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

:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --danger-color: #e74c3c;
    --success-color: #2ecc71;
    --bg-color: #ecf0f1;
    --card-bg: #ffffff;
    --text-color: #2c3e50;
    --border-color: #bdc3c7;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

#app {
    max-width: 800px;
    margin: 0 auto;
    min-height: 100vh;
    background-color: var(--card-bg);
}

header {
    background-color: var(--secondary-color);
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 1.5rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.7rem 1.2rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: background-color 0.3s;
}

.btn-primary:hover {
    background-color: #2980b9;
}

.btn-secondary {
    background-color: #95a5a6;
    color: white;
    border: none;
    padding: 0.7rem 1.2rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    margin-top: 1rem;
    width: 100%;
}

.btn-secondary:hover {
    background-color: #7f8c8d;
}

.btn-back {
    background-color: #95a5a6;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

.btn-delete {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
}

.calendar-view {
    padding: 1rem;
}

.events-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.event-card {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.event-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.event-card h3 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.event-card p {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin: 0.2rem 0;
}

.event-detail-view {
    padding: 1rem;
}

.detail-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.tabs {
    display: flex;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 1rem;
    overflow-x: auto;
}

.tab-btn {
    background: none;
    border: none;
    padding: 0.8rem 1rem;
    cursor: pointer;
    font-size: 0.9rem;
    color: #7f8c8d;
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
    white-space: nowrap;
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    font-weight: 600;
}

.tab-pane {
    display: none;
    animation: fadeIn 0.3s;
}

.tab-pane.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.3rem;
    font-weight: 600;
    color: var(--secondary-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.7rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    font-family: inherit;
}

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

.shopping-summary {
    background-color: var(--success-color);
    color: white;
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1.5rem;
    text-align: center;
}

.shopping-summary h3 {
    font-size: 1.3rem;
}

.category-section {
    margin-bottom: 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
}

.category-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.category-header h4 {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

.btn-add-product {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
}

.btn-delete-category {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85rem;
    margin-left: 0.5rem;
}

.product-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.product-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.7rem;
    background-color: #f8f9fa;
    border-radius: 5px;
}

.product-info {
    flex: 1;
}

.product-name {
    font-weight: 600;
    color: var(--secondary-color);
}

.product-details {
    font-size: 0.85rem;
    color: #7f8c8d;
}

.product-price {
    font-weight: 700;
    color: var(--success-color);
    margin-right: 0.5rem;
}

.btn-delete-product {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 0.3rem 0.6rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.8rem;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background-color: white;
    padding: 2rem;
    border-radius: 8px;
    width: 90%;
    max-width: 400px;
}

.modal-content h3 {
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.modal-content input {
    width: 100%;
    padding: 0.7rem;
    margin-bottom: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
}

.modal-buttons {
    display: flex;
    gap: 0.5rem;
}

.modal-buttons button {
    flex: 1;
}

.hidden {
    display: none;
}

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: #7f8c8d;
}

.empty-state h2 {
    margin-bottom: 0.5rem;
}

@media (max-width: 600px) {
    header h1 {
        font-size: 1.2rem;
    }

    .btn-primary {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }

    .tab-btn {
        font-size: 0.8rem;
        padding: 0.7rem 0.7rem;
    }
}