diff --git a/CMakeLists.txt b/CMakeLists.txt
index c59d1c3..446aac5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,7 @@ foreach(_p
     endif()
 endforeach()
 
-find_package(Qt6 REQUIRED COMPONENTS Core Widgets)
+find_package(Qt6 REQUIRED COMPONENTS Core Widgets Network)
 find_package(PkgConfig REQUIRED)
 find_package(Threads REQUIRED)
 
@@ -112,9 +112,10 @@ target_link_libraries(livecaption_core PUBLIC
 # ---------------------------------------------------------------------------
 add_library(livecaption_models STATIC
     src/models/modelstore.cpp
+    src/models/modeldownloader.cpp
 )
 target_include_directories(livecaption_models PUBLIC src/models)
-target_link_libraries(livecaption_models PUBLIC Qt6::Core)
+target_link_libraries(livecaption_models PUBLIC Qt6::Core Qt6::Network)
 qt_add_resources(livecaption_models "registry"
     PREFIX "/"
     BASE "${CMAKE_CURRENT_SOURCE_DIR}"
@@ -127,9 +128,11 @@ qt_add_resources(livecaption_models "registry"
 add_library(livecaption_ui STATIC
     src/ui/captionwindow.cpp
     src/ui/livetranscriber.cpp
+    src/ui/appsettings.cpp
+    src/ui/settingsdialog.cpp
 )
 target_include_directories(livecaption_ui PUBLIC src/ui)
-target_link_libraries(livecaption_ui PUBLIC livecaption_core Qt6::Widgets)
+target_link_libraries(livecaption_ui PUBLIC livecaption_core livecaption_models Qt6::Widgets)
 
 # ---------------------------------------------------------------------------
 # 可执行程序
diff --git a/README.md b/README.md
index 025fd7f..b5bb6b1 100644
--- a/README.md
+++ b/README.md
@@ -33,10 +33,16 @@ aria2c -x16 -s16 -k4M -o mmproj-Qwen3-ASR-0.6B-Q8_0.gguf "$B/mmproj-Qwen3-ASR-0.
 cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
 cmake --build build -j
 
-# 3. 悬浮字幕窗
-./build/live-caption \
-  --model Qwen3-ASR-0.6B-Q8_0.gguf \
-  --mmproj mmproj-Qwen3-ASR-0.6B-Q8_0.gguf
+# 3. 悬浮字幕窗（首次启动会打开设置对话框，引导下载并选择模型）
+./build/live-caption
+
+#    完全通过 GUI 操作：
+#      · 首次启动 → 设置对话框：下载模型 / 选择当前使用 / 选识别语言 / 下载源与代理
+#      · 点左上角的语言标签 → 再次打开设置
+#      · 托盘图标：显示/隐藏字幕、设置、退出
+#      · 窗口的 ✕ = 隐藏到托盘（用托盘菜单可以再显示回来）
+#    命令行参数仍保留，仅用于自动化测试（显式给出时覆盖设置），例如：
+#      ./build/live-caption --asr-backend sherpa --asr-model zipformer-zh-2025 --no-tray
 
 # 4. 命令行：单文件转写 / 流式转写 / 无窗口实时
 ./build/live-caption-cli --model M --mmproj MM --file some_16k_mono.wav
@@ -55,7 +61,8 @@ ctest --test-dir build --output-on-failure
 - **`sherpa`**：sherpa-onnx + 流式 ONNX 模型（X-ASR / zipformer / Nemotron）  —— 原生流式，每步成本恒定，CPU 约为前者的 1/35，中英准确率持平。
 
 模型都放在 `~/.local/share/live-caption/models/`，注册表是 `data/models.json`
-（**加模型只加一条数据，不改代码**），用 `scripts/fetch-models.sh` 下载。
+（**加模型只加一条数据，不改代码**）。GUI 里可以直接下载（支持设置下载源与代理、
+断点续传），命令行下也可以用 `scripts/fetch-models.sh`。
 
 ```bash
 # 流式后端
diff --git a/apps/common/appcli.h b/apps/common/appcli.h
index 6295e5b..639a660 100644
--- a/apps/common/appcli.h
+++ b/apps/common/appcli.h
@@ -106,6 +106,48 @@ inline void addBackendOptions(QCommandLineParser & p)
     p.addOption(makeOption("language", "语言提示，多语言模型用（zh / en / ja …）；留空=自动", "lang"));
 }
 
+// 按注册表里的模型直接构造后端（GUI 用；不依赖任何命令行参数）
+inline std::unique_ptr<IAsr> makeAsrForModel(const models::ModelInfo & m,
+                                             const QString & language,
+                                             int threads, bool verbose,
+                                             std::string * err)
+{
+    QStringList missing;
+    if (!models::ModelStore::isInstalled(m, &missing)) {
+        if (err) {
+            *err = "模型未安装，缺失: " + missing.join(QStringLiteral(", ")).toStdString();
+        }
+        return nullptr;
+    }
+
+    if (m.backend == models::Backend::LlamaCpp) {
+        AsrOptions o;
+        o.modelPath  = m.filePath(QStringLiteral("model")).toStdString();
+        o.mmprojPath = m.filePath(QStringLiteral("mmproj")).toStdString();
+        o.threads    = threads;
+        o.verbose    = verbose;
+        auto a = std::make_unique<Qwen3Asr>();
+        if (!a->load(o, err)) return nullptr;
+        return a;
+    }
+
+#if defined(LC_HAVE_SHERPA)
+    SherpaAsr::Options o;
+    o.encoder = m.filePath(QStringLiteral("encoder")).toStdString();
+    o.decoder = m.filePath(QStringLiteral("decoder")).toStdString();
+    o.joiner  = m.filePath(QStringLiteral("joiner")).toStdString();
+    o.tokens  = m.filePath(QStringLiteral("tokens")).toStdString();
+    o.threads = 1;   // 这类模型单线程最快
+    if (m.languages.size() > 1 && !language.isEmpty()) o.language = language.toStdString();
+    auto a = std::make_unique<SherpaAsr>();
+    if (!a->load(o, err)) return nullptr;
+    return a;
+#else
+    if (err) *err = "编译时未找到 sherpa-onnx";
+    return nullptr;
+#endif
+}
+
 // 按命令行选择并加载后端；失败时返回 nullptr 并把原因写进 err
 inline std::unique_ptr<IAsr> makeAsr(const QCommandLineParser & p,
                                      const AsrOptions & asrOpt, std::string * err)
diff --git a/apps/gui/main.cpp b/apps/gui/main.cpp
index 36bf1d5..3abd15d 100644
--- a/apps/gui/main.cpp
+++ b/apps/gui/main.cpp
@@ -1,111 +1,263 @@
-// 图形界面版：悬浮字幕窗。
+// 图形界面版：悬浮字幕窗 + 托盘 + 设置对话框。
+// 完全通过 GUI 使用；命令行参数保留，仅用于自动化测试（显式给出时覆盖设置）。
 #include <cstdio>
+#include <memory>
 
+#include <QAction>
 #include <QApplication>
 #include <QCommandLineOption>
 #include <QCommandLineParser>
-#include <QGuiApplication>
+#include <QIcon>
+#include <QMenu>
+#include <QMessageBox>
+#include <QPainter>
+#include <QPixmap>
+#include <QSystemTrayIcon>
 #include <QTimer>
 
 #include "appcli.h"
+#include "appsettings.h"
 #include "captionwindow.h"
-#include "livetranscriber.h"
 #include "iasr.h"
+#include "livetranscriber.h"
+#include "modelstore.h"
 #include "qwen3asr.h"
+#include "settingsdialog.h"
 #include "streamingasr.h"
 #include "transcript.h"
 
 namespace {
 
-int runGui(lc::IAsr & asr, const lc::StreamOptions & sop,
-           const QString & screenshotPath, int screenshotDelaySec, int opacityPercent)
+// 托盘图标：直接画一个，免得依赖图标资源文件
+QIcon makeTrayIcon()
 {
-    lc::CaptionWindow window;
-    window.setPanelOpacity(opacityPercent);
-    lc::LiveTranscriber live(asr);
+    QPixmap pm(64, 64);
+    pm.fill(Qt::transparent);
+    QPainter p(&pm);
+    p.setRenderHint(QPainter::Antialiasing);
+    p.setBrush(QColor(20, 20, 20, 235));
+    p.setPen(Qt::NoPen);
+    p.drawRoundedRect(2, 12, 60, 40, 10, 10);
+    p.setPen(QColor(240, 240, 240));
+    QFont f = p.font();
+    f.setPixelSize(26);
+    f.setBold(true);
+    p.setFont(f);
+    p.drawText(pm.rect(), Qt::AlignCenter, QStringLiteral("字"));
+    return QIcon(pm);
+}
 
-    QObject::connect(&live, &lc::LiveTranscriber::caption, &window,
