Revamp repo header (#27760)

Redesign repo header with following new aspects:
- responsive & better-looking repo title
- hide repo button text instead of icons in mobile view
- use same tab style as on explore and org page

<details>
<summary>Before:</summary>


![grafik](https://github.com/go-gitea/gitea/assets/47871822/57360b77-d43c-49ac-b798-2363c03da7ec)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/d4117f79-a5f5-4f36-bf65-bbada3e7e73b)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/e26f967f-e264-4337-9925-3d942e04fd6d)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/b4683c8d-9c6a-4089-afa7-8dd219e43a46)


</details>

<details>
<summary>After:</summary>


![grafik](https://github.com/go-gitea/gitea/assets/47871822/8ddbc9f6-53c7-4e4e-bea9-704fd93524ca)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/c0588aa9-788d-469c-98a0-81484fbd220c)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/206e931e-404d-4d1b-92ce-908698addfcc)

![grafik](https://github.com/go-gitea/gitea/assets/47871822/a508f9c8-fadc-4a85-94ba-18796f77e07b)

4 files changed, 102 insertions, 110 deletions

diff --git a/web_src/css/base.css b/web_src/css/base.css
index ae8eb05709..6f84f5e1d8 100644
--- a/web_src/css/base.css
+++ b/web_src/css/base.css
@@ -1358,23 +1358,6 @@ img.ui.avatar,
   padding-right: 4.5px;
 }
 
-.repo-title {
-  font-size: 1.5rem;
-  display: flex;
-  align-items: center;
-  flex: 1;
-  word-break: break-all;
-  color: var(--color-text-light);
-}
-
-.repo-title .labels {
-  margin-left: 0.5rem;
-}
-
-.repo-title .labels > * + * {
-  margin-left: 0.5rem;
-}
-
 .activity-bar-graph {
   background-color: var(--color-primary);
   color: var(--color-primary-contrast);
diff --git a/web_src/css/index.css b/web_src/css/index.css
index c1360bb194..f893531b78 100644
--- a/web_src/css/index.css
+++ b/web_src/css/index.css
@@ -47,6 +47,7 @@
 @import "./repo/list-header.css";
 @import "./repo/linebutton.css";
 @import "./repo/wiki.css";
+@import "./repo/header.css";
 
 @import "./editor/fileeditor.css";
 @import "./editor/combomarkdowneditor.css";
diff --git a/web_src/css/repo.css b/web_src/css/repo.css
index 6b6be99f74..f1356fc39b 100644
--- a/web_src/css/repo.css
+++ b/web_src/css/repo.css
@@ -4,23 +4,6 @@
   user-select: none;
 }
 
-.repository .repo-header .ui.compact.menu {
-  margin-left: 1rem;
-}
-
-.repository .repo-header .ui.header {
-  margin-top: 0;
-}
-
-.repository .repo-header .fork-flag {
-  font-size: 12px;
-  margin-top: 2px;
-}
-
-.repository .tabs .navbar {
-  justify-content: initial;
-}
-
 .repository .navbar {
   display: flex;
   justify-content: space-between;
@@ -106,14 +89,6 @@
   white-space: nowrap;
 }
 
-.repository .header-wrapper {
-  background-color: var(--color-header-wrapper);
-}
-
-.repository .header-wrapper .ui.tabular .svg {
-  margin-right: 5px;
-}
-
 .repository .filter.menu.labels .label-filter .menu .info {
   display: inline-block;
   padding: 0.5rem 0;
@@ -2593,74 +2568,6 @@ tbody.commit-list {
   overflow: hidden;
 }
 
