body {
    font-family: "Avenir Next";
    background: linear-gradient(to left bottom, rgb(70, 130, 200), rgb(20, 80, 130));
}

li {
    list-style: none;
}

.header {
    background-color: #FFCC00;
    height: 80px;
}

.header-logo {
    color: black;
    float: left;
    font-size: 25px;
    padding: 20px 40px;
    font-family: 'しっぽり明朝 B1', serif;
}

.header-logo img {
    width: 50%;
}

.header-list li {
    float: left;
    padding: 33px 20px;
}

nav {
    display: flex;
    width: 100%;
}

a {
    color: white;
    margin: 10px;
    flex-basis: 33%;
    text-align: center;
    text-decoration: none;
}

.textbox a {
    color: #4689FF;
}

h1 {
    color: red;
}

.textbox {
    border-radius: 15px;
    background-color: #FFFFAA;
    max-width: 290px;
    margin: 10px auto;
    padding: 5px 40px 20px;
}

.nav {
    display: flex;
    max-width: 380px;
    margin: 10px auto;
}

.nav-box {
    border-radius: 15px;
    background-color: #FF6600;
    margin: 5px;
    padding: 5px 25px 5px;
}

.contents-item {
    float: left;
    margin: 5px;
}

.contents-item img {
    height: 70px;
}

.footer {
    background-color: #FF9900;
    color: #fff;
    height: 120px; /* もともとは 100px で設定 */
    padding: 10px;
}

.footer-logo {
    float: left;
    font-size: 25px;
    font-family: 'しっぽり明朝 B1', serif;
}

.footer-list {
    float: right;
}