/* ===== CSS Variables ===== */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #0891b2;
    --accent: #06b6d4;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    --white: #ffffff;
    --black: #000000;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    --transition: all 0.2s ease;
    --transition-slow: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
}

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

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

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

ul {
    list-style: none;
}

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

/* ===== Container ===== */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--gray-900);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

@media (min-width: 768px) {
    h1 { font-size: 3.5rem; }
    h2 { font-size: 2.5rem; }
    h3 { font-size: 1.75rem; }
}

.section-title {
    text-align: center;
    margin-bottom: 0.75rem;
}

.section-subtitle {
    text-align: center;
    color: var(--gray-500);
    font-size: 1.125rem;
    margin-bottom: 2.5rem;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    box-shadow: var(--shadow-md), 0 0 0 0 rgba(37, 99, 235, 0.5);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 20px rgba(37, 99, 235, 0.3);
    color: var(--white);
}

.btn-secondary {
    background: var(--white);
    color: var(--gray-700);
    border: 2px solid var(--gray-200);
}

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--gray-50);
}

.btn-small {
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
}

.btn-amazon {
    background: linear-gradient(135deg, #ff9900 0%, #e88b00 100%);
    color: var(--gray-900);
}

.btn-amazon:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 20px rgba(255, 153, 0, 0.3);
    color: var(--gray-900);
}

/* ===== Header & Navigation ===== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-100);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
}

.logo:hover {
    color: var(--gray-900);
}

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

.logo-au {
    color: var(--primary);
}

.nav-links {
    display: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--gray-600);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

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

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

.mobile-menu-btn {
    display: flex;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    transition: var(--transition);
}

@media (min-width: 768px) {
    .nav-links {
        display: flex;
    }

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

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 50%, #f0fdfa 100%);
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-block;
    background: var(--white);
    color: var(--primary);
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
}

.hero h1 {
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--gray-700) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
}

@media (min-width: 768px) {
    .hero {
        padding: 6rem 0;
    }
}

/* ===== Filters Section ===== */
.filters-section {
    padding: 4rem 0 2rem;
    background: var(--white);
}

.filters {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.filter-group label {
    font-weight: 600;
    color: var(--gray-700);
    font-size: 0.875rem;
}

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

.filter-btn {
    padding: 0.625rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    background: var(--gray-100);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.filter-btn:hover {
    background: var(--gray-200);
    color: var(--gray-800);
}

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

/* ===== Products Section ===== */
.products-section {
    padding: 2rem 0 4rem;
    background: var(--gray-50);
}

.products-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .products-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ===== Product Card ===== */
.product-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition-slow);
    display: flex;
    flex-direction: column;
}

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

.product-image {
    position: relative;
    padding-top: 75%;
    background: var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-image-placeholder {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 4rem;
    opacity: 0.5;
}

.product-badges {
    position: absolute;
    top: 1rem;
    left: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-full);
}

.badge-bestseller {
    background: var(--warning);
    color: var(--gray-900);
}

.badge-new {
    background: var(--success);
    color: var(--white);
}

.badge-sale {
    background: var(--danger);
    color: var(--white);
}

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

.product-brand {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.product-name {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.product-rating {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.stars {
    color: #fbbf24;
    font-size: 0.875rem;
}

.rating-count {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.product-features {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.feature-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.75rem;
    color: var(--gray-600);
    background: var(--gray-100);
    padding: 0.25rem 0.625rem;
    border-radius: var(--radius-full);
}

.product-price {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.price-current {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.price-original {
    font-size: 0.875rem;
    color: var(--gray-400);
    text-decoration: line-through;
}

.product-cta {
    padding: 0 1.5rem 1.5rem;
}

.product-cta .btn {
    width: 100%;
}

.no-results {
    text-align: center;
    padding: 3rem;
    color: var(--gray-500);
    font-size: 1.125rem;
}

/* ===== Compare Section ===== */
.compare-section {
    padding: 4rem 0;
    background: var(--white);
}

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

@media (min-width: 768px) {
    .compare-slots {
        grid-template-columns: repeat(3, 1fr);
    }
}

.compare-slot {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.slot-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-700);
}

.compare-select {
    padding: 0.875rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-lg);
    background: var(--white);
    color: var(--gray-700);
    transition: var(--transition);
    cursor: pointer;
}

.compare-select:focus {
    outline: none;
    border-color: var(--primary);
}

.compare-table-wrapper {
    overflow-x: auto;
    margin-top: 2rem;
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

