/**
 * Smart Shopping List - Main Stylesheet
 * Responsive, clean, and intuitive design
 */

/* CSS Variables */
:root {
    --primary-color: #4CAF50;
    --primary-dark: #388E3C;
    --primary-light: #C8E6C9;
    --secondary-color: #2196F3;
    --accent-color: #FF9800;
    --danger-color: #f44336;
    --success-color: #4CAF50;
    --warning-color: #FF9800;
    --text-primary: #212121;
    --text-secondary: #757575;
    --text-light: #FFFFFF;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F5;
    --bg-dark: #212121;
    --border-color: #E0E0E0;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.2);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --header-height: 60px;
    --sidebar-width: 260px;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 0.5rem;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.1rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
}

.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--text-secondary); }
.text-danger { color: var(--danger-color); }
.text-success { color: var(--success-color); }
.text-warning { color: var(--warning-color); }
.text-center { text-align: center; }
.text-right { text-align: right; }

/* Layout */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

.container-fluid {
    width: 100%;
    padding: 0 1rem;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -0.5rem;
}

.col {
    flex: 1;
    padding: 0 0.5rem;
}

.col-auto {
    flex: 0 0 auto;
    padding: 0 0.5rem;
}

/* Grid System */
.col-1 { flex: 0 0 8.333%; max-width: 8.333%; }
.col-2 { flex: 0 0 16.667%; max-width: 16.667%; }
.col-3 { flex: 0 0 25%; max-width: 25%; }
.col-4 { flex: 0 0 33.333%; max-width: 33.333%; }
.col-5 { flex: 0 0 41.667%; max-width: 41.667%; }
.col-6 { flex: 0 0 50%; max-width: 50%; }
.col-7 { flex: 0 0 58.333%; max-width: 58.333%; }
.col-8 { flex: 0 0 66.667%; max-width: 66.667%; }
.col-9 { flex: 0 0 75%; max-width: 75%; }
.col-10 { flex: 0 0 83.333%; max-width: 83.333%; }
.col-11 { flex: 0 0 91.667%; max-width: 91.667%; }
.col-12 { flex: 0 0 100%; max-width: 100%; }

/* Header */
.header {
    background: var(--bg-primary);
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    z-index: 1000;
    display: flex;
    align-items: center;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.75rem;
}

.nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
}

.nav-link:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

.nav-link.active {
    color: var(--primary-color);
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* Main Content */
.main {
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
    padding: 2rem 0;
}

/* Cards */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: var(--transition);
    margin-bottom: 1.5rem;
}

.card:hover {
    box-shadow: var(--shadow-md);
}

.card-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0;
}

.card-body {
    padding: 1.25rem;
}

.card-footer {
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border-color);
    background: var(--bg-secondary);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

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

.btn-secondary {
    background: var(--secondary-color);
    color: var(--text-light);
}

.btn-secondary:hover {
    background: #1976D2;
    color: var(--text-light);
}

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

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

.btn-warning {
    background: var(--warning-color);
    color: var(--text-light);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 0.875rem 1.75rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
}

.btn-icon {
    padding: 0.5rem;
    border-radius: var(--radius-sm);
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-control::placeholder {
    color: var(--text-secondary);
}

.form-control:disabled {
    background: var(--bg-secondary);
    cursor: not-allowed;
}

select.form-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23757575' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    padding-right: 2.5rem;
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.form-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.25rem;
}

.form-error {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Input Groups */
.input-group {
    display: flex;
    align-items: stretch;
}

.input-group .form-control {
    flex: 1;
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group .btn {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
}

.input-group-text {
    display: flex;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-right: none;
    border-radius: var(--radius-sm) 0 0 var(--radius-sm);
    color: var(--text-secondary);
}

/* Search */
.search-container {
    position: relative;
}

.search-input {
    padding-left: 2.5rem;
}

.search-icon {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    max-height: 300px;
    overflow-y: auto;
    z-index: 100;
}

.search-result-item {
    padding: 0.75rem 1rem;
    cursor: pointer;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item:hover {
    background: var(--bg-secondary);
}

.search-result-item .name {
    font-weight: 500;
    color: var(--text-primary);
}

.search-result-item .details {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Alerts */
.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background: var(--primary-light);
    color: var(--primary-dark);
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: #FFEBEE;
    color: #C62828;
    border-left: 4px solid var(--danger-color);
}

.alert-warning {
    background: #FFF3E0;
    color: #E65100;
    border-left: 4px solid var(--warning-color);
}

.alert-info {
    background: #E3F2FD;
    color: #1565C0;
    border-left: 4px solid var(--secondary-color);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 9999px;
    text-transform: uppercase;
}

.badge-primary {
    background: var(--primary-color);
    color: var(--text-light);
}

.badge-success {
    background: var(--success-color);
    color: var(--text-light);
}

.badge-danger {
    background: var(--danger-color);
    color: var(--text-light);
}

.badge-warning {
    background: var(--warning-color);
    color: var(--text-light);
}

