Clean up "file-view" related styles (#34558)

Move "file-view" and "code-view" related styles to their own file,
remove unnecessary `!important`

Author: wxiaoguang

web_src/css/base.css

@@ -815,10 +815,6 @@ overflow-menu .ui.label {
   display: block;
 }
 
-.code-view .lines-num span::after {
-  cursor: pointer;
-}
-
 .lines-type-marker {
   vertical-align: top;
   white-space: nowrap;
@@ -855,39 +851,13 @@ overflow-menu .ui.label {
 .lines-escape {
   width: 0;
   white-space: nowrap;
+  padding: 0;
 }
 
 .lines-code {
   padding-left: 5px;
 }
 
-.file-view tr.active {
-  color: inherit !important;
-  background: inherit !important;
-}
-
-.file-view tr.active .lines-num,
-.file-view tr.active .lines-code {
-  background: var(--color-highlight-bg) !important;
-}
-
-.file-view tr.active:last-of-type .lines-code {
-  border-bottom-right-radius: var(--border-radius);
-}
-
-.file-view tr.active .lines-num {
-  position: relative;
-}
-
-.file-view tr.active .lines-num::before {
-  content: "";
-  position: absolute;
-  left: 0;
-  width: 2px;
-  height: 100%;
-  background: var(--color-highlight-fg);
-}
-
 .code-inner {
   font: 12px var(--fonts-monospace);
   white-space: pre-wrap;
@@ -938,28 +908,19 @@ overflow-menu .ui.label {
   margin-right: 4px;
 }
 
-.top-line-blame {
+tr.top-line-blame {
   border-top: 1px solid var(--color-secondary);
 }
 
-.code-view tr.top-line-blame:first-of-type {
-  border-top: none;
+tr.top-line-blame:first-of-type {
+  border-top: none; /* merge code lines belonging to the same commit into one block */
 }
 
 .lines-code .bottom-line,
 .lines-commit .bottom-line {
   border-bottom: 1px solid var(--color-secondary);
 }
 
-.code-view {
-  background: var(--color-code-bg);
-  border-radius: var(--border-radius);
-}
-
-.code-view table {
-  width: 100%;
-}
-
 .migrate .svg.gitea-git {
   color: var(--color-git);
 }

web_src/css/index.css

@@ -62,7 +62,7 @@
 @import "./repo/issue-label.css";
 @import "./repo/issue-list.css";
 @import "./repo/list-header.css";
-@import "./repo/linebutton.css";
+@import "./repo/file-view.css";
 @import "./repo/wiki.css";
 @import "./repo/header.css";
 @import "./repo/home.css";

web_src/css/markup/content.css

@@ -309,10 +309,18 @@
   box-sizing: initial;
 }
 
+.file-view.markup {
+  padding: 1em 2em;
+}
+
+.file-view.markup:has(.file-not-rendered-prompt) {
+  padding: 0; /* let the file-not-rendered-prompt layout itself */
+}
+
 /* this background ensures images can break <hr>. We can only do this on
    cases where the background is known and not transparent. */
-.markup.file-view img,
-.markup.file-view video,
+.file-view.markup img,
+.file-view.markup video,
 .comment-body .markup img, /* regular comment */
 .comment-body .markup video,
 .comment-content .markup img, /* code comment */

web_src/css/repo.css

@@ -1238,21 +1238,6 @@ td .commit-summary {
   white-space: nowrap;
 }
 
-.file-view.markup {
-  padding: 1em 2em;
-}
-
-.file-view.markup:has(.file-not-rendered-prompt) {
-  padding: 0; /* let the file-not-rendered-prompt layout itself */
-}
-
-.file-not-rendered-prompt {
-  padding: 1rem;
-  text-align: center;
-  font-size: 1rem !important; /* use consistent styles for various containers (code, markup, etc) */
-  line-height: var(--line-height-default) !important; /* same as above */
-}
-
 .repository .activity-header {
   display: flex;
   justify-content: space-between;

web_src/css/repo/file-view.css

@@ -0,0 +1,58 @@
+.file-view tr.active {
+  background: var(--color-highlight-bg);
+}
+
+.file-view tr.active:last-of-type .lines-code {
+  border-bottom-right-radius: var(--border-radius);
+}
+
+.file-view tr.active .lines-num {
+  position: relative;
+}
+
+.file-view tr.active .lines-num::before {
+  content: "";
+  position: absolute;
+  left: 0;
+  width: 2px;
+  height: 100%;
+  background: var(--color-highlight-fg);
+}
+
+.file-view .file-not-rendered-prompt {
+  padding: 1rem;
+  text-align: center;
+  font-size: 1rem !important; /* use consistent styles for various containers (code, markup, etc) */
+  line-height: var(--line-height-default) !important; /* same as above */
+}
+
+/* ".code-view" is always used with ".file-view", to show the code of a file */
+.file-view.code-view {
+  background: var(--color-code-bg);
+  border-radius: var(--border-radius);
+}
+
+.file-view.code-view table {
+  width: 100%;
+}
+
+.file-view.code-view .lines-num span::after {
+  cursor: pointer;
+}
+
+.file-view.code-view .lines-num:hover {
+  color: var(--color-text-dark);
+}
+
+.file-view.code-view .ui.button.code-line-button {
+  border: 1px solid var(--color-secondary);
+  padding: 1px 4px;
+  margin: 0;
+  min-height: 0;
+  position: absolute;
+  left: 6px;
+}
+
+.file-view.code-view .ui.button.code-line-button:hover {
+  background: var(--color-secondary);
+}