/* ============================================
 *  CSS Variables & Reset
 *  ============================================ */
:root {
    /* Colors - ML Inspired */
    --color-primary: #3483fa;
    --color-primary-dark: #2968c8;
    --color-primary-light: #4e92fb;
    --color-secondary: #ffe600;
    --color-success: #00a650;
    --color-success-light: #e6f7ed;
    --color-warning: #ff7733;
    --color-error: #f23d4f;

    /* Neutrals */
    --color-black: #333333;
    --color-gray-dark: #666666;
    --color-gray: #999999;
    --color-gray-light: #cccccc;
    --color-gray-lighter: #ededed;
    --color-gray-bg: #f5f5f5;
    --color-white: #ffffff;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Layout */
    --container-max: 1200px;
    --header-height: 60px;
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.5;
    color: var(--color-black);
    background-color: var(--color-gray-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul, ol {
    list-style: none;
}

/* ============================================
 *  Header
 *  ============================================ */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: linear-gradient(180deg, var(--color-secondary) 0%, #f5d800 100%);
    box-shadow: var(--shadow-md);
}

.header__container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header__logo {
    display: flex;
    align-items: center;
}

.header__title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-black);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.header__icon {
    font-size: var(--font-size-2xl);
}

.header__menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: var(--spacing-sm);
}

.header__menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-black);
    transition: var(--transition-fast);
}

/* ============================================
 *  Hero Section
 *  ============================================ */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, #1a5dc8 100%);
    color: var(--color-white);
    padding: var(--spacing-3xl) var(--spacing-md);
    text-align: center;
}

.hero__container {
    max-width: 800px;
    margin: 0 auto;
}

.hero__badge {
    display: inline-block;
    background: rgba(255,255,255,0.2);
    color: var(--color-white);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    backdrop-filter: blur(10px);
}

.hero__title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.hero__highlight {
    color: var(--color-secondary);
}

.hero__subtitle {
    font-size: var(--font-size-lg);
    opacity: 0.9;
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero__stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.hero__stat {
    text-align: center;
}

.hero__stat-number {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-secondary);
}

.hero__stat-label {
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

.hero__cta {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background-color: var(--color-secondary);
    color: var(--color-black);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: var(--font-size-lg);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.hero__cta:hover {
    color: var(--color-black);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.hero__cta svg {
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(5px); }
    60% { transform: translateY(3px); }
}

/* ============================================
 *  Categories Navigation
 *  ============================================ */
.categories-nav {
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-gray-lighter);
    position: sticky;
    top: var(--header-height);
    z-index: 900;
}

.categories-nav__container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-md);
}

.categories-nav__title {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-sm);
}

.categories-nav__list {
    display: flex;
    gap: var(--spacing-sm);
    overflow-x: auto;
    padding-bottom: var(--spacing-sm);
    scrollbar-width: thin;
    scrollbar-color: var(--color-gray-light) transparent;
}

.categories-nav__list::-webkit-scrollbar {
    height: 4px;
}

.categories-nav__list::-webkit-scrollbar-track {
    background: transparent;
}

.categories-nav__list::-webkit-scrollbar-thumb {
    background-color: var(--color-gray-light);
    border-radius: var(--radius-full);
}

.category-btn {
    flex-shrink: 0;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-gray-bg);
    border: 1px solid var(--color-gray-lighter);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-gray-dark);
    white-space: nowrap;
    transition: all var(--transition-fast);
}

.category-btn:hover {
    background-color: var(--color-primary-light);
    color: var(--color-white);
    border-color: var(--color-primary-light);
}

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

/* ============================================
 *  Main Content
 *  ============================================ */
.main {
    padding: var(--spacing-xl) var(--spacing-md);
}

.main__container {
    max-width: var(--container-max);
    margin: 0 auto;
}

/* Category Section */
.category-section {
    margin-bottom: var(--spacing-3xl);
    scroll-margin-top: calc(var(--header-height) + 80px);
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-primary);
}

.category-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xl);
}

.category-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-black);
}

.category-count {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
    font-weight: 400;
}

/* Products Grid */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: var(--spacing-md);
}

/* ============================================
 *  Product Card
 *  ============================================ */
.product-card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: transform var(--transition-base), box-shadow var(--transition-base);
    display: flex;
    flex-direction: column;
    position: relative;
}

.product-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.product-card__link {
    display: flex;
    flex-direction: column;
    height: 100%;
    color: inherit;
}

.product-card__link:hover {
    color: inherit;
}

/* Badges */
.product-card__badges {
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    z-index: 10;
}

.product-card__badge {
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xs);
    font-weight: 700;
    text-transform: uppercase;
}

.product-card__badge--ranking {
    background-color: var(--color-secondary);
    color: var(--color-black);
}

.product-card__badge--discount {
    background-color: var(--color-success);
    color: var(--color-white);
}

