/* --- Variables y Reset --- */
:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --success-color: #28a745;
    --success-hover: #218838;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-main: #333333;
    --text-muted: #888888;
    --border-color: #dcdfe6;
    --zone-bg: #f8faff;
    --zone-border: #a3c2f0;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
}

/* --- Contenedor Principal --- */
.card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    width: 100%;
    max-width: 550px;
    box-sizing: border-box;
}

.card-header h2 {
    margin: 0 0 20px 0;
    font-size: 24px;
    color: var(--text-main);
}

/* --- Zona de Arrastrar y Soltar --- */
.drop-zone {
    border: 2px dashed var(--zone-border);
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    background-color: var(--zone-bg);
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 10px;
}

.drop-zone:hover, .drop-zone.dragover {
    background-color: #edf3ff;
    border-color: var(--primary-color);
}

.drop-zone-icon {
    margin-bottom: 15px;
}

.drop-zone p {
    margin: 0;
    color: var(--text-muted);
    font-size: 16px;
}

.text-primary {
    color: var(--primary-color);
    font-weight: 600;
}

/* --- Textos informativos --- */
.info-row {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #a0a0a0;
    margin-bottom: 25px;
}

/* --- Vista previa del archivo (cuando ya se seleccionó uno) --- */
.file-preview {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #f8f9fa;
    border: 1px solid var(--border-color);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 25px;
}

.file-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.file-name {
    font-weight: 500;
    color: var(--text-main);
    word-break: break-all;
}

.icon-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 18px;
    cursor: pointer;
    padding: 5px;
    transition: color 0.2s;
}

.icon-btn:hover {
    color: #dc3545;
}

/* --- Footer y Botones --- */
.footer-actions {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.buttons-container {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    width: 100%;
}

.btn {
    border: none;
    padding: 12px 24px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.3);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: var(--success-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.3);
}

.btn:disabled {
    background: #e4e7ed;
    color: #a0a5b1;
    cursor: not-allowed;
}

#status {
    margin: 0;
    font-size: 14px;
    text-align: left;
}

/* --- Utilidades --- */
.hidden {
    display: none !important;
}

/* --- Responsividad para móviles --- */
@media (max-width: 480px) {
    .info-row {
        flex-direction: column;
        gap: 5px;
        text-align: center;
    }
    
    .buttons-container {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}