-                     [&window](const QString & committed, const QString & tail,
-                               const QString & lang) {
-                         window.setLanguage(
-                             QString::fromStdString(lc::languageDisplayName(lang.toStdString())));
-                         window.setCaption(committed, tail);
-                     });
-    QObject::connect(&live, &lc::LiveTranscriber::failed, &window, [](const QString & m) {
-        qWarning("采集失败: %s", qUtf8Printable(m));
-    });
-    QObject::connect(&window, &lc::CaptionWindow::closed, qApp, &QCoreApplication::quit);
-    QObject::connect(&window, &lc::CaptionWindow::languageClicked, &window, [] {
-        qInfo() << "语言标签被点击（设置界面将在 Phase 4 接入）";
-    });
+// 把设置应用到字幕窗（字号/不透明度/行数/位置）
+void applyAppearance(lc::CaptionWindow & window, const lc::AppSettings & cfg)
+{
+    window.setPanelOpacity(cfg.opacityPercent);
+    window.setTextFontSize(cfg.fontSize);
+    window.setLineCounts(cfg.collapsedLines, cfg.expandedLines);
+    if (cfg.hasWindowPos) window.move(cfg.windowPos);
+}
 
-    QString err;
-    if (!live.start(sop, &err)) {
-        qCritical("启动采集失败: %s", qUtf8Printable(err));
-        return 1;
-    }
-    qInfo("正在采集: %s", qUtf8Printable(live.deviceName()));
-
-    window.show();
-
-    if (!screenshotPath.isEmpty()) {
-        // 自截图：用于验证渲染（不依赖外部截图工具）
-        QTimer::singleShot(screenshotDelaySec * 1000, &window, [&window, screenshotPath] {
-            const bool ok1 = window.grab().save(screenshotPath);
-
-            window.setCollapsed(false);
-            QString expandedPath = screenshotPath;
-            expandedPath.replace(QStringLiteral(".png"), QStringLiteral("-expanded.png"));
-            const bool ok2 = window.grab().save(expandedPath);
-
-            std::fprintf(stderr, "截图: 折叠态 %s / 展开态 %s\n",
-                         ok1 ? "成功" : "失败", ok2 ? "成功" : "失败");
-            QCoreApplication::quit();
-        });
-    }
-
-    return QCoreApplication::exec();
+bool hasUsableModel()
+{
+    using namespace lc::models;
+    const lc::AppSettings & cfg = lc::AppSettings::instance();
+    if (cfg.modelId.isEmpty()) return false;
+    const ModelInfo * m = ModelStore::find(cfg.modelId);
+    return m && ModelStore::isInstalled(*m);
 }
 
 } // namespace
 
 int main(int argc, char ** argv)
 {
-    // 说明意图：DPI 取整策略必须在 QGuiApplication 之前定。
-    // （Deepin 的会话环境已经设了 QT_SCALE_FACTOR_ROUNDING_POLICY，
-    //   所以本机仍会看到 Qt 的那条提醒，那不是本程序的问题。）
     QGuiApplication::setHighDpiScaleFactorRoundingPolicy(
         Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
-
     QApplication app(argc, argv);
     QCoreApplication::setApplicationName(QStringLiteral("live-caption"));
+    QCoreApplication::setOrganizationName(QStringLiteral("live-caption"));
 
+    lc::AppSettings & cfg = lc::AppSettings::instance();
+    cfg.load();
+
+    // ---- 命令行（仅用于自动化测试，显式给出时覆盖设置）----
     QCommandLineParser parser;
     parser.setApplicationDescription(QStringLiteral("实时字幕（悬浮窗）"));
     parser.addHelpOption();
     lc::app::addModelOptions(parser);
     lc::app::addStreamOptions(parser);
     lc::app::addBackendOptions(parser);
-    parser.addOption(lc::app::makeOption("opacity", "字幕背景不透明度，取值 20-100", "n", "84"));
-    parser.addOption(lc::app::makeOption("screenshot", "启动后自动截图并退出（验证渲染用）", "path"));
-    parser.addOption(lc::app::makeOption("screenshot-delay", "截图前等待秒数", "sec", "6"));
+    parser.addOption(QCommandLineOption("opacity", "背景不透明度（20-100）", "n"));
+    parser.addOption(QCommandLineOption("screenshot", "启动后自动截图并退出", "path"));
+    parser.addOption(QCommandLineOption("screenshot-delay", "截图前等待秒数", "sec", "6"));
+    parser.addOption(QCommandLineOption("no-tray", "不创建托盘图标（测试用）"));
+    parser.addOption(QCommandLineOption("screenshot-settings", "打开设置对话框截图后退出", "path"));
     parser.process(app);
 
-    const lc::AsrOptions asrOpt = lc::app::asrOptions(parser);
-    lc::StreamOptions sop = lc::app::streamOptions(parser);
+    if (parser.isSet("asr-model")) cfg.modelId = parser.value("asr-model");
+    if (parser.isSet("language"))  cfg.language = parser.value("language");
+    if (parser.isSet("opacity"))   cfg.opacityPercent = parser.value("opacity").toInt();
+    if (parser.isSet("model-dir")) lc::models::ModelStore::setRootOverride(parser.value("model-dir"));
 
-    std::string err;
-    std::unique_ptr<lc::IAsr> asr = lc::app::makeAsr(parser, asrOpt, &err);
-    if (!asr) {
-        std::fprintf(stderr, "%s\n", err.c_str());
+    // 仅用于验证渲染：打开设置对话框截图后退出
+    if (parser.isSet("screenshot-settings")) {
+        const QString path = parser.value("screenshot-settings");
+        auto * dlg = new lc::SettingsDialog(!hasUsableModel());
+        dlg->show();
+        QTimer::singleShot(1200, dlg, [dlg, path] {
+            dlg->grab().save(path);
+            std::fprintf(stderr, "设置对话框截图: %s\n", qUtf8Printable(path));
+            QCoreApplication::quit();
+        });
+        return QCoreApplication::exec();
+    }
+
+    // ---- 启动：没有可用模型就先开设置 ----
+    if (!hasUsableModel()) {
+        lc::SettingsDialog dlg(true);
+        if (dlg.exec() != QDialog::Accepted || !hasUsableModel()) return 0;
+    }
+
+    lc::CaptionWindow window;
+    applyAppearance(window, cfg);
+    // 语言 pill：流式模型不提供语言识别，就显示设置里选的语言
+    if (!cfg.language.isEmpty()) {
+        window.setLanguage(QString::fromStdString(lc::languageDisplayName(cfg.language.toStdString())));
+    }
+
+    // 注意声明顺序：asr 必须在 live 之前声明，
+    // 这样析构时 live（会 join 工作线程）先销毁、asr 后销毁，避免 use-after-free。
+    std::unique_ptr<lc::IAsr> asr;
+    lc::LiveTranscriber       live;   // 后端在 startTranscriber() 里注入
+    const auto startTranscriber = [&]() -> bool {
+        live.stop();
+        asr.reset();
+
+        const lc::models::ModelInfo * m = lc::models::ModelStore::find(cfg.modelId);
+        if (!m) {
+            qCritical("找不到模型 %s", qUtf8Printable(cfg.modelId));
+            return false;
+        }
+        std::string err;
+        asr = lc::app::makeAsrForModel(*m, cfg.language, cfg.threads,
+                                       parser.isSet("verbose"), &err);
+        if (!asr) {
+            qCritical("加载模型失败: %s", err.c_str());
+            return false;
+        }
+
+        lc::StreamOptions sop;
+        if (asr->kind() == lc::AsrKind::NativeStreaming) {
+            sop.chunkSec = (cfg.chunkSec > 0.0) ? cfg.chunkSec : 0.32;
+        } else if (cfg.chunkSec > 0.0) {
+            sop.chunkSec = cfg.chunkSec;
+        }
+        QString qerr;
+        if (!live.start(*asr, sop, &qerr)) {
+            qCritical("启动采集失败: %s", qUtf8Printable(qerr));
+            return false;
+        }
+        return true;
+    };
+
+    QObject::connect(&live, &lc::LiveTranscriber::caption, &window,
+                     [&window](const QString & committed, const QString & tail,
+                               const QString & lang) {
+                         if (!lang.isEmpty()) {
+                             window.setLanguage(
+                                 QString::fromStdString(lc::languageDisplayName(lang.toStdString())));
+                         }
+                         window.setCaption(committed, tail);
+                     });
+    QObject::connect(&live, &lc::LiveTranscriber::failed, &window, [](const QString & m) {
+        qWarning("采集失败: %s", qUtf8Printable(m));
+    });
+
+    // 语言 pill → 设置
+    QObject::connect(&window, &lc::CaptionWindow::languageClicked, &window, [&] {
+        lc::SettingsDialog dlg(false);
+        if (dlg.exec() == QDialog::Accepted) {
+            applyAppearance(window, cfg);
+            if (!startTranscriber()) {
+                QMessageBox::warning(&window, QObject::tr("启动失败"),
+                                     QObject::tr("模型加载失败，请检查设置。"));
+            }
+        }
+    });
+
+    // ---- 托盘 ----
+    QSystemTrayIcon * tray = nullptr;
+    QMenu * trayMenu = nullptr;
+    if (!parser.isSet("no-tray")) {
+        tray = new QSystemTrayIcon(makeTrayIcon(), &app);
+        tray->setToolTip(QObject::tr("实时字幕"));
+        trayMenu = new QMenu;
+        auto * showAct = trayMenu->addAction(QObject::tr("显示/隐藏字幕"));
+        auto * setAct  = trayMenu->addAction(QObject::tr("设置…"));
+        trayMenu->addSeparator();
+        auto * quitAct = trayMenu->addAction(QObject::tr("退出"));
+        tray->setContextMenu(trayMenu);
+
+        QObject::connect(showAct, &QAction::triggered, &window,
+                         [&window] { window.setVisible(!window.isVisible()); });
+        QObject::connect(setAct, &QAction::triggered, &window, [&] {
+            lc::SettingsDialog dlg(false);
+            if (dlg.exec() == QDialog::Accepted) {
+                applyAppearance(window, cfg);
+                startTranscriber();
+            }
+        });
+        QObject::connect(quitAct, &QAction::triggered, &app, &QApplication::quit);
+        QObject::connect(tray, &QSystemTrayIcon::activated, &window,
+                         [&window](QSystemTrayIcon::ActivationReason r) {
+                             if (r == QSystemTrayIcon::Trigger) {
+                                 window.setVisible(!window.isVisible());
+                             }
+                         });
+        tray->show();
+    }
+
+    // 关闭按钮 = 隐藏到托盘（否则关掉就没法再打开了）
+    QObject::connect(&window, &lc::CaptionWindow::closed, &window, [&] {
+        if (tray) {
+            window.hide();
+        } else {
+            qApp->quit();
+        }
+    });
+
+    // 记住拖动后的位置
+    QObject::connect(&window, &lc::CaptionWindow::moved, &window, [&](const QPoint & p) {
+        cfg.windowPos   = p;
+        cfg.hasWindowPos = true;
+        cfg.save();
+    });
+
+    if (!startTranscriber()) {
+        QMessageBox::critical(nullptr, QObject::tr("启动失败"),
+                              QObject::tr("无法加载模型，请检查设置。"));
         return 1;
     }
-    if (asr->kind() == lc::AsrKind::NativeStreaming && !parser.isSet("stream-chunk")) {
-        sop.chunkSec = 0.32;
+
+    window.show();
+
+    // 自截图（验证渲染用）
+    if (parser.isSet("screenshot")) {
+        const QString path = parser.value("screenshot");
+        QTimer::singleShot(parser.value("screenshot-delay").toInt() * 1000, &window,
+                           [&window, path] {
+                               const bool ok1 = window.grab().save(path);
+                               window.setCollapsed(false);
+                               QString expanded = path;
+                               expanded.replace(QStringLiteral(".png"), QStringLiteral("-expanded.png"));
+                               const bool ok2 = window.grab().save(expanded);
+                               std::fprintf(stderr, "截图: 折叠态 %s / 展开态 %s\n",
+                                            ok1 ? "成功" : "失败", ok2 ? "成功" : "失败");
+                               QCoreApplication::quit();
+                           });
     }
 
-    return runGui(*asr, sop,
-                  parser.value("screenshot"),
-                  parser.value("screenshot-delay").toInt(),
-                  parser.value("opacity").toInt());
+    const int rc = QCoreApplication::exec();
+    // 显式收尾，确保工作线程停下来之后再释放后端
+    live.stop();
+    asr.reset();
+    return rc;
 }
diff --git a/data/models.json b/data/models.json
index 8977066..0e7420e 100644
--- a/data/models.json
+++ b/data/models.json
@@ -2,6 +2,25 @@
   "version": 1,
   "comment": "live-caption 的模型注册表。新增模型 = 在这里加一条，不需要改代码。",
   "models": [
+    {
+      "id": "qwen3-asr-0.6b-q8",
+      "name": "Qwen3-ASR 0.6B（通用，52 语言）",
+      "backend": "llama-cpp",
+      "languages": ["zh", "en", "ja", "ko", "fr", "de", "es", "ru", "ar", "auto"],
+      "license": "Apache-2.0",
+      "note": "973MB，准确率高、语言最全、自带语言识别；但每步成本随句子增长（CPU 约为流式后端的 35 倍）",
+      "files": {
+        "model": {
+          "name": "Qwen3-ASR-0.6B-Q8_0.gguf",
+          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/Qwen3-ASR-0.6B-Q8_0.gguf"
+        },
+        "mmproj": {
+          "name": "mmproj-Qwen3-ASR-0.6B-Q8_0.gguf",
+          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/mmproj-Qwen3-ASR-0.6B-Q8_0.gguf"
+        }
+      },
+      "options": {}
+    },
     {
       "id": "zipformer-zh-2025",
       "name": "中文流式（k2-fsa 官方 2025-06-30）",
diff --git a/src/models/modeldownloader.cpp b/src/models/modeldownloader.cpp
new file mode 100644
index 0000000..042bc4d
--- /dev/null
+++ b/src/models/modeldownloader.cpp
@@ -0,0 +1,147 @@
+#include "modeldownloader.h"
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+#include <QNetworkAccessManager>
+#include <QNetworkReply>
+#include <QNetworkRequest>
+#include <QUrl>
+
+namespace lc::models {
+
+ModelDownloader::ModelDownloader(QObject * parent) : QObject(parent) {}
+
+ModelDownloader::~ModelDownloader() { cancel(); }
+
+QString ModelDownloader::rewriteUrl(const QString & url) const
+{
+    if (mirrorBase_.isEmpty()) return url;
+    const QUrl u(url);
+    QString base = mirrorBase_;
+    while (base.endsWith(QLatin1Char('/'))) base.chop(1);
+    return base + u.path();
+}
+
+void ModelDownloader::start(const ModelInfo & model)
+{
+    if (running_) return;
+    running_ = true;
+    cancel_  = false;
+    index_   = 0;
+    queue_   = model.files;
+    dir_     = ModelStore::dirFor(model.id);
+
+    net_ = new QNetworkAccessManager(this);
+    if (!proxy_.hostName().isEmpty() || proxy_.type() != QNetworkProxy::DefaultProxy) {
+        net_->setProxy(proxy_);
+    }
+
+    QDir().mkpath(dir_);
+    startNextFile();
+}
+
+void ModelDownloader::cancel()
+{
+    cancel_ = true;
+    if (reply_) {
+        reply_->abort();
+        reply_->deleteLater();
+        reply_ = nullptr;
+    }
+    if (out_) {
+        out_->close();
+        delete out_;
+        out_ = nullptr;
+    }
+    running_ = false;
+}
+
+void ModelDownloader::startNextFile()
+{
+    if (cancel_) { cleanup(); return; }
+    if (index_ >= queue_.size()) {
+        running_ = false;
+        Q_EMIT status(QStringLiteral("下载完成"));
+        Q_EMIT finished(true, QString());
+        return;
+    }
+
+    const ModelFile & f = queue_[index_];
+    const QString path = dir_ + QLatin1Char('/') + f.name;
+    out_ = new QFile(path);
+    qint64 offset = 0;
+    if (QFileInfo::exists(path)) offset = QFileInfo(path).size();
+
+    if (offset > 0) {
+        if (!out_->open(QIODevice::ReadWrite)) {
+            Q_EMIT finished(false, QStringLiteral("无法打开文件: ") + path);
+            cleanup();
+            return;
+        }
+        out_->seek(offset);
+    } else {
+        offset = 0;
+        if (!out_->open(QIODevice::WriteOnly)) {
+            Q_EMIT finished(false, QStringLiteral("无法写入: ") + path);
+            cleanup();
+            return;
+        }
+    }
+
+    QNetworkRequest req{QUrl(rewriteUrl(f.url))};
+    req.setAttribute(QNetworkRequest::RedirectPolicyAttribute,
+                     QNetworkRequest::NoLessSafeRedirectPolicy);
+    if (offset > 0) {
+        req.setRawHeader("Range", QByteArray("bytes=") + QByteArray::number(offset) + "-");
+        Q_EMIT status(QStringLiteral("续传 %1").arg(f.name));
+    } else {
+        Q_EMIT status(QStringLiteral("下载 %1").arg(f.name));
+    }
+
+    baseOffset_ = offset;
+    reply_ = net_->get(req);
+    connect(reply_, &QNetworkReply::readyRead, this, &ModelDownloader::onReadyRead);
+    connect(reply_, &QNetworkReply::finished,  this, &ModelDownloader::onFinished);
+    connect(reply_, &QNetworkReply::downloadProgress, this,
+            [this](qint64 got, qint64 tot) {
+                Q_EMIT progress(queue_[index_].name,
+                                baseOffset_ + got,
+                                tot > 0 ? baseOffset_ + tot : -1);
+            });
+}
+
+void ModelDownloader::onReadyRead()
+{
+    if (!reply_ || !out_) return;
+    const QByteArray data = reply_->readAll();
+    out_->write(data);
+}
+
+void ModelDownloader::onFinished()
+{
+    if (!reply_) return;
+    const QNetworkReply::NetworkError err = reply_->error();
+    const QString errText = reply_->errorString();
+    if (out_) { out_->close(); delete out_; out_ = nullptr; }
+    reply_->deleteLater();
+    reply_ = nullptr;
+
+    if (err != QNetworkReply::NoError && err != QNetworkReply::OperationCanceledError) {
+        running_ = false;
+        Q_EMIT finished(false, QStringLiteral("下载失败: ") + errText);
+        return;
+    }
+    if (cancel_) { cleanup(); return; }
+
+    ++index_;
+    startNextFile();
+}
+
+void ModelDownloader::cleanup()
+{
+    running_ = false;
+    Q_EMIT finished(false, QStringLiteral("已取消"));
+}
+
+} // namespace lc::models
diff --git a/src/models/modeldownloader.h b/src/models/modeldownloader.h
new file mode 100644
index 0000000..26c10aa
--- /dev/null
+++ b/src/models/modeldownloader.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <QNetworkProxy>
+#include <QObject>
+#include <QString>
+
+#include "modelstore.h"
+
+class QNetworkAccessManager;
+class QNetworkReply;
+class QFile;
+
+namespace lc::models {
+
+// 按注册表下载模型文件。支持：
+//   - 镜像基址替换（把注册表里的地址换成用户选的源）
+//   - HTTP 代理
+//   - 断点续传（已下过的部分用 Range 续）
+class ModelDownloader : public QObject {
+    Q_OBJECT
+
+public:
+    explicit ModelDownloader(QObject * parent = nullptr);
+    ~ModelDownloader() override;
+
+    // mirrorBase 形如 https://hf-mirror.com；留空则用注册表里的原始地址
+    void setMirrorBase(const QString & mirrorBase) { mirrorBase_ = mirrorBase; }
+    void setProxy(const QNetworkProxy & proxy) { proxy_ = proxy; }
+
+    void start(const ModelInfo & model);
+    void cancel();
+    bool isRunning() const { return running_; }
+
+Q_SIGNALS:
+    void progress(const QString & file, qint64 received, qint64 total);
+    void status(const QString & message);
+    void finished(bool ok, const QString & error);
+
+private:
+    void startNextFile();
+    void onReadyRead();
+    void onFinished();
+    void cleanup();
+
+    QString rewriteUrl(const QString & url) const;
+
+    QNetworkAccessManager * net_    = nullptr;
+    QNetworkReply *         reply_  = nullptr;
+    QFile *                 out_    = nullptr;
+    std::vector<ModelFile>  queue_;
+    size_t                  index_  = 0;
+    QString                 dir_;
+    QString                 mirrorBase_;
+    QNetworkProxy           proxy_;
+    bool                    running_ = false;
+    bool                    cancel_  = false;
+    qint64                  baseOffset_ = 0;   // 断点续传的起始偏移
+};
+
+} // namespace lc::models
diff --git a/src/ui/appsettings.cpp b/src/ui/appsettings.cpp
new file mode 100644
index 0000000..e866667
--- /dev/null
+++ b/src/ui/appsettings.cpp
@@ -0,0 +1,78 @@
+#include "appsettings.h"
+
+#include <QSettings>
+
+namespace lc {
+
+AppSettings & AppSettings::instance()
+{
+    static AppSettings s;
+    return s;
+}
+
+void AppSettings::load()
+{
+    QSettings s;
+    s.beginGroup(QStringLiteral("app"));
+    modelId            = s.value(QStringLiteral("modelId")).toString();
+    language           = s.value(QStringLiteral("language")).toString();
+    autoPickByLanguage = s.value(QStringLiteral("autoPickByLanguage"), false).toBool();
+
+    opacityPercent   = s.value(QStringLiteral("opacity"), 84).toInt();
+    fontSize         = s.value(QStringLiteral("fontSize"), 15).toInt();
+    showUnstableTail = s.value(QStringLiteral("showUnstableTail"), true).toBool();
+    collapsedLines   = s.value(QStringLiteral("collapsedLines"), 2).toInt();
+    expandedLines    = s.value(QStringLiteral("expandedLines"), 8).toInt();
+
+    hasWindowPos = s.contains(QStringLiteral("windowX"));
+    if (hasWindowPos) {
+        windowPos = QPoint(s.value(QStringLiteral("windowX")).toInt(),
+                           s.value(QStringLiteral("windowY")).toInt());
+    }
+
+    mirrorBase = s.value(QStringLiteral("mirrorBase"),
+                         QStringLiteral("https://hf-mirror.com")).toString();
+    proxyMode  = s.value(QStringLiteral("proxyMode"), 0).toInt();
+    proxyHost  = s.value(QStringLiteral("proxyHost")).toString();
+    proxyPort  = s.value(QStringLiteral("proxyPort"), 0).toInt();
+    proxyUser  = s.value(QStringLiteral("proxyUser")).toString();
+    proxyPass  = s.value(QStringLiteral("proxyPass")).toString();
+
+    chunkSec = s.value(QStringLiteral("chunkSec"), 0.0).toDouble();
+    threads  = s.value(QStringLiteral("threads"), 8).toInt();
+    s.endGroup();
+}
+
+void AppSettings::save()
+{
+    QSettings s;
+    s.beginGroup(QStringLiteral("app"));
+    s.setValue(QStringLiteral("modelId"), modelId);
+    s.setValue(QStringLiteral("language"), language);
+    s.setValue(QStringLiteral("autoPickByLanguage"), autoPickByLanguage);
+
+    s.setValue(QStringLiteral("opacity"), opacityPercent);
+    s.setValue(QStringLiteral("fontSize"), fontSize);
+    s.setValue(QStringLiteral("showUnstableTail"), showUnstableTail);
+    s.setValue(QStringLiteral("collapsedLines"), collapsedLines);
+    s.setValue(QStringLiteral("expandedLines"), expandedLines);
+
+    if (hasWindowPos) {
+        s.setValue(QStringLiteral("windowX"), windowPos.x());
+        s.setValue(QStringLiteral("windowY"), windowPos.y());
+    }
+
+    s.setValue(QStringLiteral("mirrorBase"), mirrorBase);
+    s.setValue(QStringLiteral("proxyMode"), proxyMode);
+    s.setValue(QStringLiteral("proxyHost"), proxyHost);
+    s.setValue(QStringLiteral("proxyPort"), proxyPort);
+    s.setValue(QStringLiteral("proxyUser"), proxyUser);
+    s.setValue(QStringLiteral("proxyPass"), proxyPass);
+
+    s.setValue(QStringLiteral("chunkSec"), chunkSec);
+    s.setValue(QStringLiteral("threads"), threads);
+    s.endGroup();
+    s.sync();
+}
+
+} // namespace lc
diff --git a/src/ui/appsettings.h b/src/ui/appsettings.h
new file mode 100644
index 0000000..aa8b8f1
--- /dev/null
+++ b/src/ui/appsettings.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <QPoint>
+#include <QString>
+
+namespace lc {
+
+// 应用配置（QSettings）。GUI 完全靠它驱动，不再依赖命令行参数；
+// 命令行显式给出的值会覆盖这里的值（自动化测试用）。
+class AppSettings {
+public:
+    static AppSettings & instance();
+
+    // 模型
+    QString modelId;             // 当前使用的模型注册表 id
+    QString language;            // 识别语言提示；"" = 自动
+    bool    autoPickByLanguage = false;
+
+    // 显示
+    int  opacityPercent   = 84;
+    int  fontSize         = 15;
+    bool showUnstableTail = true;
+    int  collapsedLines   = 2;
+    int  expandedLines    = 8;
+
+    // 窗口
+    QPoint  windowPos;           // 空 = 默认（屏幕下方居中）
+    bool    hasWindowPos = false;
+
+    // 下载
+    QString mirrorBase = QStringLiteral("https://hf-mirror.com");
+    int     proxyMode  = 0;      // 0=不使用 1=跟随系统 2=手动
+    QString proxyHost;
+    int     proxyPort = 0;
+    QString proxyUser;
+    QString proxyPass;
+
+    // 高级
+    double chunkSec = 0.0;       // 0 = 由后端决定
+    int    threads  = 8;
+
+    void load();
+    void save();
+
+private:
+    AppSettings() = default;
+};
+
+} // namespace lc
diff --git a/src/ui/captionwindow.cpp b/src/ui/captionwindow.cpp
index 993cf8f..d27f0e7 100644
--- a/src/ui/captionwindow.cpp
+++ b/src/ui/captionwindow.cpp
@@ -127,9 +127,9 @@ void CaptionWindow::applyStyle()
         QTextEdit {
             color: #ffffff;
             background: transparent;
-            font-size: 15px;
+            font-size: %1px;
         }
-    )"));
+    )").arg(fontSize_));
 }
 
 void CaptionWindow::paintEvent(QPaintEvent *)
@@ -144,6 +144,28 @@ void CaptionWindow::paintEvent(QPaintEvent *)
     p.drawRoundedRect(rect(), kRadius, kRadius);
 }
 
+void CaptionWindow::setTextFontSize(int px)
+{
+    fontSize_ = qBound(9, px, 40);
+    applyStyle();
+    relayout();
+}
+
+void CaptionWindow::setLineCounts(int collapsed, int expanded)
+{
+    collapsedLines_ = qBound(1, collapsed, 6);
+    expandedLines_  = qBound(collapsedLines_, expanded, 40);
+    relayout();
+}
+
+void CaptionWindow::setShowTail(bool on)
+{
+    if (showTail_ == on) return;
+    showTail_ = on;
+    setCaption(QString(), QString());   // 强制重画需要外部再喂一次；这里先清空缓存
+    committed_.clear();
+}
+
 void CaptionWindow::setPanelOpacity(int percent)
 {
     const int clamped = qBound(20, percent, 100);
@@ -159,7 +181,7 @@ int CaptionWindow::lineHeight() const
 
 int CaptionWindow::textHeight() const
 {
-    return lineHeight() * (collapsed_ ? kCollapsedLines : kExpandedLines)
+    return lineHeight() * (collapsed_ ? collapsedLines_ : expandedLines_)
            + (int) text_->document()->documentMargin() * 2;
 }
 
@@ -206,8 +228,10 @@ void CaptionWindow::setCaption(const QString & committed, const QString & tail)
 
     // 已稳定部分正常色，不稳定尾部暗色 —— 和 CLI 版渲染一致
     const QString html =
-        QStringLiteral("<div>%1<span style=\"color:#9a9a9a\">%2</span></div>")
-            .arg(escapeHtml(committed_), escapeHtml(tail_));
+        showTail_
+            ? QStringLiteral("<div>%1<span style=\"color:#9a9a9a\">%2</span></div>")
+                  .arg(escapeHtml(committed_), escapeHtml(tail_))
+            : QStringLiteral("<div>%1</div>").arg(escapeHtml(committed_));
     text_->setHtml(html);
     scrollToEnd();
 }
@@ -231,6 +255,7 @@ void CaptionWindow::mouseMoveEvent(QMouseEvent * e)
 
 void CaptionWindow::mouseReleaseEvent(QMouseEvent * e)
 {
+    if (dragging_) Q_EMIT moved(pos());
     dragging_ = false;
     e->accept();
 }
diff --git a/src/ui/captionwindow.h b/src/ui/captionwindow.h
index 1cfe616..c5eee50 100644
--- a/src/ui/captionwindow.h
+++ b/src/ui/captionwindow.h
@@ -29,9 +29,14 @@ public:
     void setPanelOpacity(int percent);
     int  panelOpacity() const { return opacityPercent_; }
 
+    void setTextFontSize(int px);
+    void setLineCounts(int collapsed, int expanded);
+    void setShowTail(bool on);
+
 Q_SIGNALS:
     void languageClicked();
     void closed();
+    void moved(const QPoint & topLeft);
 
 protected:
     void mousePressEvent(QMouseEvent * e) override;
@@ -51,7 +56,11 @@ private:
     QPushButton * toggleBtn_  = nullptr;
     QTextEdit *   text_       = nullptr;
 
-    bool    collapsed_ = true;
+    bool    collapsed_   = true;
+    bool    showTail_    = true;
+    int     fontSize_    = 15;
+    int     collapsedLines_ = 2;
+    int     expandedLines_  = 8;
