:root {
  --page: #f4f6f4;
  --surface: #ffffff;
  --surface-muted: #eef2ee;
  --ink: #172019;
  --muted: #657168;
  --line: #dbe2dc;
  --accent: #16713d;
  --accent-strong: #0e5b2f;
  --accent-soft: #e4f2e9;
  --danger: #a42e2e;
  --danger-soft: #fff0f0;
  --radius-card: 16px;
  --radius-control: 10px;
  font-family: Arial, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--page);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--page);
}

button,
input,
select {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 20px 0 28px;
}

.brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 10px;
  color: #fff;
  background: var(--accent);
  font-size: 21px;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 15px;
}

.brand small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
}

.status-label {
  color: var(--muted);
  font-size: 12px;
}

.calculator,
.loading-state {
  display: grid;
  grid-template-columns: minmax(0, 1.03fr) minmax(330px, .97fr);
  gap: 18px;
}

.product-panel,
.calculation-form,
.result-panel,
.loading-state,
.error-state,
.catalog {
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--surface);
}

.product-panel {
  overflow: hidden;
}

.product-media {
  display: grid;
  min-height: 330px;
  place-items: center;
  padding: 24px;
  background: var(--surface-muted);
}

.product-media img {
  display: block;
  width: 100%;
  max-width: 480px;
  max-height: 360px;
  object-fit: contain;
}

.product-media.is-empty {
  min-height: 180px;
}

.product-copy {
  padding: 26px;
}

.section-kicker {
  margin: 0 0 9px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: .08em;
  text-transform: uppercase;
}

h1,
h2,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  max-width: 22ch;
  font-size: clamp(27px, 4vw, 42px);
  line-height: 1.08;
  letter-spacing: -.035em;
}

h2 {
  margin: 0;
  font-size: 21px;
  line-height: 1.2;
}

.product-lead,
.catalog-heading > p:last-child {
  margin: 16px 0 0;
  max-width: 58ch;
  color: #344039;
  font-size: 16px;
  line-height: 1.55;
}

.product-detail {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.calculation-form {
  align-self: start;
  padding: 26px;
}

.calculator-main {
  display: grid;
  gap: 18px;
  align-self: start;
}

.form-heading p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.fields {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.field {
  display: grid;
  gap: 7px;
}

.field > label,
.field-label {
  color: #2c3830;
  font-size: 13px;
  font-weight: 700;
}

.required-mark {
  margin-left: 3px;
  color: var(--accent);
}

input,
select {
  width: 100%;
  min-height: 46px;
  border: 1px solid #bfc9c1;
  border-radius: var(--radius-control);
  outline: none;
  color: var(--ink);
  background: #fff;
  padding: 10px 12px;
}

input:hover,
select:hover {
  border-color: #93a196;
}

input:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgb(22 113 61 / .16);
}

.radio-group {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.radio-option {
  position: relative;
}

.radio-option input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.radio-option label {
  display: grid;
  min-height: 44px;
  place-items: center;
  border: 1px solid #bfc9c1;
  border-radius: var(--radius-control);
  padding: 8px 10px;
  color: #344039;
  background: #fff;
  cursor: pointer;
  text-align: center;
  font-size: 13px;
  line-height: 1.25;
}

.radio-option input:checked + label {
  border-color: var(--accent);
  color: var(--accent-strong);
  background: var(--accent-soft);
  box-shadow: inset 0 0 0 1px var(--accent);
}

.radio-option input:focus-visible + label {
  outline: 3px solid rgb(22 113 61 / .22);
  outline-offset: 1px;
}

.primary-button,
.secondary-button {
  min-height: 48px;
  border-radius: var(--radius-control);
  padding: 11px 18px;
  font-weight: 750;
  cursor: pointer;
}

.primary-button {
  width: 100%;
  margin-top: 20px;
  border: 1px solid var(--accent);
  color: #fff;
  background: var(--accent);
}

.primary-button:hover {
  background: var(--accent-strong);
}

.primary-button:active,
.secondary-button:active,
.catalog-item:active {
  transform: translateY(1px);
}

