Add common button styling

src/main/resources/static/details.css

@@ -1,4 +1,4 @@
-@import url("./main.css");
+@import url("main.css");
 @import url('https://fonts.googleapis.com/css2?family=Flow+Circular&display=swap');
 
 :root {
@@ -226,44 +226,6 @@ a {
     display: flex;
 }
 
-#delete-btn {
-    background: #861c1c;
-}
-
-/* button styling to be revisited */
-.btn {
-    padding: .5lh 1lh;
-    border: none;
-    border-radius: .5lh;
-    --btn-color: var(--fg-color);
-    background-color: var(--btn-color);
-    color: var(--text-color);
-    font-weight: bold;
-    font-size: 1rem;
-    transition: background-color 100ms, filter 200ms;
-    transition-timing-function: ease-out;
-    --drop-shadow-opacity: .5;
-    --drop-shadow-offset-y: 0;
-    --drop-shadow-blur: .25rem;
-    --drop-shadow: drop-shadow(
-            rgba(0, 0, 0, var(--drop-shadow-opacity))
-            0 var(--drop-shadow-offset-y) var(--drop-shadow-blur)
-    );
-    filter: var(--drop-shadow);
-}
-
-.btn:focus-visible, #is-dataset:focus-visible + #is-dataset-toggle {
-    outline-offset: 2px;
-}
-
-.btn:not(:disabled):hover {
-    background-color: color-mix(in oklab, var(--btn-color) 80%, var(--bg-color));
-    --drop-shadow-opacity: .8;
-    --drop-shadow-offset-y: .25rem;
-    --drop-shadow-blur: .4rem;
-}
-
-
 #nothing-found-bg {
     background-position-x: calc(50% + 3cqh);
 }