Hi there, Coder Greetings from ayanhacks.me blog. This blog post teaches us how to use HTML and CSS code to make an I love you (heart) animation. You can propose love to your crush with the help of our I Love You Website Project.

We have an animated heart with a neon glowing effect in our project. By the time this project is through, you will know how to use HTML and CSS to design an I love you website. Let’s Get Started With A Simple HTML Structure Code For An I Love You Since I Hope You Enjoy Our Blog.

Code byal-ro
Project DownloadLink Available below
Language usedHTML ,CSS, and JS
External link / DependenciesNo
ResponsiveMaybe

HTML Code For Neon Heart

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>I Love You animation Using HTML and CSS</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
 <canvas id="canvas" width="1400" height="600">
</canvas>

<!-- js here -->
    <script src="app.js"></script>
</body>
</html>

The I Love You animation’s entire HTML code is available. We deploy canvas tags that measure 1400 in width and 600 in height. With this code, we just generate the love animation’s structure; the output is blank.

You can now view the output without JavaScript or CSS. After that, we utilize JavaScript to create this high-level animation project and write CSS for the styling of the Love animation.

CSS Code For Neon Heart

body {  
 background-color: #000;    
 margin: 0;  
 overflow: hidden;  
 background-repeat: no-repeat;  
}

JS Code For Neon Heart

var canvas = document.getElementById("canvas");

canvas.width = window.innerWidth;
canvas.height = window.innerHeight;

// Initialize the GL context
var gl = canvas.getContext('webgl');
if(!gl){
  console.error("Unable to initialize WebGL.");
}

//Time
var time = 0.0;

//************** Shader sources **************

var vertexSource = `
attribute vec2 position;
void main() {
    gl_Position = vec4(position, 0.0, 1.0);
}
`;

var fragmentSource = `
precision highp float;

uniform float width;
uniform float height;
vec2 resolution = vec2(width, height);

uniform float time;

#define POINT_COUNT 8

vec2 points[POINT_COUNT];
const float speed = -0.5;
const float len = 0.25;
float intensity = 1.3;
float radius = 0.008;

//https://www.shadertoy.com/view/MlKcDD
//Signed distance to a quadratic bezier
float sdBezier(vec2 pos, vec2 A, vec2 B, vec2 C){    
    vec2 a = B - A;
    vec2 b = A - 2.0*B + C;
    vec2 c = a * 2.0;
    vec2 d = A - pos;

    float kk = 1.0 / dot(b,b);
    float kx = kk * dot(a,b);
    float ky = kk * (2.0*dot(a,a)+dot(d,b)) / 3.0;
    float kz = kk * dot(d,a);      

    float res = 0.0;

    float p = ky - kx*kx;
    float p3 = p*p*p;
    float q = kx*(2.0*kx*kx - 3.0*ky) + kz;
    float h = q*q + 4.0*p3;

    if(h >= 0.0){ 
        h = sqrt(h);
        vec2 x = (vec2(h, -h) - q) / 2.0;
        vec2 uv = sign(x)*pow(abs(x), vec2(1.0/3.0));
        float t = uv.x + uv.y - kx;
        t = clamp( t, 0.0, 1.0 );

        // 1 root
        vec2 qos = d + (c + b*t)*t;
        res = length(qos);
    }else{
        float z = sqrt(-p);
        float v = acos( q/(p*z*2.0) ) / 3.0;
        float m = cos(v);
        float n = sin(v)*1.732050808;
        vec3 t = vec3(m + m, -n - m, n - m) * z - kx;
        t = clamp( t, 0.0, 1.0 );

        // 3 roots
        vec2 qos = d + (c + b*t.x)*t.x;
        float dis = dot(qos,qos);
        
        res = dis;

        qos = d + (c + b*t.y)*t.y;
        dis = dot(qos,qos);
        res = min(res,dis);
        
        qos = d + (c + b*t.z)*t.z;
        dis = dot(qos,qos);
        res = min(res,dis);

        res = sqrt( res );
    }
    
    return res;
}


//http://mathworld.wolfram.com/HeartCurve.html
vec2 getHeartPosition(float t){
    return vec2(16.0 * sin(t) * sin(t) * sin(t),
                            -(13.0 * cos(t) - 5.0 * cos(2.0*t)
                            - 2.0 * cos(3.0*t) - cos(4.0*t)));
}

//https://www.shadertoy.com/view/3s3GDn
float getGlow(float dist, float radius, float intensity){
    return pow(radius/dist, intensity);
}

float getSegment(float t, vec2 pos, float offset, float scale){
    for(int i = 0; i < POINT_COUNT; i++){
        points[i] = getHeartPosition(offset + float(i)*len + fract(speed * t) * 6.28);
    }
    
    vec2 c = (points[0] + points[1]) / 2.0;
    vec2 c_prev;
    float dist = 10000.0;
    
    for(int i = 0; i < POINT_COUNT-1; i++){
        //https://tinyurl.com/y2htbwkm
        c_prev = c;
        c = (points[i] + points[i+1]) / 2.0;
        dist = min(dist, sdBezier(pos, scale * c_prev, scale * points[i], scale * c));
    }
    return max(0.0, dist);
}

void main(){
    vec2 uv = gl_FragCoord.xy/resolution.xy;
    float widthHeightRatio = resolution.x/resolution.y;
    vec2 centre = vec2(0.5, 0.5);
    vec2 pos = centre - uv;
    pos.y /= widthHeightRatio;
    //Shift upwards to centre heart
    pos.y += 0.02;
    float scale = 0.000015 * height;
    
    float t = time;
    
