class ParticlesBackground extends HTMLElement {
  connectedCallback() {
    this.attachShadow({ mode: 'open' });
    this.shadowRoot.innerHTML = `
      <style>
        :host {
          display: block;
          position: fixed;
          top: 0;
          left: 0;
          width: 100%;
          height: 100%;
          z-index: -1;
          overflow: hidden;
        }
        
        canvas {
          width: 100%;
          height: 100%;
        }
      </style>
      <canvas id="particles-canvas"></canvas>
    `;
    
    // Initialize particles
    this.initParticles();
  }
  
  initParticles() {
    const canvas = this.shadowRoot.getElementById('particles-canvas');
    const ctx = canvas.getContext('2d');
    
    // Set canvas size
    canvas.width = canvas.offsetWidth;
    canvas.height = canvas.offsetHeight;
    
    // Particle system
    const particles = [];
    const particleCount = 150;
    const colors = [
      '#3B82F6', '#10B981', '#8B5CF6', '#EF4444', '#F59E0B',
      '#EC4899', '#06B6D4', '#84CC16', '#F97316', '#6366F1'
    ];
    
    // Create particles
    for (let i = 0; i < particleCount; i++) {
      particles.push({
        x: Math.random() * canvas.width,
        y: Math.random() * canvas.height,
        radius: Math.random() * 3 + 1,
        color: colors[Math.floor(Math.random() * colors.length)],
        speedX: Math.random() * 2 - 1,
        speedY: Math.random() * 2 - 1,
        opacity: Math.random() * 0.5 + 0.2
      });
    }
    
    // Mouse interaction
    let mouseX = 0;
    let mouseY = 0;
    let mouseRadius = 100;
    
    canvas.addEventListener('mousemove', (e) => {
      const rect = canvas.getBoundingClientRect();
      mouseX = e.clientX - rect.left;
      mouseY = e.clientY - rect.top;
    });
    
    // Animation
    function animate() {
      ctx.clearRect(0, 0, canvas.width, canvas.height);
      
      // Update and draw particles
      particles.forEach(p => {
        // Move particle
        p.x += p.speedX;
        p.y += p.speedY;
        
        // Bounce off edges
        if (p.x < 0 || p.x > canvas.width) p.speedX *= -1;
        if (p.y < 0 || p.y > canvas.height) p.speedY *= -1;
        
        // Draw particle
        ctx.beginPath();
        ctx.arc(p.x, p.y, p.radius, 0, Math.PI * 2);
        ctx.fillStyle = p.color;
        ctx.globalAlpha = p.opacity;
        ctx.fill();
        
        // Draw connections
        particles.forEach(p2 => {
          const dx = p.x - p2.x;
          const dy = p.y - p2.y;
          const distance = Math.sqrt(dx * dx + dy * dy);
          
          if (distance < 100) {
            ctx.beginPath();
            ctx.strokeStyle = p.color;
            ctx.globalAlpha = 0.1 * (1 - distance / 100);
            ctx.lineWidth = 0.5;
            ctx.moveTo(p.x, p.y);
            ctx.lineTo(p2.x, p2.y);
            ctx.stroke();
          }
        });
        
        // Mouse interaction
        const dx = p.x - mouseX;
        const dy = p.y - mouseY;
        const distance = Math.sqrt(dx * dx + dy * dy);
        
        if (distance < mouseRadius) {
          const angle = Math.atan2(dy, dx);
          const force = (mouseRadius - distance) / mouseRadius;
          p.x += Math.cos(angle) * force * 5;
          p.y += Math.sin(angle) * force * 5;
        }
      });
      
      requestAnimationFrame(animate);
    }
    
    // Handle resize
    window.addEventListener('resize', () => {
      canvas.width = canvas.offsetWidth;
      canvas.height = canvas.offsetHeight;
    });
    
    animate();
  }
}

customElements.define('particles-background', ParticlesBackground);