:root {
  --bg: #FAFCFF;
  --snow: #FFFFFF;
  --ink: #3A2E26;
  --ink-soft: #6E5F54;
  --divider: #E8E2D9;
  --forest: #5C8A2E;
  --hero-bg: #F1F7FF;
  --max-width: 720px;
  --max-hero-width: 920px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family:
    "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo",
    -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.75;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.container-wide {
  max-width: var(--max-hero-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ── site header (top nav) ─────────────────────────────────── */

.site-header {
  border-bottom: 1px solid var(--divider);
  background: var(--snow);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(8px);
}

.site-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  max-width: var(--max-hero-width);
  margin: 0 auto;
}

.logo {
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: 0.04em;
}

.logo-mark {
  display: inline-block;
  width: 22px;
  height: 22px;
  background: var(--ink);
  border-radius: 11px;
  vertical-align: -5px;
  margin-right: 6px;
  position: relative;
}

.logo-mark::before, .logo-mark::after {
  content: '';
  position: absolute;
  width: 3px;
  height: 3px;
  background: var(--snow);
  border-radius: 50%;
  top: 8px;
}

.logo-mark::before { left: 6px; }
.logo-mark::after { right: 6px; }

nav.top-nav {
  display: flex;
  gap: 18px;
  font-size: 13px;
}

nav.top-nav a {
  color: var(--ink-soft);
  text-decoration: none;
}

nav.top-nav a:hover {
  color: var(--forest);
}

@media (max-width: 480px) {
  nav.top-nav { gap: 12px; font-size: 12px; }
  .site-header-inner { padding: 12px 16px; }
}

/* ── hero ──────────────────────────────────────────────────── */

.hero {
  background:
    radial-gradient(circle at 20% 0%, #FFFFFF 0%, transparent 40%),
    radial-gradient(circle at 80% 100%, #FFFFFF 0%, transparent 40%),
    var(--hero-bg);
  padding: 80px 20px 60px;
  text-align: center;
}

.hero h1 {
  font-size: 38px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.4;
  margin-bottom: 16px;
}

.hero .lead {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 560px;
  margin: 0 auto 36px;
  line-height: 1.9;
}

.store-badges {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.badge {
  display: inline-block;
  padding: 14px 28px;
  background: var(--ink);
  color: var(--snow);
  text-decoration: none;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.03em;
  transition: opacity 0.15s ease;
}

.badge:hover { opacity: 0.85; }

.badge.disabled {
  background: var(--divider);
  color: var(--ink-soft);
  cursor: default;
  pointer-events: none;
}

.badge .small {
  display: block;
  font-size: 10px;
  font-weight: 400;
  opacity: 0.8;
  letter-spacing: 0.05em;
}

@media (max-width: 480px) {
  .hero { padding: 56px 16px 40px; }
  .hero h1 { font-size: 28px; }
  .hero .lead { font-size: 14px; margin-bottom: 28px; }
  .badge { padding: 12px 22px; font-size: 13px; }
}

/* ── features ──────────────────────────────────────────────── */

.section {
  padding: 64px 20px;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 40px;
  letter-spacing: 0.02em;
}

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

.feature-card {
  background: var(--snow);
  border: 1px solid var(--divider);
  border-radius: 16px;
  padding: 24px;
}

.feature-card .emoji {
  font-size: 30px;
  margin-bottom: 12px;
  display: block;
}

.feature-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--ink);
}

.feature-card p {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.85;
}

@media (max-width: 640px) {
  .features { grid-template-columns: 1fr; }
  .section { padding: 48px 16px; }
  .section-title { font-size: 19px; margin-bottom: 28px; }
}

/* ── screenshots ───────────────────────────────────────────── */

.screenshots {
  background: var(--hero-bg);
  padding: 64px 20px;
}

.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 14px;
  max-width: var(--max-hero-width);
  margin: 0 auto;
}

.screenshot {
  aspect-ratio: 9 / 19.5;
  background: var(--snow);
  border: 1px solid var(--divider);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink-soft);
  font-size: 11px;
  text-align: center;
  padding: 12px;
  line-height: 1.6;
}

