body {
    margin: 0;
    padding: 10px;
    background-color: #fff;
    color: #000;
    font-family: 'Times New Roman', serif;
    font-size: 16px;
    line-height: 1.5;
}
h1, h2 {
    font-size: 20px;
    text-align: center;
    margin: 10px 0;
}
.panel, .content-list, .post-detail {
    max-width: 600px;
    margin: 0 auto;
}
.panel {
    border: 2px solid #000;
    padding: 10px;
    margin-bottom: 20px;
}
input[type="text"], input[type="password"], textarea {
    width: 100%;
    padding: 5px;
    font-size: 16px;
    border: 2px solid #000;
    background-color: #fff;
    color: #000;
    margin-bottom: 10px;
}
textarea {
    height: 100px;
}
button {
    padding: 5px 10px;
    font-size: 16px;
    border: 2px solid #000;
    background-color: #fff;
    color: #000;
    cursor: pointer;
}
.content-item, .post-detail {
    border: 2px solid #000;
    padding: 10px;
    margin-bottom: 10px;
}
a {
    color: #000;
    text-decoration: underline;
}