feat: 完善文字画视觉并新增 PDF 导出

- 调整飞鸟、楼群与标题配色和布局
- 新增 uv + Playwright PDF 导出脚本，四边各留 1em
- 页面标题改为「封面」

assets/js/scene.js

@@ -39,22 +39,23 @@
 
   /* 飞鸟：数量减少，间距不等，仅少量成对；上下拉开分布 */
   const birds = [
-    { x: 0, y: 2, kind: 'gull' },
-    { x: 26, y: 2, kind: 'gull' },
+    { x: 0, y: 2, kind: 'magpie' },
+    { x: 26, y: 2, kind: 'magpie' },
     { x: 1, y: 4, kind: 'sparrow' },
     { x: 3, y: 8, kind: 'crow' },
-    { x: 6, y: 13, kind: 'gull' },
+    { x: 6, y: 13, kind: 'magpie' },
     { x: 9, y: 15, kind: 'sparrow' },
     { x: 26, y: 5, kind: 'crow' },
     { x: 17, y: 9, kind: 'sparrow' },
-    { x: 21, y: 12, kind: 'gull' },
+    { x: 21, y: 12, kind: 'magpie' },
     { x: 19, y: 15, kind: 'crow' },
   ];
 
-  /* 天线：单列「线」，从 y 向下叠 h 格；楼顶在第 31 行，露出部分为 3 / 4 格 */
+  /* 天线：单列「线」，从 y 向下叠 h 格；最右楼顶另加一根深色 */
   const antennas = [
     { x: 7, y: 28, h: 3 },
     { x: 22, y: 27, h: 4 },
+    { x: 26, y: 34, h: 3, cls: 'ant ant-dark' },
   ];
 
   /* 楼群：n 对应 .bld-n，最终按 x/y/w/h 铺满「楼」（高度裁到第 44 行） */
@@ -72,12 +73,13 @@
   /* 标题区：整格扣出的居中矩形，左右各留 3 格 */
   const TITLE = {
     text: '关于「甲子」的虚构故事',
+    emphasis: '甲子',
     top: 14,
     height: 5,
     side: 3,
   };
 
-  const BIRD_WORDS = { sparrow: '麻雀', gull: '海鸥', crow: '乌鸦' };
+  const BIRD_WORDS = { sparrow: '麻雀', magpie: '喜鹊', crow: '乌鸦' };
 
   const grid = Array.from({ length: ROWS }, () =>
     Array.from({ length: COLS }, () => ({ ch: '天', cls: 'sky' }))
@@ -112,8 +114,8 @@
     put(x + 1, y, b, `bird-${kind}`);
   }
 
-  for (const { x, y, h } of antennas) {
-    for (let i = 0; i < h; i++) put(x, y + i, '线', 'ant');
+  for (const { x, y, h, cls = 'ant' } of antennas) {
+    for (let i = 0; i < h; i++) put(x, y + i, '线', cls);
   }
 
   for (const { n, x, y, w, h } of buildings) {
@@ -153,7 +155,16 @@
 
   const title = document.createElement('h1');
   title.className = 'title';
-  title.textContent = TITLE.text;
+
+  const [before, after] = TITLE.text.split(TITLE.emphasis);
+  if (after === undefined) {
+    title.textContent = TITLE.text;
+  } else {
+    const em = document.createElement('span');
+    em.className = 'title-em';
+    em.textContent = TITLE.emphasis;
+    title.append(before, em, after);
+  }
 
   panel.append(title);
   scene.append(panel);