/*
 * Commercial calculator / «Предварительный расчёт» — DESIGN.md,
 * docs/homepage-structure.md §13.
 * Engineering control panel, not a generic SaaS wizard: dense technical
 * rail progress, selectable rows (real radio/checkbox underneath), one
 * large panel surface carrying real visual weight in the page.
 */

.calculator {
	position: relative;
	background: var(--ark-bg-850);
	padding-block: var(--ark-space-section-compact);
}

.calculator__layout {
	display: grid;
	grid-template-columns: minmax(280px, 520px) 1fr;
	gap: 48px;
	align-items: start;
}

.calculator__overline {
	font-size: 0.8rem;
	font-weight: 700;
	letter-spacing: 0.16em;
	color: var(--ark-text-secondary);
	margin: 0 0 16px;
}

.calculator__title {
	font-size: clamp(1.7rem, 1.2rem + 1vw, 2.3rem);
	font-weight: 600;
	line-height: 1.15;
	color: var(--ark-text-primary);
	max-width: 500px;
	margin: 0 0 18px;
}

.calculator__lead {
	font-size: 1.02rem;
	color: var(--ark-text-secondary);
	margin: 0 0 32px;
}

.calculator__lead--tight {
	margin-bottom: 22px;
}

.calculator__perks {
	display: flex;
	flex-direction: column;
	gap: 16px;
}

.calculator__perks li {
	display: flex;
	align-items: center;
	gap: 14px;
	font-size: 0.95rem;
	color: var(--ark-text-secondary);
}

.calculator__perk-number {
	flex-shrink: 0;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 30px;
	height: 30px;
	border: 1px solid var(--ark-border-soft);
	border-radius: var(--ark-radius-sm);
	font-size: 0.75rem;
	font-weight: 700;
	color: var(--ark-text-muted);
}

/* ---- Panel ---- */

.calculator__panel {
	position: relative;
	display: flex;
	flex-direction: column;
	background: var(--ark-surface-700);
	border: 1px solid var(--ark-border-medium);
	border-radius: var(--ark-radius-lg);
	padding: 40px 44px 44px;
	box-shadow: 0 24px 60px rgba(0, 0, 0, 0.3);
}

/* Measured tallest step (Step 1, 7 option rows) at 1440px ≈ 690px panel
 * height; used as a shared shell height so Steps 1–5 don't resize the
 * panel as field count varies. Only applied while the steps form is the
 * active view, so Result/Contact don't inherit forced empty space. */
.calculator__panel[data-view="steps"] {
	min-height: 700px;
}

.calculator__form {
	display: flex;
	flex-direction: column;
	flex: 1;
}

.calculator__form[hidden] {
	display: none;
}

/* ---- Progress rail ---- */

.calculator__progress {
	display: flex;
	align-items: center;
	justify-content: space-between;
	flex-wrap: wrap;
	gap: 12px;
	margin-bottom: 32px;
	padding-bottom: 24px;
	border-bottom: 1px solid var(--ark-border-soft);
}

.calculator__progress-rail {
	display: flex;
	gap: 6px;
}

.calculator__progress-rail li {
	display: flex;
	align-items: center;
	justify-content: center;
	width: 32px;
	height: 32px;
	border: 1px solid var(--ark-border-soft);
	border-radius: 6px;
	font-size: 0.72rem;
	font-weight: 700;
	color: var(--ark-text-muted);
	transition: border-color 200ms var(--ark-ease), color 200ms var(--ark-ease), background 200ms var(--ark-ease);
}

.calculator__progress-rail li[data-state="current"] {
	border-color: var(--ark-border-titanium);
	background: var(--ark-surface-650);
	color: var(--ark-text-primary);
}

.calculator__progress-rail li[data-state="done"] {
	border-color: var(--ark-border-medium);
	color: var(--ark-text-secondary);
}

.calculator__progress-label {
	font-size: 0.85rem;
	color: var(--ark-text-muted);
	margin: 0;
}

/* ---- Step ---- */

.calculator__fieldset {
	border: 0;
	padding: 0;
	margin: 0;
}

.calculator__step {
	flex: 1;
}

/* Steps/result/contact receive a programmatic focus() call (calculator.js)
 * purely to move keyboard/AT focus + trigger the live-region announcement
 * on navigation — they are non-interactive containers, not focusable
 * controls, so the default browser focus ring is suppressed here only.
 * Real interactive controls (radios, inputs, buttons, links) keep their
 * :focus-visible indicator untouched. */
.calculator__step:focus,
.calculator__result:focus,
.calculator__contact:focus {
	outline: none;
}

.calculator__step-title {
	font-size: 1.2rem;
	font-weight: 600;
	color: var(--ark-text-primary);
	margin: 0 0 22px;
	padding: 0;
}

