/* Sokuten — shared styles. Zero dependencies.
   A professional deep-navy palette, chosen for a field-survey tool —
   the calm, high-contrast look of an instrument display, not a filter. */
:root {
  --bg: #f5f7fa;
  --fg: #1a2230;
  --fg-muted: #55606f;
  --accent: #1f5c99;
  --accent-fg: #ffffff;
  --card: #ffffff;
  --border: #dde3ec;
  --code-bg: #eaeef4;
  color-scheme: light dark;

  /* Brand palette (hero).
     Deep instrument navy with a precise sky-blue readout accent. */
  --brand-deep: #0b1c33;
  --brand: #17385e;
  --brand-bright: #5fa4dc;
  --brand-on: #f3f8fd;
  --brand-on-muted: #b9cbe0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1219;
    --fg: #e6ecf3;
    --fg-muted: #94a1b2;
    --accent: #6fb0e8;
    --accent-fg: #0d1219;
    --card: #151d27;
    --border: #26313f;
    --code-bg: #182230;

    --brand-deep: #060e1a;
    --brand: #14273f;
    --brand-bright: #5fa4dc;
    --brand-on: #f3f8fd;
    --brand-on-muted: #adc1d8;
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Noto Sans JP", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.7;
}

main {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 4rem;
}

header.site {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.25rem 1.25rem 0;
}

header.site a {
  color: var(--fg-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

header.site a:hover {
  color: var(--accent);
}

h1 {
  font-size: 1.9rem;
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 1.2rem 0 0.4rem;
}

h2 {
  font-size: 1.35rem;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 2.2rem 0 0.6rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--border);
}

h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

h3 {
  font-size: 1.1rem;
  margin: 1.6rem 0 0.4rem;
}

p, ul, ol {
  margin: 0.6rem 0;
}

ul, ol {
  padding-left: 1.4rem;
}

li {
  margin: 0.3rem 0;
}

a {
  color: var(--accent);
}

strong {
  font-weight: 600;
}

code {
  background: var(--code-bg);
  border-radius: 5px;
  padding: 0.1em 0.35em;
  font-size: 0.9em;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

.meta {
  color: var(--fg-muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.lang-note {
  color: var(--fg-muted);
  font-size: 0.9rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.7rem 1rem;
  margin: 1.2rem 0;
}

.lang-note a {
  color: var(--accent);
}

section.lang {
  margin-top: 1rem;
}

section.lang + section.lang {
  margin-top: 3rem;
  border-top: 2px solid var(--border);
  padding-top: 1rem;
}

footer.site {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
  border-top: 1px solid var(--border);
  color: var(--fg-muted);
  font-size: 0.9rem;
}

footer.site nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.2rem;
  margin-bottom: 0.8rem;
}

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

footer.site a:hover {
  color: var(--accent);
}

.legal-notice {
  margin-top: 0.8rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--fg-muted);
}

/* Landing page hero */
.hero {
  text-align: center;
  margin: 1.5rem 0 2.5rem;
  padding: 3rem 1.5rem 2.8rem;
  border-radius: 28px;
  background:
    radial-gradient(120% 140% at 82% 10%, rgba(95, 164, 220, 0.28), transparent 55%),
    linear-gradient(160deg, var(--brand-deep), var(--brand) 78%);
  color: var(--brand-on);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06) inset;
}

.hero .hero-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto;
  filter: drop-shadow(0 6px 16px rgba(0, 0, 0, 0.35));
}

.store-button {
  display: inline-block;
  margin-top: 1.6rem;
  padding: 0.85rem 1.8rem;
  background: var(--brand-bright);
  color: var(--brand-deep);
  border-radius: 12px;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
}
.store-button:hover { opacity: 0.88; }

.hero h1 {
  font-size: 2.05rem;
  line-height: 1.3;
  margin: 1.2rem 0 0.7rem;
  color: var(--brand-on);
}

.hero .tagline {
  font-size: 1.1rem;
  color: var(--brand-on);
  opacity: 0.94;
  max-width: 33rem;
  margin: 0 auto;
}

.hero .tagline-en {
  font-size: 1rem;
  color: var(--brand-on-muted);
  max-width: 31rem;
  margin: 0.5rem auto 0;
}

.hero .fine-print {
  margin-top: 1.4rem;
  font-size: 0.85rem;
  color: var(--brand-on-muted);
}

/* eyebrow label above a section heading */
.eyebrow {
  display: block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.cards {
  display: grid;
  gap: 1.1rem;
  margin-top: 1.5rem;
}

.card-link {
  display: block;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.3rem 1.3rem 1.4rem;
  text-decoration: none;
  color: inherit;
}

.card-link:hover {
  border-color: var(--accent);
}

.card-link h3 {
  margin: 0 0 0.4rem;
  font-size: 1.15rem;
  color: var(--accent);
}

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

/* Feature chips on the landing page */
.features {
  display: grid;
  gap: 0.8rem;
  margin: 1.8rem 0 0;
}

.feature {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem 1.2rem;
}

.feature h3 {
  margin: 0 0 0.25rem;
  font-size: 1rem;
  color: var(--accent);
}

.feature p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 0.93rem;
}

/* FAQ */
.faq-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.1rem 1.3rem;
  margin: 1rem 0;
}

.faq-item h3 {
  margin: 0 0 0.5rem;
}

.faq-item p, .faq-item ul, .faq-item ol {
  font-size: 0.97rem;
}

.contact-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.2rem 1.3rem;
  margin: 2rem 0 0;
  text-align: center;
}

.disclaimer-box {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.1rem 1.3rem;
  margin: 1rem 0;
  font-size: 0.95rem;
}

/* Prominent field-safety / liability note */
.notice-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 14px;
  padding: 1.1rem 1.3rem;
  margin: 1.5rem 0 0;
}

.notice-box h3 {
  margin: 0 0 0.3rem;
  font-size: 1rem;
  color: var(--accent);
}

.notice-box p {
  margin: 0.3rem 0 0;
  color: var(--fg-muted);
  font-size: 0.92rem;
}

@media (min-width: 640px) {
  .cards {
    grid-template-columns: repeat(3, 1fr);
  }
  .features {
    grid-template-columns: repeat(2, 1fr);
  }
}