:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-soft: #f9fbfd;
  --ink: #10151f;
  --ink-soft: #303847;
  --muted: #596477;
  --line: #d9e1ec;
  --line-strong: #bdc9d8;
  --blue: #1f5eff;
  --blue-dark: #163fae;
  --blue-soft: #edf3ff;
  --green: #16865a;
  --green-soft: #eef9f4;
  --amber: #9a5a00;
  --amber-soft: #fff7e8;
  --danger: #a13d45;
  --danger-soft: #fff1f2;
  --radius: 10px;
  --max: 1040px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-wrap: anywhere;
  background: linear-gradient(180deg, #fbfcfe 0%, var(--bg) 32%, #eef3f7 100%);
  color: var(--ink);
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans JP', 'Hiragino Sans', 'Yu Gothic UI',
    Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

button,
input,
select {
  font: inherit;
}

button,
select {
  cursor: pointer;
}

a {
  color: inherit;
}

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

ul,
ol,
dl,
dd {
  margin: 0;
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
a:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid rgba(31, 94, 255, 0.35);
  outline-offset: 3px;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: absolute;
  z-index: 100;
  top: max(8px, env(safe-area-inset-top));
  left: 8px;
  transform: translateY(-160%);
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  padding: 10px 14px;
}

.skip-link:focus-visible {
  transform: translateY(0);
}

.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.shell,
.header-inner,
.footer-inner {
  width: min(var(--max), calc(100% - 28px));
  margin-inline: auto;
}

.tool-header {
  border-bottom: 1px solid var(--line);
  background: rgba(249, 251, 253, 0.96);
}

.header-inner {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: max(12px, env(safe-area-inset-top)) 0 12px;
}

.brand {
  display: inline-flex;
  align-items: center;
  width: fit-content;
  min-height: 44px;
  gap: 10px;
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--ink), var(--blue));
  color: #fff;
}

.brand-copy {
  display: grid;
  line-height: 1.15;
}

.brand-copy small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
}

.header-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px 8px;
}

.header-links a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: var(--ink-soft);
  font-size: 0.76rem;
  font-weight: 700;
  text-decoration: none;
}

.intro {
  padding-block: 54px 36px;
}

.eyebrow,
.panel-kicker {
  color: var(--blue);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.intro h1 {
  margin-top: 10px;
  font-size: clamp(2.4rem, 11vw, 4.6rem);
  line-height: 1.08;
  letter-spacing: -0.035em;
}

.intro-lead {
  max-width: 720px;
  margin-top: 18px;
  color: var(--ink-soft);
  font-size: clamp(1.05rem, 4.4vw, 1.35rem);
  font-weight: 650;
}

.intro-notes {
  display: grid;
  gap: 6px;
  margin-top: 20px;
  color: var(--muted);
  font-size: 0.9rem;
}

.important-note {
  margin-top: 18px;
  border-left: 4px solid var(--amber);
  background: var(--amber-soft);
  color: #50330a;
  padding: 12px 14px;
  font-size: 0.9rem;
  font-weight: 700;
}

.tool,
.output-section,
.guide,
.disclaimer,
.slarog-cta {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.tool,
.output-section,
.guide,
.disclaimer {
  padding: 20px 16px;
}

.section-heading {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.section-number {
  flex: 0 0 auto;
  color: var(--blue);
  font-size: 0.75rem;
  font-weight: 800;
  line-height: 1.4;
}

.section-heading h2 {
  font-size: clamp(1.25rem, 5vw, 1.65rem);
  line-height: 1.3;
}

.section-heading p:not(.section-number) {
  margin-top: 5px;
  color: var(--muted);
  font-size: 0.87rem;
}

.mode-switcher {
  display: grid;
  gap: 8px;
  margin-top: 20px;
}

.mode-switcher button,
.submode-switcher button {
  min-height: 52px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  color: var(--ink-soft);
  text-align: left;
}

.mode-switcher button {
  display: grid;
  gap: 2px;
  padding: 10px 13px;
}

.mode-switcher button span {
  font-weight: 780;
}

.mode-switcher button small {
  color: var(--muted);
  font-size: 0.74rem;
}

.mode-switcher button[aria-pressed='true'],
.submode-switcher button[aria-pressed='true'] {
  border-color: var(--blue);
  background: var(--blue-soft);
  color: var(--blue-dark);
  box-shadow: inset 3px 0 0 var(--blue);
}

