* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --page-bg: #f6f6f2;
  --surface: #ffffff;
  --surface-muted: #edede8;
  --surface-soft: #f8f8f4;
  --surface-strong: #111111;
  --text-primary: #111111;
  --text-body: #303531;
  --text-secondary: #60645f;
  --text-inverse: #ffffff;
  --border-color: #d8d8d0;
  --brand-primary: #111111;
  --brand-primary-dark: #000000;
  --brand-accent: #315c4f;
  --focus-ring: rgba(49, 92, 79, 0.24);
  --warning-bg: #fff7e6;
  --warning-border: #d3a642;
  --content-width: 1160px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --shadow-sm: 0 8px 22px rgba(24, 38, 33, 0.07);
  --shadow-md: 0 18px 45px rgba(24, 38, 33, 0.11);
  --heading-font: Georgia, "Times New Roman", "Noto Serif TC", serif;
  --body-font: Arial, "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

html {
  scrollbar-gutter: stable;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text-primary);
  background: var(--page-bg);
  font-family: var(--body-font);
  line-height: 1.72;
}

body,
button,
input,
textarea,
select {
  font: inherit;
}

a {
  color: inherit;
}

a:focus-visible,
summary:focus-visible,
.button:focus-visible,
.site-nav-cta:focus-visible {
  outline: 3px solid var(--brand-accent);
  outline-offset: 3px;
  box-shadow: 0 0 0 6px var(--focus-ring);
}

.skip-link {
  position: absolute;
  top: 12px;
  left: 16px;
  z-index: 20;
  transform: translateY(-150%);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  color: var(--text-inverse);
  background: var(--brand-primary);
  font-weight: 800;
}

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

.site-header {
  border-bottom: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.96);
  font-family: Arial, "Noto Sans TC", "Microsoft JhengHei", sans-serif;
}

.site-header-inner,
.site-footer-inner,
main {
  width: min(var(--content-width), calc(100% - 32px));
  max-width: 100%;
  margin: 0 auto;
}

.site-header-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 24px;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.site-brand,
.site-nav,
.site-footer-nav,
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
}

.site-brand {
  gap: 10px;
  min-height: 44px;
  color: var(--brand-primary-dark);
  font-weight: 900;
  line-height: 1.2;
  text-decoration: none;
}

.site-brand-mark {
  width: 28px;
  height: 28px;
  border: 8px solid var(--brand-primary);
  border-right-color: var(--brand-accent);
  border-radius: 50%;
}

.site-brand-text {
  line-height: 1.2;
  white-space: nowrap;
}

.site-nav {
  gap: 4px 14px;
}

.site-nav a,
.site-footer-nav a,
.site-footer-nav span {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  color: var(--text-secondary);
  font-weight: 800;
  text-decoration: none;
}

.site-nav a {
  line-height: 1.2;
}

.site-nav a:hover,
.site-nav a[aria-current="page"],
.site-footer-nav a:hover,
.site-footer-nav a[aria-current="page"] {
  color: var(--brand-primary);
}

.site-nav-cta,
.button {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 10px 15px;
  font-weight: 900;
  text-decoration: none;
}

.site-nav-cta {
  line-height: 1.2;
}

.site-nav-cta,
.button-primary {
  color: var(--text-inverse);
  background: var(--brand-primary);
}

.site-nav-cta:hover,
.button-primary:hover {
  background: var(--brand-primary-dark);
}

.button-secondary {
  border-color: var(--border-color);
  color: var(--brand-primary-dark);
  background: var(--surface);
}

main {
  padding: 24px 0 64px;
}

.breadcrumb {
  margin: 10px 0 22px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.breadcrumb li:not(:last-child)::after {
  content: "/";
  margin-left: 8px;
  color: var(--text-secondary);
}

.breadcrumb a {
  text-decoration-color: rgba(49, 92, 79, 0.35);
  text-underline-offset: 3px;
}

.method-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.32fr) minmax(280px, 0.68fr);
  gap: 24px;
  align-items: stretch;
  padding: 28px 0 30px;
}

.hero-copy,
.hero-summary,
.content-section,
.final-cta {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.hero-copy {
  padding: clamp(28px, 5vw, 54px);
}

.hero-summary {
  padding: clamp(20px, 3vw, 28px);
  background: var(--surface-soft);
}

.hero-summary h2,
.hero-summary p {
  margin-top: 0;
}

.hero-summary ul {
  margin: 0 0 16px;
  padding-left: 20px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--brand-accent);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p,
li {
  overflow-wrap: anywhere;
}

h1,
h2 {
  color: var(--text-primary);
  font-family: var(--heading-font);
}

h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(2.12rem, 5.2vw, 4rem);
  line-height: 1.08;
}

.method-hero .method-title-subject,
.method-hero .method-title-question {
  white-space: nowrap;
}

h2 {
  margin: 0;
  font-size: clamp(1.45rem, 3vw, 2.05rem);
  line-height: 1.22;
}

h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  line-height: 1.4;
}

p {
  color: var(--text-body);
}

.hero-lead,
.section-lead {
  max-width: 760px;
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.hero-lead {
  margin: 18px 0 24px;
}

