Introduce `flex-list` & `flex-item` elements for Gitea UI (#25790)

This PR introduces a new UI element type for Gitea called `flex-item`.
It consists of a horizontal card with a leading, main and trailing part:


![grafik](https://github.com/go-gitea/gitea/assets/47871822/395dd3f3-3906-4481-8f65-be6ac0acbe03)

The idea behind it is that in Gitea UI, we have many cases where we use
this kind of layout, but it is achieved in many different ways:
  - grid layout
  - `.ui.list` with additional hacky flexbox
- `.ui.key.list` - looks to me like a style set originally created for
ssh/gpg key list, was used in many other places
  - `.issue.list` - created for issue cards, used in many other places
  - ...

This new style is based on `.issue.list`, specifically the refactoring
of it done in #25750.

In this PR, the new element is introduced and lots of templates are
being refactored to use that style. This allows to remove a lot of
page-specific css, makes many of the elements responsive or simply
provides a cleaner/better-looking way to present information.

A devtest section with the new style is also available.

<details>
<summary>Screenshots (left: before, right: after)</summary>

![Bildschirmfoto vom 2023-07-09
21-01-21](https://github.com/go-gitea/gitea/assets/47871822/545b7da5-b300-475f-bd6d-b7d836950bb5)
![Bildschirmfoto vom 2023-07-09
21-01-56](https://github.com/go-gitea/gitea/assets/47871822/b6f70415-6795-4f71-a5ea-117d56107ea1)
![Bildschirmfoto vom 2023-07-09
21-02-45](https://github.com/go-gitea/gitea/assets/47871822/47407121-3f2a-4778-8f6d-ad2687c2e7b3)
![Bildschirmfoto vom 2023-07-09
21-03-44](https://github.com/go-gitea/gitea/assets/47871822/76167aaf-c3b2-46f6-9ffd-709f20aa6a34)
![Bildschirmfoto vom 2023-07-09
21-04-52](https://github.com/go-gitea/gitea/assets/47871822/af8fdde5-711e-4524-99cf-fb5d68af85b9)
![Bildschirmfoto vom 2023-07-09
21-05-25](https://github.com/go-gitea/gitea/assets/47871822/ae406946-e3e4-4109-abfe-b3588a07b468)
![Bildschirmfoto vom 2023-07-09
21-06-35](https://github.com/go-gitea/gitea/assets/47871822/2dbacc04-24d6-4f91-9e42-e16d6e4b5f1f)
![Bildschirmfoto vom 2023-07-09
21-09-03](https://github.com/go-gitea/gitea/assets/47871822/d3ca4e56-a72f-4179-adc8-98bfd638025b)
![Bildschirmfoto vom 2023-07-09
21-09-44](https://github.com/go-gitea/gitea/assets/47871822/df1fa689-499c-4e54-b6fb-3b81644b725f)
![Bildschirmfoto vom 2023-07-09
21-10-27](https://github.com/go-gitea/gitea/assets/47871822/b21cac71-a85a-4c8c-bb99-ab90373d8e09)
![Bildschirmfoto vom 2023-07-09
21-11-12](https://github.com/go-gitea/gitea/assets/47871822/89be39cf-0af9-4f2d-9fca-42f9eb5e7824)
![Bildschirmfoto vom 2023-07-09
21-12-01](https://github.com/go-gitea/gitea/assets/47871822/079579ea-1ecb-49c0-b32b-b59ed957caec)
![Bildschirmfoto vom 2023-07-09
21-17-44](https://github.com/go-gitea/gitea/assets/47871822/61ac6ec4-a319-4d5c-9c99-2e02a77295ba)
![Bildschirmfoto vom 2023-07-09
21-18-27](https://github.com/go-gitea/gitea/assets/47871822/5b55b73f-6244-47f7-a3e6-c5e4a7474585)
![Bildschirmfoto vom 2023-07-09
21-19-18](https://github.com/go-gitea/gitea/assets/47871822/c1b7c22e-3e5a-46d4-b8d6-5560db478c0b)
![Bildschirmfoto vom 2023-07-09
21-29-13](https://github.com/go-gitea/gitea/assets/47871822/82ffca8d-ab2e-4a18-9954-5b685bf6a422)
![Bildschirmfoto vom 2023-07-09
21-30-11](https://github.com/go-gitea/gitea/assets/47871822/ad2fdccc-2be8-41bb-bfdc-a084aa387b61)
![Bildschirmfoto vom 2023-07-09
21-32-44](https://github.com/go-gitea/gitea/assets/47871822/2d298ba7-d084-48b5-a139-f86d56262110)
![Bildschirmfoto vom 2023-07-09
21-33-28](https://github.com/go-gitea/gitea/assets/47871822/4cbd838e-9de8-4ad0-8ed9-438da5c9a5cb)


