html, body {
    height: 100%;
    width: 100%;
}

body {
    position: fixed;
    top: 0;
    left: 0;
}

/*
    header
*/
.header {
    height: 5%;
    min-height: 45px;
    background-color: #c17444;
}

.header > .title b {
    display: block;
    padding-left: 20px;
    padding-top: 10px;
    color: #3e3744;
}

/*
    content
*/
.content {
    /* .form-areaの突き抜け対策 */
    overflow: hidden;
    background-color: #f6f6f6;
    height: 95%;
}

/*
    ログインフォーム
*/
.form-area {
    width: 30%;
    min-width: 550px;
    height: 250px;
    background-color: whitesmoke;
    margin: 95px auto 0 auto;
    display: table;
    border-radius: 10px;
    box-shadow: 0 0 px gray;
    border-style: ridge;
    border-color: #bababa;
    border-width: 3px;
}

.form-area form {
    padding: 20px;
    display: table-cell;
    vertical-align: middle;
}

/*
    エラー表示エリア
*/
.error-area {
    width: 100%;
    height: 95px;
    /* .error突き抜け対策 */
    overflow: hidden;
}

.error {
    width: 98%;
    height: 80px;
    margin-left: 1%;
    margin-right: 1%;
    margin-top: 5px;
    color: red;
}