:root {
    --primary-color: #4CAF50; /* Un verde fresco y saludable */
    --secondary-color: #81C784; /* Verde más claro */
    --background-color: #E8F5E9; /* Un fondo verde muy pálido */
    --surface-color: #FFFFFF;
    --text-color-primary: #1B5E20; /* Verde oscuro para texto */
    --text-color-secondary: #666666;
    --accent-color: #FFC107; /* Un acento amarillo/ámbar */
    --font-family: 'Poppins', sans-serif;
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color-primary);
    display: flex;
    flex-direction: column; /* Added */
    justify-content: center;
    align-items: stretch; /* Changed from center */
    min-height: 100vh;
    padding: 1rem;
}

.calculator-container {
    width: 100%;
    max-width: 400px;
    background-color: var(--surface-color);
    border-radius: 24px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    flex-grow: 1; /* Added */
    justify-content: flex-start; /* Changed from center */
}

.calculator-header {
    background-color: var(--primary-color);
    color: var(--surface-color);
    padding: 1.5rem;
    text-align: center;
}

.calculator-header h1 {
    font-weight: 600;
    font-size: 1.75rem;
}

.calculator-header p {
    font-weight: 300;
    font-size: 1rem;
    opacity: 0.9;
}

.calculator-body {
    padding: 1.5rem;
    display: flex; /* Added */
    flex-direction: column; /* Added */
    flex-grow: 1; /* Added */
    min-height: 0; /* Added */
    overflow: hidden; /* Added */
}

.calculator-display {
    background-color: var(--background-color);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: right;
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}

.calculator-display .currency {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--text-color-secondary);
}

.calculator-display #total-amount {
    font-size: 3rem;
    font-weight: 600;
    color: var(--text-color-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.calculator-keypad {
    display: flex; /* Changed from grid */
    flex-direction: column; /* Added */
    gap: 0.5rem; /* Added */
    flex-grow: 1; /* Added */
    overflow-y: auto; /* Added */
    padding-right: 0.5rem; /* Added */
    padding-bottom: 1rem; /* Added */
}

.keypad-button {
    font-family: var(--font-family);
    font-size: 1.25rem;
    font-weight: 400;
    border: none;
    border-radius: 12px;
    background-color: var(--background-color);
    color: var(--text-color-primary);
    height: 60px;
    cursor: pointer;
    transition: background-color 0.2s, box-shadow 0.2s;
}

.keypad-button:hover {
    background-color: var(--secondary-color);
    color: var(--surface-color);
}

.keypad-button:active {
    transform: scale(0.95);
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.keypad-button.operator {
    background-color: var(--secondary-color);
    color: var(--surface-color);
    font-weight: 600;
}

.keypad-button.operator:hover {
    background-color: var(--primary-color);
}

.keypad-button.wide {
    grid-column: span 2;
}

.keypad-button.tall {
    grid-row: span 2;
    height: auto;
}

.keypad-button.accent {
    background-color: var(--accent-color);
    color: var(--text-color-primary);
}

.keypad-button.accent:hover {
    background-color: #ffca28;
}

/* Responsive Design */
@media (max-width: 420px) {
    body {
        padding: 0;
        align-items: stretch;
    }

    .calculator-container {
        border-radius: 0;
        min-height: 100vh;
    }

    .calculator-display #total-amount {
        font-size: 2.5rem;
    }

    .keypad-button {
        height: 65px;
    }
}

/* === Estilos Adicionales para la Lista de Productos y Botones === */

/* Display superior */
.calculator-display {
    flex-direction: column;
    align-items: flex-end;
}
.total-line {
    display: flex;
    align-items: baseline;
}
.original-price {
    text-decoration: line-through;
    opacity: 0.6;
    font-size: 0.75em;
    margin-right: 0.5rem;
    display: none; /* Oculto por defecto */
}
.discount-info {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 600;
    margin-top: 0.25rem;
    display: none; /* Oculto por defecto */
}

/* Estructura de la lista de productos */
.category-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
    border-bottom: 1px solid var(--background-color);
    padding-bottom: 0.25rem;
}

.category-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-color-secondary);
    text-transform: uppercase;
}

.urgent-category-title {
    color: var(--accent-color);
}

.product-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--background-color);
    border-radius: 8px;
    padding: 0.75rem;
    margin-top: 0.5rem;
}

.special-product {
    background-color: var(--secondary-color);
    margin-bottom: 1rem;
}

.special-product .product-name, .special-product .product-price {
    color: white;
}

.product-info {
    display: flex;
    flex-direction: column;
}

.product-name {
    font-weight: 600;
    font-size: 1rem;
    color: var(--text-color-primary);
}

.product-price {
    font-size: 0.9rem;
    color: var(--text-color-secondary);
}

/* Controles de productos (+, -, cantidad) */
.product-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.control-btn {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    border: none;
    background-color: var(--primary-color);
    color: white;
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
    flex-shrink: 0;
}

.control-btn:hover {
    background-color: #388E3C;
}

.quantity {
    font-size: 1.1rem;
    font-weight: 600;
    min-width: 20px;
    text-align: center;
}

/* Botones de descuento */
.discount-btn {
    font-size: 0.7rem;
    width: auto;
    padding: 0 0.5rem;
    height: 30px;
    border-radius: 6px;
    background-color: var(--accent-color);
    color: var(--text-color-primary);
}

.discount-btn.active {
    background-color: #FF8F00;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

.category-discount-btn {
    margin-left: 1rem;
}

/* Contenedor de Botones Flotantes (FAB) */
.fab-container {
    position: fixed;
    bottom: 20px;
    left: 20px;
    right: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    pointer-events: none;
    z-index: 1000;
}

.fab {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    border: none;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    pointer-events: auto;
}

.fab:hover {
    transform: scale(1.05);
}

.fab svg {
    fill: white;
}

#reset-button {
    background-color: #D32F2F; /* Rojo para reset */
}

#reset-button:hover {
    background-color: #B71C1C;
}

#profit-toggle-button {
    background-color: #1976D2; /* Azul para ganancias */
}

#profit-toggle-button:hover {
    background-color: #1565C0;
}

#profit-toggle-button.active {
    background-color: var(--accent-color); /* Amarillo cuando está activo */
}