</details>

---------

Co-authored-by: Giteabot <teabot@gitea.io>

10 files changed, 145 insertions, 308 deletions

diff --git a/web_src/css/actions.css b/web_src/css/actions.css
index 31da79cabf..f081698c66 100644
--- a/web_src/css/actions.css
+++ b/web_src/css/actions.css
@@ -52,3 +52,18 @@
   background-color: var(--color-yellow);
   color: var(--color-white);
 }
+
+.run-list-item-right {
+  flex: 0 0 15%;
+  display: flex;
+  flex-direction: column;
+  gap: 3px;
+  color: var(--color-text-light);
+}
+
+.run-list-item-right .run-list-meta {
+  display: flex;
+  flex-wrap: nowrap;
+  gap: .25rem;
+  align-items: center;
+}
diff --git a/web_src/css/dashboard.css b/web_src/css/dashboard.css
index 34428c5999..1eb480845b 100644
--- a/web_src/css/dashboard.css
+++ b/web_src/css/dashboard.css
@@ -96,61 +96,13 @@
   }
 }
 
-.feeds .news li {
-  display: flex;
-  align-items: baseline;
-  margin-top: 0.5rem;
-  margin-bottom: 0.5rem;
-}
-
-.feeds .news li img {
-  align-self: flex-start;
-}
-
-.feeds .news li > * + * {
-  margin-left: 0.35rem;
-}
-
-.feeds .news > .ui.grid {
-  margin-left: auto;
-  margin-right: auto;
-}
-
-.feeds .news .left .ui.avatar {
-  margin-top: 13px;
-}
-
-.feeds .news .time-since {
-  font-size: 13px;
-}
-
-.feeds .news .issue.title {
-  width: 80%;
-  margin: 0 0 1em;
-}
-
-.feeds .news .push.news .content ul {
-  line-height: 18px;
-  font-size: 13px;
-  list-style: none;
-  padding-left: 10px;
-}
-
-.feeds .news .push.news .content ul .text.truncate {
-  width: 80%;
-}
-
-.feeds .news .commit-id {
+.feeds .commit-id {
   font-family: var(--fonts-monospace);
 }
 
-.feeds .news code {
+.feeds code {
   padding: 2px 4px;
   border-radius: 3px;
   background-color: var(--color-markup-code-block);
   word-break: break-all;
 }
-
-.feeds .news:last-of-type .divider {
-  display: none !important;
-}
diff --git a/web_src/css/explore.css b/web_src/css/explore.css
index 139dfcb19f..08858337c0 100644
--- a/web_src/css/explore.css
+++ b/web_src/css/explore.css
@@ -10,33 +10,6 @@
   margin-right: 5px;
 }
 
