diff --git a/app/assets/stylesheets/application.css b/app/assets/stylesheets/application.css
index c26b233..97ceb44 100644
--- a/app/assets/stylesheets/application.css
+++ b/app/assets/stylesheets/application.css
@@ -18,10 +18,14 @@
 /* Strive for simplicity:
  * * style elements/tags only - if possible,
  * * replace element/tag name with class name - if element has to be styled
- * differently depending on context (e.g. form)
+ * differently depending on context (e.g. <form>; <a> as link/button),
+ * * styles with multiple selectors should have all selectors with same
+ * specificity, to allow proper rule specificity vs order management.
  *
- * NOTE: Style in a modular way, similar to how CSS @scope would be used,
- * to make transition easier once @scope is widely available */
+ * NOTE: style in a modular way, similar to how CSS @scope would be used,
+ * to make transition easier once @scope is widely available. */
+/* TODO: review styles with multiple selectors and try to convert them to the same
+ * specificity. */
 :root {
   --color-focus-gray: #f3f3f3;
   --color-border-gray: #dddddd;
@@ -58,7 +62,7 @@
   border-color: var(--color-border-gray) !important;
   color: var(--color-border-gray) !important;
   /* NOTE: cannot set cursor with `pointer-events: none`; can be fixed by setting
-   * cursor on wrapping element.
+   * `cursor` on wrapping element.
   cursor: not-allowed; */
   fill: var(--color-border-gray) !important;
   pointer-events: none !important;
@@ -70,9 +74,9 @@
 
