(function () {
		// Check if body-container exists
		const bodyContainer = document.querySelector('.body-container');
		if (!bodyContainer) return;

		// Prevent duplicates
		if (document.querySelector('#backToTopBtn')) return;

		// Create button
		const btn = document.createElement('button');
		btn.id = 'backToTopBtn';
    
		// Insert custom SVG arrow with horizontal line, moved down slightly
		btn.innerHTML = `
			<svg width = "28" height = "28" viewBox = "0 0 24 24" style = "display:block; margin:auto;">
			<!-- Horizontal line above -->
			<line x1 = "6" y1 = "7" x2 = "18" y2 = "7" stroke = "#eeeeee" stroke - width = "2"/>
			<!-- Hollow upward arrow -->
			<polyline points = "6,17 12,11 18,17" fill = "none" stroke = "#eeeeee" stroke - width = "2"/>
			</svg>
			`;

		// Initial styling
		Object.assign(btn.style, {
			position: 'fixed',
			zIndex: '9999',
			width: '50px',
			height: '50px',
			lineHeight: '50px',
			textAlign: 'center',
			textDecoration: 'none',
			cursor: 'pointer',
			opacity: '0',          // Start hidden for fade-in
			backgroundColor: '#333333',
			border: '1px solid #444444',
			borderRadius: '4px',
			right: '24px',
			bottom: '24px',
			transition: 'opacity 0.3s ease-out, background-color 0.25s ease-out, color 0.25s ease-out'
			});

		// Responsive position
		const setBtnPosition = () => {
		if (window.innerWidth <= 1250) {
			btn.style.right = '16px';
			btn.style.bottom = '16px';
		} else {
			btn.style.right = '24px';
			btn.style.bottom = '24px';
		}
	};

setBtnPosition();
window.addEventListener('resize', setBtnPosition);

    // Append to body
document.body.appendChild(btn);

    // Show/hide with easing
const toggleButton = () => {
const scrollTop = bodyContainer.scrollTop || window.scrollY;
btn.style.opacity = scrollTop > 200 ? '0.8' : '0';
};

bodyContainer.addEventListener('scroll', toggleButton);
window.addEventListener('scroll', toggleButton);

    // Scroll to top on click
btn.addEventListener('click', () => {
	if (bodyContainer.scrollTop > 0) {
	bodyContainer.scrollTo({ top: 0, behavior: 'smooth' });
} else {
	window.scrollTo({ top: 0, behavior: 'smooth' });
}
});

    // Hover/focus effect
btn.addEventListener('mouseenter', () => {
	btn.style.backgroundColor = '#fcfcfc';
btn.querySelectorAll('line, polyline').forEach(el => el.setAttribute('stroke', '#2574DB')); // lines turn #2574DB
btn.style.border = '1px solid #e1e1e1';
});
btn.addEventListener('mouseleave', () => {
	btn.style.backgroundColor = '#333333';
btn.querySelectorAll('line, polyline').forEach(el => el.setAttribute('stroke', '#eeeeee')); // lines revert
btn.style.border = '1px solid #444444';
});
	})();