-.ui.repository.list .item {
-  padding-bottom: 1.5rem;
-}
-
-.ui.repository.list .item:not(:first-child) {
-  border-top: 1px solid var(--color-secondary);
-  padding-top: 1.5rem;
-}
-
-.ui.repository.list .item .ui.header {
-  font-size: 1.5rem;
-  margin-bottom: 0.5rem;
-}
-
-.ui.repository.list .item .ui.header .name {
-  word-break: break-all;
-}
-
-.ui.repository.list .item .time {
-  font-size: 12px;
-}
-
-.ui.repository.list .repo-title .labels {
-  word-break: normal;
-  flex-shrink: 0;
-}
-
 .ui.repository.branches .info {
   font-size: 12px;
   color: var(--color-text-light);
@@ -58,27 +31,3 @@
 .ui.repository.branches table .ui.popup {
   text-align: left;
 }
-
-.ui.user.list .item {
-  padding-bottom: 25px;
-  display: flex;
-}
-
-.ui.user.list .item:not(:first-child) {
-  border-top: 1px solid var(--color-secondary);
-  padding-top: 25px;
-}
-
-.ui.user.list .item img.ui.avatar {
-  width: 40px;
-  height: 40px;
-  margin-right: 10px;
-}
-
-.ui.user.list .item .description {
-  margin-top: 5px;
-}
-
-.ui.user.list .item .description .svg:not(:first-child) {
-  margin-left: 5px;
-}
diff --git a/web_src/css/index.css b/web_src/css/index.css
index 230e032ac0..55ea67453b 100644
--- a/web_src/css/index.css
+++ b/web_src/css/index.css
@@ -13,7 +13,7 @@
 @import "./modules/svg.css";
 @import "./modules/flexcontainer.css";
 
-@import "./shared/issuelist.css";
+@import "./shared/flex-list.css";
 @import "./shared/milestone.css";
 @import "./shared/repoorg.css";
 @import "./shared/settings.css";
diff --git a/web_src/css/org.css b/web_src/css/org.css
index 9e1fa38941..4bb3b0cd57 100644
--- a/web_src/css/org.css
+++ b/web_src/css/org.css
@@ -133,7 +133,6 @@
   padding: 10px 15px;
 }
 
-.organization.teams .members .ui.avatar,
 .organization.profile .members .ui.avatar {
   width: 48px;
   height: 48px;
@@ -161,25 +160,6 @@
   height: 100%;
 }
 
-.organization.members .list .item {
-  margin-left: 0;
-  margin-right: 0;
-  border-bottom: 1px solid var(--color-secondary);
-}
-
-.organization.members .list .item .ui.avatar {
-  width: 48px;
-  height: 48px;
-  margin-right: 1rem;
-  align-self: flex-start;
-}
-
-.organization.members .list .item .meta {
-  line-height: 24px;
-  word-break: break-word;
-  min-width: 2em;
-}
-
 .organization.teams .detail .item {
   padding: 10px 15px;
 }
@@ -188,22 +168,6 @@
   border-bottom: 1px solid var(--color-secondary);
 }
 
-.organization.teams .repositories .item,
-.organization.teams .members .item {
-  padding: 10px 19px;
-}
-
-.organization.teams .repositories .item:not(:last-child),
-.organization.teams .members .item:not(:last-child) {
-  border-bottom: 1px solid var(--color-secondary);
-}
-
-.organization.teams .repositories .item .button,
-.organization.teams .members .item .button {
-  padding: 9px 10px;
-  margin: 0;
-}
-
 .org-team-navbar .active.item {
   background: var(--color-box-body) !important;
 }
diff --git a/web_src/css/repo.css b/web_src/css/repo.css
index 04cb4eed2d..efa412dc53 100644
--- a/web_src/css/repo.css
+++ b/web_src/css/repo.css
@@ -584,15 +584,6 @@
   min-width: 100px;
 }
 
-.repository.options .danger .item {
-  padding: 20px 15px;
-}
-
-.repository.options .danger .ui.divider {
-  margin: 0;
-  border-color: var(--color-error-border);
-}
-
 .repository.new.issue .comment.form .comment .avatar {
   width: 3em;
 }
@@ -1927,15 +1918,6 @@
   flex-wrap: wrap;
 }
 
-.repository.settings.collaboration .collaborator.list {
-  padding: 0;
-}
-
-.repository.settings.collaboration .collaborator.list > .item {
-  margin: 0;
-  line-height: 2;
-}
-
 .repository.settings.collaboration #repo-collab-form #search-user-box .results {
   left: 7px;
 }
@@ -2389,15 +2371,6 @@
   padding: 10px 0 0;
 }
 
