diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index a823974afa..69ce9db24c 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -82,4 +82,4 @@ jobs:
       run: composer install
 
     - name: PHPCS check
-      run: './vendor/bin/phpcs . -q --report=checkstyle --warning-severity=6 --runtime-set testVersion 7.4- | cs2pr'
+      run: './vendor/bin/phpcs . -q --report=checkstyle --runtime-set testVersion 7.4- | cs2pr'
diff --git a/.stylelintrc b/.stylelintrc
index f7007ae70b..3b8c4705a1 100644
--- a/.stylelintrc
+++ b/.stylelintrc
@@ -1,18 +1,17 @@
 {
-  "extends": [
-    "@10up/stylelint-config"
-  ],
-  "rules": {
-    "scale-unlimited/declaration-strict-value": [
-      "/color/",
-      {
-        "ignoreValues": ["currentColor", "inherit", "initial", "transparent", "unset"],
-        "severity": "warning"
-      }
-    ],
-    "font-family-no-missing-generic-family-keyword": null,
-    "declaration-property-unit-allowed-list": null,
-    "at-rule-disallowed-list": null
-  }
+	"extends": [
+		"@10up/stylelint-config"
+	],
+	"rules": {
+		"scale-unlimited/declaration-strict-value": [
+			"/color/",
+			{
+				"ignoreValues": ["currentcolor", "inherit", "initial", "transparent", "unset"],
+				"severity": "warning"
+			}
+		],
+		"font-family-no-missing-generic-family-keyword": null,
+		"declaration-property-unit-allowed-list": null
+	}
 
 }
diff --git a/assets/css/autosuggest.css b/assets/css/autosuggest.css
index 636183860c..56d4a605f1 100644
--- a/assets/css/autosuggest.css
+++ b/assets/css/autosuggest.css
@@ -1,9 +1,11 @@
+@import "./global/colors.css";
+
 .ep-autosuggest-container {
 	position: relative;
 
 	& .ep-autosuggest {
-		background: #fff;
-		border: 1px solid #ccc;
+		background: var(--ep-c-white);
+		border: 1px solid var(--ep-c-white-gray);
 		box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
 		display: none;
 		position: absolute;
@@ -19,14 +21,14 @@
 				font-family: sans-serif;
 
 				& > a.autosuggest-link {
-					color: #000;
+					color: var(--ep-c-black);
 					cursor: pointer;
 					display: block;
 					padding: 2px 10px;
 
 					&:hover,
 					&:active {
-						background-color: #eee;
+						background-color: var(--ep-c-medium-white);
 						text-decoration: none;
 					}
 				}
@@ -35,7 +37,7 @@
 	}
 
 	& .selected {
-		background-color: #eee;
+		background-color: var(--ep-c-medium-white);
 		text-decoration: none;
 	}
 }
diff --git a/assets/css/dashboard.css b/assets/css/dashboard.css
index 329f3a7c75..9ed56d97d7 100644
--- a/assets/css/dashboard.css
+++ b/assets/css/dashboard.css
@@ -1,10 +1,5 @@
 @import "@10up/component-tooltip";
-
-:root {
-	--ep-dashboard-status-ok: #6aa000;
-	--ep-dashboard-status-warning: #e3e600;
-	--ep-dashboard-status-error: #f00;
-}
+@import "./global/colors.css";
 
 html.wp-toolbar {
 	background: transparent;
@@ -40,7 +35,7 @@ h2.ep-list-features {
 }
 
 .ep-header-menu {
-	background-color: #fff;
+	background-color: var(--ep-c-white);
 	border-bottom: 2px solid #ddd;
 	margin-left: -20px;
 	padding-bottom: 5px;
@@ -96,7 +91,7 @@ h2.ep-list-features {
 
 .ep-header-menu .sync-status {
 	bottom: -1px;
-	color: #666;
+	color: var(--ep-c-medium-gray);
 	display: none;
 	font-style: italic;
 	margin-right: 8px;
@@ -105,7 +100,7 @@ h2.ep-list-features {
 }
 
 .ep-header-menu .progress-bar {
-	background-color: #d84440;
+	background-color: var(--ep-c-medium-red);
 	bottom: 0;
 	height: 5px;
 	left: 0;
@@ -132,7 +127,7 @@ h2.ep-list-features {
 
 .error-overlay.cant-connect,
 .error-overlay.syncing {
-	background-color: #fff;
+	background-color: var(--ep-c-white);
 	bottom: 0;
 	content: " ";
 	display: block;
@@ -163,7 +158,7 @@ h2.ep-list-features {
 }
 
 .ep-feature .postbox .hndle .settings-button {
-	background-color: #efefef;
+	background-color: var(--ep-c-medium-white);
 	border: none;
 	border-radius: 4px;
 	color: inherit;
@@ -180,7 +175,7 @@ h2.ep-list-features {
 }
 
 .ep-feature .settings-button::before {
-	color: #72777c;
+	color: var(--ep-c-medium-gray);
 	content: "\f140";
 	display: inline-block;
 	font: 400 19px/1 dashicons;
@@ -206,11 +201,11 @@ h2.ep-list-features {
 
 	& .postbox .hndle .settings-button::after {
 		background-color: transparent;
-		border: 1px solid var(--ep-dashboard-status-error);
+		border: 1px solid var(--ep-status-error);
 	}
 
 	& .settings .requirements-status-notice {
-		border-color: var(--ep-dashboard-status-error);
+		border-color: var(--ep-status-error);
 	}
 }
 
@@ -218,15 +213,15 @@ h2.ep-list-features {
 
 	& .postbox .hndle .settings-button::after {
 		background-color: transparent;
-		border: 1px solid var(--ep-dashboard-status-warning);
+		border: 1px solid var(--ep-status-warning);
 	}
 
 	&.feature-active .postbox .hndle .settings-button::after {
-		background-color: var(--ep-dashboard-status-warning);
+		background-color: var(--ep-status-warning);
 	}
 
 	& .settings .requirements-status-notice {
-		border-color: var(--ep-dashboard-status-warning);
+		border-color: var(--ep-status-warning);
 	}
 }
 
@@ -234,15 +229,15 @@ h2.ep-list-features {
 
 	& .postbox .hndle .settings-button::after {
 		background-color: transparent;
-		border: 1px solid var(--ep-dashboard-status-ok);
+		border: 1px solid var(--ep-status-ok);
 	}
 
 	&.feature-active .postbox .hndle .settings-button::after {
-		background-color: var(--ep-dashboard-status-ok);
+		background-color: var(--ep-status-ok);
 	}
 
 	& .settings .requirements-status-notice {
-		border-color: var(--ep-dashboard-status-ok);
+		border-color: var(--ep-status-ok);
 	}
 }
 
@@ -254,11 +249,11 @@ h2.ep-list-features {
 
 .ep-feature.saving .action-wrap::before {
 	animation: load8 1.1s infinite linear;
-	border-bottom: 5px solid #ccc;
-	border-left: 5px solid #999;
+	border-bottom: 5px solid var(--ep-c-white-gray);
+	border-left: 5px solid var(--ep-c-light-gray);
 	border-radius: 50%;
-	border-right: 5px solid #ccc;
-	border-top: 5px solid #ccc;
+	border-right: 5px solid var(--ep-c-white-gray);
+	border-top: 5px solid var(--ep-c-white-gray);
 	content: " ";
 	display: inline-block;
 	font-size: 7px;
@@ -305,18 +300,18 @@ h2.ep-list-features {
 }
 
 .ep-feature .settings .requirements-status-notice {
-	background-color: #efefef;
-	border-left: 4px solid var(--ep-dashboard-status-ok);
+	background-color: var(--ep-c-medium-white);
+	border-left: 4px solid var(--ep-status-ok);
 	margin-bottom: 10px;
 	padding: 8px 12px;
 
 	&.requirements-status-notice--reindex {
-		border-color: var(--ep-dashboard-status-warning);
+		border-color: var(--ep-status-warning);
 		display: none; /* Controlled by JavaScript. */
 	}
 
