* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}
body {
    display: flex;
    height: 100vh;
    transition: background 0.3s, color 0.3s;
    background: #f4f4f4;
    color: black;
}
.container {
    display: flex;
    width: 100%;
}
.sidebar {
    background: #333;
    color: white;
    padding: 20px;
    width: 25%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}
.sidebar .btn {
    background: #2ecc71;
    color: white;
    padding: 10px 15px;
    border: none;
    cursor: pointer;
    margin-top: 10px;
}
.content {
    flex: 1;
    padding: 50px;
    background: white;
    color: black;
}
.content .btn {
    background: #2ecc71;
    color: white;
    padding: 10px 15px;
    border: none;
    cursor: pointer;
    margin-top: 10px;
    font-size: 16px;
    font-weight: bold;
    border-radius: 5px;
}
.image-container {
    width: 40%;
    background: #eee;
}
.image-container img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.dark-theme {
    background: #222;
    color: white;
}
.dark-theme .content {
    background: #333;
    color: white;
}
.dark-theme .sidebar {
    background: #111;
    color: white;
}
.dark-theme .btn {
    background: #27ae60;
}
.popup-image {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    padding: 20px;
    border-radius: 10px;
}
.popup-image img {
    max-width: 90vw;
    max-height: 90vh;
}