     int     opacityPercent_ = 84;   // 背景不透明度（百分比）
     bool    dragging_  = false;
     QPoint  dragOffset_;
diff --git a/src/ui/livetranscriber.cpp b/src/ui/livetranscriber.cpp
index 2f81f0d..76b7bed 100644
--- a/src/ui/livetranscriber.cpp
+++ b/src/ui/livetranscriber.cpp
@@ -4,10 +4,7 @@
 
 namespace lc {
 
-LiveTranscriber::LiveTranscriber(IAsr & asr, QObject * parent)
-    : QObject(parent), asr_(asr)
-{
-}
+LiveTranscriber::LiveTranscriber(QObject * parent) : QObject(parent) {}
 
 LiveTranscriber::~LiveTranscriber()
 {
@@ -19,14 +16,14 @@ QString LiveTranscriber::deviceName() const
     return pipeline_ ? QString::fromStdString(pipeline_->deviceName()) : QString();
 }
 
-bool LiveTranscriber::start(const StreamOptions & opts, QString * error)
+bool LiveTranscriber::start(IAsr & asr, const StreamOptions & opts, QString * error)
 {
     stop();
 
     LivePipelineOptions popt;
     popt.stream = opts;
 
-    pipeline_ = std::make_unique<LivePipeline>(asr_, popt);
+    pipeline_ = std::make_unique<LivePipeline>(asr, popt);
 
     // 回调在工作线程上被调用；连到主线程的接收者时 Qt 会自动排队投递。
     pipeline_->setCaptionCallback([this](const std::string & committed,
diff --git a/src/ui/livetranscriber.h b/src/ui/livetranscriber.h
index 2d3df1d..70398ca 100644
--- a/src/ui/livetranscriber.h
+++ b/src/ui/livetranscriber.h
@@ -18,10 +18,11 @@ class LiveTranscriber : public QObject {
     Q_OBJECT
 
 public:
-    explicit LiveTranscriber(IAsr & asr, QObject * parent = nullptr);
+    explicit LiveTranscriber(QObject * parent = nullptr);
     ~LiveTranscriber() override;
 
-    bool start(const StreamOptions & opts, QString * error = nullptr);
+    // 后端在 start 时注入：设置里换了模型就 stop() 再 start()
+    bool start(IAsr & asr, const StreamOptions & opts, QString * error = nullptr);
     void stop();
 
     QString deviceName() const;
@@ -32,7 +33,6 @@ Q_SIGNALS:
     void failed(const QString & message);
 
 private:
-    IAsr &                        asr_;
     std::unique_ptr<LivePipeline> pipeline_;
 };
 
diff --git a/src/ui/settingsdialog.cpp b/src/ui/settingsdialog.cpp
new file mode 100644
index 0000000..5cebc2c
--- /dev/null
+++ b/src/ui/settingsdialog.cpp
@@ -0,0 +1,422 @@
+#include "settingsdialog.h"
+
+#include <QCheckBox>
+#include <QComboBox>
+#include <QDesktopServices>
+#include <QDir>
+#include <QDoubleSpinBox>
+#include <QFileInfo>
+#include <QFormLayout>
+#include <QGroupBox>
+#include <QHeaderView>
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QLineEdit>
+#include <QMessageBox>
+#include <QNetworkProxy>
+#include <QProgressBar>
+#include <QPushButton>
+#include <QSlider>
+#include <QSpinBox>
+#include <QTabWidget>
+#include <QTableWidget>
+#include <QUrl>
+#include <QVBoxLayout>
+
+#include "appsettings.h"
+#include "modeldownloader.h"
+#include "modelstore.h"
+
+namespace lc {
+
+using models::ModelStore;
+using models::ModelInfo;
+using models::ModelDownloader;
+
+SettingsDialog::SettingsDialog(bool firstRun, QWidget * parent)
+    : QDialog(parent), downloader_(new ModelDownloader(this)), firstRun_(firstRun)
+{
+    setWindowTitle(firstRun ? tr("实时字幕 — 首次配置") : tr("实时字幕 — 设置"));
+    setMinimumSize(620, 520);
+
+    AppSettings & cfg = AppSettings::instance();
+
+    auto * tabs = new QTabWidget(this);
+    tabs->addTab(buildModelPage(), tr("模型"));
+    tabs->addTab(buildDisplayPage(), tr("显示"));
+    tabs->addTab(buildAdvancedPage(), tr("高级"));
+
+    auto * hint = new QLabel(this);
+    hint->setWordWrap(true);
+    hint->setText(firstRun ? tr("首次使用请先下载一个模型（中文/日文建议选流式模型，通用场景选 Qwen3-ASR）。")
+                           : QString());
+
+    auto * okBtn     = new QPushButton(tr("确定"), this);
+    auto * cancelBtn = new QPushButton(tr("取消"), this);
+    okBtn->setDefault(true);
+    connect(okBtn, &QPushButton::clicked, this, [this] {
+        if (ensureModelSelected()) onApply();
+    });
+    connect(cancelBtn, &QPushButton::clicked, this, &QDialog::reject);
+
+    auto * buttons = new QHBoxLayout;
+    buttons->addStretch(1);
+    buttons->addWidget(cancelBtn);
+    buttons->addWidget(okBtn);
+
+    auto * root = new QVBoxLayout(this);
+    root->addWidget(tabs, 1);
+    if (!hint->text().isEmpty()) root->addWidget(hint);
+    root->addLayout(buttons);
+    Q_UNUSED(cfg);
+
+    refreshModelTable();
+    refreshActiveCombo();
+}
+
+SettingsDialog::~SettingsDialog() = default;
+
+// ---------------------------------------------------------------------------
+QWidget * SettingsDialog::buildModelPage()
+{
+    auto * page = new QWidget(this);
+    auto * root = new QVBoxLayout(page);
+
+    table_ = new QTableWidget(page);
+    table_->setColumnCount(4);
+    table_->setHorizontalHeaderLabels({tr("模型"), tr("语言"), tr("许可"), tr("状态")});
+    table_->horizontalHeader()->setSectionResizeMode(0, QHeaderView::Stretch);
+    for (int c = 1; c < 4; ++c) {
+        table_->horizontalHeader()->setSectionResizeMode(c, QHeaderView::ResizeToContents);
+    }
+    table_->setSelectionBehavior(QAbstractItemView::SelectRows);
+    table_->setSelectionMode(QAbstractItemView::SingleSelection);
+    table_->setEditTriggers(QAbstractItemView::NoEditTriggers);
+    table_->verticalHeader()->setVisible(false);
+    root->addWidget(table_, 1);
+
+    auto * btnRow = new QHBoxLayout;
+    downloadBtn_ = new QPushButton(tr("下载"), page);
+    deleteBtn_   = new QPushButton(tr("删除"), page);
+    auto * openBtn = new QPushButton(tr("打开模型目录"), page);
+    btnRow->addWidget(downloadBtn_);
+    btnRow->addWidget(deleteBtn_);
+    btnRow->addWidget(openBtn);
+    btnRow->addStretch(1);
+    root->addLayout(btnRow);
+
+    connect(downloadBtn_, &QPushButton::clicked, this, &SettingsDialog::onDownload);
+    connect(deleteBtn_,   &QPushButton::clicked, this, &SettingsDialog::onDelete);
+    connect(openBtn,      &QPushButton::clicked, this, &SettingsDialog::onOpenDir);
+
+    progress_ = new QProgressBar(page);
+    progress_->setVisible(false);
+    statusLabel_ = new QLabel(page);
+    root->addWidget(progress_);
+    root->addWidget(statusLabel_);
+
+    auto * form = new QFormLayout;
+    activeCombo_ = new QComboBox(page);
+    form->addRow(tr("当前使用"), activeCombo_);
+
+    languageCombo_ = new QComboBox(page);
+    languageCombo_->addItem(tr("自动检测"), QString());
+    languageCombo_->addItem(tr("中文"), QStringLiteral("zh"));
+    languageCombo_->addItem(tr("英文"), QStringLiteral("en"));
+    languageCombo_->addItem(tr("日语"), QStringLiteral("ja"));
+    form->addRow(tr("识别语言"), languageCombo_);
+
+    mirrorEdit_ = new QLineEdit(page);