 	&.requirements-status-notice--syncing {
-		border-color: var(--ep-dashboard-status-error);
+		border-color: var(--ep-status-error);
 		display: none; /* Controlled by JavaScript. */
 	}
 }
@@ -333,7 +328,7 @@ h2.ep-list-features {
 	}
 
 	& .no-dash-sync {
-		color: #aaa;
+		color: var(--ep-c-light-gray);
 		display: none;
 		line-height: 27px;
 		padding-right: 8px;
@@ -387,14 +382,14 @@ h2.ep-list-features {
 	}
 
 	& .field-description {
-		color: #666;
+		color: var(--ep-c-medium-gray);
 		font-style: italic;
 		margin-bottom: 0;
 		margin-top: 4px;
 	}
 
 	& .disabled {
-		color: #bbb;
+		color: var(--ep-c-light-gray);
 
 		& input {
 			cursor: default;
@@ -410,7 +405,7 @@ h2.ep-list-features {
 	}
 
 	& .components-form-token-field__input-container {
-		border-color: #8c8f94;
+		border-color: var(--ep-c-light-gray);
 	}
 }
 
@@ -461,7 +456,7 @@ h2.ep-list-features {
 }
 
 .intro h1 {
-	color: #626262;
+	color: var(--ep-c-medium-gray);
 	font-weight: 600;
 	margin: 0.5em 0 2em;
 	text-align: center;
@@ -484,7 +479,7 @@ h2.ep-list-features {
 	}
 
 	& h2 {
-		color: #626262;
+		color: var(--ep-c-medium-gray);
 		height: 8%;
 	}
 
@@ -576,9 +571,9 @@ h2.ep-list-features {
 }
 
 .ep-circle {
-	background: #fff;
+	background: var(--ep-c-white);
 	border-radius: 50%;
-	color: #626262;
+	color: var(--ep-c-medium-gray);
 	display: inline-block;
 	font-size: 16px;
 	font-weight: 400;
@@ -616,8 +611,8 @@ h2.ep-list-features {
 }
 
 .ep-circle--active {
-	background-color: #d73c38;
-	color: #fff;
+	background-color: var(--ep-c-medium-red);
+	color: var(--ep-c-white);
 }
 
 .wrap.intro {
@@ -644,11 +639,11 @@ h2.ep-list-features {
 
 .setup-button {
 	-webkit-appearance: none;
-	background-color: #e63e3b;
+	background-color: var(--ep-c-medium-red);
 	border: none;
 	border-radius: 10px;
 	box-shadow: 1px 1px 3px 1px rgba(0, 0, 0, 0.25);
-	color: #fff;
+	color: var(--ep-c-white);
 	display: inline-block;
 	margin: 0 0.75em;
 	padding: 1em 1.5em;
@@ -656,13 +651,13 @@ h2.ep-list-features {
 }
 
 .setup-button:hover {
-	background-color: #b93431;
-	color: #ffe8ed;
+	background-color: var(--ep-c-dark-red);
+	color: var(--ep-c-white-red);
 }
 
 .setup-message .setup-button-primary {
-	background-color: #fff;
-	color: #d84440;
+	background-color: var(--ep-c-white);
+	color: var(--ep-c-medium-red);
 }
 
 .ep-feature-search .wp-color-result.button {
@@ -761,7 +756,7 @@ h2.ep-list-features {
 
 /* @media screen and (max-width: 600px) { */
 .wrap h2.nav-tab-wrapper.ep-credentials-tabs {
-	border-bottom: 1px solid #ccc;
+	border-bottom: 1px solid var(--ep-c-white-gray);
 }
 
 /* } */
@@ -776,7 +771,7 @@ h2 .nav-tab.ep-credentials-tab {
 }
 
 .ep-credentials-tab.nav-tab-active {
-	border-bottom-color: #f1f1f1;
+	border-bottom-color: var(--ep-c-white);
 }
 
 .ep-credentials-tab img,
@@ -786,15 +781,15 @@ h2 .nav-tab.ep-credentials-tab {
 }
 
 .ep-credentials fieldset {
-	border-bottom: 1px solid #ccc;
-	border-left: 1px solid #ccc;
-	border-right: 1px solid #ccc;
+	border-bottom: 1px solid var(--ep-c-white-gray);
+	border-left: 1px solid var(--ep-c-white-gray);
+	border-right: 1px solid var(--ep-c-white-gray);
 	margin: 0;
 	padding: 0 1rem;
 }
 
 .ep-credentials fieldset.predefined {
-	border-top: 1px solid #ccc;
+	border-top: 1px solid var(--ep-c-white-gray);
 }
 
 .ep-settings .ep-credentials-general {
@@ -859,14 +854,14 @@ h2 .nav-tab.ep-credentials-tab {
 	} */
 
 	@media (--wide-min) {
-		background-color: #fff;
+		background-color: var(--ep-c-white);
 		margin-right: 28px;
 		width: 37%;
 	}
 }
 
 .stats-queries {
-	background-color: #fff;
+	background-color: var(--ep-c-white);
 	width: 100%;
 
 	/* @media( --tablet-min ) {
@@ -908,27 +903,27 @@ h2 .nav-tab.ep-credentials-tab {
 }
 
 .green-status {
-	color: var(--ep-dashboard-status-ok);
+	color: var(--ep-status-ok);
 }
 
 .yellow-status {
-	color: var(--ep-dashboard-status-warning);
+	color: var(--ep-status-warning);
 }
 
 .red-status {
-	color: var(--ep-dashboard-status-error);
+	color: var(--ep-status-error);
 }
 
 .green-status::after {
-	background-color: var(--ep-dashboard-status-ok);
+	background-color: var(--ep-status-ok);
 }
 
 .yellow-status::after {
-	background-color: var(--ep-dashboard-status-warning);
+	background-color: var(--ep-status-warning);
 }
 
 .red-status::after {
-	background-color: var(--ep-dashboard-status-error);
+	background-color: var(--ep-status-error);
 }
 
 .doc-chart {
diff --git a/assets/css/facets.css b/assets/css/facets.css
index 22a9f6e8ca..4ca5a25004 100644
--- a/assets/css/facets.css
+++ b/assets/css/facets.css
@@ -1,6 +1,6 @@
+@import "./global/colors.css";
+
 :root {
-	--ep-range-slider-background-color: #fff;
-	--ep-range-slider-track-color: #eee;
 
 	@media ( min-width: 768px ) {
 		--ep-range-slider-thumb-size: 1.25em;
@@ -73,13 +73,13 @@
 	}
 
 	& .term a:hover .ep-checkbox {
-		background-color: #ccc;
+		background-color: var(--ep-c-white-gray);
 	}
 }
 
 .ep-checkbox {
 	align-items: center;
-	background-color: #eee;
+	background-color: var(--ep-c-medium-white);
 	display: flex;
 	flex-shrink: 0;
 	height: 1em;
@@ -99,7 +99,7 @@
 }
 
 .ep-checkbox.checked {
-	background-color: #5e5e5e;
+	background-color: var(--ep-c-medium-gray);
 }
 
 .ep-checkbox.checked::after {
@@ -128,21 +128,21 @@
 }
 
 .ep-range-slider__track {
-	background: var(--ep-range-slider-track-color);
+	background: var(--ep-c-medium-white);
 	border-radius: calc(var(--ep-range-slider-track-size) / 2);
 	height: var(--ep-range-slider-track-size);
 }
 
 .ep-range-slider__track-1 {
-	background-color: currentcolor; /* stylelint-disable-line scale-unlimited/declaration-strict-value */
+	background-color: currentcolor;
 }
 
