[Port] gitea#29982 Introduce .secondary-nav and handle .page-content spacing universally

Fixes: https://github.com/go-gitea/gitea/issues/29981. Introduce
`.secondary-nav` as a universal way for styling and margin adjustments
inside `.page-content`.

If the first child of `.page-content` is `.secondary-nav`, we add margin
below it, otherwise we add padding to the first child. Notable changes:

- `--color-header-wrapper` is replaced with `--color-secondary-nav-bg`.
- `navbar` class is removed.

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

---

Conflict resolution: Trivial conflict & changed selector to reflect new
classes.
Ref: https://codeberg.org/forgejo/forgejo/issues/2776
(cherry picked from commit 3ccda41a539b8ba7841919ee12dc2877ddc03818)

web_src/css/base.css

@@ -749,9 +749,16 @@ img.ui.avatar,
   padding-bottom: 80px;
 }
 
-.page-content.new:is(.repo,.migrate,.org),
-.page-content.profile:is(.user,.organization) {
-  padding-top: 15px;
+/* add margin below .secondary nav when it is the first child */
+.page-content > :first-child.secondary-nav {
+  margin-bottom: 14px;
+}
+
+/* add padding to all content when there is no .secondary.nav. this uses padding instead of
+   margin because with the negative margin on .ui.grid we would have to set margin-top: 0,
+   but that does not work universally for all pages */
+.page-content > :first-child:not(.secondary-nav) {
+  padding-top: 14px;
 }
 
 /* overwrite semantic width of containers inside the main page content div (div with class "page-content") */
@@ -1337,7 +1344,6 @@ strong.attention-caution, svg.attention-caution {
 }
 
 overflow-menu {
-  margin-bottom: 15px !important;
   border-bottom: 1px solid var(--color-secondary) !important;
   display: flex;
 }
@@ -1351,6 +1357,10 @@ overflow-menu .overflow-menu-items .item {
   margin-bottom: 0 !important; /* reset fomantic's margin, because the active menu has special bottom border */
 }
 
+overflow-menu .ui.label {
+  margin-left: 7px !important; /* save some space */
+}
+
 .activity-bar-graph {
   background-color: var(--color-primary);
   color: var(--color-primary-contrast);

web_src/css/dashboard.css

@@ -77,22 +77,22 @@
   margin: 0 1px; /* Accommodate for Semantic's 1px hacks on .attached elements */
 }
 
-.dashboard .dashboard-navbar {
-  padding: 4px 12px;
+.dashboard .secondary-nav {
+  padding: 1px 12px; /* match .overflow-menu-items in height */
 }
 
-.dashboard .dashboard-navbar .right.menu {
+.dashboard .secondary-nav .right.menu {
   gap: .35714286em;
 }
 
-.dashboard .dashboard-navbar .right.menu div.item {
+.dashboard .secondary-nav .right.menu div.item {
   padding-left: 0.5rem;
 }
 
-.dashboard .dashboard-navbar .org-visibility .label {
+.dashboard .secondary-nav .org-visibility .label {
   margin-left: 5px;
 }
 
-.dashboard .dashboard-navbar .ui.dropdown {
+.dashboard .secondary-nav .ui.dropdown {
   max-width: 100%;
 }

web_src/css/explore.css

@@ -1,10 +1,8 @@
-.explore .navbar {
-  margin-bottom: 15px !important;
-  background-color: var(--color-header-wrapper) !important;
+.explore .secondary-nav {
   border-width: 1px !important;
 }
 
-.explore .navbar .svg {
+.explore .secondary-nav .svg {
   width: 16px;
   text-align: center;
   margin-right: 5px;

web_src/css/modules/navbar.css

@@ -136,3 +136,7 @@
   justify-content: center;
   z-index: 1; /* prevent menu button background from overlaying icon */
 }
+
+.secondary-nav {
+  background: var(--color-secondary-nav-bg) !important; /* important because of .ui.secondary.menu */
+}

web_src/css/repo.css

@@ -4,16 +4,6 @@
   user-select: none;
 }
 
-.repository .navbar {
-  display: flex;
-  justify-content: space-between;
-}
-
-.repository .navbar .ui.label {
-  margin-left: 7px;
-  padding: 3px 5px;
-}
-
 .repository .owner.dropdown {
   min-width: 40% !important;
 }

web_src/css/repo/header.css

@@ -1,4 +1,8 @@
-.header-wrapper .fork-flag {
+.repository .secondary-nav {
+  padding-top: 12px;
+}
+
+.repository .secondary-nav .fork-flag {
   margin-top: 0.5rem;
   font-size: 12px;
 }
@@ -63,8 +67,3 @@
 .repo-buttons .ui.labeled.button.disabled > .button {
   pointer-events: none !important;
 }
-
-.repository .header-wrapper {
-  padding-top: 12px;
-  background-color: var(--color-header-wrapper);
-}

web_src/css/themes/theme-gitea-dark.css

@@ -197,7 +197,6 @@
   --color-input-toggle-background: #2e353b;
   --color-input-border: var(--color-secondary);
   --color-input-border-hover: var(--color-secondary-dark-1);
-  --color-header-wrapper: #181c20;
   --color-light: #00001728;
   --color-light-mimic-enabled: rgba(0, 0, 0, calc(40 / 255 * 222 / 255 / var(--opacity-disabled)));
   --color-light-border: #e8e8ff28;
@@ -227,6 +226,7 @@
   --color-nav-bg: #16191c;
   --color-nav-hover-bg: var(--color-secondary-light-1);
   --color-nav-text: var(--color-text);
+  --color-secondary-nav-bg: #181c20;
   --color-label-text: var(--color-text);
   --color-label-bg: #73828e4b;
   --color-label-hover-bg: #73828ea0;

web_src/css/themes/theme-gitea-light.css

@@ -197,7 +197,6 @@
   --color-input-toggle-background: #d0d7de;
   --color-input-border: var(--color-secondary);
   --color-input-border-hover: var(--color-secondary-dark-1);
-  --color-header-wrapper: #f9fafb;
   --color-light: #00001706;
   --color-light-mimic-enabled: rgba(0, 0, 0, calc(6 / 255 * 222 / 255 / var(--opacity-disabled)));
   --color-light-border: #0000171d;
@@ -227,6 +226,7 @@
   --color-nav-bg: #f6f7fa;
   --color-nav-hover-bg: var(--color-secondary-light-1);
   --color-nav-text: var(--color-text);
+  --color-secondary-nav-bg: #f9fafb;
   --color-label-text: var(--color-text);
   --color-label-bg: #949da64b;
   --color-label-hover-bg: #949da6a0;

web_src/css/user.css

@@ -125,10 +125,6 @@
   border: 1px solid var(--color-secondary);
 }
 
-#notification_div {
-  padding-top: 15px;
-}
-
 #notification_table {
   background: var(--color-box-body);
   border: 1px solid var(--color-secondary);