-.settings .list.key .meta {
-  padding-top: 5px;
-  color: var(--color-text-light-2);
-}
-
-.settings .list.collaborator > .item {
-  padding: 0;
-}
-
 .ui.vertical.menu .header.item {
   font-size: 1.1em;
   background: var(--color-box-header);
diff --git a/web_src/css/repo/issue-list.css b/web_src/css/repo/issue-list.css
index 7769a16f5f..2a0a86c081 100644
--- a/web_src/css/repo/issue-list.css
+++ b/web_src/css/repo/issue-list.css
@@ -32,3 +32,36 @@
     order: 2 !important;
   }
 }
+
+#issue-list .flex-item-body .branches {
+  display: inline-flex;
+}
+
+#issue-list .flex-item-body .branches .branch {
+  background-color: var(--color-secondary-alpha-40);
+  border-radius: 3px;
+  padding: 0 4px;
+}
+
+#issue-list .flex-item-body .branches .truncated-name {
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 10em;
+}
+
+#issue-list .flex-item-body .checklist progress {
+  margin-left: 2px;
+  width: 80px;
+  height: 6px;
+  display: inline-block;
+  border-radius: 3px;
+}
+
+#issue-list .flex-item-body .checklist progress::-webkit-progress-value {
+  background-color: var(--color-secondary-dark-4);
+}
+
+#issue-list .flex-item-body .checklist progress::-moz-progress-bar {
+  background-color: var(--color-secondary-dark-4);
+}
\ No newline at end of file
diff --git a/web_src/css/shared/flex-list.css b/web_src/css/shared/flex-list.css
new file mode 100644
index 0000000000..7982241684
--- /dev/null
+++ b/web_src/css/shared/flex-list.css
@@ -0,0 +1,94 @@
+.flex-list {
+  list-style: none;
+}
+
+.flex-item {
+  display: flex;
+  gap: 8px;
+  align-items: flex-start;
+}
+
+.flex-item:not(:last-child) {
+  padding-bottom: 8px;
+}
+
+.flex-item-baseline {
+  align-items: baseline;
+}
+
+.flex-item-center {
+  align-items: center;
+}
+
+.flex-item .flex-item-leading {
+  display: flex;
+  align-items: flex-start;
+}
+
+.flex-item .flex-item-main {
+  display: flex;
+  flex-direction: column;
+  flex-grow: 1;
+  min-width: 0;
+}
+
+.flex-item-header {
+  display: flex;
+  gap: .25rem;
+  justify-content: space-between;
+  flex-wrap: wrap;
+}
+
+.flex-item a:not(.label, .button):hover {
+  color: var(--color-primary) !important;
+}
+
+.flex-item .flex-item-icon svg {
+  margin-top: 1px;
+}
+
+.flex-item .flex-item-trailing {
+  display: flex;
+  gap: 0.5rem;
+  align-items: center;
+  flex-grow: 0;
+  flex-wrap: wrap;
+  justify-content: end;
+  flex-shrink: 2;
+}
+
+.flex-item .flex-item-title {
+  display: inline-flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: .25rem;
+  max-width: 100%;
+  color: var(--color-text);
+  font-size: 16px;
+  min-width: 0;
+  font-weight: var(--font-weight-semibold);
+}
+
+.flex-item .flex-item-title a {
+  color: var(--color-text);
+  overflow-wrap: anywhere;
+}
+
+.flex-item .flex-item-body {
+  font-size: 13px;
+  display: flex;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: .25rem;
+  color: var(--color-text-light-2);
+}
+
+.flex-item .flex-item-body a {
+  color: inherit;
+  overflow-wrap: anywhere;
+}
+
+.flex-list > .flex-item + .flex-item {
+  border-top: 1px solid var(--color-secondary);
+  padding-top: 8px;
+}
diff --git a/web_src/css/shared/issuelist.css b/web_src/css/shared/issuelist.css
deleted file mode 100644
