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

:root {
    --primary-blue: #0066cc;
    --dark-blue: #004c99;
    --light-blue: #e6f2ff;
    --accent-green: #00cc88;
    --dark-gray: #333333;
    --medium-gray: #666666;
    --light-gray: #f5f5f5;
    --white: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--dark-gray);
    overflow-x: hidden;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    z-index: 1000;
    padding: 1rem 5%;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-blue);
}

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

.nav-links a {
    text-decoration: none;
    color: var(--dark-gray);
    font-weight: 500;
    transition: color 0.3s;
}

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

.cta-button {
    background: var(--primary-blue);
    color: var(--white);
    padding: 0.7rem 1.5rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.3s;
}

.cta-button:hover {
    background: var(--dark-blue);
}

/* Page Header */
.page-header {
    margin-top: 80px;
    padding: 3rem 5%;
    background: linear-gradient(135deg, var(--light-blue) 0%, var(--white) 100%);
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    color: var(--dark-blue);
    margin-bottom: 0.5rem;
}

.page-header p {
    font-size: 1.2rem;
    color: var(--medium-gray);
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: 4rem 5%;
    background: linear-gradient(135deg, var(--light-blue) 0%, var(--white) 100%);
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    color: var(--dark-blue);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero .subtitle {
    font-size: 1.3rem;
    color: var(--medium-gray);
    margin-bottom: 2rem;
}

.hero-highlight {
    background: var(--accent-green);
    color: var(--white);
    padding: 1rem 2rem;
    border-radius: 10px;
    display: inline-block;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 2rem;
}

/* Impact Section */
.impact-section {
    padding: 4rem 5%;
    background: var(--white);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    color: var(--dark-blue);
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: var(--medium-gray);
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.impact-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto 3rem;
}

.stat-card {
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,102,204,0.2);
}

.stat-number {
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Features Section */
.features-section {
    padding: 4rem 5%;
    background: var(--light-gray);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 25px rgba(0,0,0,0.15);
}

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

.feature-card h3 {
    color: var(--dark-blue);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.feature-card p {
    color: var(--medium-gray);
    line-height: 1.7;
}

.feature-card ul {
    list-style-position: inside;
    color: var(--medium-gray);
}

.feature-card ul li {
    margin-bottom: 0.5rem;
}

/* Use Cases Section */
.use-cases-section {
    padding: 4rem 5%;
    background: var(--white);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.use-case-card {
    background: var(--light-blue);
    padding: 2rem;
    border-radius: 10px;
    border-left: 5px solid var(--primary-blue);
}

.use-case-card h3 {
    color: var(--dark-blue);
    margin-bottom: 1rem;
}

/* How It Works Section */
.how-it-works-section {
    padding: 4rem 5%;
    background: var(--dark-blue);
    color: var(--white);
}

.how-it-works-section .section-title {
    color: var(--white);
}

.how-it-works-section .section-subtitle {
    color: rgba(255,255,255,0.8);
}

.steps-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.step-card {
    background: rgba(255,255,255,0.1);
    padding: 2rem;
    border-radius: 10px;
    backdrop-filter: blur(10px);
}

.step-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--accent-green);
    margin-bottom: 1rem;
}

.step-card h3 {
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

/* Applications Section */
.applications-section {
    padding: 4rem 5%;
    background: var(--light-gray);
}

.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.application-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}

.application-card h3 {
    color: var(--dark-blue);
    margin-bottom: 1rem;
}

.application-card ul {
    list-style-position: inside;
    color: var(--medium-gray);
}

.application-card ul li {
    margin-bottom: 0.5rem;
}
/* Spec Grid */
.spec-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
}

.spec-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.spec-card h3 {
    color: var(--dark-blue);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.spec-card p {
    color: var(--medium-gray);
    font-size: 1rem;
}

.spec-card strong {
    color: var(--primary-blue);
    font-size: 1.2rem;
}

/* Comparison Container */
.comparison-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.comparison-card {
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}

.comparison-card.disadvantage {
    background: #fff5f5;
    border-left: 5px solid #e53e3e;
}

.comparison-card.advantage {
    background: #f0fff4;
    border-left: 5px solid var(--accent-green);
}

.comparison-card h3 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.comparison-card ul {
    list-style: none;
}

.comparison-card ul li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.comparison-card ul li:before {
    content: '';
    position: absolute;
    left: 0;
}

.impact-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 10px;
    border-left: 5px solid var(--accent-green);
    box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}

.impact-card h3 {
    color: var(--dark-blue);
    margin-bottom: 1rem;
}

.impact-card p {
    color: var(--medium-gray);
    margin-bottom: 0.75rem;
}

.impact-card strong {
    color: var(--dark-gray);
}

/* CTA Section */
.cta-section {
    padding: 4rem 5%;
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    text-align: center;
}

.cta-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

.btn-primary, .btn-secondary {
    padding: 1rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn-primary {
    background: var(--accent-green);
    color: var(--white);
}

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

.btn-primary:hover, .btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.3);
}

/* Footer */
footer {
    background: var(--dark-gray);
    color: var(--white);
    padding: 3rem 5% 1rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: var(--accent-green);
}

.footer-section p, .footer-section li {
    opacity: 0.8;
    line-height: 1.8;
}

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

.footer-section a {
    color: var(--white);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: var(--accent-green);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    color: var(--white);
    text-decoration: none;
    transition: background 0.3s, transform 0.3s;
    font-size: 1.2rem;
}

.social-icon:hover {
    background: var(--accent-green);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    opacity: 0.7;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero .subtitle {
        font-size: 1.1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .stat-number {
        font-size: 2.5rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
}