* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #eef2f5;
}

.container {
    display: flex;
    gap: 20px;
    padding: 20px;
    max-width: 1200px;
    margin: auto;
}

.form-box,
.preview-box {
    background: #ffffff;
    padding: 20px;
    border-radius: 8px;
    width: 100%;
}

/* Desktop */
@media (min-width: 901px) {
    .form-box { width: 35%; }
    .preview-box { width: 65%; }
}

label {
    font-size: 14px;
    color: #444;
}

input[type="text"],
input[type="file"] {
    width: 100%;
    padding: 12px;
    margin-bottom: 12px;
    font-size: 15px;
}

button {
    width: 100%;
    padding: 12px;
    background: #0b6f4e;
    color: #ffffff;
    border: none;
    font-size: 16px;
    cursor: pointer;
    border-radius: 4px;
}

iframe {
    width: 100%;
    min-height: 260px;
    border: 1px solid #ddd;
    background: #fff;
}

@media (max-width: 900px) {
    .container {
        flex-direction: column;
    }

    iframe {
        min-height: 320px;
    }
}