/* ---- Selectable option rows ---- */

.calc-options {
	display: flex;
	flex-direction: column;
	gap: 10px;
}

.calc-options--grid {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 10px;
}

.calc-option {
	display: flex;
	align-items: center;
	gap: 14px;
	min-height: 44px;
	padding: 13px 18px;
	border: 1px solid var(--ark-border-soft);
	border-radius: var(--ark-radius-md);
	background: var(--ark-bg-850);
	cursor: pointer;
	transition: border-color 150ms var(--ark-ease), background 150ms var(--ark-ease);
}

.calc-option:hover {
	border-color: var(--ark-border-medium);
}

.calc-option:has(.calc-option__input:checked) {
	border-color: var(--ark-border-titanium);
	background: var(--ark-surface-650);
}

.calc-option:has(.calc-option__input:focus-visible) {
	outline: 2px solid var(--ark-border-titanium);
	outline-offset: 2px;
}

/* Real input, visually hidden but focusable/keyboard-operable. */
.calc-option__input {
	position: absolute;
	width: 1px;
	height: 1px;
	margin: -1px;
	overflow: hidden;
	clip: rect(0, 0, 0, 0);
	white-space: nowrap;
	border: 0;
	padding: 0;
}

.calc-option__indicator {
	position: relative;
	flex-shrink: 0;
	width: 18px;
	height: 18px;
	border: 1px solid var(--ark-border-medium);
}

.calc-option__indicator--radio {
	border-radius: 50%;
}

.calc-option__indicator--checkbox {
	border-radius: 4px;
}

.calc-option__indicator::after {
	content: "";
	position: absolute;
	inset: 3px;
	background: var(--ark-text-primary);
	opacity: 0;
	transition: opacity 150ms var(--ark-ease);
}

.calc-option__indicator--radio::after {
	border-radius: 50%;
}

.calc-option__indicator--checkbox::after {
	border-radius: 2px;
}

.calc-option__input:checked ~ .calc-option__indicator::after {
	opacity: 1;
}

.calc-option__label {
	font-size: 0.95rem;
	color: var(--ark-text-secondary);
}

.calc-option:has(.calc-option__input:checked) .calc-option__label {
	color: var(--ark-text-primary);
}

.calc-option--compact {
	padding: 12px 16px;
}

/* ---- Text/number fields (step 2, contact) ---- */

.calc-field {
	margin-bottom: 18px;
}

.calc-field--wide {
	grid-column: 1 / -1;
}

.calc-field label,
.calc-field__label-static {
	display: block;
	font-size: 0.78rem;
	color: var(--ark-text-muted);
	margin-bottom: 6px;
}

.calc-field__input {
	width: 100%;
	height: 48px;
	padding-inline: 14px;
	background: var(--ark-bg-850);
	border: 1px solid var(--ark-border-soft);
	border-radius: var(--ark-radius-sm);
	color: var(--ark-text-primary);
	font-family: var(--ark-font-sans);
	font-size: 0.92rem;
	transition: border-color 150ms var(--ark-ease), box-shadow 150ms var(--ark-ease);
}

.calc-field__textarea {
	height: auto;
	padding-block: 12px;
	resize: vertical;
}

.calc-field__input:focus-visible {
	outline: none;
	border-color: var(--ark-border-titanium);
	box-shadow: 0 0 0 3px rgba(166, 159, 147, 0.18);
}

/* Hide native number spinners (Calculator only) — keeps type="number",
 * min/max/step and keyboard numeric entry; no custom +/- controls added. */
.calc-field__input[type="number"] {
	-moz-appearance: textfield;
	appearance: textfield;
}

.calc-field__input[type="number"]::-webkit-outer-spin-button,
.calc-field__input[type="number"]::-webkit-inner-spin-button {
	-webkit-appearance: none;
	margin: 0;
}

.calc-field__hint {
	font-size: 0.78rem;
	color: var(--ark-text-muted);
	margin: 6px 0 0;
}

/* ---- File upload (visual only) ---- */

.calc-upload {
	display: inline-flex;
	align-items: center;
	height: 44px;
	padding-inline: 18px;
	border: 1px solid var(--ark-border-medium);
	border-radius: var(--ark-radius-sm);
	color: var(--ark-text-secondary);
	font-size: 0.88rem;
	cursor: pointer;
	transition: border-color 150ms var(--ark-ease), color 150ms var(--ark-ease);
}

.calc-upload:hover {
	border-color: var(--ark-border-titanium);
	color: var(--ark-text-primary);
}

.calc-upload__input {
	position: absolute;
	width: 1px;
	height: 1px;
	margin: -1px;
	overflow: hidden;
	clip: rect(0, 0, 0, 0);
	white-space: nowrap;
	border: 0;
	padding: 0;
}

