body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    padding: 1.5em;
    margin: 0;
    display: flex;
    justify-content: center;
    background: #f0f2f5;
    color: #333;
}
.container {
    width: 100%;
    max-width: 600px;
    background: white;
    padding: 2em;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
h2 {
    text-align: center;
    margin-bottom: 1.5em;
    color: #1c1e21;
}
label {
    margin-top: 1em;
    display: block;
    font-weight: 600;
}
select, textarea, button {
    width: 100%;
    padding: 0.8em;
    margin-top: 0.5em;
    font-size: 1em;
    box-sizing: border-box;
    border: 1px solid #ccc;
    border-radius: 6px;
}
textarea {
    resize: vertical;
    min-height: 120px;
}
button {
    margin-top: 1.5em;
    background: #007BFF;
    color: white;
    border: none;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
}
button:hover {
    background: #0056b3;
}
button:disabled {
    background: #a0c7ff;
    cursor: not-allowed;
}
.hidden {
    display: none !important;
}
#progress-container, #output, #error-container {
    margin-top: 2em;
    text-align: center;
    padding: 1.5em;
    border-radius: 8px;
}
#progress-container {
    background-color: #e9f5ff;
    border: 1px solid #b3d7ff;
}
.progress-bar {
    width: 100%;
    background-color: #d1e7fd;
    border-radius: 4px;
    overflow: hidden;
    margin-top: 1em;
}
#progress-bar-fill {
    height: 20px;
    width: 0%;
    background-color: #007BFF;
    border-radius: 4px;
    transition: width 0.5s ease-in-out;
}
#output {
    background-color: #e4f8e9;
    border: 1px solid #a3e0b2;
}
#error-container {
    background-color: #fbe9e9;
    border: 1px solid #f2a6a6;
    color: #d93025;
}
audio {
    width: 100%;
    margin-top: 1em;
}
#download {
    display: inline-block;
    margin-top: 1em;
    padding: 0.6em 1.2em;
    background: #28a745;
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 500;
}
#download:hover {
    background: #1e7e34;
}