body {
    font-family: Arial, sans-serif;
    width: 100vw;
    height: 100vh;
    background: #101010;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;  
}
.container {
    background: #212121;
    padding: 24px 32px;
    border-radius: 8px;
    max-width: 400px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
.active {
    background-color: #007bff;
    color: white;
}
main {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    max-width: 400px;
    background: #121212;
}
nav {
    padding: 10px 18px;
    border-radius: 8px;
    width: 100%;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08)
}
h2 {
    margin-bottom: 20px;
    color: #ccc;
}
label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}
input[type="file"] {
    margin-bottom: 16px;
}
button[type="submit"] {
    background: #007bff;
    color: #fff;
    border: none;
    padding: 10px 18px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
}
button:hover {
    background: #0056b3;
}
.preview {
    margin-top: 16px;
    max-width: 100%;
    max-height: 200px;
    display: none;
    border: 1px solid #ddd;
    border-radius: 4px;
}