.primary-button:focus-visible,
.secondary-button:focus-visible,
.catalog-item:focus-visible {
  outline: 3px solid rgb(22 113 61 / .25);
  outline-offset: 2px;
}

.primary-button:disabled {
  cursor: wait;
  opacity: .75;
}

.button-loading {
  display: none;
}

.primary-button.is-loading .button-default {
  display: none;
}

.primary-button.is-loading .button-loading {
  display: inline;
}

.secondary-button {
  border: 1px solid #aeb9b0;
  color: var(--ink);
  background: #fff;
}

.form-error {
  margin-top: 16px;
  border: 1px solid #efc5c5;
  border-radius: var(--radius-control);
  padding: 11px 12px;
  color: var(--danger);
  background: var(--danger-soft);
  font-size: 13px;
  line-height: 1.4;
}

.result-panel {
  display: grid;
  gap: 18px;
  align-self: start;
  border-color: #bfd8c6;
  padding: 24px 26px;
  background: #f4faf6;
}

.result-label {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: 13px;
}

.result-price {
  margin: 0;
  color: var(--accent-strong);
  font-size: clamp(30px, 5vw, 44px);
  font-weight: 800;
  letter-spacing: -.035em;
}

.result-unit,
.result-note {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.result-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.result-meta span {
  border-radius: 7px;
  padding: 7px 9px;
  color: #344039;
  background: #e6f1e9;
  font-size: 12px;
}

.catalog {
  padding: 34px;
}

.catalog-heading h1 {
  max-width: 20ch;
}

.catalog-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 28px;
}

.catalog-item {
  display: grid;
  grid-template-rows: 180px auto;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  color: inherit;
  background: #fff;
  text-decoration: none;
}

.catalog-item img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 14px;
  background: var(--surface-muted);
}

.catalog-item-copy {
  padding: 16px;
}

.catalog-item h2 {
  font-size: 17px;
}

.catalog-item p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

.empty-state,
.error-state {
  padding: 40px;
  text-align: left;
}

.empty-state p,
.error-state p {
  margin: 10px 0 20px;
  color: var(--muted);
}

.loading-state {
  padding: 18px;
}

.loading-fields {
  padding: 20px 14px;
}

.skeleton {
  border-radius: var(--radius-control);
  background: linear-gradient(100deg, #e9eeea 30%, #f5f7f5 45%, #e9eeea 60%);
  background-size: 240% 100%;
  animation: skeleton-shift 1.5s ease-in-out infinite;
}

.skeleton-media {
  min-height: 370px;
}

.skeleton-title {
  width: 78%;
  height: 38px;
}

.skeleton-line {
  width: 92%;
  height: 16px;
  margin-top: 14px;
}

.skeleton-input {
  height: 48px;
  margin-top: 24px;
}

.skeleton-button {
  height: 48px;
  margin-top: 20px;
}

.footer-note {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  padding: 17px 4px 0;
  color: var(--muted);
  font-size: 12px;
}

.footer-note a {
  color: inherit;
}

.is-hidden {
  display: none !important;
}

@keyframes skeleton-shift {
  from { background-position: 100% 0; }
  to { background-position: -100% 0; }
}

@media (max-width: 820px) {
  .calculator,
  .loading-state {
    grid-template-columns: 1fr;
  }

  .catalog-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .product-media {
    min-height: 260px;
  }
}

@media (max-width: 560px) {
  .shell {
    width: min(100% - 20px, 1120px);
    padding-top: 12px;
  }

  .status-label {
    display: none;
  }

  .product-copy,
  .calculation-form,
  .result-panel,
  .catalog {
    padding: 20px;
  }

  .product-media {
    min-height: 210px;
    padding: 16px;
  }

  .catalog-list,
  .radio-group {
    grid-template-columns: 1fr;
  }

  .catalog-item {
    grid-template-columns: 110px minmax(0, 1fr);
    grid-template-rows: auto;
  }

  .catalog-item img {
    min-height: 130px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}