:root {
    --primary-color: #8A2BE2; /* A nice purple */
    --primary-hover: #7B24CB;
    --secondary-color: #28a745;
    --background-color: #f4f7f9;
    --card-background: #ffffff;
    --text-color: #333;
    --border-color: #e0e0e0;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --border-radius: 8px;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    direction: ltr;
}

.container { max-width: 600px; width: 100%; }
.card { background: var(--card-background); padding: 30px; border-radius: var(--border-radius); box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1); }
header { text-align: center; margin-bottom: 25px; }
header h1 { margin: 0; color: var(--primary-color); }
header p { color: #6c757d; }

.upload-area input[type="file"] { display: none; }
.file-label { display: block; text-align: center; padding: 12px; background-color: var(--primary-color); color: white; border-radius: var(--border-radius); cursor: pointer; transition: background-color 0.3s; }
.file-label:hover { background-color: var(--primary-hover); }

.status-box {
    margin-top: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    text-align: center;
}
#status-text { margin: 0; color: #495057; }
#progress-bar { width: 100%; margin-top: 10px; }
.hidden { display: none; }

.tracks-container { margin-top: 20px; }
.tracks-container h3 { margin-top: 0; }
#tracks-list { border: 1px solid var(--border-color); border-radius: var(--border-radius); padding: 10px; min-height: 50px; max-height: 150px; overflow-y: auto; }
.track-item { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.track-item-info { display: flex; align-items: center; gap: 8px; }
.preview-btn {
    padding: 3px 8px;
    font-size: 0.8rem;
    border: 1px solid var(--border-color);
    background: #f8f9fa;
    border-radius: 4px;
    cursor: pointer;
}
.preview-btn:hover { background: #e2e6ea; }

.output-options {
    margin-top: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

#extract-btn {
    width: 100%;
    padding: 12px;
    margin-top: 15px;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s;
}
#extract-btn:disabled { background-color: #8fdfa3; cursor: not-allowed; }

.preview-box {
    margin-top: 15px;
    background: #2d333b;
    color: #cdd9e5;
    padding: 15px;
    border-radius: var(--border-radius);
}
.preview-box h4 { margin-top: 0; }
#preview-content {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: monospace;
    max-height: 150px;
    overflow-y: auto;
}