padding: 5px 20px;
    font-size: 18px;
}
.intro {
    padding: 15px;
    color: #555;
}
.intro h1 {
    text-align: center;
}
.skills, .projects, .contact {
    padding: 15px;
    color: #555;
}

iframe {
  width: 100%; /* 任意の横幅を指定 */
  height: auto;
  aspect-ratio: 16/9;
}