Fix UI on mobile view (#25315)

Various fixes to pages or elements which were looking ugly on mobile.
<details>
<summary>Screenshots</summary>

![Bildschirmfoto vom 2023-06-17
20-38-41](https://github.com/go-gitea/gitea/assets/47871822/30b5d3ce-df3b-43eb-a4c2-c3790667fb9d)
![Bildschirmfoto vom 2023-06-17
20-39-27](https://github.com/go-gitea/gitea/assets/47871822/27c07b25-3602-4fb2-b34d-d5e875e054e9)
![Bildschirmfoto vom 2023-06-17
20-41-27](https://github.com/go-gitea/gitea/assets/47871822/dacdbb4e-e3dd-4b94-abf0-c68e3d64bd3b)
![Bildschirmfoto vom 2023-06-17
20-41-48](https://github.com/go-gitea/gitea/assets/47871822/72432c35-7c4a-4c7f-a767-3562f26a5c14)
![Bildschirmfoto vom 2023-06-17
20-42-37](https://github.com/go-gitea/gitea/assets/47871822/737c26ed-1910-4467-98ef-e8769bbbe6f0)
![Bildschirmfoto vom 2023-06-17
20-42-52](https://github.com/go-gitea/gitea/assets/47871822/1813b4bc-43c0-4912-8acb-5d799c090bf3)
![Bildschirmfoto vom 2023-06-17
20-43-06](https://github.com/go-gitea/gitea/assets/47871822/136466e8-34e5-419d-97ec-5202ff819fd2)
![Bildschirmfoto vom 2023-06-17
20-43-42](https://github.com/go-gitea/gitea/assets/47871822/59270bb2-d661-4a84-8504-3e50f771f767)
![Bildschirmfoto vom 2023-06-17
20-44-44](https://github.com/go-gitea/gitea/assets/47871822/494e274d-3771-4141-9419-0a4bbd8b7f64)

</details>

Co-authored by @silverwind

---------

Co-authored-by: silverwind <me@silverwind.io>

1 files changed, 66 insertions, 0 deletions

diff --git a/web_src/css/shared/milestone.css b/web_src/css/shared/milestone.css
new file mode 100644
index 0000000000..511a1be714
--- /dev/null
+++ b/web_src/css/shared/milestone.css
@@ -0,0 +1,66 @@
+.milestone-list {
+  list-style: none;
+}
+
+.milestone-card {
+  width: 100%;
+  padding-top: 10px;
+  padding-bottom: 10px;
+}
+
+.milestone-card + .milestone-card {
+  border-top: 1px solid var(--color-secondary);
+}
+
+.milestone-card .content {
+  padding-top: 10px;
+}
+
+.milestone-header progress {
+  width: 200px;
+  height: 16px;
+}
+
+.milestone-header {
+  display: flex;
+  align-items: center;
+  margin: 0;
+  flex-wrap: wrap;
+  justify-content: space-between;
+}
+
+.milestone-toolbar {
+  padding-top: 5px;
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  justify-content: space-between;
+}
+
+.milestone-toolbar .group {
+  color: var(--color-text-light-2);
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+}
+
+.milestone-toolbar .group .overdue {
+  color: var(--color-red);
+}
+
+.milestone-toolbar .group > a {
+  font-size: 15px;
+  color: var(--color-text-light-2);
+}
+
+.milestone-toolbar .group > a:hover {
+  color: var(--color-text);
+}
+
+@media (max-width: 767.98px) {
+  .milestone-card {
+    display: flex;
+    flex-direction: column;
+    gap: 8px;
+  }
+}