diff --git a/package.json b/package.json
index 82e8eaf..7f0a24f 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,9 @@
 		"test": "echo success"
 	},
 	"dependencies": {
+		"@jamescoyle/vue-icon": "^0.1.2",
 		"@mdi/font": "^7.4.47",
+		"@mdi/js": "^7.4.47",
 		"pinia": "^2.2.6",
 		"vue": "^3.5.13",
 		"vue-router": "^4.4.5"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index f7b85dd..7673810 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -8,9 +8,15 @@ importers:
 
   .:
     dependencies:
+      '@jamescoyle/vue-icon':
+        specifier: ^0.1.2
+        version: 0.1.2
       '@mdi/font':
         specifier: ^7.4.47
         version: 7.4.47
+      '@mdi/js':
+        specifier: ^7.4.47
+        version: 7.4.47
       pinia:
         specifier: ^2.2.6
         version: 2.2.6(typescript@5.6.3)(vue@3.5.13(typescript@5.6.3))
@@ -556,12 +562,18 @@ packages:
     resolution: {integrity: sha512-c7hNEllBlenFTHBky65mhq8WD2kbN9Q6gk0bTk8lSBvc554jpXSkST1iePudpt7+A/AQvuHs9EMqjHDXMY1lrA==}
     engines: {node: '>=18.18'}
 
+  '@jamescoyle/vue-icon@0.1.2':
+    resolution: {integrity: sha512-KFrImXx5TKIi6iQXlnyLEBl4rNosNKbTeRnr70ucTdUaciVmd9qK9d/pZAaKt1Ob/8xNnX2GMp8LisyHdKtEgw==}
+
   '@jridgewell/sourcemap-codec@1.5.0':
     resolution: {integrity: sha512-gv3ZRaISU3fjPAgNsriBRqGWQL6quFx04YMPW/zD8XMLsU32mhCCbfbO6KZFLjvYpCZ8zyDEgqsgf+PwPaM7GQ==}
 
   '@mdi/font@7.4.47':
     resolution: {integrity: sha512-43MtGpd585SNzHZPcYowu/84Vz2a2g31TvPMTm9uTiCSWzaheQySUcSyUH/46fPnuPQWof2yd0pGBtzee/IQWw==}
 
+  '@mdi/js@7.4.47':
+    resolution: {integrity: sha512-KPnNOtm5i2pMabqZxpUz7iQf+mfrYZyKCZ8QNz85czgEt7cuHcGorWfdzUMWYA0SD+a6Hn4FmJ+YhzzzjkTZrQ==}
+
   '@nodelib/fs.scandir@2.1.5':
     resolution: {integrity: sha512-vq24Bq3ym5HEQm2NKCr3yXDwjc7vTsEThRDnkp2DK9p1uqLR+DHurm/NOTo0KG7HYHU7eppKZj3MyqYuMBf62g==}
     engines: {node: '>= 8'}
@@ -979,8 +991,8 @@ packages:
     resolution: {integrity: sha512-cgwlv/1iFQiFnU96XXgROh8xTeetsnJiDsTc7TYCLFd9+/WNkIqPTxiM/8pSd8VIrhXGTf1Ny1q1hquVqDJB5w==}
     engines: {node: '>= 4'}
 
-  domutils@3.1.0:
-    resolution: {integrity: sha512-H78uMmQtI2AhgDJjWeQmHwJJ2bLPD3GMmO7Zja/ZZh84wkm+4ut+IUnUdRa8uCGX88DiVx1j6FRe1XfxEgjEZA==}
+  domutils@3.2.2:
+    resolution: {integrity: sha512-6kZKyUajlDuqlHKVX1w7gyslj9MPIXzIFiz/rGu35uC1wMi+kMhQwGhl4lt9unC9Vb9INnY9Z3/ZA3+FhASLaw==}
 
   electron-to-chromium@1.5.60:
     resolution: {integrity: sha512-HcraRUkTKJ+8yA3b10i9qvhUlPBRDlKjn1XGek1zDGVfAKcvi8TsUnImGqLiEm9j6ZulxXIWWIo9BmbkbCTGgA==}
@@ -2315,10 +2327,14 @@ snapshots:
 
   '@humanwhocodes/retry@0.4.1': {}
 
+  '@jamescoyle/vue-icon@0.1.2': {}
+
   '@jridgewell/sourcemap-codec@1.5.0': {}
 
   '@mdi/font@7.4.47': {}
 
+  '@mdi/js@7.4.47': {}
+
   '@nodelib/fs.scandir@2.1.5':
     dependencies:
       '@nodelib/fs.stat': 2.0.5
@@ -2740,7 +2756,7 @@ snapshots:
     dependencies:
       domelementtype: 2.3.0
 
