```css
/* Main Stylesheet for HydroBox Africa */
:root {
    --primary-blue: #0066cc;
    --secondary-blue: #03c9a9;
    --dark-blue: #003366;
    --light-blue: #e6f2ff;
    --accent-green: #2ecc71;
}

/* Base Styles */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: #333;
}

/* Hydroelectric Theme Elements */
.hydro-gradient {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--secondary-blue) 100%);
}

.turbine-icon {
    background-image: url('http://static.photos/industry/200x200/15');
    background-size: contain;
    background-repeat: no-repeat;
}

/* Navigation */
.navbar {
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Hydro Components */
.hydro-card {
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid rgba(0, 102, 204, 0.1);
}

.hydro-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 102, 204, 0.15);
}

/* Water Animation Effects */
.water-effect {
    position: relative;
    overflow: hidden;
}

.water-effect::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -60%;
    width: 200%;
    height: 200%;
    background: rgba(255, 255, 255, 0.1);
    transform: rotate(30deg);
    animation: waterFlow 6s infinite linear;
}

@keyframes waterFlow {
    0% { left: -60%; }
    100% { left: 100%; }
}

/* Responsive Hydro Layouts */
@media (max-width: 768px) {
    .hydro-feature {
        flex-direction: column;
    }
    
    .hydro-stats {
        grid-template-columns: 1fr;
    }
}

/* Hydroelectric Specific Components */
.turbine-diagram {
    background: url('http://static.photos/technology/640x360/20') center/cover no-repeat;
    min-height: 300px;
}

.power-output-gauge {
    background: linear-gradient(to right, var(--light-blue), var(--accent-green));
    height: 8px;
    border-radius: 4px;
}

/* Hydro Animation */
@keyframes spinTurbine {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.turbine-spin {
    animation: spinTurbine 4s linear infinite;
}
```

And let's update the HTML to link to this CSS file: