Initial commit: 译泡 PopLingo v1.0.0

AI 划词翻译 Chrome 扩展（Manifest V3）：
- 支持 DeepSeek/OpenAI/Kimi/智谱/通义/Gemini/Claude/Ollama 等 10 种服务商
- 流式输出、左右分栏对照、原文一键展开收起
- 划词图标/自动翻译/Alt+T 快捷键/右键菜单四种触发方式

popup/popup.css

@@ -0,0 +1,62 @@
+* { box-sizing: border-box; margin: 0; padding: 0; }
+
+body {
+  width: 300px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
+  background: #f8fafc;
+  color: #111827;
+}
+
+.head {
+  display: flex; align-items: center; justify-content: space-between;
+  padding: 14px 16px 12px;
+  background: linear-gradient(135deg, #4f46e5, #8b5cf6);
+  color: #fff;
+}
+.brand { display: flex; align-items: center; gap: 10px; }
+.brand img { border-radius: 6px; }
+.brand h1 { font-size: 14px; font-weight: 700; }
+.status { font-size: 11px; opacity: .85; }
+
+.switch { position: relative; width: 40px; height: 22px; flex: none; }
+.switch input { opacity: 0; width: 0; height: 0; }
+.slider {
+  position: absolute; inset: 0; background: rgba(255,255,255,.35);
+  border-radius: 99px; cursor: pointer; transition: background .2s;
+}
+.slider::before {
+  content: ''; position: absolute; left: 3px; top: 3px;
+  width: 16px; height: 16px; border-radius: 50%; background: #fff;
+  transition: transform .2s;
+}
+.switch input:checked + .slider { background: #22c55e; }
+.switch input:checked + .slider::before { transform: translateX(18px); }
+
+.provider { margin: 10px 12px 0; padding: 4px 12px; background: #fff; border-radius: 10px; border: 1px solid #e5e7eb; }
+.row {
+  display: flex; align-items: center; justify-content: space-between;
+  padding: 8px 0; font-size: 12.5px;
+}
+.row + .row { border-top: 1px solid #f3f4f6; }
+.label { color: #6b7280; }
+.value { font-weight: 600; color: #111827; max-width: 170px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11.5px; font-weight: 500; color: #4f46e5; }
+.warn { color: #f59e0b; }
+.ok { color: #10b981; }
+
+.form { display: grid; gap: 8px; padding: 10px 12px 4px; }
+.field { display: grid; gap: 4px; font-size: 12px; color: #6b7280; }
+.field select {
+  padding: 7px 10px; border-radius: 8px; border: 1px solid #e5e7eb;
+  background: #fff; font-size: 13px; color: #111827; outline: none; cursor: pointer;
+}
+.field select:focus { border-color: #8b5cf6; box-shadow: 0 0 0 3px rgba(139,92,246,.15); }
+
+.foot { display: flex; align-items: center; justify-content: space-between; padding: 12px 16px 14px; }
+.btn {
+  border: none; cursor: pointer; font-size: 12.5px; font-weight: 600;
+  padding: 8px 14px; border-radius: 8px; background: #eef2ff; color: #4f46e5;
+  transition: all .15s;
+}
+.btn:hover { background: #e0e7ff; transform: translateY(-1px); }
+.hint { font-size: 10.5px; color: #9ca3af; }