-  domutils@3.1.0:
+  domutils@3.2.2:
     dependencies:
       dom-serializer: 2.0.0
       domelementtype: 2.3.0
@@ -3002,7 +3018,7 @@ snapshots:
     dependencies:
       domelementtype: 2.3.0
       domhandler: 5.0.3
-      domutils: 3.1.0
+      domutils: 3.2.2
       entities: 4.5.0
 
   ignore@5.3.2: {}
diff --git a/src/constants/index.ts b/src/constants/index.ts
index 29cc1c8..986a0c6 100644
--- a/src/constants/index.ts
+++ b/src/constants/index.ts
@@ -11,3 +11,38 @@ export const PAYMENTS = {
 };
 
 export const TAX = 0.04;
+
+export const TipFromSum = {
+	gas: {
+		[PAYMENTS['gas']['only4']]:
+			"Если сессия закрыта только с оценками 'хорошо' или если вы только поступили",
+		[PAYMENTS['gas']['miss']]:
+			"Если сессия закрыта только с оценками 'хорошо', или если вы только поступили",
+		[PAYMENTS['gas']['with4and5']]: "Если сессия закрыта с оценками 'хорошо' и 'отлично'",
+		[PAYMENTS['gas']['only5']]: "Если сессия закрыта с только с оценками 'отлично'",
+		[PAYMENTS['gas']['only4'] * (1 - TAX)]:
+			"Если сессия закрыта только с оценками 'хорошо' или если вы только поступили; за вычетом профсоюзного взноса.",
+		[PAYMENTS['gas']['miss'] * (1 - TAX)]:
+			"Если сессия закрыта только с оценками 'хорошо', или если вы только поступили; за вычетом профсоюзного взноса.",
+		[PAYMENTS['gas']['with4and5'] * (1 - TAX)]:
+			"Если сессия закрыта с оценками 'хорошо' и 'отлично'; за вычетом профсоюзного взноса.",
+		[PAYMENTS['gas']['only5'] * (1 - TAX)]:
+			"Если сессия закрыта с только с оценками 'отлично'; за вычетом профсоюзного взноса.",
+	},
+	pgas: {
+		[PAYMENTS['pgas']]: 'Вы получаете повышенную академическую стипендию',
+		[PAYMENTS['pgas'] * (1 - TAX)]:
+			'Вы получаете повышенную академическую стипендию; за вычетом профсоюзного взноса.',
+	},
+	gss: {
+		[PAYMENTS['gss']]: 'Вы получаете государственную социальную стипендию',
+		[PAYMENTS['gss'] * (1 - TAX)]:
+			'Вы получаете государственную социальную стипендию; за вычетом профсоюзного взноса.',
+	},
+	pgss: {
+		[PAYMENTS['pgss']]: 'Вы получаете повышенную государственную социальную стипендию',
+		[PAYMENTS['pgss'] * (1 - TAX)]:
+			'Вы получаете повышенную государственную социальную стипендию; за вычетом профсоюзного взноса.',
+	},
+	proffee: '4% от всей полученной суммы',
+};
diff --git a/src/pages/ReverseCalc.vue b/src/pages/ReverseCalc.vue
index 05118d0..f019d55 100644
--- a/src/pages/ReverseCalc.vue
+++ b/src/pages/ReverseCalc.vue
@@ -1,7 +1,9 @@
 <script setup lang="ts">
 import { computed, ref } from 'vue';
+import { useDisplay } from 'vuetify';
+import { mdiInformationOutline } from '@mdi/js';
 import IrdomSection from '../components/IrdomSection.vue';
-import { PAYMENTS, TAX } from '../constants/';
+import { PAYMENTS, TAX, TipFromSum } from '../constants/';
 import { lz } from '../utils';
 
 interface Result {
@@ -29,7 +31,8 @@ const emptyResult: Result = {
 	tax: 0,
 };
 
-const screenWidth = window.innerWidth;
+const { width } = useDisplay();
+const isNarrow = computed(() => width.value < 800);
 
 const flattenStipend = (options: typeof PAYMENTS): typeof convertedStipend => {
 	const newOptions: typeof convertedStipend = Object.assign({}, convertedStipend);
@@ -112,26 +115,27 @@ function formatInput(input: string) {
 	}
 }
 