 .ep-range-slider__thumb {
-	background-color: currentcolor; /* stylelint-disable-line scale-unlimited/declaration-strict-value */
+	background-color: currentcolor;
 	border-radius: calc(var(--ep-range-slider-thumb-size) / 2);
 	box-shadow:
 		inset 0 0 0 calc(var(--ep-range-slider-thumb-size) / 10) currentcolor,
-		inset 0 0 0 calc((var(--ep-range-slider-thumb-size) - var(--ep-range-slider-track-size)) / 2) var(--ep-range-slider-background-color);
+		inset 0 0 0 calc((var(--ep-range-slider-thumb-size) - var(--ep-range-slider-track-size)) / 2) var(--ep-c-white);
 	height: var(--ep-range-slider-thumb-size);
 	width: var(--ep-range-slider-thumb-size);
 }
@@ -155,7 +155,7 @@
 
 		& .ep-radio {
 			appearance: none;
-			border: 1px solid #eee;
+			border: 1px solid var(--ep-c-medium-white);
 			border-radius: 50%;
 			height: 1em;
 			margin-right: 0.25em;
@@ -165,7 +165,7 @@
 
 			&:checked {
 				background-color: transparent;
-				border: 5px solid #5e5e5e;
+				border: 5px solid var(--ep-c-medium-gray);
 
 				&::after {
 					opacity: 0;
diff --git a/assets/css/global/colors.css b/assets/css/global/colors.css
new file mode 100644
index 0000000000..66569fe649
--- /dev/null
+++ b/assets/css/global/colors.css
@@ -0,0 +1,27 @@
+/*
+ * Colors
+ */
+:root {
+
+	/**
+	 * Brand colors
+	 */
+	--ep-c-white: #fff;
+	--ep-c-medium-white: #eee;
+	--ep-c-white-gray: #ccc;
+	--ep-c-white-red: #ffe8ed;
+	--ep-c-white-yellow: #fdeeca;
+	--ep-c-medium-gray: #626262;
+	--ep-c-light-gray: #999;
+	--ep-c-black: #000;
+	--ep-c-medium-red: #d73c38;
+	--ep-c-dark-red: #b93431;
+	--ep-c-medium-dark-blue: #0073aa;
+
+	/**
+	 * Status colors
+	 */
+	--ep-status-ok: #6aa000;
+	--ep-status-warning: #e3e600;
+	--ep-status-error: #f00;
+}
diff --git a/assets/css/instant-results.css b/assets/css/instant-results.css
index 25a110f9d6..0bf5317945 100644
--- a/assets/css/instant-results.css
+++ b/assets/css/instant-results.css
@@ -1,3 +1,4 @@
+@import "./global/colors.css";
 @import "instant-results/utilities.css";
 @import "instant-results/checkbox.css";
 @import "instant-results/input.css";
@@ -17,8 +18,6 @@
 @import "instant-results/toolbar.css";
 
 :root {
-	--ep-search-background-color: #fff;
-	--ep-search-alternate-background-color: #efefef;
 	--ep-search-border-color: #dfdfdf;
 	--ep-search-range-thumb-size: 1.625em;
 	--ep-search-range-track-size: 0.75em;
diff --git a/assets/css/instant-results/modal.css b/assets/css/instant-results/modal.css
index 081dfffc0a..f66631ae7d 100644
--- a/assets/css/instant-results/modal.css
+++ b/assets/css/instant-results/modal.css
@@ -13,19 +13,6 @@
 	top: 0;
 	z-index: 9999;
 
-	@nest .rtl & {
-		direction: rtl;
-		text-align: right;
-	}
-
-	@nest .admin-bar & {
-		top: 32px;
-
-		@media ( max-width: 782px ) {
-			top: 46px;
-		}
-	}
-
 	&[aria-hidden="true"] {
 		display: none;
 	}
@@ -35,8 +22,25 @@
 	}
 }
 
+.rtl .ep-search-modal {
+	direction: rtl;
+	text-align: right;
+}
+
+.admin-bar .ep-search-modal {
+	top: 32px;
+}
+
+@media ( max-width: 782px ) {
+
+	.admin-bar .ep-search-modal {
+		top: 46px;
+	}
+}
+
+
 .ep-search-modal__content {
-	background-color: var(--ep-search-background-color);
+	background-color: var(--ep-c-white);
 	bottom: 0;
 	display: flex;
 	flex-direction: column;
diff --git a/assets/css/instant-results/pagination.css b/assets/css/instant-results/pagination.css
index c0eb1b2bfa..3d69e61e13 100644
--- a/assets/css/instant-results/pagination.css
+++ b/assets/css/instant-results/pagination.css
@@ -4,10 +4,10 @@
 	grid-template-columns: 1fr 1fr 1fr;
 	margin-top: auto;
 	text-align: center;
+}
 
-	@nest .rtl & {
-		direction: rtl;
-	}
+.rtl .ep-search-pagination {
+	direction: rtl;
 }
 
 .ep-search-pagination__next {
diff --git a/assets/css/instant-results/panel.css b/assets/css/instant-results/panel.css
index cfa0620f19..32d5cfa82d 100644
--- a/assets/css/instant-results/panel.css
+++ b/assets/css/instant-results/panel.css
@@ -2,10 +2,10 @@
 	border: 1px solid var(--ep-search-border-color);
 	margin: 0;
 	padding: 0;
+}
 
-	@nest .ep-search-panel + & {
-		border-top-width: 0;
-	}
+.ep-search-panel + .ep-search-panel {
+	border-top-width: 0;
 }
 
 .ep-search-panel__heading {
diff --git a/assets/css/instant-results/range-slider.css b/assets/css/instant-results/range-slider.css
index 521fa79c96..cdc09d95c1 100644
--- a/assets/css/instant-results/range-slider.css
+++ b/assets/css/instant-results/range-slider.css
@@ -6,7 +6,7 @@
 }
 
 .ep-search-range-slider__track {
-	background: var(--ep-search-alternate-background-color);
+	background: var(--ep-c-medium-white);
 	border-radius: calc(var(--ep-search-range-track-size) / 2);
 	height: var(--ep-search-range-track-size);
 }
@@ -20,7 +20,7 @@
 	border-radius: calc(var(--ep-search-range-thumb-size) / 2);
 	box-shadow:
 		inset 0 0 0 calc(var(--ep-search-range-thumb-size) / 10) currentcolor,
-		inset 0 0 0 calc((var(--ep-search-range-thumb-size) - var(--ep-search-range-track-size)) / 2) var(--ep-search-background-color);
+		inset 0 0 0 calc((var(--ep-search-range-thumb-size) - var(--ep-search-range-track-size)) / 2) var(--ep-c-white);
 	height: var(--ep-search-range-thumb-size);
 	width: var(--ep-search-range-thumb-size);
 }
diff --git a/assets/css/instant-results/result.css b/assets/css/instant-results/result.css
index 333769be1a..d0081747a8 100644
--- a/assets/css/instant-results/result.css
+++ b/assets/css/instant-results/result.css
@@ -61,7 +61,7 @@
 }
 
 .ep-search-result__type {
-	background-color: var(--ep-search-alternate-background-color);
+	background-color: var(--ep-c-medium-white);
 	border-radius: 0.25em;
 	display: inline-block;
 	font-size: 0.875em;
diff --git a/assets/css/instant-results/sort.css b/assets/css/instant-results/sort.css
index be9e085b4c..264fd13385 100644
--- a/assets/css/instant-results/sort.css
+++ b/assets/css/instant-results/sort.css
@@ -2,23 +2,26 @@
 	flex-shrink: 0;
 	gap: 0.5em;
 	margin: 0;
+}
 
-	@nest .ep-search-results & {
-		display: none;
+.ep-search-sidebar .ep-search-sort {
+	display: flex;
+	flex-direction: column;
+	margin-bottom: 1em;
+}
 
-		@media ( min-width: 768px ) {
-			align-items: center;
-			display: flex;
-		}
-	}
+.ep-search-results .ep-search-sort {
+	display: none;
+}
+
+@media ( min-width: 768px ) {
 
-	@nest .ep-search-sidebar & {
+	.ep-search-results .ep-search-sort {
+		align-items: center;
 		display: flex;
-		flex-direction: column;
-		margin-bottom: 1em;
+	}
 