-.repo-header {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  flex-wrap: wrap;
-  word-break: break-word;
-  gap: 0.5rem;
-}
-
-@media (max-width: 767.98px) {
-  .repo-header + .container {
-    margin-top: 7px;
-  }
-}
-
-.repo-buttons {
-  align-items: center;
-  display: flex;
-  flex-direction: row;
-  flex-wrap: wrap;
-  word-break: keep-all;
-  gap: 0.25em;
-}
-
-@media (max-width: 767.98px) {
-  .repo-buttons {
-    margin-top: 1em;
-  }
-}
-
-.repo-buttons .ui.labeled.button > .label:hover {
-  color: var(--color-primary-light-2);
-  background: var(--color-light);
-}
-
-.repo-buttons button[disabled] ~ .label {
-  opacity: var(--opacity-disabled);
-  color: var(--color-text-dark);
-  background: var(--color-light-mimic-enabled) !important;
-}
-
-.repo-buttons button[disabled] ~ .label:hover {
-  color: var(--color-primary-dark-1);
-}
-
-.repo-buttons .ui.labeled.button.disabled {
-  pointer-events: inherit !important;
-}
-
-.repo-buttons .ui.labeled.button.disabled > .label {
-  color: var(--color-text-dark);
-  background: var(--color-light-mimic-enabled) !important;
-}
-
-.repo-buttons .ui.labeled.button.disabled > .label:hover {
-  color: var(--color-primary-dark-1);
-}
-
-.repo-buttons .ui.labeled.button.disabled > .button {
-  pointer-events: none !important;
-}
-
-@media (max-width: 767.98px) {
-  .repo-buttons .ui.labeled.button .svg {
-    display: none;
-  }
-}
-
 .tag-code {
   height: 28px;
 }
diff --git a/web_src/css/repo/header.css b/web_src/css/repo/header.css
new file mode 100644
index 0000000000..d5c7d212e8
--- /dev/null
+++ b/web_src/css/repo/header.css
@@ -0,0 +1,101 @@
+.fork-flag {
+  margin-top: 0.5rem;
+  font-size: 12px;
+}
+
+.repo-header {
+  display: flex;
+  flex-flow: row wrap;
+  justify-content: space-between;
+  gap: 0.5rem;
+}
+
+.repo-header .flex-item {
+  padding: 0;
+}
+
+.repo-header .btn.interact-bg:hover {
+  text-decoration: none;
+}
+
+.repo-header .flex-item-main {
+  flex-basis: unset;
+}
+
+.repo-header .flex-item-trailing {
+  flex-wrap: nowrap;
+}
+
+.repo-header .flex-item-trailing .repo-icon {
+  display: none;
+}
+
+.repo-buttons {
+  align-items: center;
+  display: flex;
+  flex-flow: row wrap;
+  word-break: keep-all;
+  gap: 0.25em;
+}
+
+.repo-buttons .ui.labeled.button > .label:hover {
+  color: var(--color-primary-light-2);
+  background: var(--color-light);
+}
+
+.repo-buttons button[disabled] ~ .label {
+  opacity: var(--opacity-disabled);
+  color: var(--color-text-dark);
+  background: var(--color-light-mimic-enabled) !important;
+}
+
+.repo-buttons button[disabled] ~ .label:hover {
+  color: var(--color-primary-dark-1);
+}
+
+.repo-buttons .ui.labeled.button.disabled {
+  pointer-events: inherit !important;
+}
+
+.repo-buttons .ui.labeled.button.disabled > .label {
+  color: var(--color-text-dark);
+  background: var(--color-light-mimic-enabled) !important;
+}
+
+.repo-buttons .ui.labeled.button.disabled > .label:hover {
+  color: var(--color-primary-dark-1);
+}
+
+.repo-buttons .ui.labeled.button.disabled > .button {
+  pointer-events: none !important;
+}
+
+.repository .header-wrapper {
+  background-color: var(--color-header-wrapper);
+}
+
+.repository .header-wrapper .new-menu {
+  padding-top: 0 !important;
+  margin-top: 0 !important;
+  margin-bottom: 0 !important;
+}
+
+.repository .header-wrapper .new-menu .item {
+  margin-left: 0 !important;
+  margin-right: 0 !important;
+}
+
+@media (max-width: 767.98px) {
+  .repo-header .flex-item {
+    flex-grow: 1;
+  }
+  .repo-buttons .ui.labeled.button .text {
+    display: none;
+  }
+  .repo-header .flex-item-trailing .label {
+    display: none;
+  }
+  .repo-header .flex-item-trailing .repo-icon {
+    display: initial;
+  }
+}