body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
    background-color: #f8f9fa;
    margin: 0;
}

.upload-container {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    width: 100%;
    max-width: 700px;
}

h2 {
    margin-top: 0;
    color: #2d3436;
    text-align: center;
    margin-bottom: 30px;
}

#drop-zone {
    border: 2px dashed #cbd5e0;
    padding: 50px 20px;
    text-align: center;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    background-color: #fdfdfd;
}

#drop-zone.dragover {
    transform: scale(1.02);
    border-color: #007bff;
    background-color: #f0f7ff;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.1);
}

#drop-zone:hover {
    border-color: #007bff;
    background-color: #f0f7ff;
}

button {
    background-color: #007bff;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    width: 100%;
    font-size: 16px;
    transition: background 0.2s;
}

button:hover {
    background-color: #0056b3;
}

button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

label {
    display: block;
    margin: 15px auto;
    text-align: center;
    font-size: 13px;
    color: #718096;
}

#progress-container {
    display: none;
    width: 100%;
    height: 8px;
    background-color: #edf2f7;
    border-radius: 4px;
    margin: 25px 0 10px 0;
    overflow: hidden;
}

#progress-bar {
    width: 0%;
    height: 100%;
    background-color: #007bff;
    transition: width 0.4s ease;
}

#status-message {
    font-size: 14px;
    color: #4a5568;
    text-align: center;
    margin-bottom: 10px;
}

#seccion-acumulados {
    width: 100%;
    max-width: 800px;
    margin-top: 30px;
}

#lista-facturas {
    display: flex;
    flex-direction: column;
    gap: 15px;
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
}

.factura-item {
    background: #ffffff;
    padding: 15px;
    border-left: 5px solid #28a745;
    border-radius: 6px;
    font-size: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    border: 1px solid #e2e8f0;
    border-left-width: 5px;
}

.factura-item b {
    color: #2d3748;
}

#btn-descargar {
    background-color: #28a745;
    margin-top: 25px;
    padding: 15px;
    font-size: 18px;
}

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