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

:root {
    --primary-color: #0066cc;
    --secondary-color: #004999;
    --accent-color: #0099ff;
    --text-dark: #333333;
    --text-light: #666666;
    --text-lighter: #999999;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 5px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

/* Header Styles */
.header {
    background-color: var(--bg-white);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 28px;
    font-weight: 700;
}

.nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

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

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: white;
    padding: 150px 0 100px;
    margin-top: 60px;
}

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

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero .subtitle {
    font-size: 24px;
    margin-bottom: 15px;
    opacity: 0.95;
}

.hero .description {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.9;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background-color: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

/* Section Styles */
section {
    padding: 80px 0;
}

section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-dark);
    position: relative;
}

section h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--primary-color);
    margin: 15px auto 0;
}

/* Overview Section */
.overview {
    background-color: var(--bg-light);
}

.overview-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.placeholder-image {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    height: 400px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    font-weight: 600;
    box-shadow: var(--shadow);
}

.overview-content p {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: 20px;
}

.highlights {
    list-style: none;
}

.highlights li {
    padding: 10px 0;
    padding-left: 30px;
    position: relative;
    color: var(--text-dark);
    font-weight: 500;
}

.highlights li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* Specifications Section */
.specifications {
    background-color: var(--bg-white);
}

.spec-group {
    margin-bottom: 50px;
}

.spec-group h3 {
    font-size: 24px;
    color: var(--primary-color);
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border-color);
}

.spec-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    padding: 15px 20px;
    background-color: var(--bg-light);
    border-radius: 5px;
    border-left: 4px solid var(--primary-color);
    transition: all 0.3s ease;
}

.spec-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.spec-label {
    font-weight: 600;
    color: var(--text-dark);
}

.spec-value {
    color: var(--text-light);
    text-align: right;
    max-width: 60%;
}

/* Features Section */
.features {
    background-color: var(--bg-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--bg-white);
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 20px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* Applications Section */
.applications {
    background-color: var(--bg-white);
}

.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.application-item {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: 10px;
    border-top: 4px solid var(--primary-color);
    transition: all 0.3s ease;
}

.application-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.application-item h3 {
    font-size: 20px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.application-item p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* Footer */
.footer {
    background-color: var(--text-dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--accent-color);
}

.footer-section p {
    font-size: 14px;
    line-height: 1.8;
    opacity: 0.9;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: white;
    text-decoration: none;
    opacity: 0.9;
    transition: opacity 0.3s ease;
}

.footer-section ul li a:hover {
    opacity: 1;
    text-decoration: underline;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    font-size: 14px;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav ul {
        gap: 15px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero {
        padding: 120px 0 80px;
    }

    .hero h1 {
        font-size: 32px;
    }

    .hero .subtitle {
        font-size: 20px;
    }

    .hero .description {
        font-size: 16px;
    }

    section {
        padding: 60px 0;
    }

    section h2 {
        font-size: 28px;
    }

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

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

    .spec-item {
        flex-direction: column;
        gap: 10px;
    }

    .spec-value {
        text-align: left;
        max-width: 100%;
    }

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

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

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

@media (max-width: 480px) {
    .hero h1 {
        font-size: 24px;
    }

    .hero .subtitle {
        font-size: 16px;
    }

    .nav ul {
        gap: 10px;
    }

    .nav a {
        font-size: 14px;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Animation */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.application-item,
.spec-item {
    animation: fadeIn 0.6s ease-out;
}