.compare-table th,
.compare-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-100);
}

.compare-table th {
    background: var(--gray-50);
    font-weight: 600;
    color: var(--gray-700);
}

.compare-table th:first-child {
    border-radius: var(--radius-lg) 0 0 0;
}

.compare-table th:last-child {
    border-radius: 0 var(--radius-lg) 0 0;
}

.compare-table td:first-child {
    font-weight: 600;
    color: var(--gray-600);
    background: var(--gray-50);
}

.compare-table tr:hover td {
    background: var(--gray-50);
}

.compare-table tr:hover td:first-child {
    background: var(--gray-100);
}

.compare-product-header {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.compare-product-name {
    font-weight: 700;
    color: var(--gray-900);
}

.compare-product-price {
    color: var(--primary);
    font-weight: 600;
}

/* ===== Guide Section ===== */
.guide-section {
    padding: 4rem 0;
    background: var(--gray-50);
}

.guide-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .guide-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.guide-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
}

.guide-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.guide-card h3 {
    margin-bottom: 1rem;
    color: var(--gray-900);
}

.guide-card p {
    color: var(--gray-600);
    margin-bottom: 0.75rem;
    font-size: 0.9375rem;
}

.guide-card p:last-child {
    margin-bottom: 0;
}

/* ===== Benefits Section ===== */
.benefits-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

.benefits-section .section-title {
    color: var(--white);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-top: 2rem;
}

@media (min-width: 768px) {
    .benefits-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.benefit-card {
    text-align: center;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    backdrop-filter: blur(10px);
}

.benefit-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 1rem;
}

.benefit-card h3 {
    color: var(--white);
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.benefit-card p {
    font-size: 0.875rem;
    opacity: 0.9;
}

/* ===== FAQ Section ===== */
.faq-section {
    padding: 4rem 0;
    background: var(--white);
}

.faq-grid {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-800);
    background: var(--white);
    text-align: left;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--gray-50);
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--primary);
    transition: var(--transition);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 1.25rem 1.25rem;
    color: var(--gray-600);
}

/* ===== SEO Section ===== */
.seo-section {
    padding: 4rem 0;
    background: var(--gray-50);
}

.seo-content {
    max-width: 900px;
    margin: 0 auto;
}

.seo-content h2 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--gray-900);
}

.seo-content h3 {
    font-size: 1.25rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--gray-800);
}

.seo-content p {
    color: var(--gray-600);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.seo-content ul {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.seo-content li {
    color: var(--gray-600);
    margin-bottom: 0.75rem;
    line-height: 1.7;
    list-style: disc;
}

.seo-content strong {
    color: var(--gray-800);
}

/* ===== Footer ===== */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: 4rem 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (min-width: 768px) {
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1fr;
    }
}

.footer-brand .logo {
    margin-bottom: 1rem;
}

.footer-brand .logo-text {
    color: var(--white);
}

.footer-brand p {
    font-size: 0.875rem;
    opacity: 0.8;
}

.footer-links h4 {
    color: var(--white);
    font-size: 1rem;
    margin-bottom: 1rem;
}

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

.footer-links a {
    color: var(--gray-400);
    font-size: 0.875rem;
    transition: var(--transition);
}

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

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--gray-800);
    text-align: center;
}

.footer-bottom p {
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.affiliate-disclosure {
    font-size: 0.75rem;
    opacity: 0.7;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.product-card {
    animation: fadeInUp 0.4s ease forwards;
}

.product-card:nth-child(2) { animation-delay: 0.1s; }
.product-card:nth-child(3) { animation-delay: 0.2s; }
.product-card:nth-child(4) { animation-delay: 0.3s; }
.product-card:nth-child(5) { animation-delay: 0.4s; }
.product-card:nth-child(6) { animation-delay: 0.5s; }

/* ===== Utility Classes ===== */
.text-center { text-align: center; }
.text-primary { color: var(--primary); }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mb-0 { margin-bottom: 0; }
.hidden { display: none; }

/* ===== Responsive Adjustments ===== */
@media (max-width: 640px) {
    .hero-stats {
        gap: 1.5rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .benefits-grid {
        grid-template-columns: 1fr;
    }

    .filter-buttons {
        overflow-x: auto;
        flex-wrap: nowrap;
        -webkit-overflow-scrolling: touch;
        padding-bottom: 0.5rem;
    }

    .filter-btn {
        flex-shrink: 0;
    }
}