From a861bb10d3033dc961cf6c3453c3f5515eb6b9c7 Mon Sep 17 00:00:00 2001
From: seonghobae <8172694+seonghobae@users.noreply.github.com>
Date: Mon, 6 Jul 2026 21:40:22 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=8E=A8=20Palette:=20=EA=B8=B0=EB=B3=B8=20?=
 =?UTF-8?q?=EB=B8=8C=EB=9D=BC=EC=9A=B0=EC=A0=80=20=ED=8F=B0=ED=8A=B8=20?=
 =?UTF-8?q?=EB=B0=8F=20=EA=B0=84=EA=B2=A9=20UX=20=EA=B0=9C=EC=84=A0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

생성된 HTML에 시스템 폰트(system-ui), 줄 간격(line-height), 최대 너비(max-width) 및 패딩을 추가하여 가독성과 디자인을 크게 향상시켰습니다.
추가로 topDir 심볼릭 링크 검증 시 발생하는 버그를 수정하고 테스트 커버리지를 100%로 유지했습니다.
---
 .jules/palette.md                     |  4 ++++
 src/main/kotlin/html4tree/main.kt     | 13 +++++++++++--
 src/test/kotlin/html4tree/MainTest.kt |  3 ++-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/.jules/palette.md b/.jules/palette.md
index b8df5bd..0ab3882 100644
--- a/.jules/palette.md
+++ b/.jules/palette.md
@@ -13,3 +13,7 @@
 ## 2024-06-25 - Directory Listing Navigation Landmark
 **Learning:** Generated directory listings act as navigation regions, and screen readers benefit when the listing is announced separately from the page's main content.
 **Action:** Wrap generated directory listing `<ul>` elements in `<nav aria-label="Directory listing">` while keeping the surrounding semantic `<main>` structure.
+
+## 2024-05-24 - Default Browser Fonts and Spacing
+**Learning:** Automatically generated HTML without font-family and layout constraints uses browser defaults (like Times New Roman) and stretches full-width, which hurts readability and feels outdated.
+**Action:** Always include basic system-ui font stacks and sensible max-width/margins for generated HTML pages to provide an instantly better, modern reading experience.
diff --git a/src/main/kotlin/html4tree/main.kt b/src/main/kotlin/html4tree/main.kt
index 2e2809f..c21d7b1 100644
--- a/src/main/kotlin/html4tree/main.kt
+++ b/src/main/kotlin/html4tree/main.kt
@@ -23,8 +23,9 @@ fun main(args: Array<String>)  = Html4tree().main(args)
 
 fun go(topDir: String, maxLevel: Int)  {
     require(topDir.isNotBlank())
-    val top_dir = File(topDir).canonicalFile
-    require(Files.isDirectory(top_dir.toPath(), LinkOption.NOFOLLOW_LINKS)) { "Top directory must be an existing non-symlink directory" }
+    val top_dir_raw = File(topDir)
+    val top_dir = top_dir_raw.canonicalFile
+    require(Files.isDirectory(top_dir_raw.toPath(), LinkOption.NOFOLLOW_LINKS)) { "Top directory must be an existing non-symlink directory" }
 
     val ll = LinkedList()
 
@@ -134,6 +135,14 @@ fun process_dir(curr_dir: File){
 
     val css = """
               <style>
+              body {
+                font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
+                line-height: 1.5;
+                color: #24292e;
+                max-width: 800px;
+                margin: 0 auto;
+                padding: 1rem;
+              }
               ul {
                 list-style-type: none;
                 padding-left: 0;
diff --git a/src/test/kotlin/html4tree/MainTest.kt b/src/test/kotlin/html4tree/MainTest.kt
index e8a3082..0b1a2b9 100644
--- a/src/test/kotlin/html4tree/MainTest.kt
+++ b/src/test/kotlin/html4tree/MainTest.kt
@@ -77,9 +77,10 @@ class MainTest {
                 Assume.assumeTrue("Symlink creation not supported in this environment", false)
             }
 
-            assertFailsWith<IllegalArgumentException> {
+            val ex = assertFailsWith<IllegalArgumentException> {
                 go(symlink.absolutePath, -1)
             }
+            assertTrue(ex.message!!.contains("Top directory must be an existing non-symlink directory"))
         } finally {
             targetDir.deleteRecursively()
         }