/* Shopping List Items */
.list-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    margin-bottom: 0.75rem;
    transition: var(--transition);
}

.list-item:hover {
    box-shadow: var(--shadow-sm);
}

.list-item.purchased {
    opacity: 0.6;
    background: var(--bg-secondary);
}

.list-item.purchased .item-name {
    text-decoration: line-through;
}

.item-checkbox {
    margin-right: 1rem;
}

.item-checkbox input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.item-content {
    flex: 1;
}

.item-name {
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.item-details {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.item-quantity {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-right: 1rem;
}

.item-actions {
    display: flex;
    gap: 0.5rem;
}

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
}

.empty-state-icon {
    font-size: 4rem;
    color: var(--border-color);
    margin-bottom: 1rem;
}

.empty-state-title {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.empty-state-text {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow: hidden;
    transform: scale(0.9);
    transition: var(--transition);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.modal-body {
    padding: 1.25rem;
    overflow-y: auto;
    max-height: calc(90vh - 140px);
}

.modal-footer {
    padding: 1rem 1.25rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
}

/* Loading Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: calc(var(--header-height) + 1rem);
    right: 1rem;
    z-index: 3000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background: var(--bg-primary);
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 300px;
    animation: slideIn 0.3s ease;
}

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--danger-color);
}

.toast.warning {
    border-left: 4px solid var(--warning-color);
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Footer */
.footer {
    background: var(--bg-dark);
    color: var(--text-light);
    padding: 2rem 0;
    margin-top: auto;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
}

.footer-links a:hover {
    color: var(--text-light);
}

/* Auth Pages */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--bg-secondary) 100%);
    padding: 2rem 1rem;
}

.auth-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 450px;
    padding: 2.5rem;
}

.auth-header {
    text-align: center;
    margin-bottom: 2rem;
}

.auth-logo {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.auth-title {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.auth-subtitle {
    color: var(--text-secondary);
}

.auth-footer {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .col-md-1 { flex: 0 0 8.333%; max-width: 8.333%; }
    .col-md-2 { flex: 0 0 16.667%; max-width: 16.667%; }
    .col-md-3 { flex: 0 0 25%; max-width: 25%; }
    .col-md-4 { flex: 0 0 33.333%; max-width: 33.333%; }
    .col-md-5 { flex: 0 0 41.667%; max-width: 41.667%; }
    .col-md-6 { flex: 0 0 50%; max-width: 50%; }
    .col-md-7 { flex: 0 0 58.333%; max-width: 58.333%; }
    .col-md-8 { flex: 0 0 66.667%; max-width: 66.667%; }
    .col-md-9 { flex: 0 0 75%; max-width: 75%; }
    .col-md-10 { flex: 0 0 83.333%; max-width: 83.333%; }
    .col-md-11 { flex: 0 0 91.667%; max-width: 91.667%; }
    .col-md-12 { flex: 0 0 100%; max-width: 100%; }
}

@media (max-width: 768px) {
    :root {
        --header-height: 55px;
    }
    
    .menu-toggle {
        display: block;
    }
    
    .nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: var(--bg-primary);
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        width: 100%;
        padding: 0.75rem;
    }
    
    .col-sm-1 { flex: 0 0 8.333%; max-width: 8.333%; }
    .col-sm-2 { flex: 0 0 16.667%; max-width: 16.667%; }
    .col-sm-3 { flex: 0 0 25%; max-width: 25%; }
    .col-sm-4 { flex: 0 0 33.333%; max-width: 33.333%; }
    .col-sm-5 { flex: 0 0 41.667%; max-width: 41.667%; }
    .col-sm-6 { flex: 0 0 50%; max-width: 50%; }
    .col-sm-7 { flex: 0 0 58.333%; max-width: 58.333%; }
    .col-sm-8 { flex: 0 0 66.667%; max-width: 66.667%; }
    .col-sm-9 { flex: 0 0 75%; max-width: 75%; }
    .col-sm-10 { flex: 0 0 83.333%; max-width: 83.333%; }
    .col-sm-11 { flex: 0 0 91.667%; max-width: 91.667%; }
    .col-sm-12 { flex: 0 0 100%; max-width: 100%; }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .list-item {
        flex-wrap: wrap;
    }
    
    .item-quantity {
        width: 100%;
        margin: 0.5rem 0;
        justify-content: flex-start;
    }
    
    .item-actions {
        width: 100%;
        justify-content: flex-end;
    }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .container {
        padding: 0 0.75rem;
    }
    
    .auth-card {
        padding: 1.5rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .modal {
        width: 95%;
    }
    
    .toast {
        min-width: auto;
        width: calc(100vw - 2rem);
    }
    
    .toast-container {
        left: 1rem;
        right: 1rem;
    }
}

/* Print Styles */
@media print {
    .header,
    .nav,
    .btn,
    .item-actions,
    .modal-overlay,
    .toast-container {
        display: none !important;
    }
    
    .main {
        margin-top: 0;
    }
    
    .card {
        box-shadow: none;
        border: 1px solid #ddd;
    }
    
    body {
        background: white;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Screen reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}