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

:root {
    --primary: #2271b1;
    --primary-dark: #135e96;
    --secondary: #0073aa;
    --accent: #00a0d2;
    --dark: #1d2327;
    --text: #2c3338;
    --gray: #646970;
    --light-gray: #dcdcde;
    --lighter-gray: #f0f0f1;
    --white: #ffffff;
    --success: #00a32a;
    --warning: #f0b849;
    --danger: #d63638;
    --border: #c3c4c7;
    --sidebar-bg: #f0f0f1;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background: #f0f0f1;
    min-height: 100vh;
    color: var(--text);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Call Banner - Responsive */
.call-banner {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: linear-gradient(135deg, #0f2027 0%, #203a43 50%, #2c5364 100%);
    text-align: center;
    padding: 10px 20px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.3);
}

.call-banner > div {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.call-banner span {
    color: rgba(255,255,255,0.9);
    font-weight: 600;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.call-banner a {
    color: #fff;
    text-decoration: none;
    background: linear-gradient(90deg, #0072ff 0%, #00c6ff 100%);
    padding: 6px 18px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s;
    box-shadow: 0 4px 15px rgba(0,114,255,0.3);
    white-space: nowrap;
}

/* Navbar - Fully Responsive */
.navbar {
    background: var(--dark);
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
    position: sticky;
    top: 0;
    z-index: 999;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0;
    min-height: 60px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--white);
    font-size: 1.3rem;
    font-weight: 600;
    padding: 15px 20px;
    transition: all 0.2s ease;
}

.logo:hover {
    background: rgba(255, 255, 255, 0.05);
}

.logo svg {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
}

.logo span {
    white-space: nowrap;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0;
    height: 60px;
}

.nav-links a {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.7);
    font-weight: 400;
    font-size: 14px;
    padding: 0 15px;
    height: 60px;
    display: flex;
    align-items: center;
    transition: all 0.2s ease;
    position: relative;
}

.nav-links a:hover {
    color: var(--accent);
    background: rgba(255, 255, 255, 0.05);
}

.cart-btn {
    background: var(--primary) !important;
    color: white !important;
    padding: 8px 16px !important;
    border-radius: 3px;
    margin: 0 15px;
    height: auto !important;
    gap: 8px;
    font-weight: 500;
}

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

.cart-count {
    background: var(--danger);
    color: white;
    border-radius: 10px;
    min-width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 600;
    padding: 0 6px;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--white);
    padding: 0 20px;
    order: 3;
}

.mobile-cart-btn {
    display: none;
}

/* Products Section - Responsive Grid */
.products-section {
    padding: 40px 0;
    background: var(--lighter-gray);
}

.section-title {
    font-size: 28px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 30px;
    padding-left: 0;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.product-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    transition: all 0.2s ease;
    position: relative;
}

.product-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border-color: var(--primary);
}

.product-image {
    width: 100%;
    height: 200px;
    object-fit: contain;
    padding: 20px;
    background: #fafafa;
    border-bottom: 1px solid var(--lighter-gray);
}

.product-info {
    padding: 20px;
}

.product-brand {
    font-size: 12px;
    color: var(--gray);
    text-transform: uppercase;
    font-weight: 500;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.product-name {
    font-size: 16px;
    font-weight: 500;
    color: var(--text);
    margin-bottom: 12px;
    line-height: 1.4;
    min-height: 44px;
}

.product-pricing {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.price-original {
    color: var(--gray);
    text-decoration: line-through;
    font-size: 14px;
}

.price-current {
    color: var(--success);
    font-size: 24px;
    font-weight: 600;
}

.product-stock {
    color: var(--success);
    font-size: 13px;
    margin-bottom: 15px;
    font-weight: 500;
}

.add-to-cart-btn {
    width: 100%;
    padding: 10px 16px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 3px;
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.add-to-cart-btn:hover {
    background: var(--primary-dark);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Cart Page - Responsive */
.cart-container {
    min-height: 80vh;
    padding: 30px 0;
    background: var(--lighter-gray);
}

.cart-header {
    background: white;
    padding: 25px 30px;
    border: 1px solid var(--border);
    border-radius: 4px;
    margin-bottom: 20px;
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
}

.cart-header h1 {
    color: var(--dark);
    font-size: 28px;
    font-weight: 600;
}

.cart-content {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 20px;
}

.cart-items {
    background: white;
    border: 1px solid var(--border);
    border-radius: 4px;
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
}

.cart-item {
    display: grid;
    grid-template-columns: 120px 1fr auto;
    gap: 20px;
    padding: 25px;
    border-bottom: 1px solid var(--lighter-gray);
    align-items: center;
}

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

.cart-item-image {
    width: 120px;
    height: 120px;
    object-fit: contain;
    background: #fafafa;
    border: 1px solid var(--lighter-gray);
    border-radius: 4px;
    padding: 10px;
}

