:root {
  color-scheme: dark;
  --background: #0D1117;
  --card: #161B22;
  --border: #21262D;
  --text: #E6EDF3;
  --muted: #8B949E;
  --accent: #00E5C0;
  --accent-soft: rgba(0, 229, 192, 0.12);
  --accent-text: #06231D;
  --container: 1040px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-wrap: anywhere;
  background: var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", "BIZ UDPGothic", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body:lang(ja) {
  line-height: 1.8;
}

h1,
h2,
h3 {
  margin-top: 0;
  color: var(--text);
  word-break: auto-phrase;
  text-wrap: balance;
}

h1 {
  margin-bottom: 24px;
  font-size: clamp(2.75rem, 7vw, 5.25rem);
  font-weight: 750;
  letter-spacing: -0.045em;
  line-height: 1.04;
}

h2 {
  margin-bottom: 32px;
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.16;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.125rem;
  font-weight: 650;
  line-height: 1.35;
}

p {
  margin-top: 0;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible,
.button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.container {
  width: min(calc(100% - 40px), var(--container));
  margin-inline: auto;
}

.site-header {
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: 1.125rem;
  font-weight: 650;
  letter-spacing: -0.015em;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: block;
  width: 28px;
  height: 28px;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 22px;
  font-size: 0.875rem;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
}

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

.site-nav .language-link {
  color: var(--accent);
}

.hero {
  padding: 112px 0 104px;
}

.hero-copy {
  max-width: 880px;
}

.hero-subtitle {
  max-width: 760px;
  margin-bottom: 36px;
  color: var(--muted);
  font-size: clamp(1.125rem, 2.3vw, 1.375rem);
  line-height: 1.7;
}

.cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border: 1px solid transparent;
  border-radius: 10px;
  font-weight: 650;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  transition: background-color 150ms ease, border-color 150ms ease, filter 150ms ease;
}

.button:hover {
  text-decoration: none;
}

.button-primary {
  background: var(--accent);
  color: var(--accent-text);
}

.button-primary:hover {
  color: var(--accent-text);
  filter: brightness(1.08);
}

.button-secondary {
  border-color: var(--accent);
  color: var(--accent);
}

.button-secondary:hover {
  background: var(--accent-soft);
}

.button-disabled {
  cursor: default;
  background: var(--border);
  color: var(--muted);
  user-select: none;
}

.section {
  padding: 80px 0;
}

.section-heading {
  max-width: 720px;
}

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

.card {
  padding: 26px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
}

.card p {
  margin-bottom: 0;
  color: var(--muted);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  counter-reset: steps;
}

.step {
  min-height: 100%;
  counter-increment: steps;
}

.step::before {
  display: block;
  margin-bottom: 18px;
  color: var(--accent);
  content: counter(steps, decimal-leading-zero);
  font-size: 2.5rem;
  font-weight: 750;
  line-height: 1;
}

.download-card {
  display: flex;
  min-height: 230px;
  flex-direction: column;
  align-items: flex-start;
}

.requirements {
  margin-bottom: 24px;
  color: var(--muted);
}

.download-card .button {
  margin-top: auto;
}

.download-note {
  max-width: 820px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 0.875rem;
}

.privacy-main {
  padding: 80px 0 96px;
}

.privacy-content {
  max-width: 800px;
}

.privacy-content h1 {
  margin-bottom: 12px;
  font-size: clamp(2.5rem, 6vw, 4rem);
}

.effective-date {
  margin-bottom: 34px;
  color: var(--muted);
}

.summary-card {
  margin-bottom: 56px;
  padding: 24px 26px;
  border: 1px solid var(--accent);
  border-radius: 14px;
  background: var(--accent-soft);
  color: var(--text);
  font-size: 1.0625rem;
}

.summary-card p {
  margin: 0;
}

.policy-section {
  margin-top: 44px;
}

.policy-section h2 {
  margin-bottom: 14px;
  font-size: 1.5rem;
  letter-spacing: -0.015em;
}

.policy-section p,
.policy-section li {
  color: var(--muted);
}

.policy-section p {
  margin-bottom: 0;
}

.policy-section ul {
  margin: 0;
  padding-left: 24px;
}

.policy-section li + li {
  margin-top: 10px;
}

.site-footer {
  padding: 30px 0;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--muted);
  font-size: 0.875rem;
}

.footer-inner p {
  margin: 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--text);
}

@media (max-width: 760px) {
  .header-inner {
    min-height: auto;
    flex-direction: column;
    align-items: flex-start;
    padding-block: 18px;
  }

  .site-nav {
    width: 100%;
    flex-wrap: wrap;
    justify-content: flex-start;
    gap: 10px 18px;
  }

  .hero {
    padding: 80px 0 72px;
  }

  .section {
    padding: 64px 0;
  }

  .card-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .cta-group {
    flex-direction: column;
  }

  .cta-group .button {
    width: 100%;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

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

  .button {
    transition: none;
  }
}