-		@media ( min-width: 768px ) {
-			display: none;
-		}
+	.ep-search-sidebar .ep-search-sort {
+		display: none;
 	}
 }
diff --git a/assets/css/instant-results/tokens.css b/assets/css/instant-results/tokens.css
index a09d20f17a..8237f5b6b1 100644
--- a/assets/css/instant-results/tokens.css
+++ b/assets/css/instant-results/tokens.css
@@ -1,6 +1,3 @@
-.ep-search-tokens {
-
-	@nest .ep-search-toolbar & {
-		display: contents;
-	}
+.ep-search-toolbar .ep-search-tokens {
+	display: contents;
 }
diff --git a/assets/css/ordering.css b/assets/css/ordering.css
index db0814af3a..f6c3b7ccf5 100644
--- a/assets/css/ordering.css
+++ b/assets/css/ordering.css
@@ -1,9 +1,11 @@
+@import "./global/colors.css";
+
 #ep-ordering {
 	border-left-width: 0;
 	border-right-width: 0;
 
 	& .inside {
-		background-color: #f1f1f1;
+		background-color: var(--ep-c-white);
 		margin: 0;
 		padding: 0;
 	}
@@ -11,13 +13,13 @@
 	& .pointers,
 	& .pointer-search,
 	& .loading {
-		background-color: #fff;
-		border-left: 1px solid #eee;
-		border-right: 1px solid #eee;
+		background-color: var(--ep-c-white);
+		border-left: 1px solid var(--ep-c-medium-white);
+		border-right: 1px solid var(--ep-c-medium-white);
 	}
 
 	& .new-post {
-		background: #fff;
+		background: var(--ep-c-white);
 		padding: 0 1em;
 	}
 
@@ -32,9 +34,9 @@
 	}
 
 	& .pointer-type {
-		border: 2px solid #0073aa;
+		border: 2px solid var(--ep-c-medium-dark-blue);
 		border-radius: 2px;
-		color: #0073aa;
+		color: var(--ep-c-medium-dark-blue);
 		display: inline-block;
 		font-size: 0.75em;
 		font-weight: 700;
@@ -49,16 +51,16 @@
 			padding: 1em;
 
 			&:nth-child(odd) {
-				background-color: #f9f9f9;
+				background-color: var(--ep-c-white);
 			}
 		}
 
 		& .title {
-			color: #0073aa;
+			color: var(--ep-c-medium-dark-blue);
 		}
 
 		& .removed .title {
-			color: #999;
+			color: var(--ep-c-light-gray);
 		}
 
 		& .pointer-actions {
@@ -74,15 +76,15 @@
 		}
 
 		& .next-page-notice {
-			background-color: #fdeeca;
+			background-color: var(--ep-c-white-yellow);
 			padding: 1em 0;
 			text-align: center;
 		}
 	}
 
 	& .legend {
-		background: #fff;
-		border-bottom: 1px solid #eee;
+		background: var(--ep-c-white);
+		border-bottom: 1px solid var(--ep-c-medium-white);
 		padding: 1em 0;
 		text-align: center;
 	}
@@ -102,8 +104,8 @@
 		}
 
 		& .section-title {
-			border-bottom: 1px solid #eee;
-			border-top: 1px solid #eee;
+			border-bottom: 1px solid var(--ep-c-medium-white);
+			border-top: 1px solid var(--ep-c-medium-white);
 			box-shadow: 0 1px 1px rgba(0, 0, 0, 0.04);
 			font-weight: 700;
 		}
@@ -135,7 +137,7 @@
 			}
 
 			&:hover {
-				background-color: #f9f9f9;
+				background-color: var(--ep-c-white);
 			}
 		}
 	}
diff --git a/assets/css/woocommerce/admin/components/combobox.css b/assets/css/woocommerce/admin/components/combobox.css
index fc3cbdd639..39bd1d7f7e 100644
--- a/assets/css/woocommerce/admin/components/combobox.css
+++ b/assets/css/woocommerce/admin/components/combobox.css
@@ -1,7 +1,5 @@
 :root {
-	--ep-combobox-list-background: #fff;
 	--ep-combobox-list-background-selected: #f5f5f5;
-	--ep-combobox-list-border: #8c8f94;
 }
 
 .ep-combobox {
@@ -9,8 +7,8 @@
 }
 
 .ep-combobox__list {
-	background-color: var(--ep-combobox-list-background);
-	border: 1px solid var(--ep-combobox-list-border);
+	background-color: var(--ep-c-white);
+	border: 1px solid var(--ep-c-light-gray);
 	border-radius: 4px;
 	box-shadow: 0 2px 6px rgb(0 0 0 / 5%);
 	box-sizing: border-box;
@@ -23,9 +21,10 @@
 	width: 100%;
 	z-index: 1;
 
-	@nest .ep-combobox__input[aria-expanded="true"] ~ & {
-		display: block;
-	}
+}
+
+.ep-combobox__input[aria-expanded="true"] ~ .ep-combobox__list {
+	display: block;
 }
 
 .ep-combobox__option {
diff --git a/assets/css/woocommerce/admin/components/suggestion.css b/assets/css/woocommerce/admin/components/suggestion.css
index bcf2ed9fc8..4700ba4dcf 100644
--- a/assets/css/woocommerce/admin/components/suggestion.css
+++ b/assets/css/woocommerce/admin/components/suggestion.css
@@ -10,10 +10,10 @@
 	display: block;
 	font-size: small;
 	font-weight: 600;
+}
 
-	@nest [aria-selected="true"] & {
-		color: var(--wp-admin-theme-color);
-	}
+[aria-selected="true"] .ep-suggestion__title {
+	color: var(--wp-admin-theme-color);
 }
 
 .ep-suggestion__footer {
diff --git a/assets/css/woocommerce/admin/orders.css b/assets/css/woocommerce/admin/orders.css
index 7e96809cd2..0493062a4a 100644
--- a/assets/css/woocommerce/admin/orders.css
+++ b/assets/css/woocommerce/admin/orders.css
@@ -1,3 +1,4 @@
+@import "../../global/colors.css";
 @import "components/combobox.css";
 @import "components/suggestion.css";
 
diff --git a/assets/js/api-search/src/utilities.js b/assets/js/api-search/src/utilities.js
index 60b315b994..587020e4ff 100644
--- a/assets/js/api-search/src/utilities.js
+++ b/assets/js/api-search/src/utilities.js
@@ -135,9 +135,9 @@ export const getUrlParamsFromArgs = (args, schema, prefix = '') => {
  * @property {any} [default] Default arg value.
  * @property {Array} [allowedValues] Array of allowed values.
  *
- * @param {Object<string, ArgSchema>} argsSchema Schema to build args from.
+ * @param {{[key: string]: ArgSchema}} argsSchema Schema to build args from.
  * @param {string} [paramPrefix] Parameter prefix.
- * @returns {Object<string, any>} Query args.
+ * @returns {{[key: string]: any}} Query args.
  */
 export const getArgsFromUrlParams = (argsSchema, paramPrefix = '') => {
 	const urlParams = new URLSearchParams(window.location.search);
@@ -159,8 +159,8 @@ export const getArgsFromUrlParams = (argsSchema, paramPrefix = '') => {
 /**
  * Build request args from defaults provided in a given schema.
  *
- * @param {Object<string, ArgSchema>} argsSchema Schema to build args from.
- * @returns {Object<string, any>} Query args.
+ * @param {{[key: string]: ArgSchema}} argsSchema Schema to build args from.
+ * @returns {{[key: string]: any}} Query args.
  */
 export const getDefaultArgsFromSchema = (argsSchema) => {
 	return Object.entries(argsSchema).reduce((args, [arg, schema]) => {
diff --git a/assets/js/sync-ui/css/advanced-control.css b/assets/js/sync-ui/css/advanced-control.css
index 4757c3abf9..bb89b51438 100644
--- a/assets/js/sync-ui/css/advanced-control.css
+++ b/assets/js/sync-ui/css/advanced-control.css
@@ -1,10 +1,6 @@
 .ep-sync-advanced-control {
 	margin-bottom: 24px;
 