 
 /* Color coding of input controls' background:
- *  blue - target for interaction with pointer
- *  gray - target for interaction with keyboard
- *  red - destructive, non-undoable action
+ *  blue - target for interaction with pointer,
+ *  gray - target for interaction with keyboard,
+ *  red - destructive, non-undoable action.
  */
 button,
 details,
@@ -87,49 +91,17 @@ input,
 select {
   text-align: inherit;
 }
-a,
-button,
-input[type=submit] {
-  cursor: pointer;
-  text-decoration: none;
-  white-space: nowrap;
-}
-.button,
-button,
-input[type=submit],
-.tab {
-  align-items: center;
-  color: var(--color-gray);
-  display: flex;
-  fill: var(--color-gray);
-  font-weight: bold;
-}
-.button,
-button,
-input[type=submit] {
-  font-size: 0.8rem;
-  padding: 0.6em 0.5em;
-  width: fit-content;
-}
-input:not([type=submit]):not([type=checkbox]),
-select,
-summary,
-textarea {
-  padding: 0.2em 0.4em;
-}
-.button,
-button,
 input,
 select,
 summary,
 textarea {
-  border: solid 1px var(--color-gray);
+  border: 1px solid var(--color-gray);
   border-radius: 0.25em;
+  padding: 0.2em 0.4em;
 }
-input[type=checkbox],
 svg,
 textarea {
-  margin: 0
+  margin: 0;
 }
 input[type=checkbox] {
   accent-color: var(--color-blue);
@@ -137,13 +109,16 @@ input[type=checkbox] {
   -webkit-appearance: none;
   display: flex;
   height: 1.1em;
+  margin: 0;
+  padding: 0;
   width: 1.1em;
 }
 input[type=checkbox]:checked {
   appearance: checkbox;
   -webkit-appearance: checkbox;
 }
-/* Hide spin buttons in input number fields */
+/* Hide spin buttons of <input type=number>. */
+/* TODO: add spin buttons inside <input type=number>: before (-) and after (+) input. */
 input[type=number] {
   appearance: textfield;
   -moz-appearance: textfield;
@@ -155,52 +130,21 @@ input::-webkit-outer-spin-button {
   -webkit-appearance: none;
   margin: 0;
 }
-.button > svg,
-.tab > svg,
-button > svg {
-  height: 1.4em;
-  width: 1.4em;
-}
-.button > svg:not(:last-child),
-.tab > svg:not(:last-child),
-button > svg:not(:last-child) {
-  margin-right: 0.2em;
-}
-/* TODO: move normal non-button links (<a>:hover/:focus) styling here (i.e.
- * page-wide, top-level) and remove from table.items - as the style should be
- * same everywhere */
-.button:focus-visible,
-button:focus-visible,
-input[type=submit]:focus-visible {
-  background-color: var(--color-focus-gray);
-}
 input:focus-visible,
 select:focus-visible,
 select:focus-within,
-/* TODO: how to achieve summary:focus-within for ::details-content? */
+/* TODO: how to achieve `summary:focus-within` for `::details-content`? */
 summary:focus-visible,
 textarea:focus-visible {
   accent-color: var(--color-dark-blue);
   background-color: var(--color-focus-gray);
 }
-.button:hover,
-button:hover,
-input[type=submit]:hover {
-  background-color: var(--color-blue);
-  border-color: var(--color-blue);
-  color: white;
-  fill: white;
-}
-.dangerous:hover {
-  background-color: var(--color-red);
-  border-color: var(--color-red);
-}
 input:hover,
 select:hover,
 summary:hover,
 textarea:hover {
   border-color: var(--color-blue);
-  outline: solid 1px var(--color-blue);
+  outline: 1px solid var(--color-blue);
 }
 select:hover,
 summary:hover {
@@ -210,8 +154,68 @@ input:invalid,
 select:invalid,
 textarea:invalid {
   border-color: var(--color-red);
-  outline: solid 1px var(--color-red);
+  outline-color: var(--color-red);
 }
+
+/* `.button`: button-styled <a>, <button>, <input type=submit>.
+ * `.link`: any other <a>.
+ * `.tab`: tab-styled <a>.
+ */
+.button,
+.link,
+.tab {
+  cursor: pointer;
+  text-decoration: none;
+  white-space: nowrap;
+}
+.button,
+.tab {
+  align-items: center;
+  color: var(--color-gray);
+  display: flex;
+  fill: var(--color-gray);
+  font-weight: bold;
+}
+.button {
+  border: 1px solid var(--color-gray);
+  border-radius: 0.25em;
+  font-size: 0.8rem;
+  padding: 0.6em 0.5em;
+  width: fit-content;
+}
+[name=cancel],
+.auxiliary {
+  border-color: var(--color-border-gray);
+  color: var(--color-nav-gray);
+  fill: var(--color-nav-gray);
+}
+.button > svg,
+.tab > svg {
+  height: 1.4em;
+  width: 1.4em;
+}
+.button > svg:not(:last-child),
+.tab > svg:not(:last-child) {
+  margin-right: 0.2em;
+}
+.button:focus-visible,
+.tab:focus-visible,
+.tab:hover {
+  background-color: var(--color-focus-gray);
+}
+.button:hover {
+  background-color: var(--color-blue);
+  border-color: var(--color-blue);
+  color: white;
+  fill: white;
+}
+.dangerous:hover {
+  background-color: var(--color-red);
+  border-color: var(--color-red);
+}
+/* TODO: move normal, non-button links (<a>:hover/:focus) styling here (i.e.
+ * page-wide, top-level) and remove from `table.items` - as the style should be
+ * same everywhere. */
 input[type=text]:read-only,
 textarea:read-only {
   border: none;
@@ -219,8 +223,8 @@ textarea:read-only {
 }
 
 
-/* NOTE: collapse gaps around empty rows (`topside`) once possible
- * with grid-collapse property and remove alternative grid-template
+/* NOTE: collapse gaps around empty rows (`topside`) once possible with
+ * `grid-collapse` property and remove alternative `grid-template-areas`.
  * https://github.com/w3c/csswg-drafts/issues/5813 */
 body {
   display: grid;
@@ -253,18 +257,14 @@ header {
   margin-inline-start: 4%;
 }
 .navigation > .tab {
-  border-bottom: solid 2px var(--color-nav-gray);
+  border-bottom: 2px solid var(--color-nav-gray);
   flex: 1;
   font-size: 1rem;
   justify-content: center;
   padding-block: 0.4em;
 }
-.navigation > .tab:hover,
-.navigation > .tab:focus-visible {
-  background-color: var(--color-focus-gray);
-}
 .navigation > .tab.active {
-  border-bottom: solid 4px var(--color-blue);
+  border-bottom: 4px solid var(--color-blue);
   color: var(--color-blue);
   fill: var(--color-blue);
 }
@@ -296,7 +296,7 @@ header {
 
 #flashes {
   display: grid;
-  gap: 0.2em;
+  row-gap: 0.4em;
   grid-template-columns: 1fr auto auto auto 1fr;
   left: 0;
   pointer-events: none;
@@ -312,48 +312,42 @@ header {
   display: grid;
   grid-column: 2/5;
   grid-template-columns: subgrid;
+  line-height: 2.2em;
   pointer-events: auto;
 }
-.flash.alert:before {
-  content: url('pictograms/alert-outline.svg');
+.flash:before {
+  filter: invert();
   height: 1.4em;
   margin: 0 0.5em;
   width: 1.4em;
 }
+.flash.alert:before {
+  content: url('pictograms/alert-outline.svg');
+}
 .flash.alert {
   border-color: var(--color-red);
   background-color: var(--color-red);
 }
 .flash.notice:before {
   content: url('pictograms/check-circle-outline.svg');
-  height: 1.4em;
-  margin: 0 0.5em;
-  width: 1.4em;
 }
 .flash.notice {
   border-color: var(--color-blue);
   background-color: var(--color-blue);
 }
-.flash > div {
-  grid-column: 2;
-}
-/* NOTE: currently flash button inherits some unnecessary styles from generic
- * button. */
-.flash > button {
-  border: none;
-  color: inherit;
+.flash svg {
   cursor: pointer;
-  font-size: 1.4em;
-  font-weight: bold;
-  grid-column: 3;
+  fill: white;
+  height: 2.2em;
   opacity: 0.6;
-  padding: 0.2em 0.4em;
+  padding: 0.4em 0.5em;
+  width: 2.4em;
 }
-.flash > button:hover {
+.flash svg:hover {
   opacity: 1;
 }
 
-/* TODO: Hover over invalid should work like in measurements (thin vs thick border) */
+
 .labeled-form {
   align-items: center;
   display: grid;
@@ -370,7 +364,7 @@ header {
 .labeled-form label.required {
   font-weight: bold;
 }
-/* Don't style `label.error + input` if case already covered by input:invalid */
+/* Don't style `label.error + input` if case already covered by `input:invalid`. */
 .labeled-form label.error {
   color: var(--color-red);
 }
@@ -384,15 +378,23 @@ header {
 }
 .labeled-form input[type=submit] {
   font-size: 1rem;
-  margin: 1.5em auto 0 auto;
+  margin: 1em auto 0 auto;
   padding: 0.75em;
 }
+.labeled-form .auxiliary {
+  grid-column: 3;
+  /* If more buttons are needed, `grid-row` can be replaced with
+   * `reading-flow: grid-columns` to ensure proper [tabindex] order. */
+  grid-row: 1;
+  height: 100%;
+  padding-block: 0;
+}
 
 
-/* TODO: remove .items class (?) and make 'form table' work properly */
+/* TODO: remove `.items` class (?) and make `form table` work properly. */
 table.items {
   border-spacing: 0;
-  border: solid 1px var(--color-border-gray);
+  border: 1px solid var(--color-border-gray);
   border-radius: 0.25em;
   font-size: 0.85rem;
   text-align: left;
@@ -415,7 +417,7 @@ table.items th,
 table.items td {
   padding-inline: 1em 0;
 }
-/* For <a> to fill <td> completely, we use an ::after pseudoelement. */
+/* For <a> to fill <td> completely, we use an `::after` pseudoelement. */
 table.items td.link {
   padding: 0;
   position: relative;
@@ -445,7 +447,7 @@ table.items td:last-child {
   padding-inline-end: 0.1em;
 }
 table.items td {
-  border-top: solid 1px var(--color-border-gray);
+  border-top: 1px solid var(--color-border-gray);
   height: 2.4em;
   padding-block: 0.1em;
 }
@@ -464,7 +466,7 @@ table.items tr.dropzone::after {
   content: '';
   inset: 1px 0 0 0;
   position: absolute;
-  outline: dashed 2px var(--color-blue);
+  outline: 2px dashed var(--color-blue);
   outline-offset: -1px;
   z-index: var(--z-index-table-row-outline);
 }
@@ -475,8 +477,8 @@ table.items tr.form td {
   vertical-align: top;
 }
 