+    mirrorEdit_->setPlaceholderText(QStringLiteral("https://hf-mirror.com"));
+    form->addRow(tr("下载源"), mirrorEdit_);
+
+    proxyCombo_ = new QComboBox(page);
+    proxyCombo_->addItem(tr("不使用代理"), 0);
+    proxyCombo_->addItem(tr("跟随系统"), 1);
+    proxyCombo_->addItem(tr("手动设置"), 2);
+    proxyHost_ = new QLineEdit(page);
+    proxyHost_->setPlaceholderText(tr("主机"));
+    proxyPort_ = new QSpinBox(page);
+    proxyPort_->setRange(0, 65535);
+    proxyUser_ = new QLineEdit(page);
+    proxyUser_->setPlaceholderText(tr("用户名（可选）"));
+    proxyPass_ = new QLineEdit(page);
+    proxyPass_->setEchoMode(QLineEdit::Password);
+    proxyPass_->setPlaceholderText(tr("密码（可选）"));
+
+    auto * proxyRow = new QWidget(page);
+    auto * proxyLay = new QHBoxLayout(proxyRow);
+    proxyLay->setContentsMargins(0, 0, 0, 0);
+    proxyLay->addWidget(proxyCombo_);
+    proxyLay->addWidget(proxyHost_);
+    proxyLay->addWidget(proxyPort_);
+    form->addRow(tr("代理"), proxyRow);
+    form->addRow(QString(), proxyUser_);
+    form->addRow(QString(), proxyPass_);
+
+    root->addLayout(form);
+
+    const auto updateProxyEnabled = [this] {
+        const bool manual = proxyCombo_->currentData().toInt() == 2;
+        proxyHost_->setEnabled(manual);
+        proxyPort_->setEnabled(manual);
+        proxyUser_->setEnabled(manual);
+        proxyPass_->setEnabled(manual);
+    };
+    connect(proxyCombo_, &QComboBox::currentIndexChanged, this,
+            [updateProxyEnabled](int) { updateProxyEnabled(); });
+    updateProxyEnabled();
+
+    // 回填已保存的设置
+    AppSettings & cfg = AppSettings::instance();
+    mirrorEdit_->setText(cfg.mirrorBase);
+    proxyCombo_->setCurrentIndex(proxyCombo_->findData(cfg.proxyMode));
+    proxyHost_->setText(cfg.proxyHost);
+    proxyPort_->setValue(cfg.proxyPort);
+    proxyUser_->setText(cfg.proxyUser);
+    proxyPass_->setText(cfg.proxyPass);
+    updateProxyEnabled();
+    languageCombo_->setCurrentIndex(
+        qMax(0, languageCombo_->findData(cfg.language)));
+
+    connect(activeCombo_, &QComboBox::currentIndexChanged, this, [this](int idx) {
+        if (idx >= 0) {
+            AppSettings::instance().modelId = activeCombo_->itemData(idx).toString();
+            AppSettings::instance().save();
+        }
+    });
+
+    connect(downloader_, &ModelDownloader::status,  this, [this](const QString & m) {
+        statusLabel_->setText(m);
+    });
+    connect(downloader_, &ModelDownloader::progress, this,
+            [this](const QString &, qint64 got, qint64 total) {
+                progress_->setVisible(true);
+                if (total > 0) {
+                    progress_->setRange(0, 100);
+                    progress_->setValue((int) (got * 100 / total));
+                } else {
+                    progress_->setRange(0, 0);   // 未知总量
+                }
+            });
+    connect(downloader_, &ModelDownloader::finished, this,
+            [this](bool ok, const QString & err) {
+                progress_->setVisible(false);
+                downloadBtn_->setEnabled(true);
+                deleteBtn_->setEnabled(true);
+                refreshModelTable();
+                refreshActiveCombo();
+                if (!ok && !err.isEmpty()) statusLabel_->setText(err);
+            });
+    return page;
+}
+
+// ---------------------------------------------------------------------------
+QWidget * SettingsDialog::buildDisplayPage()
+{
+    auto * page = new QWidget(this);
+    auto * form = new QFormLayout(page);
+    AppSettings & cfg = AppSettings::instance();
+
+    fontSpin_ = new QSpinBox(page);
+    fontSpin_->setRange(9, 40);
+    fontSpin_->setValue(cfg.fontSize);
+    form->addRow(tr("字号"), fontSpin_);
+
+    showTailCheck_ = new QCheckBox(tr("用灰色显示尚未稳定的尾部"), page);
+    showTailCheck_->setChecked(cfg.showUnstableTail);
+    form->addRow(QString(), showTailCheck_);
+
+    collapsedSpin_ = new QSpinBox(page);
+    collapsedSpin_->setRange(1, 6);
+    collapsedSpin_->setValue(cfg.collapsedLines);
+    form->addRow(tr("折叠行数"), collapsedSpin_);
+
+    expandedSpin_ = new QSpinBox(page);
+    expandedSpin_->setRange(2, 30);
+    expandedSpin_->setValue(cfg.expandedLines);
+    form->addRow(tr("展开行数"), expandedSpin_);
+
+    opacitySlider_ = new QSlider(Qt::Horizontal, page);
+    opacitySlider_->setRange(20, 100);
+    opacitySlider_->setValue(cfg.opacityPercent);
+    opacityLabel_ = new QLabel(QStringLiteral("%1%").arg(cfg.opacityPercent), page);
+    auto * opRow = new QWidget(page);
+    auto * opLay = new QHBoxLayout(opRow);
+    opLay->setContentsMargins(0, 0, 0, 0);
+    opLay->addWidget(opacitySlider_, 1);
+    opLay->addWidget(opacityLabel_);
+    form->addRow(tr("背景不透明度"), opRow);
+    connect(opacitySlider_, &QSlider::valueChanged, this, [this](int v) {
+        opacityLabel_->setText(QStringLiteral("%1%").arg(v));
+    });
+
+    return page;
+}
+
+// ---------------------------------------------------------------------------
+QWidget * SettingsDialog::buildAdvancedPage()
+{
+    auto * page = new QWidget(this);
+    auto * form = new QFormLayout(page);
+    AppSettings & cfg = AppSettings::instance();
+
+    chunkSpin_ = new QDoubleSpinBox(page);
+    chunkSpin_->setRange(0.0, 5.0);
+    chunkSpin_->setSingleStep(0.1);
+    chunkSpin_->setDecimals(2);
+    chunkSpin_->setSpecialValueText(tr("自动"));
+    chunkSpin_->setValue(cfg.chunkSec);
+    form->addRow(tr("更新粒度（秒）"), chunkSpin_);
+
+    threadsSpin_ = new QSpinBox(page);
+    threadsSpin_->setRange(1, 32);
+    threadsSpin_->setValue(cfg.threads);
+    form->addRow(tr("线程数"), threadsSpin_);
+
+    auto * note = new QLabel(
+        tr("说明：流式模型（zipformer / X-ASR / Nemotron）会自动使用单线程，"
+           "因为这类模型多线程反而更慢；线程数只影响 Qwen3-ASR。"), page);
+    note->setWordWrap(true);
+    form->addRow(QString(), note);
+    return page;
+}
+
+// ---------------------------------------------------------------------------
+void SettingsDialog::refreshModelTable()
+{
+    const auto & reg = ModelStore::registry();
+    table_->setRowCount((int) reg.size());
+    for (int i = 0; i < (int) reg.size(); ++i) {
+        const ModelInfo & m = reg[i];
+        QStringList missing;
+        const bool installed = ModelStore::isInstalled(m, &missing);
+
+        QStringList langs = m.languages;
+        QString langText = langs.mid(0, 4).join(QStringLiteral(", "));
+        if (langs.size() > 4) langText += QStringLiteral(" …");
+        table_->setItem(i, 0, new QTableWidgetItem(m.name));
+        table_->setItem(i, 1, new QTableWidgetItem(langText));