-	@nest fieldset& {
-		margin-bottom: 16px;
-	}
-
 	&.components-flex .components-flex-item {
 		flex-grow: 2;
 	}
@@ -14,6 +10,10 @@
 	}
 }
 
+fieldset.ep-sync-advanced-control {
+	margin-bottom: 16px;
+}
+
 .ep-sync-advanced-control__label {
 	display: inline-block;
 	font-size: 11px;
diff --git a/assets/js/sync-ui/css/progress-bar.css b/assets/js/sync-ui/css/progress-bar.css
index cd30f368ff..9e3431d1a9 100644
--- a/assets/js/sync-ui/css/progress-bar.css
+++ b/assets/js/sync-ui/css/progress-bar.css
@@ -17,16 +17,16 @@
 	padding: 0 8px;
 	transition: all 500ms ease-in-out;
 	white-space: nowrap;
+}
 
-	@nest .ep-sync-progress-bar--complete & {
-		background: var(--ep-sync-color-success);
-	}
+.ep-sync-progress-bar--complete .ep-sync-progress-bar__progress {
+	background: var(--ep-sync-color-success);
+}
 
-	@nest .ep-sync-progress-bar--paused & {
-		opacity: 0.5;
-	}
+.ep-sync-progress-bar--paused .ep-sync-progress-bar__progress {
+	opacity: 0.5;
+}
 
-	@nest .ep-sync-progress-bar--failed & {
-		background: var(--ep-sync-color-error);
-	}
+.ep-sync-progress-bar--failed .ep-sync-progress-bar__progress {
+	background: var(--ep-sync-color-error);
 }
diff --git a/assets/js/synonyms/css/list-table.css b/assets/js/synonyms/css/list-table.css
index e9af067b42..f5f344499d 100644
--- a/assets/js/synonyms/css/list-table.css
+++ b/assets/js/synonyms/css/list-table.css
@@ -46,10 +46,10 @@
 
 .ep-synonyms-list-table__primary-column {
 	width: 25%;
+}
 
-	@nest .ep-synonyms-list-table--replacements & {
-		width: auto;
-	}
+.ep-synonyms-list-table--replacements .ep-synonyms-list-table__primary-column {
+	width: auto;
 }
 
 .ep-synonyms-list-table__actions-column {
diff --git a/includes/classes/Command.php b/includes/classes/Command.php
index 0ae7e9bcd8..873de8c194 100644
--- a/includes/classes/Command.php
+++ b/includes/classes/Command.php
@@ -1114,14 +1114,13 @@ private function maybe_change_host( $assoc_args ) {
 		if ( isset( $assoc_args['ep-host'] ) ) {
 			add_filter(
 				'ep_host',
-				function ( $host ) use ( $assoc_args ) {
+				function () use ( $assoc_args ) {
 					return $assoc_args['ep-host'];
 				}
 			);
 		}
 	}
 
-
 	/**
 	 * maybe change index prefix on the fly
 	 *
@@ -1133,7 +1132,7 @@ private function maybe_change_index_prefix( $assoc_args ) {
 		if ( isset( $assoc_args['ep-prefix'] ) ) {
 			add_filter(
 				'ep_index_prefix',
-				function ( $prefix ) use ( $assoc_args ) {
+				function ( $prefix ) use ( $assoc_args ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
 					return $assoc_args['ep-prefix'];
 				}
 			);
diff --git a/includes/classes/Feature/Facets/Renderer.php b/includes/classes/Feature/Facets/Renderer.php
index 03fec4ba30..c31c253031 100644
--- a/includes/classes/Feature/Facets/Renderer.php
+++ b/includes/classes/Feature/Facets/Renderer.php
@@ -72,7 +72,8 @@ protected function order_values( array $values, string $orderby = 'count', $orde
 	 * @param string       $url         URL for the facet item.
 	 * @return string|null
 	 */
-	public function get_facet_item_value_html( $item, string $url ) {
+	public function get_facet_item_value_html( $item, string $url ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed
+		// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
 		return null;
 	}
 }
diff --git a/includes/classes/Feature/RelatedPosts/RelatedPosts.php b/includes/classes/Feature/RelatedPosts/RelatedPosts.php
index e5c321c569..9ed6e8920f 100644
--- a/includes/classes/Feature/RelatedPosts/RelatedPosts.php
+++ b/includes/classes/Feature/RelatedPosts/RelatedPosts.php
@@ -122,14 +122,14 @@ public function formatted_args( $formatted_args, $args ) {
 	 * Search Elasticsearch for related content
 	 *
 	 * @param  int $post_id Post ID
-	 * @param  int $return Return code
+	 * @param  int $post_return Number of posts to return
 	 * @since  4.1.0
 	 * @return WP_Query
 	 */
-	public function get_related_query( $post_id, $return = 5 ) {
+	public function get_related_query( $post_id, $post_return = 5 ) {
 		$args = array(
 			'more_like'           => $post_id,
-			'posts_per_page'      => $return,
+			'posts_per_page'      => $post_return,
 			'ep_integrate'        => true,
 			'ignore_sticky_posts' => true,
 		);
@@ -149,15 +149,15 @@ public function get_related_query( $post_id, $return = 5 ) {
 	 * Search Elasticsearch for related content
 	 *
 	 * @param  int $post_id Post ID
-	 * @param  int $return Return code
+	 * @param  int $post_return Number of posts to return
 	 *
 	 * @since  2.1
 	 * @uses get_related_query
 	 *
 	 * @return array|bool
 	 */
-	public function find_related( $post_id, $return = 5 ) {
-		$query = $this->get_related_query( $post_id, $return );
+	public function find_related( $post_id, $post_return = 5 ) {
+		$query = $this->get_related_query( $post_id, $post_return );
 
 		if ( ! $query->have_posts() ) {
 			return false;
diff --git a/includes/classes/Feature/Search/Weighting.php b/includes/classes/Feature/Search/Weighting.php
index f7d582b9fc..2b34e62053 100644
--- a/includes/classes/Feature/Search/Weighting.php
+++ b/includes/classes/Feature/Search/Weighting.php
@@ -351,9 +351,10 @@ public function render_settings_page() {
 	 * @param string $post_type      Current post type we're rendering
 	 * @param array  $field          Current field to render
 	 * @param array  $current_values Current stored weighting values
+	 *
 	 * @deprecated
 	 */
-	public function render_settings_section( $post_type, $field, $current_values ) {
+	public function render_settings_section( $post_type, $field, $current_values ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed
 		_doing_it_wrong(
 			__METHOD__,
 			esc_html( 'Weighting sections display are now handled via React components.' ),
@@ -381,7 +382,7 @@ public function handle_save() {
 	 * @param string $redirect_url Redirect URL.
 	 * @deprecated
 	 */
-	protected function redirect( $redirect_url ) {
+	protected function redirect( $redirect_url ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed,Generic.CodeAnalysis.UnusedFunctionParameter.Found
 		_doing_it_wrong(
 			__METHOD__,
 			esc_html( 'Weighting settings are now updated using the REST API, and do not redirect server-side.' ),
@@ -397,7 +398,7 @@ protected function redirect( $redirect_url ) {
 	 * @since 3.4.1
 	 * @deprecated
 	 */
-	public function save_weighting_configuration( $settings ) {
+	public function save_weighting_configuration( $settings ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.FoundAfterLastUsed,Generic.CodeAnalysis.UnusedFunctionParameter.Found
 		_doing_it_wrong(
 			__METHOD__,
 			esc_html( 'Weighting sections display are now handled via React components.' ),
diff --git a/includes/classes/Feature/WooCommerce/OrdersAutosuggest.php b/includes/classes/Feature/WooCommerce/OrdersAutosuggest.php
index ef2c9036a4..f38ca3f9dc 100644
--- a/includes/classes/Feature/WooCommerce/OrdersAutosuggest.php
+++ b/includes/classes/Feature/WooCommerce/OrdersAutosuggest.php
@@ -312,7 +312,7 @@ public function get_search_template() {
 
 		add_filter( 'ep_bypass_exclusion_from_search', '__return_true', 10 );
 		add_filter( 'ep_intercept_remote_request', '__return_true' );
-		add_filter( 'ep_do_intercept_request', [ $this, 'intercept_search_request' ], 10, 4 );
+		add_filter( 'ep_do_intercept_request', [ $this, 'intercept_search_request' ], 10, 3 );
 		add_filter( 'ep_is_integrated_request', [ $this, 'is_integrated_request' ], 10, 2 );
 
