:root {
  color-scheme: light;
  --color-primary: #175cd3;
  --color-primary-hover: #1849a9;
  --color-heading: #101828;
  --color-body: #475467;
  --color-muted: #667085;
  --color-border: #d0d5dd;
  --color-border-light: #e4e7ec;
  --color-surface: #ffffff;
  --color-surface-subtle: #f8fafc;
  --color-accent-subtle: #eff8ff;
  --color-danger: #b42318;
  --content-width: 1120px;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Hiragino Kaku Gothic ProN", "Yu Gothic", YuGothic, Meiryo, Arial, sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-surface);
  color: var(--color-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-wrap: break-word;
}

a {
  color: var(--color-primary);
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--color-primary-hover);
}

button,
input {
  font: inherit;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  color: var(--color-heading);
  font-weight: 700;
  line-height: 1.45;
}

h1 {
  margin-bottom: 24px;
  font-size: clamp(34px, 5.6vw, 56px);
  letter-spacing: 0.04em;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(24px, 3vw, 32px);
}

.container {
  width: min(calc(100% - 48px), var(--content-width));
  margin-inline: auto;
}

.container--narrow {
  max-width: 880px;
}

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

.eyebrow {
  margin-bottom: 8px;
  color: var(--color-primary);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.site-header {
  border-bottom: 1px solid var(--color-border-light);
  background: rgba(255, 255, 255, 0.96);
}

.site-header__inner {
  display: flex;
  width: min(calc(100% - 48px), var(--content-width));
  min-height: 72px;
  margin-inline: auto;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-name {
  color: var(--color-heading);
  font-size: 17px;
  font-weight: 700;
  text-decoration: none;
}

.site-nav {
  display: flex;
  gap: 24px;
}

.site-nav a {
  color: var(--color-body);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
}

.site-nav a:hover {
  color: var(--color-primary);
}

.hero {
  padding: 80px 0 64px;
  background: linear-gradient(180deg, #f5f9ff 0%, #ffffff 100%);
}

.hero__inner {
  max-width: 920px;
  text-align: center;
}

.hero__lead {
  margin-bottom: 0;
  color: var(--color-body);
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.9;
}

.calculator-section {
  padding: 24px 0 96px;
}

.calculator {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(340px, 0.92fr);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.calculator__form,
.calculator__results {
  min-width: 0;
  padding: 48px;
}

.calculator__results {
  border-left: 1px solid var(--color-border);
  background: var(--color-surface-subtle);
}

.calculator__results h2 {
  margin-bottom: 8px;
  font-size: 26px;
}

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

.calculator__modes legend {
  margin-bottom: 12px;
  color: var(--color-heading);
  font-size: 14px;
  font-weight: 700;
}

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

.calculator__mode {
  position: relative;
  cursor: pointer;
}

.calculator__mode input {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.calculator__mode > span {
  display: grid;
  min-height: 80px;
  align-content: center;
  gap: 2px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 12px 16px;
  background: var(--color-surface);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.calculator__mode strong {
  color: var(--color-heading);
  font-size: 15px;
}

.calculator__mode small {
  color: var(--color-muted);
  font-size: 12px;
  line-height: 1.5;
}

.calculator__mode input:checked + span {
  border: 2px solid var(--color-primary);
  padding: 11px 15px;
  background: var(--color-accent-subtle);
}

.calculator__mode input:focus-visible + span {
  outline: 3px solid rgba(23, 92, 211, 0.2);
  outline-offset: 2px;
}

.calculator__fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 20px;
  margin-top: 32px;
}

.calculator__field[hidden],
.calculator__result-row[hidden] {
  display: none;
}

.calculator__field label {
  display: block;
  margin-bottom: 6px;
  color: var(--color-heading);
  font-size: 14px;
  font-weight: 700;
}

.calculator__input-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-surface);
}

.calculator__input-wrap:focus-within {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(23, 92, 211, 0.14);
}

.calculator__input-wrap input {
  width: 100%;
  min-width: 0;
  border: 0;
  padding: 12px 14px;
  background: transparent;
  color: var(--color-heading);
  font-size: 16px;
  outline: 0;
}

.calculator__input-wrap > span {
  padding: 0 14px 0 6px;
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 600;
}

.calculator__field small {
  display: block;
  margin-top: 6px;
  color: var(--color-muted);
  font-size: 12px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  padding: 11px 22px;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.4;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.button:focus-visible {
  outline: 3px solid rgba(23, 92, 211, 0.24);
  outline-offset: 3px;
}