/* Image */
.product-card__image-container {
    position: relative;
    padding-top: 100%;
    background-color: var(--color-gray-bg);
    overflow: hidden;
}

.product-card__image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: var(--spacing-md);
    transition: transform var(--transition-base);
}

.product-card:hover .product-card__image {
    transform: scale(1.05);
}

/* Content */
.product-card__content {
    padding: var(--spacing-md);
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.product-card__title {
    font-size: var(--font-size-sm);
    font-weight: 400;
    color: var(--color-black);
    line-height: 1.4;
    margin-bottom: var(--spacing-sm);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    min-height: 2.8em;
}

/* Price */
.product-card__price {
    margin-top: auto;
}

.product-card__price-original {
    font-size: var(--font-size-xs);
    color: var(--color-gray);
    text-decoration: line-through;
}

.product-card__price-current {
    display: flex;
    align-items: baseline;
    gap: 2px;
}

.product-card__price-symbol {
    font-size: var(--font-size-sm);
    color: var(--color-black);
}

.product-card__price-integer {
    font-size: var(--font-size-xl);
    font-weight: 400;
    color: var(--color-black);
}

.product-card__price-decimals {
    font-size: var(--font-size-xs);
    color: var(--color-black);
}

.product-card__price-discount {
    font-size: var(--font-size-xs);
    color: var(--color-success);
    font-weight: 600;
    margin-left: var(--spacing-sm);
}

/* Shipping */
.product-card__shipping {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
    font-size: var(--font-size-xs);
    color: var(--color-success);
    font-weight: 600;
}

.product-card__shipping-icon {
    width: 14px;
    height: 14px;
}

.product-card__fulfillment {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    background-color: var(--color-success-light);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    margin-left: var(--spacing-xs);
}

.product-card__fulfillment svg {
    width: 12px;
    height: 12px;
}

/* CTA Button */
.product-card__cta {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-primary);
    color: var(--color-white);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-align: center;
    transition: background-color var(--transition-fast);
}

.product-card:hover .product-card__cta {
    background-color: var(--color-primary-dark);
}

/* ============================================
 *  Back to Top Button
 *  ============================================ */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 48px;
    height: 48px;
    background-color: var(--color-primary);
    color: var(--color-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: 800;
}

.back-to-top--visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
}

/* ============================================
 *  Footer
 *  ============================================ */
.footer {
    background-color: var(--color-black);
    color: var(--color-white);
    padding: var(--spacing-3xl) var(--spacing-md) var(--spacing-xl);
}

.footer__container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.footer__content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer__title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--color-secondary);
}

.footer__text {
    font-size: var(--font-size-sm);
    color: var(--color-gray-light);
    line-height: 1.6;
}

.footer__text--small {
    font-size: var(--font-size-xs);
}

.footer__list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer__list li {
    font-size: var(--font-size-sm);
    color: var(--color-gray-light);
}

.footer__bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-gray-dark);
}

.footer__bottom p {
    font-size: var(--font-size-sm);
    color: var(--color-gray);
}

/* ============================================
 *  Loading
 *  ============================================ */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--color-white);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--transition-base);
}

.loading--hidden {
    opacity: 0;
    pointer-events: none;
}

.loading__spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--color-gray-lighter);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.loading__text {
    margin-top: var(--spacing-md);
    color: var(--color-gray);
    font-size: var(--font-size-sm);
}

/* ============================================
 *  Responsive Design
 *  ============================================ */
@media (max-width: 768px) {
    .hero__title {
        font-size: var(--font-size-2xl);
    }

    .hero__stats {
        gap: var(--spacing-lg);
    }

    .hero__stat-number {
        font-size: var(--font-size-xl);
    }

    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
    }

    .product-card__content {
        padding: var(--spacing-sm);
    }

    .product-card__title {
        font-size: var(--font-size-xs);
    }

    .product-card__price-integer {
        font-size: var(--font-size-lg);
    }

    .category-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .back-to-top {
        bottom: var(--spacing-md);
        right: var(--spacing-md);
        width: 40px;
        height: 40px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: var(--spacing-2xl) var(--spacing-md);
    }

    .hero__title {
        font-size: var(--font-size-xl);
    }

    .hero__subtitle {
        font-size: var(--font-size-base);
    }

    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .product-card__cta {
        display: none;
    }
}

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

    html {
        scroll-behavior: auto;
    }
}

.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;
}

/* Focus States */
a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ============================================
 *  Print Styles
 *  ============================================ */
@media print {
    .header,
    .categories-nav,
    .hero__cta,
    .back-to-top,
    .product-card__cta {
        display: none;
    }

    .hero {
        background: none;
        color: var(--color-black);
        padding: var(--spacing-md);
    }

    .product-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid var(--color-gray-light);
    }
}