index 82fafedec0..0000000000
--- a/web_src/css/shared/issuelist.css
+++ /dev/null
@@ -1,134 +0,0 @@
-.issue.list {
-  list-style: none;
-  margin-top: 1rem;
-}
-
-.issue.list .item {
-  display: flex;
-  align-items: baseline;
-  padding: 8px 0;
-}
-
-.issue.list .item .issue-item-left {
-  display: flex;
-  align-items: flex-start;
-}
-
-.issue.list .item .issue-item-main {
-  display: flex;
-  flex-direction: column;
-  width: 100%;
-}
-
-.issue.list .item .issue-item-header {
-  display: flex;
-  justify-content: space-between;
-  align-items: center;
-  flex-wrap: wrap;
-}
-
-.issue.list a:not(.label):hover {
-  color: var(--color-primary) !important;
-}
-
-.issue.list > .item .issue-item-icon svg {
-  margin-right: 0.75rem;
-  margin-top: 1px;
-}
-
-.issue.list .item .issue-item-right {
-  display: flex;
-  gap: 0.5rem;
-}
-
-.issue.list > .action-item {
-  align-items: normal;
-}
-
-.issue.list > .item .action-item-center {
-  display: flex;
-  align-items: center;
-  padding-left: 4px;
-  padding-right: 12px;
-}
-
-.issue.list > .item .action-item-right {
-  flex: 0 0 15%;
-  display: flex;
-  flex-direction: column;
-  gap: 3px;
-  color: var(--color-text-light);
-}
-
-.issue.list > .item .issue-item-title {
-  max-width: 100%;
-  color: var(--color-text);
-  font-size: 16px;
-  min-width: 0;
-  font-weight: var(--font-weight-semibold);
-}
-
-.issue.list > .item .issue-item-title a.index {
-  max-width: fit-content;
-  display: -webkit-box;
-  -webkit-box-orient: vertical;
-  -webkit-line-clamp: 2;
-  overflow: hidden;
-  word-break: break-all;
-}
-
-.issue.list > .item .title {
-  color: var(--color-text);
-  overflow-wrap: anywhere;
-}
-
-.issue.list > .item .issue-item-body {
-  font-size: 13px;
-  display: flex;
-  align-items: center;
-  flex-wrap: wrap;
-  gap: .25rem;
-  color: var(--color-text-light-2);
-}
-
-.issue.list > .item .issue-item-body a {
-  color: inherit;
-  word-break: break-word;
-}
-
-.issue.list > .item .issue-item-body .checklist progress {
-  margin-left: 2px;
-  width: 80px;
-  height: 6px;
-  display: inline-block;
-  border-radius: 3px;
-}
-
-.issue.list > .item .issue-item-body .checklist progress::-webkit-progress-value {
-  background-color: var(--color-secondary-dark-4);
-}
-
-.issue.list > .item .issue-item-body .checklist progress::-moz-progress-bar {
-  background-color: var(--color-secondary-dark-4);
-}
-
-.issue.list .branches {
-  display: inline-flex;
-}
-
-.issue.list .branches .branch {
-  background-color: var(--color-secondary-alpha-40);
-  border-radius: 3px;
-  padding: 0 4px;
-}
-
-.issue.list .branches .truncated-name {
-  white-space: nowrap;
-  overflow: hidden;
-  text-overflow: ellipsis;
-  max-width: 10em;
-}
-
-.issue.list > .item + .item {
-  border-top: 1px solid var(--color-secondary);
-}
diff --git a/web_src/css/user.css b/web_src/css/user.css
index ab94c826b2..33e64bbb7c 100644
--- a/web_src/css/user.css
+++ b/web_src/css/user.css
@@ -58,15 +58,6 @@
   }
 }
 
-.user.profile .ui.repository.list {
-  margin-top: 25px;
-}
-
-.user.profile .ui.repository.list .repo-title .labels {
-  word-break: normal;
-  flex-shrink: 0;
-}
-
 .user.profile #loading-heatmap {
   margin-bottom: 1em;
 }