.button--primary {
  border: 2px solid var(--color-primary);
  background: var(--color-primary);
  color: #ffffff;
}

.button--primary:hover {
  border-color: var(--color-primary-hover);
  background: var(--color-primary-hover);
  color: #ffffff;
}

.button--secondary {
  flex: 0 0 auto;
  border: 1px solid var(--color-primary);
  background: var(--color-surface);
  color: var(--color-primary);
}

.button--secondary:hover {
  background: var(--color-accent-subtle);
  color: var(--color-primary-hover);
}

.calculator__submit {
  margin-top: 32px;
}

.calculator__privacy {
  margin: 18px 0 0;
  color: var(--color-muted);
  font-size: 12px;
  line-height: 1.8;
}

.calculator__status {
  min-height: 3.5em;
  margin: 0 0 20px;
  color: var(--color-muted);
  font-size: 13px;
}

.calculator__status[data-state="error"] {
  color: var(--color-danger);
  font-weight: 700;
}

.calculator__result-list {
  margin: 0;
  border-top: 1px solid var(--color-border-light);
}

.calculator__result-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: baseline;
  border-bottom: 1px solid var(--color-border-light);
  padding: 14px 0;
}

.calculator__result-row dt {
  color: var(--color-body);
  font-size: 13px;
  font-weight: 600;
}

.calculator__result-row dd {
  margin: 0;
  color: var(--color-heading);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1.35;
  text-align: right;
}

.calculator__formula {
  margin: 20px 0 0;
  color: var(--color-muted);
  font-size: 12px;
  line-height: 1.8;
}

.product-introduction {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 48px;
  align-items: center;
  border-bottom: 1px solid var(--color-border);
  padding: 36px 0;
}

.product-introduction h2 {
  margin-bottom: 12px;
  font-size: clamp(22px, 3vw, 28px);
}

.product-introduction p:last-child {
  max-width: 760px;
  margin-bottom: 0;
}

.information-section {
  padding: 88px 0;
  background: var(--color-surface-subtle);
}

.information-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 72px;
}

.information-grid > div + div {
  border-left: 1px solid var(--color-border);
  padding-left: 72px;
}

.information-grid p:last-child {
  margin-bottom: 0;
}

.faq-section {
  padding: 96px 0;
}

.faq-list {
  margin-top: 40px;
  border-top: 1px solid var(--color-border);
}

.faq-list details {
  border-bottom: 1px solid var(--color-border);
}

.faq-list summary {
  padding: 22px 40px 22px 0;
  color: var(--color-heading);
  font-weight: 700;
  cursor: pointer;
}

.faq-list summary:focus-visible {
  outline: 3px solid rgba(23, 92, 211, 0.22);
  outline-offset: 4px;
}

.faq-list details p {
  max-width: 760px;
  margin: 0;
  padding: 0 0 24px;
}

.site-footer {
  border-top: 1px solid var(--color-border-light);
  padding: 28px 0;
  background: var(--color-surface-subtle);
}

.site-footer__inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.site-footer p {
  margin: 0;
  color: var(--color-muted);
  font-size: 13px;
}

@media (max-width: 880px) {
  .calculator {
    grid-template-columns: minmax(0, 1fr);
  }

  .calculator__results {
    border-top: 1px solid var(--color-border);
    border-left: 0;
  }

  .product-introduction {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }

  .product-introduction .button {
    justify-self: start;
  }

  .information-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 48px;
  }

  .information-grid > div + div {
    border-top: 1px solid var(--color-border);
    border-left: 0;
    padding-top: 48px;
    padding-left: 0;
  }
}

@media (max-width: 600px) {
  .container,
  .site-header__inner {
    width: min(calc(100% - 32px), var(--content-width));
  }

  .site-header__inner {
    min-height: 64px;
  }

  .site-nav {
    display: none;
  }

  .hero {
    padding: 56px 0 48px;
  }

  .hero__lead br {
    display: none;
  }

  .calculator-section {
    padding-bottom: 72px;
  }

  .calculator__form,
  .calculator__results {
    padding: 32px 16px;
  }

  .calculator__mode-list,
  .calculator__fields {
    grid-template-columns: minmax(0, 1fr);
  }

  .calculator__submit,
  .product-introduction .button {
    width: 100%;
  }

  .product-introduction {
    padding: 32px 0;
  }

  .information-section,
  .faq-section {
    padding: 72px 0;
  }

  .site-footer__inner {
    flex-direction: column;
    gap: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}