.mode-panel {
  margin-top: 22px;
  border-top: 1px solid var(--line);
  padding-top: 20px;
}

.panel-heading {
  display: grid;
  gap: 8px;
}

.panel-heading h2 {
  margin-top: 4px;
  font-size: 1.2rem;
  line-height: 1.35;
}

.example {
  width: fit-content;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--muted);
  padding: 5px 10px;
  font-size: 0.76rem;
}

.field-grid {
  display: grid;
  gap: 18px 12px;
  margin-top: 20px;
}

.field {
  min-width: 0;
}

.field > label,
.choice-fieldset legend,
.confirmation-fieldset legend {
  display: block;
  margin-bottom: 6px;
  color: var(--ink-soft);
  font-size: 0.86rem;
  font-weight: 760;
}

.field-control {
  position: relative;
  display: flex;
  min-width: 0;
  align-items: center;
}

.field input,
.field select,
.field--wide select {
  width: 100%;
  min-width: 0;
  min-height: 50px;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  padding: 10px 44px 10px 12px;
  font-size: 1rem;
}

.field--wide select {
  padding-right: 12px;
}

.field input[aria-invalid='true'],
.field select[aria-invalid='true'] {
  border-color: var(--danger);
  box-shadow: 0 0 0 2px rgba(161, 61, 69, 0.12);
}

.field-unit {
  position: absolute;
  right: 12px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  pointer-events: none;
}

.field-hint,
.field-error {
  min-height: 1.3em;
  margin-top: 5px;
  font-size: 0.74rem;
}

.field-hint {
  color: var(--muted);
}

.field-error {
  color: var(--danger);
  font-weight: 650;
}

.calculate-button,
.secondary-button {
  min-height: 50px;
  border-radius: 8px;
  font-weight: 780;
}

.calculate-button {
  width: 100%;
  margin-top: 22px;
  border: 1px solid var(--blue);
  background: var(--blue);
  color: #fff;
  padding: 11px 18px;
}

.calculate-button:hover {
  background: var(--blue-dark);
}

.secondary-button {
  border: 1px solid var(--line-strong);
  background: var(--surface);
  color: var(--ink);
  padding: 9px 14px;
}

.advanced-inputs {
  margin-top: 22px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding-block: 4px 18px;
}

.advanced-inputs summary,
.explanation summary {
  min-height: 48px;
  padding: 12px 0;
  font-weight: 780;
}

.advanced-inputs > p {
  color: var(--muted);
  font-size: 0.82rem;
}

.submode-switcher {
  display: grid;
  gap: 7px;
  margin-top: 18px;
}

.submode-switcher button {
  padding: 9px 12px;
  font-size: 0.86rem;
  font-weight: 760;
}

.subpanel-heading {
  margin-top: 20px;
}

.subpanel-heading h3 {
  font-size: 1.08rem;
}

.subpanel-heading p {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.82rem;
}

.dynamic-list {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}

.dynamic-row {
  min-width: 0;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  padding: 14px 12px 16px;
}

.dynamic-row > legend {
  padding: 0;
  font-size: 0.9rem;
  font-weight: 800;
}

.dynamic-row__header {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  margin-top: -35px;
}

.text-button {
  min-height: 44px;
  border: 0;
  background: transparent;
  padding: 7px 4px;
  font-size: 0.75rem;
  font-weight: 700;
}

.danger-button {
  color: var(--danger);
}

.text-button:disabled {
  color: var(--muted);
  cursor: not-allowed;
}

.dynamic-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
}

.undo-notice {
  color: var(--muted);
  font-size: 0.78rem;
}

.undo-notice button {
  min-height: 44px;
  border: 0;
  background: transparent;
  color: var(--blue-dark);
  font-weight: 760;
  text-decoration: underline;
}

.choice-fieldset,
.confirmation-fieldset {
  min-width: 0;
  margin: 18px 0 0;
  border: 0;
  padding: 0;
}

.choice-row {
  display: grid;
  gap: 7px;
}

.choice-row label,
.confirmation-fieldset label {
  display: flex;
  min-height: 48px;
  align-items: center;
  gap: 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  padding: 9px 11px;
  font-size: 0.84rem;
  font-weight: 680;
}