 		$query = new \WP_Query(
@@ -363,10 +363,9 @@ public function is_integrated_request( $is_integrated, $context ) {
 	 * @param object $response Response
 	 * @param array  $query Query
 	 * @param array  $args WP_Query argument array
-	 * @param int    $failures Count of failures in request loop
 	 * @return object $response Response
 	 */
-	public function intercept_search_request( $response, $query = [], $args = [], $failures = 0 ) {
+	public function intercept_search_request( $response, $query = [], $args = [] ) {
 		$this->search_template = $query['args']['body'];
 
 		return wp_remote_request( $query['url'], $args );
diff --git a/includes/classes/IndexHelper.php b/includes/classes/IndexHelper.php
index ffc761b582..143dee551e 100644
--- a/includes/classes/IndexHelper.php
+++ b/includes/classes/IndexHelper.php
@@ -1168,21 +1168,21 @@ public function get_last_sync(): array {
 	 * We used to have two different filters for this (one for the dashboard, another for CLI),
 	 * this method combines both.
 	 *
-	 * @param {stdClass}  $object Object to be checked
+	 * @param {stdClass}  $indexable_object Object to be checked
 	 * @param {Indexable} $indexable Indexable
 	 * @return boolean
 	 */
-	protected function should_skip_object_index( $object, $indexable ) {
+	protected function should_skip_object_index( $indexable_object, $indexable ) {
 		/**
 		 * Filter whether to not sync specific item in dashboard or not
 		 *
 		 * @since  2.1
 		 * @hook ep_item_sync_kill
 		 * @param  {boolean} $kill False means dont sync
-		 * @param  {array} $object Object to sync
+		 * @param  {array} $indexable_object Object to sync
 		 * @return {Indexable} Indexable that object belongs to
 		 */
-		$ep_item_sync_kill = apply_filters( 'ep_item_sync_kill', false, $object, $indexable );
+		$ep_item_sync_kill = apply_filters( 'ep_item_sync_kill', false, $indexable_object, $indexable );
 
 		/**
 		 * Conditionally kill indexing for a post
@@ -1192,7 +1192,7 @@ protected function should_skip_object_index( $object, $indexable ) {
 		 * @param  {int} $object_id Object ID
 		 * @return {bool} New value
 		 */
-		$ep_indexable_sync_kill = apply_filters( 'ep_' . $indexable->slug . '_index_kill', false, $object->ID );
+		$ep_indexable_sync_kill = apply_filters( 'ep_' . $indexable->slug . '_index_kill', false, $indexable_object->ID );
 
 		return $ep_item_sync_kill || $ep_indexable_sync_kill;
 	}
diff --git a/includes/classes/Indexable/Post/QueryIntegration.php b/includes/classes/Indexable/Post/QueryIntegration.php
index 06d78c9781..846bb8187e 100644
--- a/includes/classes/Indexable/Post/QueryIntegration.php
+++ b/includes/classes/Indexable/Post/QueryIntegration.php
@@ -64,7 +64,7 @@ public function __construct( $indexable_slug = 'post' ) {
 		add_filter( 'posts_pre_query', array( $this, 'get_es_posts' ), 10, 2 );
 
 		// Properly restore blog if necessary
-		add_action( 'loop_end', array( $this, 'maybe_restore_blog' ), 10, 1 );
+		add_action( 'loop_end', array( $this, 'maybe_restore_blog' ), 10 );
 
 		// Properly switch to blog if necessary
 		add_action( 'the_post', array( $this, 'maybe_switch_to_blog' ), 10, 2 );
@@ -194,10 +194,11 @@ public function maybe_switch_to_blog( $post, $query = null ) {
 	/**
 	 * Make sure the correct blog is restored
 	 *
-	 * @param  WP_Query $query WP_Query instance
+	 * @param WP_Query $query WP_Query instance
+	 *
 	 * @since 0.9
 	 */
-	public function maybe_restore_blog( $query ) {
+	public function maybe_restore_blog( $query ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
 		if ( ! is_multisite() ) {
 			// @codeCoverageIgnoreStart
 			return;
diff --git a/includes/classes/Indexables.php b/includes/classes/Indexables.php
index a2011c616a..c405f1edc3 100644
--- a/includes/classes/Indexables.php
+++ b/includes/classes/Indexables.php
@@ -118,24 +118,24 @@ public function is_active( string $slug ): bool {
 	/**
 	 * Get all indexable instances
 	 *
-	 * @param  boolean $global    If true or false, will only get Indexables with that global property.
+	 * @param  boolean $global_property    If true or false, will only get Indexables with that global property.
 	 * @param  boolean $slug_only True returns an array of only string slugs.
 	 * @param  string  $status    Whether to return active indexables or all registered.
 	 * @since  3.0, 4.5.0 Added $status
 	 * @return array
 	 */
-	public function get_all( $global = null, $slug_only = false, $status = 'active' ) {
+	public function get_all( $global_property = null, $slug_only = false, $status = 'active' ) {
 		$indexables = [];
 		$list       = ( 'active' === $status ) ? $this->active_indexables : $this->registered_indexables;
 
 		foreach ( $list as $slug => $indexable ) {
-			if ( null === $global ) {
+			if ( null === $global_property ) {
 				if ( $slug_only ) {
 					$indexables[] = $slug;
 				} else {
 					$indexables[] = $indexable;
 				}
-			} elseif ( $global === $indexable->global ) {
+			} elseif ( $global_property === $indexable->global ) {
 				if ( $slug_only ) {
 					$indexables[] = $slug;
 				} else {
diff --git a/includes/classes/Installer.php b/includes/classes/Installer.php
index c5a54bb4f5..c62235059d 100644
--- a/includes/classes/Installer.php
+++ b/includes/classes/Installer.php
@@ -33,18 +33,17 @@ class Installer {
 	 */
 	public function setup() {
 		add_action( 'admin_init', [ $this, 'calculate_install_status' ], 9 );
-		add_filter( 'admin_title', [ $this, 'filter_admin_title' ], 10, 2 );
+		add_filter( 'admin_title', [ $this, 'filter_admin_title' ], 10 );
 	}
 
 	/**
 	 * Filter admin title for install page
 	 *
 	 * @param  string $admin_title Current title
-	 * @param  string $title       Original title
 	 * @since  3.0
 	 * @return string
 	 */
-	public function filter_admin_title( $admin_title, $title ) {
+	public function filter_admin_title( $admin_title ) {
 		if ( 'install' === Screen::factory()->get_current_screen() ) {
 			// translators: Site Name
 			return sprintf( esc_html__( 'ElasticPress Setup &lsaquo; %s &#8212; WordPress', 'elasticpress' ), esc_html( get_bloginfo( 'name' ) ) );
diff --git a/includes/classes/REST/MetaKeys.php b/includes/classes/REST/MetaKeys.php
index ae75cd595a..f7c8d56f40 100644
--- a/includes/classes/REST/MetaKeys.php
+++ b/includes/classes/REST/MetaKeys.php
@@ -50,10 +50,9 @@ public function check_permission() {
 	/**
 	 * Get indexed meta keys.
 	 *
-	 * @param \WP_REST_Request $request Full details about the request.
 	 * @return array
 	 */
-	public function get_meta_keys( \WP_REST_Request $request ) {
+	public function get_meta_keys() {
 		$post_indexable = Indexables::factory()->get( 'post' );
 
 		try {
diff --git a/includes/classes/REST/Sync.php b/includes/classes/REST/Sync.php
index 41280bdddc..7c16fe0fbe 100644
--- a/includes/classes/REST/Sync.php
+++ b/includes/classes/REST/Sync.php
@@ -177,10 +177,9 @@ public function output( array $message ) {
 	/**
 	 * Get the status of a sync in progress.
 	 *
-	 * @param \WP_REST_Request $request Full details about the request.
 	 * @return void
 	 */
-	public function get_sync_status( \WP_REST_Request $request ) {
+	public function get_sync_status() {
 		nocache_headers();
 
