:root {
  --bg: #f6f8fc;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --accent: #007aff;
  --accent-dark: #0056b3;
  --border: #e2e8f0;
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
  --radius: 16px;
  --max: 1080px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family:
    system-ui,
    -apple-system,
    'Segoe UI',
    'Hiragino Sans',
    'Hiragino Kaku Gothic ProN',
    'Noto Sans JP',
    sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  font-size: 1rem;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(246, 248, 252, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  gap: 1rem;
}

.logo {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
}
.logo:hover {
  text-decoration: none;
  color: var(--accent);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.25rem;
  font-size: 0.92rem;
}
.nav-links a {
  color: var(--muted);
  font-weight: 500;
}
.nav-links a:hover {
  color: var(--accent);
}

.lang-select {
  font-size: 0.85rem;
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.hero {
  padding: 3.5rem 0 4rem;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 48%, #0c4a6e 100%);
  color: #f8fafc;
}

.hero .container {
  display: grid;
  gap: 2rem;
}

@media (min-width: 880px) {
  .hero .container {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: center;
  }
}

.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.hero-lead {
  margin: 0 0 1.75rem;
  font-size: 1.08rem;
  color: rgba(248, 250, 252, 0.88);
  max-width: 36rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

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

.store-badge-row {
  margin-top: 1.5rem;
}

.store-badge-label {
  margin: 0 0 0.6rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: rgba(248, 250, 252, 0.78);
  letter-spacing: 0.02em;
}

.store-badge-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
}

.store-badge-link {
  display: inline-block;
  line-height: 0;
  text-decoration: none;
}
.store-badge-link:hover {
  text-decoration: none;
  opacity: 0.9;
}
.store-badge-link:focus-visible {
  outline: 2px solid rgba(255, 255, 255, 0.85);
  outline-offset: 3px;
  border-radius: 4px;
}
.store-badge-link img {
  display: block;
  height: auto;
  max-height: 52px;
  width: auto;
}

.store-badge-row--footer {
  margin-top: 0;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid rgba(148, 163, 184, 0.22);
}

.site-footer .store-badge-label {
  color: #94a3b8;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.35rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 10px 30px rgba(0, 122, 255, 0.35);
}
.btn-primary:hover {
  background: var(--accent-dark);
  color: #fff;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.28);
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
}

.hero-card {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius);
  padding: 1.5rem;
  backdrop-filter: blur(8px);
}

.hero-card h2 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
  font-weight: 600;
  color: #e0f2fe;
}

.hero-card ul {
  margin: 0;
  padding-left: 1.15rem;
  color: rgba(248, 250, 252, 0.9);
  font-size: 0.92rem;
}

section.content {
  padding: 3.5rem 0;
}

section.content.alt {
  background: var(--surface);
  border-block: 1px solid var(--border);
}

h2.section-title {
  margin: 0 0 0.5rem;
  font-size: 1.65rem;
  letter-spacing: -0.02em;
}

p.section-intro {
  margin: 0 0 2rem;
  color: var(--muted);
  max-width: 42rem;
}

.card-grid {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 640px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .card-grid.three {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1rem;
}

.steps li {
  position: relative;
  padding: 1.25rem 1.25rem 1.25rem 3.5rem;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.04);
}

.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.steps strong {
  display: block;
  margin-bottom: 0.25rem;
}

.sample-box {
  background: linear-gradient(180deg, #eff6ff 0%, var(--surface) 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius);
  padding: 1.5rem;
}

.sample-box h3 {
  margin-top: 0;
}

.article-body {
  max-width: 42rem;
}

.article-body h2 {
  margin-top: 2.25rem;
  margin-bottom: 0.75rem;
  font-size: 1.35rem;
}

.article-body h3 {
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.article-body p,
.article-body ul {
  color: var(--muted);
}

.article-body ul {
  padding-left: 1.25rem;
}

.article-figure {
  margin: 0 0 1.75rem;
}
.article-figure img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  display: block;
}
.article-figure figcaption {
  margin-top: 0.5rem;
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.45;
}

.guide-link-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
}
.guide-link-list li {
  margin-bottom: 1.1rem;
  line-height: 1.55;
}
.guide-link-list a {
  font-weight: 600;
  color: var(--accent);
}

.faq-list {
  margin: 0;
}
.faq-list dt {
  font-weight: 700;
  margin-top: 1.35rem;
  color: var(--text);
}
.faq-list dt:first-child {
  margin-top: 0;
}
.faq-list dd {
  margin: 0.45rem 0 0;
  padding: 0;
  color: var(--muted);
}

.ad-slot {
  margin: 2.5rem 0;
  min-height: 120px;
  padding: 1rem;
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  text-align: center;
}

.ad-slot .label {
  font-size: 0.75rem;
  color: #94a3b8;
  margin-bottom: 0.5rem;
}

.site-footer {
  padding: 2.5rem 0;
  background: #0f172a;
  color: #94a3b8;
  font-size: 0.9rem;
}

.site-footer a {
  color: #cbd5e1;
}

.site-footer .cols {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .site-footer .cols {
    grid-template-columns: 1fr 1fr;
  }
}

.site-footer .bottom {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(148, 163, 184, 0.25);
  font-size: 0.82rem;
}

.breadcrumb {
  font-size: 0.88rem;
  color: var(--muted);
  margin: 1rem 0 0;
}
.breadcrumb a {
  color: var(--muted);
}

.page-hero {
  padding: 2.5rem 0 1rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.page-hero .lead {
  margin: 0;
  color: var(--muted);
  max-width: 40rem;
}

.article-meta {
  font-size: 0.82rem;
  color: var(--muted);
  margin: 0.6rem 0 0;
}