:root {
    --primary: #4a6bff;
    --primary-dark: #3a56cc;
    --secondary: #ff6b6b;
    --dark: #2d3748;
    --light: #f8f9fa;
    --gray: #e2e8f0;
    --dark-gray: #718096;
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--dark);
    background-color: var(--light);
}

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

header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary);
}

.logo span {
    color: var(--secondary);
}

.nav-links {
    display: flex;
    gap: 30px;
}

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

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


.btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary);
    color: white;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background-color: var(--primary);
    color: white;
}
.btn-link {
    width: auto; /* don't stretch */
    flex-grow: 0; /* prevent expanding */
    padding: 10px 20px; /* tight padding */
    background-color: var(--primary);
    color: white;
    font-weight: 400;
    border-radius: 4px;
    font-size: inherit;
    text-align: center;
}


.btn-link:hover {
    background-color: var(--primary-dark); /* darker on hover */
    text-decoration: none; /* no underline */
}

/* Hero Section */
.hero {
    padding: 100px 0;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: var(--dark);
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 30px;
    color: var(--dark-gray);
}

.hero-btns {
    display: flex;
    gap: 15px;
    justify-content: center;
}

/* Section Titles */
.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title h2 {
    font-size: 2.2rem;
    color: var(--dark);
    margin-bottom: 15px;
}

.section-title p {
    color: var(--dark-gray);
    max-width: 600px;
    margin: 0 auto;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--light);
    border-radius: 10px;
    padding: 30px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 2.5rem;
    text-align: center;
    color: var(--primary);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--dark-gray);
}

/* Algorithms Section */
.algorithms {
    padding: 80px 0;
    background-color: var(--light);
}

.algorithms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.algorithm-card {
    background-color: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: all 0.3s;
}

.algorithm-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.algorithm-img {
    height: 150px;
    background-color: var(--gray);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--dark-gray);
    font-family: 'Source Code Pro', monospace;
    font-size: 1.5rem;
    font-weight: 600;
}

.algorithm-content {
    padding: 20px;
}

.algorithm-content h3 {
    margin-bottom: 10px;
    color: var(--dark);
}

.algorithm-content p {
    color: var(--dark-gray);
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.algorithm-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--dark-gray);
}


/* Screenshots Section */
.screenshot-gallery {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.screenshot-row {
    display: flex;
    gap: 20px;
    justify-content: space-between;
}

.screenshot-container {
    flex: 1;
    background-color: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s;
    display: flex;
    flex-direction: column;
}

.screenshot-container:hover {
    transform: translateY(-5px);
}

.image-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f8f9fa;
    padding: 15px;
    max-height: 300px;
    overflow: hidden;
}

.screenshot-img {
    max-width: 100%;
    max-height: 270px; /* 300px wrapper - 15px padding x2 */
    width: auto;
    height: auto;
    object-fit: contain;
    border-radius: 5px;
}

.screenshot-caption {
    padding: 15px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--dark-gray);
    border-top: 1px solid var(--gray);
    margin-top: auto;
}

/* Responsive Design for Screenshots */
@media (max-width: 768px) {
    .screenshot-row {
        flex-direction: column;
    }
    
    .image-wrapper {
        max-height: none;
        padding: 10px;
    }
    
    .screenshot-img {
        max-height: none;
    }
}

/* How to Use Guide */
.guide {
    padding: 80px 0;
    background-color: var(--light);
}

.guide-steps {
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    align-items: flex-start;
}

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

.step-content h3 {
    margin-bottom: 10px;
    color: var(--dark);
}

.step-content p {
    color: var(--dark-gray);
}

/* System Requirements */
.requirements {
    padding: 80px 0;
    background-color: white;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    max-width: 800px;
    margin: 0 auto;
}

.requirement-card {
    background-color: var(--light);
    border-radius: 10px;
    padding: 30px;
    text-align: center;
}

.requirement-card i {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 20px;
}

.requirement-card h3 {
    margin-bottom: 20px;
    color: var(--dark);
}

.requirement-card ul {
    list-style: none;
    text-align: left;
}

.requirement-card ul li {
    margin-bottom: 10px;
    color: var(--dark-gray);
    position: relative;
    padding-left: 20px;
}

.requirement-card ul li:before {
    content: "•";
    color: var(--primary);
    position: absolute;
    left: 0;
}

/* Demo Section */
.demo {
    padding: 80px 0;
    background-color: var(--light);
}

.demo-container {
    display: flex;
    align-items: center;
    gap: 50px;
}

.demo-text {
    flex: 1;
}

.demo-text h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--dark);
}

.demo-text ul {
    margin: 20px 0;
    padding-left: 20px;
}

.demo-text ul li {
    margin-bottom: 10px;
    color: var(--dark-gray);
}


/* Demo Section */
.demo-container {
    display: flex;
    gap: 40px;
    align-items: center;
    flex-wrap: wrap; /* Ensures responsiveness for smaller screens */
}

.demo-video {
    flex: 1;
    min-width: 0;
    width: 100%; /* Ensures it takes up the full width of the container */
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .demo-container {
        flex-direction: column;
        gap: 20px; /* Adjusts the space between items on small screens */
    }

    .video-wrapper {
        margin-top: 30px;
    }
}


/* Download Section */
.download {
    padding: 80px 0;
    background-color: var(--primary);
    color: white;
    text-align: center;
}

.download h2 {
    font-size: 2.2rem;
    margin-bottom: 20px;
}

.download p {
    max-width: 600px;
    margin: 0 auto 30px;
    opacity: 0.9;
}

.download-btns {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 30px;
}

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

.download .btn:hover {
    background-color: var(--light);
}

.download .btn-outline {
    background-color: transparent;
    border: 2px solid white;
    color: white;
}

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

.download-info {
    display: flex;
    justify-content: center;
    gap: 30px;
    font-size: 0.9rem;
}

.download-info p {
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Footer */
footer {
    background-color: var(--dark);
    color: white;
    padding: 50px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.footer-column h3 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: var(--gray);
}

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

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

.footer-column ul li a {
    color: var(--gray);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-column ul li a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    color: var(--gray);
    font-size: 1.2rem;
    transition: color 0.3s;
}

.social-links a:hover {
    color: white;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: var(--gray);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .demo-container, .guide-steps {
        flex-direction: column;
    }
    
    .hero-btns, .download-btns {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 250px;
        margin-bottom: 10px;
    }

    .btn-link {
        width: 50%;
        max-width: 250px;
        margin-bottom: 10px;
    }
    
    .download-info {
        flex-direction: column;
        gap: 10px;
    }
}