styles.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    flex-grow: 1; 
    text-align: center;
}

h1 {
    font-size: 2em;
    margin-bottom: 20px;
    color: #333;
}

.upload-section {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.file-upload {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    padding: 10px 20px;
    font-size: 1em;
    font-weight: bold;
    color: #fff;
    background-color: #007BFF;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    overflow: hidden;
    transition: background-color 0.3s ease;
    width: 100%; 
    max-width: 250px; 
}

.file-upload:hover {
    background-color: #0056b3;
}

.file-upload input {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.file-name {
    margin-top: 10px;
    color: #fff;
    font-size: 0.9em;
}

.preview-section {
    margin-top: 20px;
    margin-bottom: 20px;
}

.preview-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.preview-title {
    font-size: 1.2em;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
}

canvas {
    border: 1px solid #ddd;
    border-radius: 5px;
    background-color: #f9f9f9;
    width: 100%;
    max-width: 300px; 
    height: auto;
}

#changes {
    margin-top: 20px;
    text-align: left;
    font-size: 1em;
    color: #333;
    line-height: 1.5;
    max-width: 300px;
    word-wrap: break-word; 
}

.btn {
    display: inline-block;
    padding: 10px 20px;
    font-size: 1em;
    font-weight: bold;
    color: #fff;
    background-color: #28a745;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    width: 100%; 
    max-width: 250px; 
}

.btn:hover {
    background-color: #218838;
}

.btn:active {
    transform: scale(0.98);
}

#downloadAlteredQR {
    margin-top: 20px;
}

footer {
    background-color: #f8f9fa;
    padding: 10px 0;
    text-align: center;
    font-size: 0.9em;
    color: #666;
    width: 100%;
    border-top: 1px solid #ddd;
}

@media (min-width: 768px) {
    .upload-section {
        flex-direction: row;
        justify-content: center;
    }
   
    .preview-container {
        flex-direction: row;
        justify-content: space-between;
    } 
  
    #changes {
        text-align: center;
    }
}

@media (min-width: 1024px) {
    h1 {
        font-size: 2.5em;
    }
    
    .file-upload {
        font-size: 1.1em;
    }
    
    .preview-title {
        font-size: 1.5em;
    }

    canvas {
        max-width: 350px; 
    }
    
    #changes {
        font-size: 1.1em;
        max-width: 400px;
    }
}

a {
    text-decoration: none;
}