@media (max-width: 768px) {
  .screenshot-grid {
    grid-template-columns: repeat(2, 1fr);
    max-width: 480px;
  }
}

@media (max-width: 380px) {
  .screenshot-grid { grid-template-columns: 1fr; }
}

/* ── developer note ────────────────────────────────────────── */

.dev-note {
  background: var(--snow);
  border: 1px solid var(--divider);
  border-radius: 16px;
  padding: 32px;
  max-width: 560px;
  margin: 0 auto;
  text-align: center;
}

.dev-note p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 2;
  margin-bottom: 12px;
}

.dev-note p:last-child { margin-bottom: 0; }

.dev-note .signature {
  font-size: 13px;
  color: var(--ink);
  font-weight: 700;
  margin-top: 18px;
}

/* ── footer ────────────────────────────────────────────────── */

footer.site-footer {
  background: var(--ink);
  color: var(--snow);
  padding: 48px 20px 32px;
}

.footer-inner {
  max-width: var(--max-hero-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 32px;
}

footer.site-footer h4 {
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: 0.04em;
}

footer.site-footer p {
  font-size: 12px;
  line-height: 1.85;
  opacity: 0.78;
  margin-bottom: 6px;
}

footer.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

footer.site-footer ul li {
  margin-bottom: 8px;
  font-size: 13px;
}

footer.site-footer ul a {
  color: var(--snow);
  text-decoration: none;
  opacity: 0.78;
}

footer.site-footer ul a:hover { opacity: 1; }

footer.site-footer a[href^="mailto:"] {
  color: var(--snow);
  opacity: 0.85;
  text-decoration: underline;
}

.footer-bottom {
  max-width: var(--max-hero-width);
  margin: 32px auto 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 11px;
  opacity: 0.6;
  text-align: center;
}

@media (max-width: 640px) {
  .footer-inner { grid-template-columns: 1fr; gap: 24px; }
  footer.site-footer { padding: 36px 16px 24px; }
}

/* ── article (privacy/terms) ───────────────────────────────── */

.article {
  padding: 32px 20px 80px;
}

.article-header {
  border-bottom: 1px solid var(--divider);
  padding-bottom: 16px;
  margin-bottom: 32px;
}

.article-header .brand-link {
  font-size: 14px;
  color: var(--ink-soft);
  letter-spacing: 0.08em;
  text-decoration: none;
}

.article-header .brand-link:hover { color: var(--forest); }

.article h1 {
  font-size: 26px;
  font-weight: 700;
  margin-top: 16px;
  margin-bottom: 8px;
}

.updated {
  font-size: 13px;
  color: var(--ink-soft);
  margin-bottom: 32px;
}

.article h2 {
  font-size: 18px;
  font-weight: 700;
  margin-top: 36px;
  margin-bottom: 12px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--divider);
}

.article h3 {
  font-size: 15px;
  font-weight: 700;
  margin-top: 24px;
  margin-bottom: 8px;
}

.article p { margin-bottom: 14px; font-size: 15px; }

.article ul, .article ol {
  margin-left: 20px;
  margin-bottom: 14px;
}

.article li { margin-bottom: 6px; font-size: 15px; }

.article table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

.article th, .article td {
  border: 1px solid var(--divider);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

.article th { background: var(--snow); font-weight: 700; }

.article a { color: var(--forest); text-decoration: underline; text-underline-offset: 2px; }

.article-footer {
  margin-top: 64px;
  padding-top: 20px;
  border-top: 1px solid var(--divider);
  font-size: 12px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.nav-links {
  display: flex;
  gap: 16px;
  margin-top: 12px;
  font-size: 13px;
}

.nav-links a {
  color: var(--ink-soft);
  text-decoration: none;
}

.nav-links a:hover { color: var(--forest); }

@media (max-width: 480px) {
  .article { padding: 20px 16px 64px; }
  .article h1 { font-size: 22px; }
  .article h2 { font-size: 16px; }
  .article table { font-size: 13px; }
  .article th, .article td { padding: 8px; }
}

@media print {
  body { background: #fff; }
  .site-header, footer.site-footer, .article-footer { display: none; }
  .article { padding: 0; }
}