    //Get first segment
  float dist = getSegment(t, pos, 0.0, scale);
  float glow = getGlow(dist, radius, intensity);
  
  vec3 col = vec3(0.0);

    //White core
  col += 10.0*vec3(smoothstep(0.003, 0.001, dist));
  //Pink glow
  col += glow * vec3(1.0,0.05,0.3);
  
  //Get second segment
  dist = getSegment(t, pos, 3.4, scale);
  glow = getGlow(dist, radius, intensity);
  
  //White core
  col += 10.0*vec3(smoothstep(0.003, 0.001, dist));
  //Blue glow
  col += glow * vec3(0.1,0.4,1.0);
        
    //Tone mapping
    col = 1.0 - exp(-col);

    //Gamma
    col = pow(col, vec3(0.4545));

    //Output to screen
     gl_FragColor = vec4(col,1.0);
}
`;

//************** Utility functions **************

window.addEventListener('resize', onWindowResize, false);

function onWindowResize(){
  canvas.width  = window.innerWidth;
  canvas.height = window.innerHeight;
    gl.viewport(0, 0, canvas.width, canvas.height);
  gl.uniform1f(widthHandle, window.innerWidth);
  gl.uniform1f(heightHandle, window.innerHeight);
}


//Compile shader and combine with source
function compileShader(shaderSource, shaderType){
  var shader = gl.createShader(shaderType);
  gl.shaderSource(shader, shaderSource);
  gl.compileShader(shader);
  if(!gl.getShaderParameter(shader, gl.COMPILE_STATUS)){
      throw "Shader compile failed with: " + gl.getShaderInfoLog(shader);
  }
  return shader;
}

//From https://codepen.io/jlfwong/pen/GqmroZ
//Utility to complain loudly if we fail to find the attribute/uniform
function getAttribLocation(program, name) {
  var attributeLocation = gl.getAttribLocation(program, name);
  if (attributeLocation === -1) {
      throw 'Cannot find attribute ' + name + '.';
  }
  return attributeLocation;
}

function getUniformLocation(program, name) {
  var attributeLocation = gl.getUniformLocation(program, name);
  if (attributeLocation === -1) {
      throw 'Cannot find uniform ' + name + '.';
  }
  return attributeLocation;
}

//************** Create shaders **************

//Create vertex and fragment shaders
var vertexShader = compileShader(vertexSource, gl.VERTEX_SHADER);
var fragmentShader = compileShader(fragmentSource, gl.FRAGMENT_SHADER);

//Create shader programs
var program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);

gl.useProgram(program);

//Set up rectangle covering entire canvas 
var vertexData = new Float32Array([
  -1.0,  1.0,     // top left
  -1.0, -1.0,     // bottom left
   1.0,  1.0,     // top right
   1.0, -1.0,     // bottom right
]);

//Create vertex buffer
var vertexDataBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexDataBuffer);
gl.bufferData(gl.ARRAY_BUFFER, vertexData, gl.STATIC_DRAW);

// Layout of our data in the vertex buffer
var positionHandle = getAttribLocation(program, 'position');

gl.enableVertexAttribArray(positionHandle);
gl.vertexAttribPointer(positionHandle,
  2,                 // position is a vec2 (2 values per component)
  gl.FLOAT, // each component is a float
  false,         // don't normalize values
  2 * 4,         // two 4 byte float components per vertex (32 bit float is 4 bytes)
  0                 // how many bytes inside the buffer to start from
  );

//Set uniform handle
var timeHandle = getUniformLocation(program, 'time');
var widthHandle = getUniformLocation(program, 'width');
var heightHandle = getUniformLocation(program, 'height');

gl.uniform1f(widthHandle, window.innerWidth);
gl.uniform1f(heightHandle, window.innerHeight);

var lastFrame = Date.now();
var thisFrame;

function draw(){
    
  //Update time
    thisFrame = Date.now();
  time += (thisFrame - lastFrame)/1000;    
    lastFrame = thisFrame;

    //Send uniforms to program
  gl.uniform1f(timeHandle, time);
  //Draw a triangle strip connecting vertices 0-4
  gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);

  requestAnimationFrame(draw);
}

draw();

Final Output Of Neon Heart Using HTML and CSS Code

See the Pen NEON LOVE by al-ro (@al-ro) on CodePen.

Gratitude to Developer ❤️

I wanted to express on behalf of our team how appreciative we are of your kindness in allowing the public access to the Neon Love source code. Not only is your choice to make this code publicly available a gift to the programming community, but it also serves as motivation for us as budding developers.

It is really admirable that you are prepared to contribute to the open-source environment. You have not only given us a priceless learning resource by lending your knowledge and efforts, but you have also exemplified the collaborative spirit that fosters success in the tech industry.

Categorized in:

CSS Tricks, Tutorial,

Last Update: December 2, 2023