body {
    background-color: #000000;
    color: #ffffff;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background-color: #001f3f;
    padding: 20px;
    text-align: center;
}
nav a {
    color: #ffffff;
    text-decoration: none;
    margin: 0 15px;
    font-weight: bold;
}
.container {
    width: 80%;
    margin: 30px auto;
    background-color: #0a192f;
    padding: 20px;
    border-radius: 8px;
}
input, button, textarea {
    padding: 10px;
    margin: 10px 0;
    width: 100%;
    box-sizing: border-box;
}
button {
    background-color: #001f3f;
    color: white;
    border: 1px solid white;
    cursor: pointer;
}
button:hover { background-color: #003366; }
.auth-container {
    display: flex;
    gap: 20px;
    justify-content: space-between;
    flex-wrap: wrap;
}
.auth-box {
    flex: 1;
    min-width: 300px;
    background-color: #001f3f;
    padding: 20px;
    border-radius: 8px;
    border: 1px solid #003366;
}
.kitap-kart {
    background-color: #001f3f;
    padding: 15px;
    margin-bottom: 15px;
    border-radius: 5px;
    border-left: 5px solid white;
}
.kitap-kart h3 { margin-top: 0; }
.kitap-kart p { margin: 5px 0; color: #cccccc; }