.choice-row input,
.confirmation-fieldset input {
  width: 20px;
  height: 20px;
  flex: 0 0 auto;
}

.confirmation-fieldset {
  display: grid;
  gap: 6px;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.error-summary {
  margin-top: 18px;
  border: 1px solid #d79ba0;
  border-left: 5px solid var(--danger);
  border-radius: 8px;
  background: var(--danger-soft);
  padding: 14px;
}

.error-summary h2 {
  font-size: 1rem;
}

.error-summary ul {
  margin-top: 7px;
  padding-left: 20px;
  color: #69272c;
  font-size: 0.82rem;
}

.output-section {
  scroll-margin-top: 12px;
}

.output-surface,
[data-output-key] {
  min-width: 0;
}

.output-surface {
  margin-top: 18px;
}

.stale-banner {
  margin-bottom: 12px;
  border: 1px solid #d9b16c;
  border-radius: 8px;
  background: var(--amber-soft);
  color: #5a3908;
  padding: 10px 12px;
  font-size: 0.83rem;
  font-weight: 760;
}

.is-stale {
  opacity: 0.62;
}

.result-group + .result-group {
  margin-top: 20px;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

.result-group__title {
  margin-bottom: 10px;
  font-size: 0.94rem;
}

.metric-grid {
  display: grid;
  gap: 8px;
}

.metric {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  padding: 12px;
}

.metric--primary {
  border-color: #cad8f3;
  background: #f5f8ff;
}

.metric__meta {
  display: flex;
  align-items: center;
  gap: 7px;
}

.provenance {
  flex: 0 0 auto;
  border-radius: 999px;
  background: #e8eef8;
  color: #3a506f;
  padding: 2px 7px;
  font-size: 0.65rem;
  font-weight: 800;
}

.metric__label {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 700;
}

.metric__value {
  margin-top: 4px;
  font-size: 1.28rem;
  font-weight: 820;
  font-variant-numeric: tabular-nums;
  line-height: 1.35;
}

.metric--primary .metric__value {
  font-size: clamp(1.45rem, 7vw, 2rem);
}

.metric__note {
  margin-top: 5px;
  color: var(--muted);
  font-size: 0.72rem;
}

.empty-note {
  margin-top: 16px;
  color: var(--muted);
  font-size: 0.86rem;
}

.validation-message {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 3px 10px;
  margin-top: 10px;
  border: 1px solid var(--line);
  border-left-width: 4px;
  border-radius: 8px;
  padding: 11px 12px;
  font-size: 0.82rem;
}

.validation-message--error {
  border-left-color: var(--danger);
  background: var(--danger-soft);
}

.validation-message--warning {
  border-left-color: var(--amber);
  background: var(--amber-soft);
}

.validation-message--info {
  border-left-color: var(--blue);
  background: var(--blue-soft);
}

.validation-message__label {
  grid-row: 1 / span 2;
}

.validation-correction {
  color: var(--muted);
}

.boundary-grid {
  display: grid;
  gap: 10px;
  margin-top: 16px;
}

.boundary-panel {
  border-left: 4px solid var(--green);
  background: var(--green-soft);
  padding: 13px 14px;
}

.boundary-panel--unknown {
  border-left-color: var(--muted);
  background: var(--surface-soft);
}

.boundary-panel h3 {
  font-size: 0.92rem;
}

.boundary-panel ul {
  display: grid;
  gap: 4px;
  margin-top: 7px;
  padding-left: 18px;
  color: var(--ink-soft);
  font-size: 0.8rem;
}

.explanation {
  margin-top: 10px;
  border-top: 1px solid var(--line);
}

.explanation h4 {
  margin-top: 10px;
  font-size: 0.8rem;
}

.explanation-list {
  display: grid;
  grid-template-columns: minmax(90px, auto) 1fr;
  gap: 4px 10px;
  margin-top: 5px;
  font-size: 0.78rem;
}

.explanation-list dt {
  color: var(--muted);
}

.explanation-list dd {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.formula-list,
.assumption-list {
  display: grid;
  gap: 4px;
  margin-top: 5px;
  padding-left: 20px;
  font-size: 0.78rem;
  overflow-wrap: anywhere;
}

.slarog-cta {
  display: grid;
  gap: 16px;
  padding: 20px 16px;
  background: linear-gradient(135deg, #f8fbff, #eef4ff);
}

