:root {
    --primary: #3498db;
    --primary-dark: #2980b9;
    --secondary: #2c3e50;
    --success: #27ae60;
    --danger: #e74c3c;
    --warning: #f39c12;
    --light: #ecf0f1;
    --dark: #2c3e50;
    --gray: #95a5a6;
    --white: #ffffff;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --radius: 12px;
    --radius-sm: 8px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--light);
    color: var(--dark);
    line-height: 1.5;
    padding-bottom: 80px;
}

.app {
    max-width: 600px;
    margin: 0 auto;
    min-height: 100vh;
}

.header {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: var(--white);
    padding: 24px 20px;
    text-align: center;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.header p {
    opacity: 0.9;
    font-size: 0.9rem;
}

.main {
    padding: 20px;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

.product-form {
    background: var(--white);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
}

.product-form h2, .products-list h2 {
    font-size: 1.2rem;
    margin-bottom: 16px;
    color: var(--secondary);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--secondary);
}

.form-group input, .form-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    transition: border-color 0.2s;
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--primary);
}

.ingredients-section h3 {
    font-size: 1rem;
    color: var(--secondary);
    margin-bottom: 12px;
}

.ingredients-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 12px;
}

.ingredient-add{
    align-items: center;
    padding: 10px;
    background: var(--light);
    border-radius: var(--radius-sm);
}

.ingredient-row {
    display: flex;
    gap: 6px;
    align-items: center;
    flex-wrap: wrap;
    padding: 10px;
    background: var(--light);
    border-radius: var(--radius-sm);
}

.ingredient-row input {
    flex: 1;
    min-width: 60px;
    padding: 8px;
}

.ingredient-row input[type="text"] {
    flex: 1.5;
    min-width: 100px;
}

.ingredient-row select {
    width: auto;
    min-width: 50px;
    padding: 8px;
}

.ingredient-row input[type="number"] {
    width: 60px;
    min-width: 50px;
}

.btn-remove {
    background: var(--danger);
    color: var(--white);
    border: none;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 1.2rem;
    line-height: 1;
}

.btn {
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
    width: 100%;
    margin-top: 16px;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px dashed var(--primary);
    width: 100%;
}

.btn-outline:hover {
    background: rgba(52, 152, 219, 0.1);
}

.total-section {
    background: var(--light);
    padding: 16px;
    border-radius: var(--radius-sm);
    margin-top: 16px;
}

.total-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
}

.total-row span:last-child {
    color: var(--success);
    font-size: 1.3rem;
}

.profit-section {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--light);
}

.profit-section label {
    font-weight: 500;
    color: var(--secondary);
}

.profit-section input {
    width: 80px;
    padding: 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
}

.ingredients-header {
    display: none;
}

@media (min-width: 600px) {
    .ingredients-header {
        display: grid;
        grid-template-columns: 1.5fr 1fr 80px 1fr 80px 80px 40px;
        gap: 8px;
        padding: 8px 4px;
        font-size: 0.85rem;
        font-weight: 600;
        color: var(--gray);
        border-bottom: 1px solid var(--light);
        margin-bottom: 8px;
    }
    
    .ingredient-row {
        display: grid;
        grid-template-columns: 1.5fr 1fr 80px 1fr 80px 80px 40px;
        gap: 8px;
        align-items: center;
    }
    
    .ingredient-row input, .ingredient-row select {
        width: 100%;
    }
}

.products-list {
    background: var(--white);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
}

.saved-products {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.product-card {
    background: var(--light);
    border-radius: var(--radius-sm);
    padding: 16px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.product-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.product-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.product-card-title {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--secondary);
}

.product-card-cost {
    font-weight: 700;
    color: var(--success);
    font-size: 1.1rem;
}

.product-card-ingredients {
    font-size: 0.85rem;
    color: var(--gray);
}

.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--white);
    display: flex;
    justify-content: space-around;
    padding: 12px;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    z-index: 100;
}

.nav-btn {
    padding: 12px 24px;
    border: none;
    background: transparent;
    color: var(--gray);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

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

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 200;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--white);
    border-radius: var(--radius);
    padding: 24px;
    max-width: 400px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-content h3 {
    margin-bottom: 16px;
    color: var(--secondary);
}

.modal-ingredient {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--light);
}

.modal-actions {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.modal-actions .btn {
    flex: 1;
}

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

.btn-danger:hover {
    background: #c0392b;
}

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

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

.btn-success:hover {
    background: #219a52;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--gray);
}

.empty-state p {
    margin-bottom: 8px;
}

/* PWA Install Prompt */
.install-prompt {
    position: fixed;
    bottom: 80px;
    left: 20px;
    right: 20px;
    background: var(--white);
    padding: 18px;
    border-radius: var(--radius);
    box-shadow: 0 -4px 20px rgba(0,0,0,0.15);
    z-index: 1000;
}
.install-prompt-content p {
    margin-bottom: 15px;
    font-weight: 500;
    color: var(--secondary);
    text-align: center;
    font-size: 1.05rem;
}
.install-actions {
    display: flex;
    flex-direction: column;
}

@media (max-width: 480px) {
    .header {
        padding: 20px 16px;
    }
    
    .main {
        padding: 16px;
    }
    
    .product-form, .products-list {
        padding: 16px;
    }
    
    .ingredient-row {
        flex-wrap: wrap;
    }
    
    .ingredient-row input, .ingredient-row select {
        flex: 1 1 auto;
    }
}