-let result: Result = emptyResult;
-const recount = computed(() => {
-	const tempInput = inputSum.value.replace(',', '.');
-	result =
-		combinations.find(o => o.sum <= Number(tempInput) + 1 && o.sum >= Number(tempInput) - 1) ??
-		emptyResult;
-	return result;
+const parsedSum = computed(() => {
+	const s = inputSum.value.trim().replace(',', '.');
+	if (!s) return null;
+	const n = Number(s);
+	return Number.isFinite(n) ? n : null;
 });
 
 const found = computed(() => {
-	const foundResult = combinations.find(
-		o => o.sum <= Number(inputSum.value) + 1 && o.sum >= Number(inputSum.value) - 1
-	);
-	if (foundResult) {
-		return true;
-	} else {
-		return false;
-	}
+	const target = parsedSum.value;
+	if (target === null) return false;
+	return combinations.some(o => Math.abs(o.sum - target) <= 1);
+});
+
+const recount = computed(() => {
+	const target = parsedSum.value;
+	if (target === null) return emptyResult;
+	return combinations.find(o => Math.abs(o.sum - target) <= 1) ?? emptyResult;
 });
 
+const hasInput = computed(() => inputSum.value.trim().length > 0);
+
 const formattedStipend = (stipend: number): string => {
 	let thousands: number;
 	let rest: number;
@@ -148,6 +152,15 @@ const formattedStipend = (stipend: number): string => {
 	if (thousands) return `${thousands} ${lz(rest, 3)},${lz(float, 2)} ₽`;
 	return `${rest},${lz(float, 2)} ₽`;
 };
+
+type StipendField = 'gas' | 'pgas' | 'gss' | 'pgss';
+
+const getTooltipText = (field: StipendField): string => {
+	if (!hasInput.value || !found.value) return '';
+	const value = recount.value[field];
+	const tips = TipFromSum[field] as Record<number, string>;
+	return tips[value] ?? '';
+};
 </script>
 