+        table_->setItem(i, 2, new QTableWidgetItem(m.license));
+        table_->setItem(i, 3, new QTableWidgetItem(installed ? tr("已安装") : tr("未安装")));
+        table_->item(i, 0)->setData(Qt::UserRole, m.id);
+        if (installed) {
+            for (int c = 0; c < 4; ++c) table_->item(i, c)->setToolTip(m.note);
+        } else {
+            table_->item(i, 3)->setToolTip(tr("缺失: %1").arg(missing.join(QStringLiteral(", "))));
+        }
+    }
+}
+
+void SettingsDialog::refreshActiveCombo()
+{
+    const QString current = AppSettings::instance().modelId;
+    activeCombo_->blockSignals(true);
+    activeCombo_->clear();
+    for (const ModelInfo & m : ModelStore::registry()) {
+        if (ModelStore::isInstalled(m)) {
+            activeCombo_->addItem(m.name, m.id);
+        }
+    }
+    const int idx = activeCombo_->findData(current);
+    if (idx >= 0) activeCombo_->setCurrentIndex(idx);
+    activeCombo_->blockSignals(false);
+    if (idx >= 0) AppSettings::instance().modelId = activeCombo_->itemData(idx).toString();
+}
+
+void SettingsDialog::onDownload()
+{
+    const int row = table_->currentRow();
+    if (row < 0) { statusLabel_->setText(tr("请先在上面选一个模型")); return; }
+    const QString id = table_->item(row, 0)->data(Qt::UserRole).toString();
+    const ModelInfo * m = ModelStore::find(id);
+    if (!m) return;
+
+    downloader_->setMirrorBase(mirrorEdit_->text().trimmed());
+    QNetworkProxy proxy;
+    const int mode = proxyCombo_->currentData().toInt();
+    if (mode == 1) {
+        proxy = QNetworkProxy::applicationProxy();
+    } else if (mode == 2 && !proxyHost_->text().isEmpty()) {
+        proxy.setType(QNetworkProxy::HttpProxy);
+        proxy.setHostName(proxyHost_->text().trimmed());
+        proxy.setPort((quint16) proxyPort_->value());
+        if (!proxyUser_->text().isEmpty()) {
+            proxy.setUser(proxyUser_->text());
+            proxy.setPassword(proxyPass_->text());
+        }
+    }
+    downloader_->setProxy(proxy);
+
+    downloadBtn_->setEnabled(false);
+    deleteBtn_->setEnabled(false);
+    progress_->setVisible(true);
+    progress_->setRange(0, 0);
+    statusLabel_->setText(tr("开始下载…"));
+    downloader_->start(*m);
+}
+
+void SettingsDialog::onDelete()
+{
+    const int row = table_->currentRow();
+    if (row < 0) return;
+    const QString id = table_->item(row, 0)->data(Qt::UserRole).toString();
+    if (QMessageBox::question(this, tr("删除模型"),
+                              tr("确定要删除「%1」已下载的文件吗？").arg(id))
+        != QMessageBox::Yes) {
+        return;
+    }
+    QDir(ModelStore::dirFor(id)).removeRecursively();
+    if (AppSettings::instance().modelId == id) AppSettings::instance().modelId.clear();
+    refreshModelTable();
+    refreshActiveCombo();
+}
+
+void SettingsDialog::onOpenDir()
+{
+    QDir().mkpath(ModelStore::root());
+    QDesktopServices::openUrl(QUrl::fromLocalFile(ModelStore::root()));
+}
+
+bool SettingsDialog::ensureModelSelected()
+{
+    AppSettings & cfg = AppSettings::instance();
+    if (cfg.modelId.isEmpty() || !ModelStore::find(cfg.modelId) ||
+        !ModelStore::isInstalled(*ModelStore::find(cfg.modelId))) {
+        QMessageBox::warning(this, tr("还没有可用模型"),
+                             tr("请先在「模型」页下载一个模型，然后在「当前使用」里选中它。"));
+        return false;
+    }
+    return true;
+}
+
+void SettingsDialog::onApply()
+{
+    AppSettings & cfg = AppSettings::instance();
+    cfg.mirrorBase = mirrorEdit_->text().trimmed();
+    if (cfg.mirrorBase.isEmpty()) cfg.mirrorBase = QStringLiteral("https://hf-mirror.com");
+    cfg.proxyMode = proxyCombo_->currentData().toInt();
+    cfg.proxyHost = proxyHost_->text().trimmed();
+    cfg.proxyPort = proxyPort_->value();
+    cfg.proxyUser = proxyUser_->text();
+    cfg.proxyPass = proxyPass_->text();
+    cfg.language  = languageCombo_->currentData().toString();
+
+    cfg.fontSize         = fontSpin_->value();
+    cfg.showUnstableTail = showTailCheck_->isChecked();
+    cfg.collapsedLines   = collapsedSpin_->value();
+    cfg.expandedLines    = expandedSpin_->value();
+    cfg.opacityPercent   = opacitySlider_->value();
+
+    cfg.chunkSec = chunkSpin_->value();
+    cfg.threads  = threadsSpin_->value();
+
+    if (activeCombo_->currentIndex() >= 0) {
+        cfg.modelId = activeCombo_->currentData().toString();
+    }
+    cfg.save();
+    Q_EMIT settingsApplied();
+    accept();
+}
+
+} // namespace lc
diff --git a/src/ui/settingsdialog.h b/src/ui/settingsdialog.h
new file mode 100644
index 0000000..fcbec7f
--- /dev/null
+++ b/src/ui/settingsdialog.h
@@ -0,0 +1,75 @@
+#pragma once
+
+#include <QDialog>
+
+class QComboBox;
+class QCheckBox;
+class QDoubleSpinBox;
+class QLabel;
+class QLineEdit;
+class QProgressBar;
+class QPushButton;
+class QSlider;
+class QSpinBox;
+class QTableWidget;
+
+namespace lc {
+
+namespace models { class ModelDownloader; }
+
+// 设置对话框：模型管理（下载/删除/选择）、显示、窗口、下载源与代理、高级。
+// GUI 用户完全靠它驱动，不再需要命令行参数。
+class SettingsDialog : public QDialog {
+    Q_OBJECT
+
+public:
+    explicit SettingsDialog(bool firstRun, QWidget * parent = nullptr);
+    ~SettingsDialog() override;
+
+Q_SIGNALS:
+    // 设置已变更且用户点了确定
+    void settingsApplied();
+
+private:
+    QWidget * buildModelPage();
+    QWidget * buildDisplayPage();
+    QWidget * buildAdvancedPage();
+
+    void refreshModelTable();
+    void refreshActiveCombo();
+    void onDownload();
+    void onDelete();
+    void onOpenDir();
+    void onApply();
+    bool ensureModelSelected();
+
+    QTableWidget * table_      = nullptr;
+    QComboBox *    activeCombo_ = nullptr;
+    QComboBox *    languageCombo_ = nullptr;
+    QPushButton *  downloadBtn_ = nullptr;
+    QPushButton *  deleteBtn_   = nullptr;
+    QProgressBar * progress_    = nullptr;
+    QLabel *       statusLabel_ = nullptr;
+
+    QLineEdit * mirrorEdit_ = nullptr;
+    QComboBox * proxyCombo_ = nullptr;
+    QLineEdit * proxyHost_  = nullptr;
+    QSpinBox *  proxyPort_  = nullptr;
+    QLineEdit * proxyUser_  = nullptr;
+    QLineEdit * proxyPass_  = nullptr;
+
+    QSpinBox *  fontSpin_      = nullptr;
+    QCheckBox * showTailCheck_ = nullptr;
+    QSpinBox *  collapsedSpin_ = nullptr;
+    QSpinBox *  expandedSpin_  = nullptr;
+    QSlider *   opacitySlider_ = nullptr;
+    QLabel *    opacityLabel_  = nullptr;
+
+    QDoubleSpinBox * chunkSpin_   = nullptr;
+    QSpinBox *       threadsSpin_ = nullptr;
+
+    models::ModelDownloader * downloader_ = nullptr;
+    bool              firstRun_   = false;
+};
+
+} // namespace lc