.slarog-cta h2 {
  margin-top: 4px;
  font-size: 1.18rem;
}

.slarog-cta p:not(.panel-kicker) {
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.84rem;
}

.slarog-cta > a {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--blue);
  border-radius: 8px;
  background: var(--surface);
  color: var(--blue-dark);
  padding: 9px 14px;
  font-weight: 780;
  text-decoration: none;
}

.formula-grid {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.formula-card {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  padding: 15px 14px;
}

.formula-card h3 {
  font-size: 0.92rem;
}

.formula-card p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.78rem;
}

.formula-card .formula-expression {
  border-left: 3px solid var(--blue);
  background: var(--surface);
  color: var(--ink-soft);
  padding: 7px 9px;
  font-weight: 760;
  overflow-wrap: anywhere;
}

.rounding-note {
  margin-top: 16px;
  border-left: 4px solid var(--amber);
  background: var(--amber-soft);
  color: #50330a;
  padding: 12px 14px;
  font-size: 0.8rem;
}

.tool-faq .faq-list {
  display: grid;
  gap: 8px;
  margin-top: 18px;
}

.tool-faq details {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
}

.tool-faq summary {
  display: flex;
  min-height: 48px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  padding: 11px 13px;
  font-size: 0.84rem;
  font-weight: 780;
}

.tool-faq summary::-webkit-details-marker {
  display: none;
}

.tool-faq summary::after {
  content: '+';
  flex: 0 0 auto;
  color: var(--blue);
  font-size: 1.1rem;
}

.tool-faq details[open] summary::after {
  content: '−';
}

.tool-faq details p {
  border-top: 1px solid var(--line);
  color: var(--muted);
  padding: 12px 13px 14px;
  font-size: 0.78rem;
}

.steps {
  display: grid;
  gap: 14px;
  margin-top: 18px;
  padding: 0;
  list-style: none;
}

.steps li {
  display: flex;
  gap: 12px;
}

.steps li > span {
  display: grid;
  width: 32px;
  height: 32px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: var(--blue-soft);
  color: var(--blue-dark);
  font-size: 0.76rem;
  font-weight: 800;
}

.steps h3 {
  font-size: 0.9rem;
}

.steps p {
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.78rem;
}

.disclaimer {
  margin-bottom: 36px;
  background: var(--surface-soft);
}

.disclaimer h2 {
  font-size: 1rem;
}

.disclaimer p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.78rem;
}

.tool-footer {
  border-top: 1px solid var(--line);
  background: #edf2f7;
  padding: 26px 0 max(24px, env(safe-area-inset-bottom));
}

.footer-inner {
  display: grid;
  gap: 16px;
}

.footer-inner > div > a {
  font-weight: 800;
  text-decoration: none;
}

.footer-inner p,
.tool-footer > small {
  color: var(--muted);
  font-size: 0.75rem;
}

.footer-inner nav {
  display: flex;
  flex-wrap: wrap;
  gap: 5px 14px;
}

.footer-inner nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  font-size: 0.76rem;
}

.tool-footer > small {
  display: block;
  width: min(var(--max), calc(100% - 28px));
  margin: 16px auto 0;
}

@media (min-width: 600px) {
  .shell,
  .header-inner,
  .footer-inner,
  .tool-footer > small {
    width: min(var(--max), calc(100% - 48px));
  }

  .header-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .header-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 2px 16px;
  }

  .intro {
    padding-block: 72px 46px;
  }

  .tool,
  .output-section,
  .guide,
  .disclaimer {
    padding: 28px;
  }

  .mode-switcher,
  .submode-switcher {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .field-grid,
  .metric-grid,
  .boundary-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

  .slarog-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 24px 28px;
  }

  .slarog-cta > a {
    min-width: 190px;
  }

  .footer-inner {
    grid-template-columns: 1fr auto;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .header-links a {
    font-size: 0.8rem;
  }

  .tool,
  .output-section,
  .guide,
  .disclaimer {
    padding: 34px 38px;
  }

  .panel-heading {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }

  .metric-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .metric--primary {
    grid-column: span 1;
  }

  .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

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

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

@media (forced-colors: active) {
  .mode-switcher button[aria-pressed='true'],
  .submode-switcher button[aria-pressed='true'] {
    outline: 2px solid CanvasText;
  }
}