.cart-item-details h3 {
    margin-bottom: 8px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text);
}

.cart-item-details .product-brand {
    margin-bottom: 10px;
}

.cart-item-price {
    color: var(--success);
    font-weight: 600;
    font-size: 20px;
    margin-bottom: 10px;
}

.quantity-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.qty-btn {
    width: 32px;
    height: 32px;
    border: 1px solid var(--border);
    background: white;
    color: var(--text);
    border-radius: 3px;
    cursor: pointer;
    font-weight: 500;
    font-size: 16px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.qty-btn:hover {
    background: var(--lighter-gray);
    border-color: var(--primary);
    color: var(--primary);
}

.remove-btn {
    background: transparent;
    color: var(--danger);
    border: 1px solid var(--danger);
    padding: 8px 16px;
    border-radius: 3px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 500;
    transition: all 0.2s ease;
}

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

.cart-summary {
    background: white;
    border: 1px solid var(--border);
    padding: 25px;
    border-radius: 4px;
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
    height: fit-content;
    position: sticky;
    top: 80px;
}

.cart-summary h2 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--dark);
}

.summary-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--lighter-gray);
    font-size: 14px;
}

.summary-row:last-of-type {
    border-bottom: 2px solid var(--border);
    margin-bottom: 20px;
}

.summary-total {
    font-size: 20px;
    font-weight: 600;
    color: var(--dark);
}

.checkout-btn {
    width: 100%;
    padding: 12px 20px;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 3px;
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.checkout-btn:hover {
    background: var(--primary-dark);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.empty-cart {
    text-align: center;
    padding: 60px 30px;
    background: white;
    border: 1px solid var(--border);
    border-radius: 4px;
}

.empty-cart h2 {
    margin: 20px 0;
    color: var(--text);
    font-weight: 500;
}

.empty-cart p {
    color: var(--gray);
    margin-bottom: 30px;
}

/* Checkout Page - Responsive */
.checkout-container {
    padding: 30px 0;
    background: var(--lighter-gray);
}

.checkout-content {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 20px;
}

.checkout-form {
    background: white;
    border: 1px solid var(--border);
    padding: 30px;
    border-radius: 4px;
    box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
}

.form-section {
    margin-bottom: 30px;
}

.form-section h2 {
    margin-bottom: 20px;
    color: var(--dark);
    font-size: 20px;
    font-weight: 600;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--lighter-gray);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text);
    font-size: 14px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 3px;
    font-size: 14px;
    font-family: inherit;
    transition: border-color 0.2s ease;
    background: white;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 1px var(--primary);
}

.payment-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.payment-method {
    padding: 20px 15px;
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    text-align: center;
    transition: all 0.2s ease;
    background: white;
}

.payment-method:hover {
    border-color: var(--primary);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.payment-method.active {
    border-color: var(--primary);
    background: rgba(34, 113, 177, 0.05);
    box-shadow: 0 0 0 1px var(--primary);
}

.payment-method p {
    margin-top: 10px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text);
}

.payment-details {
    margin-top: 20px;
}

.place-order-btn {
    width: 100%;
    padding: 12px 20px;
    background: var(--success);
    color: white;
    border: none;
    border-radius: 3px;
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.place-order-btn:hover {
    background: #008a24;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Order Success Page - Responsive */
.success-container {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    background: var(--lighter-gray);
}

.success-card {
    background: white;
    border: 1px solid var(--border);
    padding: 50px 40px;
    border-radius: 4px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    text-align: center;
    max-width: 600px;
    width: 100%;
}

.success-icon {
    width: 80px;
    height: 80px;
    background: var(--success);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
}

.success-card h1 {
    color: var(--dark);
    margin-bottom: 15px;
    font-size: 28px;
    font-weight: 600;
}

.order-number {
    color: var(--gray);
    margin-bottom: 25px;
    font-size: 14px;
}

.success-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
    flex-wrap: wrap;
}

.btn-primary {
    padding: 10px 24px;
    background: var(--primary);
    color: white;
    text-decoration: none;
    border-radius: 3px;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.2s ease;
}

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.btn-secondary {
    padding: 10px 24px;
    background: white;
    color: var(--primary);
    text-decoration: none;
    border: 1px solid var(--primary);
    border-radius: 3px;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.2s ease;
}

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

/* ====================================
   RESPONSIVE BREAKPOINTS
   ==================================== */

/* Large Desktop (1440px+) */
@media (min-width: 1440px) {
    .container {
        max-width: 1600px;
    }
    
    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

/* Desktop (1024px - 1439px) */
@media (max-width: 1439px) {
    .cart-content,
    .checkout-content {
        grid-template-columns: 1fr 340px;
    }
}

/* Tablet Landscape (900px - 1023px) */
@media (max-width: 1023px) {
    .cart-content,
    .checkout-content {
        grid-template-columns: 1fr;
    }