 		$index_meta = Utils\get_indexing_status();
@@ -211,10 +210,9 @@ public function get_sync_status( \WP_REST_Request $request ) {
 	/**
 	 * Cancel a sync in progress.
 	 *
-	 * @param \WP_REST_Request $request Full details about the request.
 	 * @return void
 	 */
-	public function cancel_sync( \WP_REST_Request $request ) {
+	public function cancel_sync() {
 		nocache_headers();
 
 		$index_meta = Utils\get_indexing_status();
diff --git a/includes/classes/REST/Taxonomies.php b/includes/classes/REST/Taxonomies.php
index 582cccb333..92caf0af73 100644
--- a/includes/classes/REST/Taxonomies.php
+++ b/includes/classes/REST/Taxonomies.php
@@ -49,10 +49,9 @@ public function check_permission() {
 	/**
 	 * Get filterable taxonomies.
 	 *
-	 * @param \WP_REST_Request $request Full details about the request.
 	 * @return array
 	 */
-	public function get_taxonomies( \WP_REST_Request $request ) {
+	public function get_taxonomies() {
 		$filterable_taxonomies = Features::factory()->get_registered_feature( 'facets' )->types['taxonomy']->get_facetable_taxonomies();
 
 		$taxonomies = [];
diff --git a/includes/classes/REST/Token.php b/includes/classes/REST/Token.php
index a999de8de6..3afe88bf73 100644
--- a/includes/classes/REST/Token.php
+++ b/includes/classes/REST/Token.php
@@ -81,10 +81,9 @@ public function get_token( \WP_REST_Request $request ) {
 	/**
 	 * Refresh the temporary token.
 	 *
-	 * @param \WP_REST_Request $request Full details about the request.
 	 * @return string|false
 	 */
-	public function refresh_token( \WP_REST_Request $request ) {
+	public function refresh_token() {
 		$user_id = get_current_user_id();
 
 		$endpoint = $this->get_token_endpoint();
diff --git a/includes/compat.php b/includes/compat.php
index 173db48b06..4fa0ce9437 100644
--- a/includes/compat.php
+++ b/includes/compat.php
@@ -51,16 +51,16 @@ public function __construct( $code, $message = null ) {
  * Search Elasticsearch for related content
  *
  * @param  int $post_id Post ID
- * @param  int $return Number of posts to get
+ * @param  int $post_return Number of posts to get
  * @since  2.1
  * @return array|bool
  */
-function ep_find_related( $post_id, $return = 5 ) {
+function ep_find_related( $post_id, $post_return = 5 ) {
 	_deprecated_function( __FUNCTION__, '3.0', 'ElasticPress\Features::factory()->get_registered_feature' );
 
 	$feature = \ElasticPress\Features::factory()->get_registered_feature( 'related_posts' );
 
-	return ( ! empty( $feature ) ) ? $feature->find_related( $post_id, $return ) : false;
+	return ( ! empty( $feature ) ) ? $feature->find_related( $post_id, $post_return ) : false;
 }
 
 /**
diff --git a/tests/php/features/TestAutosuggest.php b/tests/php/features/TestAutosuggest.php
index e4501dad41..66775d0278 100644
--- a/tests/php/features/TestAutosuggest.php
+++ b/tests/php/features/TestAutosuggest.php
@@ -347,7 +347,7 @@ public function test_autosuggest_ngram_fields_for_ajax_request() {
 
 		add_filter(
 			'ep_query_request_path',
-			function ( $path, $index, $type, $query, $query_args, $query_object ) {
+			function ( $path, $index, $type, $query ) {
 				$fields = $query['query']['function_score']['query']['bool']['should'][0]['bool']['must'][0]['bool']['should'][1]['multi_match']['fields'];
 
 				$this->assertContains( 'term_suggest^1', $fields );
@@ -355,7 +355,7 @@ function ( $path, $index, $type, $query, $query_args, $query_object ) {
 				return $path;
 			},
 			10,
-			6
+			4
 		);
 
 		$query = new \WP_Query(
@@ -399,7 +399,7 @@ public function test_autosuggest_ngram_fields_for_ajax_request_negative() {
 
 		add_filter(
 			'ep_query_request_path',
-			function ( $path, $index, $type, $query, $query_args, $query_object ) {
+			function ( $path, $index, $type, $query ) {
 				$fields = $query['query']['function_score']['query']['bool']['should'][0]['bool']['must'][0]['bool']['should'][1]['multi_match']['fields'];
 
 				$this->assertNotContains( 'term_suggest^1', $fields );
@@ -407,7 +407,7 @@ function ( $path, $index, $type, $query, $query_args, $query_object ) {
 				return $path;
 			},
 			10,
-			6
+			4
 		);
 
 		$query = new \WP_Query(
@@ -449,12 +449,12 @@ public function test_fuziness_with_type_auto_set_for_ajax_call() {
 
 		add_filter(
 			'ep_query_request_path',
-			function ( $path, $index, $type, $query, $query_args, $query_object ) {
+			function ( $path, $index, $type, $query ) {
 				$this->assertEquals( 'auto', $query['query']['function_score']['query']['bool']['should'][2]['multi_match']['fuzziness'] );
 				return $path;
 			},
 			10,
-			6
+			4
 		);
 
 		$query = new \WP_Query(
@@ -500,12 +500,12 @@ public function test_fuziness_with_type_auto_set_for_ajax_call_negative() {
 
 		add_filter(
 			'ep_query_request_path',
-			function ( $path, $index, $type, $query, $query_args, $query_object ) {
+			function ( $path, $index, $type, $query ) {
 				$this->assertNotEquals( 'auto', $query['query']['function_score']['query']['bool']['should'][2]['multi_match']['fuzziness'] );
 				return $path;
 			},
 			10,
-			6
+			4
 		);
 
 		$query = new \WP_Query(
diff --git a/tests/php/features/TestDidYouMean.php b/tests/php/features/TestDidYouMean.php
index ff30159242..d514f99082 100644
--- a/tests/php/features/TestDidYouMean.php
+++ b/tests/php/features/TestDidYouMean.php
@@ -252,12 +252,12 @@ function () use ( $search_analyzer ) {
 
 		add_filter(
 			'ep_query_request_args',
-			function ( $request_args, $path, $index, $type, $query, $query_args, $query_object ) use ( $search_analyzer ) {
+			function ( $request_args, $path, $index, $type, $query ) use ( $search_analyzer ) {
 				$this->assertEquals( $search_analyzer, $query['suggest']['ep_suggestion'] );
 				return $request_args;
 			},
 			10,
-			7
+			5
 		);
 
 		$query = new \WP_Query(
diff --git a/tests/php/features/TestFacetTypeDate.php b/tests/php/features/TestFacetTypeDate.php
index 637ff7c26b..d2a95c1d6a 100644
--- a/tests/php/features/TestFacetTypeDate.php
+++ b/tests/php/features/TestFacetTypeDate.php
@@ -254,7 +254,7 @@ public function testGetFacetOptions() {
 			],
 		];
 
-		$change_filter_type = function ( $options ) use ( $modified_options ) {
+		$change_filter_type = function ( $options ) use ( $modified_options ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
 			return $modified_options;
 		};
 
diff --git a/tests/php/features/TestFacetTypeMeta.php b/tests/php/features/TestFacetTypeMeta.php
index a82ae8f644..93f2f25593 100644
--- a/tests/php/features/TestFacetTypeMeta.php
+++ b/tests/php/features/TestFacetTypeMeta.php
@@ -365,9 +365,9 @@ public function testGetSanitizeCallback() {
 		$expected_result = sanitize_text_field( $test_meta );
 		$this->assertArrayHasKey( $expected_result, $selected['meta']['new_meta_key_1']['terms'] );
 
