Fix project board view (#34470)

Fix #34469

Author: wxiaoguang

web_src/css/features/projects.css

@@ -10,7 +10,7 @@
 
 .project-header {
   padding: 0.5em 0;
-  overflow-x: auto; /* in fullscreen mode, the position is fixed, so we can't use "flex wrap" which would change the height */
+  flex-wrap: wrap;
 }
 
 .project-header h2 {
@@ -101,17 +101,11 @@
   opacity: 0;
 }
 
-.fullscreen.projects-view .project-header {
-  position: fixed;
-  z-index: 1000;
-  top: 0;
-  left: 0;
-  right: 0;
-  padding: 0.5em;
-  width: 100%;
-  max-width: 100%;
-  background-color: var(--color-body);
-  border-bottom: 1px solid var(--color-secondary);
+.fullscreen.projects-view {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  flex-direction: column;
 }
 
 /* Hide project-description in full-screen due to its variable height. No need to show it for better space use. */
@@ -120,9 +114,7 @@
 }
 
 .fullscreen.projects-view #project-board {
-  position: absolute;
-  top: 60px;
-  left: 0;
-  right: 0;
-  max-height: calc(100vh - 70px);
+  flex: 1;
+  max-height: unset;
+  padding-bottom: 0.5em;
 }