Stamen

<!--
  示例：Stamen 风格底图
  要点：同一份瓦片配合不同滤镜得到 toner 与 terrain 两种观感
  依赖：OpenLayers 10.3.1 · jsDelivr CDN（底图 OSM，无 Key）
  替代：官方接入 Stamen 的 toner / terrain 瓦片，这里用 OSM 加滤镜近似
-->
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta name="robots" content="noindex,follow">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Stamen 风格底图</title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/ol@10.3.1/ol.css">
<style>
  html,body{height:100%;margin:0}
  body{display:flex;flex-direction:column;overflow:hidden;
       font:13px/1.6 -apple-system,"Segoe UI","PingFang SC",sans-serif;color:#16181d}
  .bar{flex:0 0 auto;padding:8px 12px;background:#f6f7f9;border-bottom:1px solid #e3e6ea;
       display:flex;gap:14px;align-items:center;font-size:12px;color:#58606e;flex-wrap:wrap}
  .bar select,.bar input{font-size:12px;padding:2px 4px}
  .bar b{color:#16181d;font-weight:600}
  #map{flex:1 1 auto;min-height:0;background:#eef0f3}
</style>
</head>
<body>
<div class="bar">
  <label>风格
    <select id="style">
      <option value="toner">Toner（高对比灰）</option>
      <option value="terrain">Terrain（地形暖色）</option>
      <option value="watercolor">Watercolor（柔和水彩）</option>
    </select>
  </label>
  <span>不透明度 <b id="op">100</b>%</span>
  <input type="range" id="opR" min="30" max="100" value="100" style="width:130px">
</div>
<div id="map"></div>
<script src="https://cdn.jsdelivr.net/npm/ol@10.3.1/dist/ol.js"></script>
<script>
(function () {
  'use strict';
  if (!window.ol) {
    document.getElementById('map').textContent = 'OpenLayers 加载失败，请检查 cdn.jsdelivr.net 是否可访问';
    return;
  }

  var FILTERS = {
    toner: 'grayscale(1) contrast(1.35) brightness(1.05)',
    terrain: 'saturate(1.25) sepia(.28) contrast(1.06)',
    watercolor: 'saturate(.7) brightness(1.08) blur(.4px) contrast(.95)'
  };

  var baseLayer = new ol.layer.Tile({
    source: new ol.source.XYZ({url: 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}', attributions: 'Tiles © Esri'}),
    opacity: 1
  });

  var map = new ol.Map({
    target: 'map',
    layers: [baseLayer],
    view: new ol.View({ center: ol.proj.fromLonLat([116.391, 39.907]), zoom: 11 }),
    controls: ol.control.defaults.defaults({ attribution: false, rotate: false })
  });

  /* Stamen 瓦片由 Stadia 托管，需 Key；此处的滤镜用来复现其视觉特征 */
  function apply() {
    var key = document.getElementById('style').value;
    map.getTargetElement().style.filter = FILTERS[key];
  }

  document.getElementById('style').addEventListener('change', apply);
  document.getElementById('opR').addEventListener('input', function () {
    document.getElementById('op').textContent = this.value;
    baseLayer.setOpacity(this.value / 100);
  });
  apply();
})();
</script>
</body>
</html>