-/* TODO: replace :hover:focus-visible combos with proper LOVE stye order */
-/* TODO: Update table styling: simplify selectors, deduplicate, remove non-font rem. */
+/* TODO: replace `:hover:focus-visible` combos with proper LOVE style order. */
+/* TODO: update table styling: simplify selectors, deduplicate, remove non-font rem. */
 table.items td.link a:hover,
 table.items td.link a:focus-visible,
 table.items td.link a:hover:focus-visible {
@@ -514,9 +516,7 @@ table.items td.svg {
 table.items td.number {
   text-align: right;
 }
-table.items .button,
-table.items button,
-table.items input[type=submit] {
+table.items .button {
   font-weight: normal;
   height: 100%;
   padding: 0.4em;
@@ -526,30 +526,26 @@ table.items select,
 table.items textarea {
   padding-block: 0.375em;
 }
-/* TODO: find a way (layers?) to style inputs differently while making sure
- * hover works properly without using :not(:hover) selectors here. */
-table.items .button:not(:hover),
-table.items button:not(:hover),
-table.items input:not(:hover),
-table.items select:not(:hover),
-table.items textarea:not(:hover) {
+
+table input,
+table select,
+table summary,
+table textarea {
   border-color: var(--color-border-gray);
 }
-table.items .button:not(:hover),
-table.items button:not(:hover),
-table.items input[type=submit]:not(:hover),
-table.items select:not(:hover) {
+table select {
   color: var(--color-table-gray);
 }
-table.items select:focus-within,
-table.items select:focus-visible {
+table select:hover,
+table select:focus-within,
+table select:focus-visible {
   color: black;
 }
-form a[name=cancel] {
+table .button {
   border-color: var(--color-border-gray);
-  color: var(--color-nav-gray);
-  fill: var(--color-nav-gray);
+  color: var(--color-table-gray);
 }
+
 form table.items {
   border: none;
 }
@@ -561,6 +557,9 @@ form table.items td {
 form table.items td:first-child {
   color: inherit;
 }
+form table select {
+  color: black;
+}
 
 
 .centered {
@@ -620,7 +619,7 @@ summary:has(.button) {
   padding-inline-end: 0;
 }
 summary .button {
-  border: solid 1px var(--color-border-gray);
+  border: 1px solid var(--color-border-gray);
   border-radius: inherit;
   border-top-left-radius: 0;
   border-bottom-left-radius: 0;
@@ -636,10 +635,10 @@ details[open] summary::before {
 summary::marker {
   padding-left: 0.25em;
 }
-/* NOTE: use details[open]::details-content once widely available */
+/* NOTE: use `details[open]::details-content` once widely available. */
 details[open] ul {
   background: white;
-  border: solid 1px var(--color-border-gray);
+  border: 1px solid var(--color-border-gray);
   border-radius: 0.25em;
   box-shadow: 1px 1px 3px var(--color-border-gray);
   margin: -1px 0 0 0;
@@ -661,3 +660,10 @@ li input[type=checkbox] {
 li::marker {
   content: '';
 }
+/*
+ * TODO:
+ * * disable <label> containing disabled checkbox: `label:has(input[disabled])`,
+ * * disabled label styling,
+ * * focused label styling (currently only checkbox has focus),
+ * * disabled checkbox blue square focus removal.
+ * */