.calc-upload__input:focus-visible ~ .calc-upload,
.calc-upload:has(.calc-upload__input:focus-visible) {
	outline: 2px solid var(--ark-border-titanium);
	outline-offset: 2px;
}

/* ---- Nav ---- */

.calculator__nav {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 16px;
	margin-top: auto;
	padding-top: 32px;
}

.calculator__back {
	margin-right: auto;
}

.calculator__next {
	margin-left: auto;
}

/* ---- Result ---- */

.calculator__result-title {
	font-size: 1.2rem;
	font-weight: 600;
	color: var(--ark-text-primary);
	margin: 0 0 14px;
}

.calculator__result-range {
	font-size: clamp(1.5rem, 1.1rem + 1.4vw, 2.1rem);
	font-weight: 700;
	color: var(--ark-text-primary);
	margin: 0 0 10px;
}

.calculator__result-disclaimer {
	font-size: 0.85rem;
	color: var(--ark-text-muted);
	max-width: 560px;
	margin: 0 0 28px;
	padding-bottom: 24px;
	border-bottom: 1px solid var(--ark-border-soft);
}

.calculator__result-summary-title {
	font-size: 0.72rem;
	font-weight: 700;
	letter-spacing: 0.1em;
	text-transform: uppercase;
	color: var(--ark-text-muted);
	margin: 0 0 14px;
}

.calculator__result-list {
	display: flex;
	flex-direction: column;
	gap: 10px;
	margin: 0 0 28px;
}

.calculator__result-item {
	display: flex;
	justify-content: space-between;
	gap: 16px;
	padding-bottom: 10px;
	border-bottom: 1px solid var(--ark-border-soft);
	font-size: 0.92rem;
}

.calculator__result-item-label {
	color: var(--ark-text-muted);
}

.calculator__result-item-value {
	color: var(--ark-text-primary);
	font-weight: 600;
	text-align: right;
}

.calculator__result-next {
	font-size: 0.92rem;
	color: var(--ark-text-secondary);
	max-width: 560px;
	margin: 0 0 28px;
}

.calculator__result-actions {
	display: flex;
	align-items: center;
	gap: 20px;
	flex-wrap: wrap;
}

.calculator__reset {
	background: transparent;
	border: 0;
	color: var(--ark-text-muted);
	font-size: 0.88rem;
	text-decoration: underline;
	text-underline-offset: 3px;
	cursor: pointer;
	transition: color 150ms var(--ark-ease);
}

.calculator__reset:hover,
.calculator__reset:focus-visible {
	color: var(--ark-text-primary);
}

/* ---- Contact step ---- */

.calculator__contact-form {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 0 20px;
}

.calculator__contact-actions {
	grid-column: 1 / -1;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 16px;
	margin-top: 10px;
}

.calculator__submitted-title {
	font-size: 1.2rem;
	font-weight: 600;
	color: var(--ark-text-primary);
	margin: 0 0 10px;
}

.calculator__submitted-text {
	color: var(--ark-text-secondary);
	margin: 0 0 20px;
}

/* ---- Responsive ---- */

@media (max-width: 1024px) {
	.calculator__layout {
		grid-template-columns: 1fr;
		gap: 40px;
	}

	.calculator__perks {
		flex-direction: row;
		flex-wrap: wrap;
		gap: 20px;
	}

	/* Shell parity only matters while intro and panel sit side by side.
	 * Once stacked to a single column, a forced 700px shell leaves large
	 * empty space under short steps (e.g. Step 2). Resetting min-height
	 * alone isn't enough: .calculator__form and .calculator__step still
	 * carry flex: 1 (flex-basis 0), which lets them absorb any leftover
	 * space in the flex column and push .calculator__nav's margin-top:
	 * auto down with it. Drop both to content-based sizing here too. */
	.calculator__panel[data-view="steps"] {
		min-height: auto;
	}

	.calculator__form,
	.calculator__step {
		flex: none;
	}

	.calculator__nav {
		margin-top: 0;
	}
}

@media (max-width: 900px) {
	.calc-options--grid {
		grid-template-columns: 1fr;
	}
}

@media (max-width: 640px) {
	.calculator__panel {
		padding: 28px 22px 32px;
	}

	.calculator__contact-form {
		grid-template-columns: 1fr;
	}

	.calculator__nav,
	.calculator__result-actions,
	.calculator__contact-actions {
		flex-wrap: wrap;
	}

	.calculator__back,
	.calculator__next {
		width: 100%;
		margin: 0;
	}
}

@media (prefers-reduced-motion: reduce) {
	.calculator__progress-rail li,
	.calc-option,
	.calc-option__indicator::after,
	.calc-field__input,
	.calc-upload {
		transition: none;
	}
}