html {
    background: #000000;
}

body {
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0 auto;
    width: 100%;
    max-width: 800px;
    word-wrap: break-word;
    padding: 10px;
    box-sizing: border-box;
    background: #fff;
}

a:link, a:hover, a:visited, a:active {
    color: #4169e1;
}

.center {
    text-align: center;
}

.left {
    text-align: left;
}

header {
    text-align: center;
}

header img {
    width: 100%;
    max-width: 800px;
}

form {
    margin: 0 auto;
    font-size: 18px;
}

form input {
    box-sizing: border-box;
    width: 100%;
    max-width: 300px;
    font-size: 18px;
    padding: 5px;
    margin: 5px 0 20px;
}

.input_title {
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    text-align: left;
}

.radio_input {
    width:5%;
}

.radio_input_div {
    width: 100%;
    max-width: 300px;
    margin: 0 auto;
    text-align: left;
}

.confirm_title {
    width: 100%;
    max-width: 300px;
    margin: 0 auto 30px;
    text-align: left;
}

h4 {
    font-size: 20px;
    text-align: center;
}

.input_area {
    width: 90%;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}


.caution {
    width: 90%;
    font-size: 16px;
    max-width: 640px;
    margin: 30px auto 50px;
    line-height: 1.5em;
}

.input_submit {
    width: 200px;
    margin: 30px auto 70px;
    font-size: 20px;
}

.confirm_submit {
    width: 200px;
    margin: 30px auto 10px;
    font-size: 20px;
}

.top_link {
    text-align: center;
    margin: 0 0 70px;
}

h3 {
    text-align: center;
    margin: 50px;
}

.mail {
    color: #20b2aa;
    text-decoration: underline;
}

.complete_text {
    text-align: left;
    font-size: 18px;
    width: 90%;
    max-width: 480px;
    margin: 0 auto;
}