    .cart-summary {
        position: static;
    }
    
    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    }
}

/* Tablet Portrait (768px - 899px) */
@media (max-width: 899px) {
    .section-title {
        font-size: 24px;
    }

    .nav-links a {
        padding: 0 12px;
        font-size: 13px;
    }

    .cart-btn {
        padding: 6px 12px !important;
        font-size: 13px;
    }

    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 15px;
    }
}

/* Mobile Landscape (600px - 767px) */
@media (max-width: 767px) {
    .container {
        padding: 0 15px;
    }

    .call-banner {
        padding: 8px 15px;
    }

    .call-banner span {
        font-size: 0.8rem;
    }

    .call-banner a {
        font-size: 0.85rem;
        padding: 5px 15px;
    }

    .section-title {
        font-size: 22px;
        margin-bottom: 20px;
    }

    .products-section {
        padding: 30px 0;
    }

    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }

    .cart-header {
        padding: 20px;
    }

    .cart-header h1 {
        font-size: 24px;
    }

    .cart-item {
        grid-template-columns: 100px 1fr;
        gap: 15px;
        padding: 20px;
    }

    .cart-item-image {
        width: 100px;
        height: 100px;
    }

    .cart-item-actions {
        grid-column: 1 / -1;
        margin-top: 10px;
    }

    .cart-summary {
        padding: 20px;
    }

    .checkout-form {
        padding: 25px;
    }

    .success-card {
        padding: 40px 30px;
    }

    .success-card h1 {
        font-size: 24px;
    }

    .success-icon {
        width: 70px;
        height: 70px;
    }
}

/* Mobile Portrait (480px - 599px) */
@media (max-width: 599px) {
    .logo span {
        font-size: 1.1rem;
    }

    .logo svg {
        width: 28px;
        height: 28px;
    }

    .products-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
        gap: 12px;
    }

    .product-image {
        height: 160px;
        padding: 15px;
    }

    .product-info {
        padding: 15px;
    }

    .product-name {
        font-size: 14px;
        min-height: auto;
    }

    .price-current {
        font-size: 20px;
    }

    .cart-item {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 15px;
    }

    .cart-item-image {
        margin: 0 auto;
        width: 120px;
        height: 120px;
    }

    .cart-item-details h3 {
        font-size: 15px;
    }

    .cart-item-price {
        font-size: 18px;
    }

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

    .payment-methods {
        grid-template-columns: 1fr;
    }

    .success-actions {
        flex-direction: column;
        gap: 10px;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        text-align: center;
    }
}

/* Small Mobile (below 480px) */
@media (max-width: 479px) {
    .nav-content {
        flex-wrap: wrap;
        position: relative;
    }

    .logo {
        order: 1;
        flex: 0 0 auto;
    }

    .mobile-cart-btn {
        display: flex !important;
        order: 2;
        margin-left: auto;
        background: var(--primary) !important;
        color: white !important;
        padding: 8px 12px !important;
        border-radius: 3px;
        height: auto !important;
        gap: 6px;
        font-weight: 500;
        text-decoration: none;
        align-items: center;
        margin-right: 10px;
    }

    .mobile-cart-btn .cart-count {
        background: var(--danger);
        color: white;
        border-radius: 10px;
        min-width: 20px;
        height: 20px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 11px;
        font-weight: 600;
        padding: 0 6px;
    }

    .mobile-menu-btn {
        display: block;
        order: 3;
    }

    .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        height: auto;
        background: var(--dark);
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        order: 4;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        width: 100%;
        height: auto;
        padding: 15px 20px;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    .nav-links .cart-btn {
        display: none !important;
    }

    .logo {
        padding: 15px;
    }

    .logo span {
        font-size: 1rem;
    }

    .section-title {
        font-size: 20px;
    }

    .products-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .cart-header h1 {
        font-size: 20px;
    }

    .checkout-form {
        padding: 20px;
    }

    .form-section h2 {
        font-size: 18px;
    }

    .success-card {
        padding: 30px 20px;
    }

    .success-card h1 {
        font-size: 22px;
    }

    .success-icon {
        width: 60px;
        height: 60px;
    }

    .call-banner {
        padding: 8px 10px;
    }

    .call-banner > div {
        gap: 8px;
    }

    .call-banner span {
        font-size: 0.75rem;
    }

    .call-banner span svg {
        width: 16px;
        height: 16px;
    }

    .call-banner a {
        font-size: 0.8rem;
        padding: 5px 12px;
    }
}

/* Extra Small Mobile (below 360px) */
@media (max-width: 359px) {
    .container {
        padding: 0 10px;
    }

    .logo span {
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 18px;
    }

    .product-info {
        padding: 12px;
    }

    .cart-item {
        padding: 12px;
    }

    .checkout-form {
        padding: 15px;
    }

    .success-card {
        padding: 25px 15px;
    }
}