feat: 添加首页雪花效果插件

添加雪花效果插件，包含CSS样式、PHP插件文件和JS动画逻辑

css/snow.css

@@ -0,0 +1,10 @@
+#effectiveAppsSnow {
+  display: block;
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  pointer-events: none;
+  z-index: 1000;
+}

js/snow-canvas.js

@@ -0,0 +1,83 @@
+(function(){
+  function init(){
+    var canvas = document.getElementById('effectiveAppsSnow');
+    if (!canvas) return;
+    var context = canvas.getContext('2d');
+    var viewportWidth = window.innerWidth;
+    var viewportHeight = window.innerHeight;
+    var devicePixelRatio = window.devicePixelRatio || 1;
+
+    function resizeCanvas(){
+      viewportWidth = window.innerWidth;
+      viewportHeight = window.innerHeight;
+      var displayWidth = viewportWidth;
+      var displayHeight = viewportHeight;
+      canvas.style.width = displayWidth + 'px';
+      canvas.style.height = displayHeight + 'px';
+      canvas.width = Math.floor(displayWidth * devicePixelRatio);
+      canvas.height = Math.floor(displayHeight * devicePixelRatio);
+      context.setTransform(devicePixelRatio, 0, 0, devicePixelRatio, 0, 0);
+    }
+
+    resizeCanvas();
+
+    var snowflakeCount = Math.floor(Math.min(400, Math.max(120, (viewportWidth * viewportHeight) / 12000)));
+    var snowflakes = [];
+    for (var i = 0; i < snowflakeCount; i++){
+      snowflakes.push({
+        positionX: Math.random() * viewportWidth,
+        positionY: Math.random() * viewportHeight,
+        radius: Math.random() * 2 + 1,
+        driftSpeed: Math.random() * 0.6 + 0.4,
+        swingAmplitude: Math.random() * 0.8 + 0.2
+      });
+    }
+
+    function updateSnowflakes(){
+      for (var j = 0; j < snowflakes.length; j++){
+        var flake = snowflakes[j];
+        flake.positionY += flake.driftSpeed * 2 + flake.radius * 0.25;
+        flake.positionX += Math.sin(flake.positionY * 0.01) * flake.swingAmplitude;
+        if (flake.positionY > viewportHeight + 5){
+          flake.positionY = -5;
+          flake.positionX = Math.random() * viewportWidth;
+          flake.radius = Math.random() * 2 + 1;
+          flake.driftSpeed = Math.random() * 0.6 + 0.4;
+          flake.swingAmplitude = Math.random() * 0.8 + 0.2;
+        }
+      }
+    }
+
+    function drawSnowflakes(){
+      context.clearRect(0, 0, viewportWidth, viewportHeight);
+      context.fillStyle = 'rgba(255,255,255,0.9)';
+      context.beginPath();
+      for (var k = 0; k < snowflakes.length; k++){
+        var flake = snowflakes[k];
+        context.moveTo(flake.positionX, flake.positionY);
+        context.arc(flake.positionX, flake.positionY, flake.radius, 0, Math.PI * 2);
+      }
+      context.fill();
+    }
+
+    function animate(){
+      updateSnowflakes();
+      drawSnowflakes();
+      requestAnimationFrame(animate);
+    }
+
+    window.addEventListener('resize', function(){
+      resizeCanvas();
+      viewportWidth = window.innerWidth;
+      viewportHeight = window.innerHeight;
+    });
+
+    animate();
+  }
+
+  if (document.readyState === 'loading'){
+    document.addEventListener('DOMContentLoaded', init);
+  } else {
+    init();
+  }
+})();

yoone-snow.php

@@ -0,0 +1,39 @@
+<?php
+/*
+Plugin Name: Yoone Snow
+Description: 首页 canvas 雪花效果
+Version: 1.1.0
+Author: Yoone
+*/
+
+if (!defined('ABSPATH')) { exit; }
+
+function yoone_snow_is_enabled() {
+    return function_exists('is_front_page') ? is_front_page() : false;
+}
+
+function yoone_snow_enqueue_assets() {
+    if (!yoone_snow_is_enabled()) { return; }
+    $style_handle = 'yoone-snow-style';
+    $style_src = plugins_url('css/snow.css', __FILE__);
+    wp_register_style($style_handle, $style_src, array(), '1.1.0', 'all');
+    wp_enqueue_style($style_handle);
+
+    $script_handle = 'yoone-snow-script';
+    $script_src = plugins_url('js/snow-canvas.js', __FILE__);
+    wp_register_script($script_handle, $script_src, array(), '1.1.0', true);
+    wp_enqueue_script($script_handle);
+}
+
+function yoone_snow_render_overlay() {
+    if (!yoone_snow_is_enabled()) { return; }
+    static $yoone_snow_rendered = false;
+    if ($yoone_snow_rendered) { return; }
+    $yoone_snow_rendered = true;
+    echo '<canvas id="effectiveAppsSnow" aria-hidden="true"></canvas>';
+}
+
+add_action('wp_enqueue_scripts', 'yoone_snow_enqueue_assets');
+add_action('wp_body_open', 'yoone_snow_render_overlay');
+add_action('wp_footer', 'yoone_snow_render_overlay', 100);
+