 <template>
@@ -157,33 +170,165 @@ const formattedStipend = (stipend: number): string => {
 				<v-text-field v-model="inputSum" label="Полученная сумма" :rules="[formatInput]" />
 				<v-divider class="ma-0" />
 			</IrdomSection>
+
 			<div class="ma-0">
-				<div class="d-flex justify-space-between">
+				<!-- ГАС -->
+				<div class="d-flex justify-space-between align-center">
 					<div class="pay">ГАС</div>
-					<div id="gas" class="sum-plus bg-primary">{{ formattedStipend(recount['gas']) }}</div>
+					<div class="right-group">
+						<div id="gas" class="sum-plus bg-primary">{{ formattedStipend(recount['gas']) }}</div>
+						<span v-show="hasInput && found && getTooltipText('gas')">
+							<v-tooltip :text="getTooltipText('gas')" location="end" content-class="tooltip-large">
+								<template #activator="{ props }">
+									<v-btn
+										v-bind="props"
+										:icon="mdiInformationOutline"
+										variant="tonal"
+										size="x-small"
+										color="grey"
+										style="font-size: medium"
+									/>
+								</template>
+							</v-tooltip>
+						</span>
+					</div>
 				</div>
-				<div class="d-flex justify-space-between">
-					<v-sheet class="pay">ПГАС</v-sheet>
-					<div id="pgas" class="sum-plus bg-primary">{{ formattedStipend(recount['pgas']) }}</div>
+
+				<!-- ПГАС -->
+				<div class="d-flex justify-space-between align-center">
+					<div class="pay">ПГАС</div>
+					<div class="right-group">
+						<div id="pgas" class="sum-plus bg-primary">{{ formattedStipend(recount['pgas']) }}</div>
+						<span v-show="getTooltipText('pgas')">
+							<v-tooltip
+								:text="getTooltipText('pgas')"
+								location="end"
+								content-class="tooltip-large"
+							>
+								<template #activator="{ props }">
+									<v-btn
+										v-bind="props"
+										:icon="mdiInformationOutline"
+										variant="tonal"
+										size="x-small"
+										color="grey"
+										style="font-size: medium"
+									/>
+								</template>
+							</v-tooltip>
+						</span>
+					</div>
 				</div>
-				<div class="d-flex justify-space-between">
-					<v-sheet class="pay">ГСС</v-sheet>
-					<div id="gss" class="sum-plus bg-primary">{{ formattedStipend(recount['gss']) }}</div>
+
+				<!-- ГСС -->
+				<div class="d-flex justify-space-between align-center">
+					<div class="pay">ГСС</div>
+					<div class="right-group">
+						<div id="gss" class="sum-plus bg-primary">{{ formattedStipend(recount['gss']) }}</div>
+						<span v-show="hasInput && found && getTooltipText('gss')">
+							<v-tooltip
+								:text="getTooltipText('gss')"
+								location="start"
+								content-class="tooltip-large"
+							>
+								<template #activator="{ props }">
+									<v-btn
+										v-bind="props"
+										:icon="mdiInformationOutline"
+										variant="tonal"
+										size="x-small"
+										color="grey"
+										style="font-size: medium"
+									/>
+								</template>
+							</v-tooltip>
+						</span>
+					</div>
 				</div>
-				<div class="d-flex justify-space-between">
-					<v-sheet class="pay">ПГСС</v-sheet>
-					<div id="pgss" class="sum-plus bg-primary">{{ formattedStipend(recount['pgss']) }}</div>
+
+				<!-- ПГСС -->
+				<div class="d-flex justify-space-between align-center">
+					<div class="pay">ПГСС</div>
+					<div class="right-group">
+						<div id="pgss" class="sum-plus bg-primary">{{ formattedStipend(recount['pgss']) }}</div>
+						<span v-show="hasInput && found && getTooltipText('pgss')">
+							<v-tooltip
+								:text="getTooltipText('pgss')"
+								location="start"
+								content-class="tooltip-large"
+							>
+								<template #activator="{ props }">
+									<v-btn
+										v-bind="props"
+										:icon="mdiInformationOutline"
+										variant="tonal"
+										size="x-small"
+										color="grey"
+										style="font-size: medium"
+									/>
+								</template>
+							</v-tooltip>
+						</span>
+					</div>
 				</div>
-				<div class="d-flex justify-space-between">
-					<v-sheet class="pay">Профвзнос</v-sheet>
-					<div id="tax" class="sum-plus bg-primary">{{ formattedStipend(recount['tax']) }}</div>
+
+				<!-- Профвзнос -->
+				<div class="d-flex justify-space-between align-center">
+					<div class="pay">Профвзнос</div>
+					<div class="right-group">
+						<div id="tax" class="sum-plus bg-primary">{{ formattedStipend(recount['tax']) }}</div>
+						<span v-show="hasInput && found && recount['tax'] !== 0">
+							<v-tooltip
+								:text="TipFromSum['proffee']"
+								location="start"
+								content-class="tooltip-large"
+							>
+								<template #activator="{ props }">
+									<v-btn
+										v-bind="props"
+										:icon="mdiInformationOutline"
+										variant="tonal"
+										size="x-small"
+										color="grey"
+										style="font-size: medium"
+									/>
+								</template>
+							</v-tooltip>
+						</span>
+					</div>
 				</div>
 			</div>
+
 			<v-divider />
+
+			<!-- Итоговая строка -->
 			<div class="your d-flex justify-space-between">
 				<div class="text-h4">Сумма:</div>
-				<div class="stipend bg-secondary" :class="screenWidth < 800 ? 'text-h5' : 'text-h4'">
-					{{ found ? formattedStipend(recount['sum']) : 'Не найдено' }}
+				<div class="right-group">
+					<div
+						class="stipend"
+						:class="[found ? 'bg-primary' : 'bg-secondary', isNarrow ? 'text-h5' : 'text-h4']"
+					>
+						{{ found ? formattedStipend(recount['sum']) : hasInput ? 'Не найдено' : '0,00 ₽' }}
+					</div>
+					<span v-show="hasInput && !found">
+						<v-tooltip
+							text="Не найден такой вариант суммы"
+							location="start"
+							content-class="tooltip-large"
+						>
+							<template #activator="{ props }">
+								<v-btn
+									v-bind="props"
+									:icon="mdiInformationOutline"
+									variant="tonal"
+									size="x-small"
+									color="grey"
+									style="font-size: medium"
+								/>
+							</template>
+						</v-tooltip>
+					</span>
 				</div>
 			</div>
 		</div>
@@ -198,12 +343,17 @@ const formattedStipend = (stipend: number): string => {
 	margin: 13px 0 10px;
 }
 
+.right-group {
+	display: flex;
+	align-items: center;
+	gap: 8px;
+}
+
 .sum-plus {
 	height: 54px;
 	display: flex;
 	align-items: center;
 	font-size: 20px;
-	background: green;
 	color: white;
 	border-radius: 999px;
 	margin: 10px 0;
@@ -245,4 +395,8 @@ const formattedStipend = (stipend: number): string => {
 	height: 100%;
 	padding: 24px 24px 112px;
 }
+
+.tooltip-large {
+	font-size: 1rem !important;
+}
 </style>
diff --git a/src/vuetify.ts b/src/vuetify.ts
index a7d659f..52f1148 100644
--- a/src/vuetify.ts
+++ b/src/vuetify.ts
@@ -37,6 +37,11 @@ export const vuetify = createVuetify({
 		VCheckbox: {
 			color: 'rgb(0, 1, 76)',
 		},
+		VTooltip: {
+			'open-on-click': true,
+			'open-on-hover': true,
+			'open-on-focus': true,
+		},
 	},
 	theme: {
 		defaultTheme: 'profcomffLight',