.section-lead {
  margin: 0 0 18px;
}

.hero-actions {
  gap: 12px;
}

.content-section,
.final-cta {
  margin-top: 22px;
  padding: clamp(22px, 4vw, 34px);
}

.section-heading {
  display: grid;
  gap: 8px;
  max-width: 780px;
  margin-bottom: 20px;
}

.process-track {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.process-track li,
.explain-grid article,
.formula-card,
.scenario-grid article,
.comparison-panel > div,
.scope-list li,
.details-stack details,
.scenario-explainer > div,
.scenario-example {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.process-track li {
  padding: 20px;
}

.step-number {
  display: inline-flex;
  width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  border: 1px solid var(--border-color);
  border-radius: 50%;
  color: var(--brand-primary);
  background: var(--surface-muted);
  font-weight: 900;
}

.process-track p,
.explain-grid p,
.formula-card p,
.scenario-grid p,
.comparison-panel p,
.final-cta p {
  margin: 0;
}

.explain-grid,
.formula-grid,
.scenario-grid,
.comparison-panel,
.scenario-explainer {
  display: grid;
  gap: 14px;
}

.explain-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

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

.explain-grid article,
.scenario-grid article,
.comparison-panel > div,
.scenario-explainer > div,
.scenario-example {
  padding: 18px;
}

.formula-card {
  display: grid;
  gap: 10px;
  padding: 18px;
}

.formula-row {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  column-gap: 10px;
  align-items: start;
}

.formula-row strong {
  color: var(--brand-primary);
  white-space: nowrap;
}

.formula-row span {
  min-width: 0;
}

code {
  display: block;
  max-width: 100%;
  border-radius: var(--radius-sm);
  background: var(--surface-muted);
  color: var(--text-primary);
  padding: 10px;
  font-family: Consolas, "Courier New", monospace;
  font-size: 0.92rem;
  line-height: 1.55;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}

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

.comparison-panel ul,
.scenario-explainer ul,
.scenario-example ul,
.scope-list {
  margin: 10px 0 0;
  padding-left: 20px;
}

.scenario-explainer,
.scenario-example {
  margin-top: 14px;
}

.formula-strip {
  margin: 0 0 16px;
}

.warning-box {
  border-left: 5px solid var(--warning-border);
  border-radius: var(--radius-sm);
  background: var(--warning-bg);
  padding: 12px 14px;
  color: var(--text-body);
}

.scope-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  padding: 0;
  list-style: none;
}

.scope-list li {
  padding: 14px 16px;
}

.details-stack {
  display: grid;
  gap: 12px;
}

.details-stack details {
  padding: 0;
}

.details-stack summary {
  cursor: pointer;
  padding: 16px 18px;
  color: var(--brand-primary);
  font-weight: 900;
}

.details-stack p {
  margin: 0;
  padding: 0 18px 18px;
}

.final-cta {
  display: grid;
  gap: 12px;
  justify-items: start;
  background: var(--surface-soft);
}

.site-footer {
  border-top: 1px solid var(--border-color);
  background: var(--surface);
}

.site-footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  align-items: center;
  justify-content: space-between;
  padding: 30px 0;
}

.site-footer-brand {
  margin: 0 0 4px;
  font-weight: 900;
}

.site-footer-note {
  max-width: 420px;
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.site-footer-nav {
  gap: 2px 16px;
}

.site-footer-nav span {
  color: var(--text-secondary);
  cursor: default;
}

@media (max-width: 900px) {
  .method-hero .method-title-subject,
  .method-hero .method-title-question {
    display: block;
  }

  .method-hero,
  .process-track,
  .explain-grid,
  .formula-grid,
  .two-columns,
  .scenario-grid,
  .comparison-panel,
  .scenario-explainer,
  .scope-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 840px) {
  .site-header-inner,
  .site-footer-inner,
  main {
    width: min(100% - 24px, var(--content-width));
  }

  .site-nav {
    order: 3;
    width: 100%;
  }

  .site-nav-cta {
    margin-left: auto;
  }

  .hero-actions .button {
    width: 100%;
  }
}

@media (max-width: 520px) {
  .site-nav {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
  }

  .site-nav a {
    justify-content: center;
    padding: 5px 4px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--surface);
    font-size: 0.92rem;
    text-align: center;
    white-space: normal;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .hero-copy,
  .hero-summary,
  .content-section,
  .final-cta {
    padding: 20px;
  }
}

@media (max-width: 420px) {
  .site-header-inner,
  .site-footer-inner,
  main {
    width: min(100% - 20px, var(--content-width));
  }

  h1 {
    font-size: clamp(2.12rem, 11vw, 3rem);
  }

  h2 {
    font-size: clamp(1.7rem, 8vw, 2.25rem);
  }

  .site-brand-text {
    white-space: normal;
  }
}

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

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}