static/styles/app.css

body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background: linear-gradient(135deg, #6e8efb, #a777e3);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    color: #fff;
}

.container {
    background: rgba(255, 255, 255, 0.1);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
    text-align: center;
    width: 400px;
}

h1 {
    margin-bottom: 20px;
    color: #fff;
    font-size: 24px;
}

.file-upload {
    position: relative;
    margin-bottom: 20px;
}

.file-upload input[type="file"] {
    display: none;
}

.file-label {
    display: inline-block;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    outline: none;
    color: #fff;
    background-color: #4CAF50;
    border: none;
    border-radius: 5px;
    box-shadow: 0 5px #999;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.file-label:hover {
    background-color: #3e8e41;
}

.file-label:active {
    background-color: #3e8e41;
    box-shadow: 0 3px #666;
    transform: translateY(2px);
}

.button {
    display: inline-block;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    outline: none;
    color: #fff;
    background-color: #4CAF50;
    border: none;
    border-radius: 5px;
    box-shadow: 0 5px #999;
    margin-top: 20px;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.button:hover {
    background-color: #3e8e41;
}

.button:active {
    background-color: #3e8e41;
    box-shadow: 0 3px #666;
    transform: translateY(2px);
}

.progress {
    display: none;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    margin-top: 20px;
}

.progress-bar {
    width: 0%;
    height: 20px;
    background-color: #4caf50;
    border-radius: 8px;
    text-align: center;
    color: white;
}

#message {
    margin-top: 20px;
    color: #fff;
}