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

:root {
    --primary-color: #0077b6;
    --primary-dark: #005a8c;
    --primary-light: #00a8e8;
    --secondary-color: #48cae4;
    --accent-color: #90e0ef;
    --text-dark: #1a1a2e;
    --text-medium: #4a4a5a;
    --text-light: #6b6b7b;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-alt: #e8f4f8;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --border-color: #e2e8f0;
    --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 25px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

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: 700;
    line-height: 1.3;
    color: var(--text-dark);
}

h1 { font-size: 2.75rem; }
h2 { font-size: 2.25rem; margin-bottom: 1rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.75rem; }
h4 { font-size: 1.25rem; margin-bottom: 0.5rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-medium);
}

/* Navigation */
.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

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

.nav-links a {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

.nav-links a:hover {
    color: white;
    border-bottom-color: white;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 2px;
    background-color: white;
    transition: var(--transition);
}

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

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 20px 2rem;
}

.hero h1 {
    color: white;
    margin-bottom: 1.5rem;
    font-size: 3rem;
}

.hero p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.25rem;
    margin-bottom: 2rem;
}

.cta-button {
    display: inline-block;
    background-color: white;
    color: var(--primary-color);
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    border: 2px solid white;
}

.cta-button:hover {
    background-color: transparent;
    color: white;
}

.cta-secondary {
    background-color: transparent;
    border: 2px solid white;
    color: white;
}

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

/* Sections */
.section {
    padding: 5rem 0;
}

.section-alt {
    background-color: var(--bg-alt);
}

.section-intro {
    font-size: 1.15rem;
    max-width: 700px;
    margin: 0 auto 3rem;
    text-align: center;
}

/* Introduction Section */
.intro-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 3rem;
    align-items: start;
}

.intro-text p {
    font-size: 1.1rem;
}

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

.stat-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 1.5rem;
    border-radius: var(--radius-md);
    text-align: center;
    box-shadow: var(--shadow-md);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* Types Grid */
.types-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.type-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.type-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.type-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.type-features {
    list-style: none;
    margin: 1rem 0;
    padding: 1rem 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.type-features li {
    padding: 0.35rem 0;
    color: var(--text-medium);
    font-size: 0.95rem;
}

.type-features li::before {
    content: "✓";
    color: var(--success-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

.type-best {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.product-mention {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 0;
}

/* Benefits Grid */
.benefits-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 4rem;
}

.benefit-card {
    text-align: center;
    padding: 2rem;
}

.benefit-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.benefit-card h3 {
    color: var(--primary-color);
}

/* Comparison Table */
.comparison-table-wrapper {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.comparison-table-wrapper h3 {
    text-align: center;
    margin-bottom: 1.5rem;
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
}

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

.comparison-table th {
    background-color: var(--bg-alt);
    font-weight: 600;
}

.comparison-table td.pro {
    color: var(--success-color);
}

.comparison-table td.con {
    color: var(--warning-color);
}

/* Installation Section */
.installation-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.tools-needed {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    height: fit-content;
}

.tools-needed ul {
    list-style: none;
    margin: 1rem 0;
}

.tools-needed li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.tools-needed li::before {
    content: "•";
    color: var(--primary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

.tools-note {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
    margin-bottom: 0;
}

.installation-steps {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.step {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.step:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.step:first-child {
    padding-top: 0;
}

.step-number {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
}

.step-content h4 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.step-content p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

.installation-tips {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

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

.tip {
    padding: 1rem;
    background: var(--bg-alt);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
}

.tip strong {
    color: var(--primary-color);
}

/* Products Section */
.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.product-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    position: relative;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.product-card.featured {
    border: 2px solid var(--primary-color);
}

.product-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 0.35rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    white-space: nowrap;
}

.product-card h3 {
    font-size: 1.15rem;
    margin-top: 0.5rem;
}

.product-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.product-card > p {
    font-size: 0.9rem;
    flex-grow: 1;
}

.product-features {
    list-style: none;
    margin: 1rem 0;
    padding: 1rem 0;
    border-top: 1px solid var(--border-color);
}

.product-features li {
    font-size: 0.85rem;
    padding: 0.25rem 0;
    color: var(--text-medium);
}

.product-features li::before {
    content: "✓";
    color: var(--success-color);
    margin-right: 0.5rem;
}

.product-cta {
    display: block;
    text-align: center;
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9rem;
    margin-top: auto;
}

.product-cta:hover {
    background: var(--primary-dark);
    color: white;
}

/* Buying Guide */
.buying-guide {
    background: var(--bg-alt);
    padding: 2rem;
    border-radius: var(--radius-lg);
}

.considerations-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.consideration h4 {
    color: var(--primary-color);
}

.consideration p {
    font-size: 0.9rem;
    margin-bottom: 0;
}

/* How to Use Section */
.usage-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 3rem;
}

.usage-steps {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.usage-step {
    display: flex;
    gap: 1.5rem;
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--border-color);
}

.usage-step:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.usage-step:first-child {
    padding-top: 0;
}

.usage-number {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: var(--secondary-color);
    color: var(--text-dark);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.usage-text h4 {
    margin-bottom: 0.35rem;
}

.usage-text p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

.usage-tips {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    height: fit-content;
}

.usage-tips ul {
    list-style: none;
}

.usage-tips li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}

.usage-tips li:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.usage-tips strong {
    color: var(--primary-color);
}

/* FAQ Section */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-white);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-dark);
    text-align: left;
    transition: var(--transition);
}

.faq-question:hover {
    background-color: var(--bg-light);
}

.faq-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
    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 1.5rem 1.5rem;
    margin-bottom: 0;
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    text-align: center;
    color: white;
}

.cta-section h2 {
    color: white;
}

.cta-section p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.15rem;
    max-width: 600px;
    margin: 0 auto 2rem;
}

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

/* Footer */
.footer {
    background-color: var(--text-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 4rem 0 2rem;
}

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

.footer-section h4 {
    color: white;
    margin-bottom: 1rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    padding: 0.35rem 0;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.affiliate-disclosure {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.6);
    margin-bottom: 0.75rem;
}

.copyright {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
    margin-bottom: 0;
}

/* Mobile Responsiveness */
@media (max-width: 1024px) {
    .types-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

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

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--primary-dark);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
    }

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

    .nav-links li {
        padding: 0.75rem 0;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-content {
        padding: 3rem 20px 1rem;
    }

    .hero h1 {
        font-size: 2.25rem;
    }

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

    .intro-stats {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .stat-card {
        flex: 1;
        min-width: 150px;
    }

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

    .installation-content {
        grid-template-columns: 1fr;
    }

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

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

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

    .usage-content {
        grid-template-columns: 1fr;
    }

    .comparison-table {
        font-size: 0.9rem;
    }

    .comparison-table th,
    .comparison-table td {
        padding: 0.75rem 0.5rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .cta-button {
        width: 100%;
        max-width: 300px;
    }
}

@media (max-width: 480px) {
    .section {
        padding: 3rem 0;
    }

    .stat-card {
        padding: 1rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .type-card,
    .product-card {
        padding: 1.25rem;
    }

    .step,
    .usage-step {
        flex-direction: column;
        gap: 0.75rem;
    }

    .step-number,
    .usage-number {
        width: 32px;
        height: 32px;
        font-size: 0.9rem;
    }
}