body {
    font-family: Arial, sans-serif;
    background-color: #2C3E50;
    color: #f2f2f2;
    margin: 0;
    padding: 0;
    line-height: 1.4;
}

.container {
    max-width: 1200px;
    margin: 60px auto 20px;
    background-color: #fff;
    color: #333;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    padding: 20px;
}

h1, h2, h3 {
    color: #3498db;
}

a {
    color: #3498db;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

input, textarea {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
    border: 1px solid #ddd;
    border-radius: 3px;
    box-sizing: border-box;
}

button, .button {
    display: inline-block;
    padding: 10px 15px;
    background-color: #3498db;
    color: #fff;
    border: none;
    border-radius: 3px;
    cursor: pointer;
    text-decoration: none;
}

button:hover, .button:hover {
    background-color: #2980b9;
}

.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 160px;
    box-shadow: 0px 8px 16px rgba(0,0,0,0.2);
    z-index: 1001;
    top: 100%;
    left: 0;
}

.dropdown:hover .dropdown-content {
    display: block;
}

main {
    padding-top: 40px;
    position: relative;
    z-index: 1;
}

.tab {
    display: flex;
    justify-content: center;
    background-color: black;
    border-radius: 5px 5px 0 0;
    margin-top: 60px;
}

.tab button {
    background-color: inherit;
    border: none;
    cursor: pointer;
    padding: 14px 16px;
    transition: 0.3s;
    font-size: 17px;
    font-weight: bold;
}

.tab button:hover {
    background-color: #ddd;
}

.tab button.active {
    background-color: #3498db;
    color: white;
}

.tabcontent {
    display: none;
    padding: 20px;
    border: 1px solid #ccc;
    border-top: none;
    border-radius: 0 0 5px 5px;
}

.book-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.book-buttons button {
    padding: 10px 15px;
    background-color: #ecf0f1;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: 0.3s;
    color: #333;
}

.book-buttons button:hover {
    background-color: #bdc3c7;
}

.youtube-playlist {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    max-width: 80%;
    background: #000;
    margin: 20px auto;
}

.youtube-playlist iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.footer-center {
    text-align: center;
    margin: 20px 0;
    color: #777;
}

.login-container {
    background-color: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    max-width: 300px;
    margin: auto;
}

.login-container h1 {
    text-align: center;
    margin-bottom: 1.5rem;
}

.login-form input {
    width: 100%;
    padding: 0.5rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.error-message {
    color: red;
    text-align: center;
    margin-bottom: 1rem;
}

.article {
    background: #34495E;
    color: #f2f2f2;
    margin-bottom: 20px;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.article-title, .article h2 {
    color: #FFD700;
    margin-bottom: 10px;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
}

.article small {
    color: #FFD700;
    display: block;
    margin-top: 10px;
}

.article .read-more, .article .edit-link {
    display: inline-block;
    margin-top: 10px;
    padding: 5px 10px;
    background-color: #3498db;
    color: #fff;
    text-decoration: none;
    border-radius: 3px;
    cursor: pointer;
}

.article .read-more:hover, .article .edit-link:hover {
    background-color: #2980b9;
}

.pagination {
    margin: 20px 0;
    text-align: center;
}

.pagination a {
    display: inline-block;
    margin: 0 5px;
    padding: 10px 20px;
    background-color: #3498db;
    color: #fff;
    text-decoration: none;
    border-radius: 3px;
    cursor: pointer;
}

.pagination a:hover {
    background-color: #2980b9;
}