:root {
    --bg-primary: #0b0b0c;
    --bg-secondary: #111111;
    --surface-grey: #1a1a1a;
    --light-grey: #c0c0c0;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --accent-blue: #60a5fa;
    --glow-blue: rgba(96, 165, 250, 0.35);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.2);
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --container-max: 1400px;
    --header-height: 80px;
}

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

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: var(--surface-grey);
    border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

img {
    max-width: 100%;
    display: block;
    object-fit: cover;
}

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

ul {
    list-style: none;
}

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

/* Layout Utilities */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 5%;
}

.section {
    padding: 120px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 3rem;
    max-width: 600px;
}

.grid {
    display: grid;
    gap: 2rem;
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    z-index: 100;
    transition: var(--transition);
    display: flex;
    align-items: center;
}

header.scrolled {
    background: rgba(11, 11, 12, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand-logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    z-index: 101;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--text-primary);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent-blue);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    z-index: 101;
}

.cart-icon-wrapper {
    position: relative;
}

.cart-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    background: var(--accent-blue);
    color: #fff;
    font-size: 0.65rem;
    font-weight: 700;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    display: none;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    z-index: 101;
}

.menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* Mobile Menu */
.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--bg-primary);
    z-index: 99;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
}

.mobile-menu-overlay.active {
    opacity: 1;
    pointer-events: all;
}

.mobile-menu-overlay .nav-links {
    flex-direction: column;
    text-align: center;
    gap: 2rem;
}

.mobile-menu-overlay .nav-links a {
    font-size: 2rem;
}

/* Hero Section */
.hero {
    height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(11,11,12,0.3), var(--bg-primary)), url('images/zingspacecircl-hero-bg-sneaker.jpg') center/cover no-repeat;
    background-color: var(--surface-grey); /* Fallback */
    z-index: 1;
    transform: scale(1.05);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    padding: 0 20px;
}

.hero-title {
    font-size: 4.5rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -0.04em;
    background: linear-gradient(to right, #fff, var(--light-grey));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--light-grey);
    margin-bottom: 2.5rem;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    background: var(--text-primary);
    color: var(--bg-primary);
    font-weight: 600;
    border-radius: var(--radius-xl);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.btn-primary:hover {
    box-shadow: 0 0 20px var(--glow-blue);
    background: var(--accent-blue);
    color: #fff;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    font-weight: 600;
    border-radius: var(--radius-xl);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    border-color: var(--accent-blue);
    background: rgba(96, 165, 250, 0.1);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* Product Cards */
.product-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.product-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
    position: relative;
    display: flex;
    flex-direction: column;
}

.product-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.product-img-wrapper {
    position: relative;
    padding-top: 100%;
    overflow: hidden;
    background: var(--surface-grey);
}

.product-img-wrapper img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.product-card:hover .product-img-wrapper img {
    transform: scale(1.08);
}

.product-info {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.product-category {
    font-size: 0.75rem;
    color: var(--accent-blue);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.product-name {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.product-price {
    font-size: 1rem;
    color: var(--light-grey);
    margin-bottom: 1rem;
    margin-top: auto;
}

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

.btn-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-grey);
    border-radius: 50%;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.btn-icon:hover {
    background: var(--accent-blue);
    color: #fff;
    border-color: var(--accent-blue);
}

.btn-add-cart {
    flex-grow: 1;
    background: var(--surface-grey);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    font-size: 0.875rem;
    font-weight: 500;
    transition: var(--transition);
}

.btn-add-cart:hover {
    background: var(--text-primary);
    color: var(--bg-primary);
}

/* Sections specific */
.features-grid {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 3rem;
}

.feature-card {
    text-align: center;
}

.feature-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1.5rem;
    background: var(--surface-grey);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-blue);
}

.feature-title {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

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

/* Projects / Campaigns */
.campaign-banner {
    position: relative;
    height: 60vh;
    min-height: 500px;
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 2rem;
}

.campaign-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.campaign-content {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(11,11,12,0.9), transparent);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 4rem;
}

/* Footer */
footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 80px 0 40px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 4rem;
}

.footer-brand p {
    color: var(--text-secondary);
    margin-top: 1rem;
    max-width: 300px;
}

.footer-links h4 {
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.footer-links a:hover {
    color: var(--accent-blue);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Product Detail */
.product-detail-section {
    padding-top: calc(var(--header-height) + 60px);
}

.product-detail-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 4rem;
}

.product-gallery .main-img {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--surface-grey);
    margin-bottom: 1rem;
}

.product-gallery .thumbnails {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

.thumb {
    border-radius: var(--radius-sm);
    cursor: pointer;
    border: 2px solid transparent;
    transition: var(--transition);
}

.thumb.active, .thumb:hover {
    border-color: var(--accent-blue);
}

.product-info-detail h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.product-info-detail .price {
    font-size: 1.5rem;
    color: var(--accent-blue);
    margin-bottom: 2rem;
}

.product-info-detail p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.size-selector {
    margin-bottom: 2rem;
}

.size-selector h4 {
    margin-bottom: 1rem;
    font-weight: 500;
}

.sizes-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.size-btn {
    width: 60px;
    height: 40px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    transition: var(--transition);
}

.size-btn:hover, .size-btn.active {
    border-color: var(--accent-blue);
    background: rgba(96, 165, 250, 0.1);
    color: var(--accent-blue);
}

.add-to-cart-large {
    width: 100%;
    padding: 1.25rem;
    font-size: 1.125rem;
}

/* Cart & Checkout */
.cart-section, .checkout-section {
    padding-top: calc(var(--header-height) + 60px);
    min-height: 80vh;
}

.cart-grid, .checkout-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
}

.cart-items-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.cart-item {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    align-items: center;
}

.cart-item-img {
    width: 100px;
    height: 100px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    background: var(--surface-grey);
}

.cart-item-info {
    flex-grow: 1;
}

.cart-item-title {
    font-size: 1.125rem;
    font-weight: 600;
}

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

.cart-item-price {
    font-weight: 600;
    margin-top: 0.5rem;
    color: var(--accent-blue);
}

.qty-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--surface-grey);
    padding: 0.5rem;
    border-radius: var(--radius-sm);
}

.qty-btn {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
}

.btn-remove {
    color: #ef4444;
    font-size: 0.875rem;
    margin-left: 1rem;
}

.order-summary {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    height: fit-content;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.summary-total {
    display: flex;
    justify-content: space-between;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--light-grey);
}

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

.form-control:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px rgba(96, 165, 250, 0.2);
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.toast {
    background: var(--surface-grey);
    color: var(--text-primary);
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--accent-blue);
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    transform: translateX(120%);
    transition: transform 0.3s ease-out;
}

.toast.show {
    transform: translateX(0);
}

/* Animations */
.reveal {
    opacity: 0;
    visibility: hidden;
}

/* Responsive */
@media (max-width: 1024px) {
    .hero-title { font-size: 3.5rem; }
    .product-detail-grid { grid-template-columns: 1fr; gap: 2rem; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .menu-toggle { display: flex; }
    .hero-title { font-size: 2.5rem; }
    .hero-subtitle { font-size: 1rem; }
    .cart-grid, .checkout-grid { grid-template-columns: 1fr; }
    .campaign-content { padding: 2rem; }
    .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
    .cart-item { flex-direction: column; align-items: flex-start; }
    .cart-item-img { width: 100%; height: 200px; }
}