-		$sanitize_function = function ( $function ) {
+		$sanitize_function = function ( $callback ) {
 
-			$this->assertSame( 'sanitize_text_field', $function );
+			$this->assertSame( 'sanitize_text_field', $callback );
 
 			return 'sanitize_title';
 		};
diff --git a/tests/php/features/TestFacetTypeTaxonomy.php b/tests/php/features/TestFacetTypeTaxonomy.php
index e7a626d901..4292d5fc5a 100644
--- a/tests/php/features/TestFacetTypeTaxonomy.php
+++ b/tests/php/features/TestFacetTypeTaxonomy.php
@@ -219,9 +219,9 @@ public function testGetSanitizeCallback() {
 		$expected_result = sanitize_title( $test_taxonomy );
 		$this->assertArrayHasKey( $expected_result, $selected['taxonomies']['taxonomy']['terms'] );
 
-		$sanitize_function = function ( $function ) {
+		$sanitize_function = function ( $callback ) {
 
-			$this->assertSame( 'sanitize_title', $function );
+			$this->assertSame( 'sanitize_title', $callback );
 
 			return 'sanitize_text_field';
 		};
diff --git a/tests/php/features/WooCommerce/TestWooCommerceProduct.php b/tests/php/features/WooCommerce/TestWooCommerceProduct.php
index b2c9eb170f..ce991468bf 100644
--- a/tests/php/features/WooCommerce/TestWooCommerceProduct.php
+++ b/tests/php/features/WooCommerce/TestWooCommerceProduct.php
@@ -439,7 +439,7 @@ public function testProductListInAdminUseElasticSearch() {
 
 		add_filter(
 			'ep_post_filters',
-			function ( $filters, $args, $query ) {
+			function ( $filters ) {
 				$expected_result = array(
 					'terms' => array(
 						'post_type.raw' => array(
@@ -452,7 +452,6 @@ function ( $filters, $args, $query ) {
 				return $filters;
 			},
 			10,
-			3
 		);
 
 		parse_str( 'post_type=product&s=product', $_GET );
@@ -487,7 +486,7 @@ public function testProductListSearchInAdminUseElasticSearch() {
 
 		add_filter(
 			'ep_post_formatted_args',
-			function ( $formatted_args, $args, $wp_query ) {
+			function ( $formatted_args, ) {
 				$this->assertEquals( 'findme', $formatted_args['query']['function_score']['query']['bool']['should'][0]['multi_match']['query'] );
 				$this->assertEquals(
 					$args['search_fields'],
@@ -504,8 +503,7 @@ function ( $formatted_args, $args, $wp_query ) {
 
 				return $formatted_args;
 			},
-			10,
-			3
+			10
 		);
 
 		parse_str( 'post_type=product&s=findme', $_GET );
diff --git a/tests/php/includes/classes/mock/class-wp-cli.php b/tests/php/includes/classes/mock/class-wp-cli.php
index b4e0c48a95..64a1c971d0 100644
--- a/tests/php/includes/classes/mock/class-wp-cli.php
+++ b/tests/php/includes/classes/mock/class-wp-cli.php
@@ -34,10 +34,9 @@ public static function success( $message ) {
 	/**
 	 * Display debug message.
 	 *
-	 * @param string  $message Message to display to the end user.
-	 * @param boolean $group   Group
+	 * @param string $message Message to display to the end user.
 	 */
-	public static function debug( $message, $group = false ) {
+	public static function debug( $message ) {
 		print $message;
 	}
 
@@ -54,13 +53,13 @@ public static function warning( $message ) {
 	 * Display error message.
 	 *
 	 * @param string  $message Message to display to the end user.
-	 * @param boolean $exit    Whether exit or not.
+	 * @param boolean $should_exit    Whether exit or not.
 	 * @return void
 	 * @throws Exception Exception
 	 */
-	public static function error( $message, $exit = true ) {
+	public static function error( $message, $should_exit = true ) {
 
-		if ( ! $exit ) {
+		if ( ! $should_exit ) {
 			print $message;
 			return;
 		}
diff --git a/tests/php/includes/wp-cli-utils.php b/tests/php/includes/wp-cli-utils.php
index 40693f7008..02bfd05e0d 100644
--- a/tests/php/includes/wp-cli-utils.php
+++ b/tests/php/includes/wp-cli-utils.php
@@ -19,9 +19,9 @@
  *
  * @param array  $assoc_args  Arguments array.
  * @param string $flag        Flag to get the value.
- * @param mixed  $default     Default value for the flag. Default: NULL
+ * @param mixed  $default_value     Default value for the flag. Default: NULL
  * @return mixed
  */
-function get_flag_value( $assoc_args, $flag, $default = null ) {
-	return isset( $assoc_args[ $flag ] ) ? $assoc_args[ $flag ] : $default;
+function get_flag_value( $assoc_args, $flag, $default_value = null ) {
+	return isset( $assoc_args[ $flag ] ) ? $assoc_args[ $flag ] : $default_value;
 }
diff --git a/tests/php/indexables/TestPost.php b/tests/php/indexables/TestPost.php
index b6c16fedde..ebfbda75b7 100644
--- a/tests/php/indexables/TestPost.php
+++ b/tests/php/indexables/TestPost.php
@@ -3827,11 +3827,11 @@ public function testAutoDraftPostStatus() {
 	 *
 	 * @param array|WP_Error $response  HTTP response or WP_Error object.
 	 * @param string         $type Context under which the hook is fired.
-	 * @param string         $class HTTP transport used.
+	 * @param string         $http_class HTTP transport used.
 	 * @param array          $args HTTP request arguments.
 	 * @param string         $url The request URL.
 	 */
-	public function check404( $response, $type, $class, $args, $url ) {
+	public function check404( $response, $type, $http_class, $args, $url ) {
 		$response_code = $response['response']['code'];
 		if ( 404 === $response_code ) {
 			$this->is_404 = true;
@@ -8320,7 +8320,7 @@ public function testHighlightTagsWithCustomClass() {
 
 		add_filter(
 			'ep_highlighting_class',
-			function ( $class ) {
+			function ( $highlight_class ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
 				return 'my-custom-class';
 			}
 		);
@@ -8358,7 +8358,7 @@ public function testHighlightTagsOnlyForTitle() {
 
 		add_filter(
 			'ep_highlighting_fields',
-			function ( $fields ) {
+			function ( $fields ) { // phpcs:ignore Generic.CodeAnalysis.UnusedFunctionParameter.Found
 				return array( 'post_title' );
 			}
 		);
@@ -8434,14 +8434,14 @@ public function testHighlightTagsNotSetWhenSearchIsEmpty() {
 
 		add_action(
 			'pre_http_request',
-			function ( $preempt, $parsed_args, $url ) {
+			function ( $preempt, $parsed_args ) {
 
 				$body = json_decode( $parsed_args['body'], true );
 				$this->assertArrayNotHasKey( 'highlight', $body );
 				return $preempt;
 			},
 			10,
-			3
+			2
 		);
 
 		$args  = array(
diff --git a/tests/php/screen/TestStatusReport.php b/tests/php/screen/TestStatusReport.php
index cebc284d67..4049a69eab 100644
--- a/tests/php/screen/TestStatusReport.php
+++ b/tests/php/screen/TestStatusReport.php
@@ -60,7 +60,7 @@ public function testGetReportsFilter() {
 	public function testGetReportsSkipped() {
 		$status_report = new StatusReport();
 
-		parse_str( 'ep-skip-reports[]=wordpress&ep-skip-reports[]=indexable', $_GET ); // phpcs:ignore WordPress.WP.CapitalPDangit.Misspelled
+		parse_str( 'ep-skip-reports[]=wordpress&ep-skip-reports[]=indexable', $_GET ); // phpcs:ignore WordPress.WP.CapitalPDangit.MisspelledInText
 
 		$reports = $status_report->get_reports();
 		$this->assertSame(