/* ===== Base ===== */
:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-accent: #06b6d4;
  --color-text: #0f172a;
  --color-muted: #475569;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-border: #e2e8f0;
  --max-width: 1080px;
  --radius: 12px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
    "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

img { max-width: 100%; height: auto; display: block; }

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--color-border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo { display: inline-flex; align-items: center; gap: 10px; }
.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: block;
}
.logo-text {
  font-weight: 800;
  font-size: 22px;
  letter-spacing: 0.5px;
  color: var(--color-text);
}
.site-nav { display: flex; gap: 24px; }
.site-nav a {
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 600;
}
.site-nav a:hover { color: var(--color-primary); text-decoration: none; }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(180deg, #eff6ff 0%, #ffffff 100%);
  padding: 80px 0 64px;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 48px;
  align-items: center;
}
.eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  padding: 4px 12px;
  background: #eff6ff;
  color: var(--color-primary-dark);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  border-radius: 999px;
}
.hero h1 {
  font-size: 40px;
  line-height: 1.3;
  margin: 0 0 16px;
  letter-spacing: -0.01em;
}
.hero strong { color: var(--color-text); font-weight: 800; }
.lead {
  font-size: 17px;
  color: var(--color-muted);
  margin: 0 0 28px;
}
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 15px;
  transition: transform 0.05s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-secondary {
  background: #fff;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover { border-color: var(--color-primary); color: var(--color-primary); }

.placeholder-image {
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 9 / 16;
  max-width: 320px;
  margin: 0 auto;
  border-radius: 24px;
  background: linear-gradient(135deg, #dbeafe, #cffafe);
  color: var(--color-muted);
  font-weight: 700;
  letter-spacing: 0.05em;
  border: 1px dashed var(--color-border);
}
.hero-screenshot {
  display: block;
  max-width: 320px;
  width: 100%;
  margin: 0 auto;
  border-radius: 32px;
  box-shadow: 0 24px 48px rgba(15, 23, 42, 0.18);
}

/* ===== Sections ===== */
.section { padding: 72px 0; }
.section:nth-of-type(even) { background: var(--color-bg-alt); }
.section-title {
  font-size: 28px;
  margin: 0 0 8px;
  text-align: center;
}
.section-subtitle {
  text-align: center;
  color: var(--color-muted);
  margin: 0 0 32px;
  font-size: 14px;
}

/* ===== Features ===== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}
.feature-card h3 { margin: 12px 0 8px; font-size: 18px; }
.feature-card p { margin: 0; color: var(--color-muted); font-size: 15px; }
.feature-icon { font-size: 28px; }

/* ===== Science blocks ===== */
.science-block {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
  margin-top: 48px;
  padding-top: 48px;
  border-top: 1px solid var(--color-border);
}
.science-block:first-of-type {
  border-top: none;
  padding-top: 16px;
}
.science-block.reverse { grid-template-columns: 1fr 1.2fr; }
.science-block.reverse .science-text { order: 2; }
.science-block.reverse .science-visual { order: 1; }
.science-text h3 {
  font-size: 22px;
  margin: 0 0 12px;
  line-height: 1.4;
}
.science-text p {
  margin: 0 0 12px;
  color: var(--color-muted);
  font-size: 16px;
}
.science-text em {
  font-style: normal;
  color: var(--color-primary-dark);
  font-weight: 700;
}
.science-visual img {
  display: block;
  max-width: 280px;
  width: 100%;
  margin: 0 auto;
  border-radius: 28px;
  box-shadow: 0 16px 36px rgba(15, 23, 42, 0.14);
}

/* ===== Screens grid ===== */
.screen-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 24px;
}
.screen-grid figure {
  margin: 0;
  text-align: center;
}
.screen-grid img {
  display: block;
  width: 100%;
  border-radius: 18px;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.12);
}
.screen-grid figcaption {
  margin-top: 10px;
  color: var(--color-muted);
  font-size: 13px;
  font-weight: 600;
}

/* ===== Steps ===== */
.steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.steps li {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}
.steps h3 { margin: 0 0 8px; font-size: 17px; color: var(--color-primary); }
.steps p { margin: 0; color: var(--color-muted); }

/* ===== Download ===== */
.download-inner { text-align: center; }
.store-badges {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
  flex-wrap: wrap;
}
.store-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 180px;
  padding: 14px 20px;
  background: #0f172a;
  color: #fff;
  border-radius: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
}
.store-badge:hover { background: #1e293b; text-decoration: none; }

/* ===== Contact ===== */
.contact { text-align: center; }
.contact-email {
  font-size: 18px;
  font-weight: 700;
  margin-top: 8px;
}
.company-info {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 8px 24px;
  max-width: 640px;
  margin: 32px auto 0;
  padding: 24px 28px;
  text-align: left;
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}
.company-info dt {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-muted);
  letter-spacing: 0.04em;
}
.company-info dd {
  margin: 0;
  font-size: 14px;
  color: var(--color-text);
}

/* ===== Legal pages ===== */
.legal {
  padding: 56px 0 80px;
}
.legal h1 {
  font-size: 28px;
  margin: 0 0 8px;
}
.legal-meta {
  color: var(--color-muted);
  font-size: 13px;
  margin: 0 0 24px;
}
.legal h2 {
  font-size: 18px;
  margin: 32px 0 8px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}
.legal p, .legal ul, .legal ol { color: var(--color-text); }
.legal ul, .legal ol { padding-left: 1.4em; }
.legal ol { margin: 0 0 12px; }
.legal ol > li { margin-bottom: 6px; }
.legal ol ul { margin-top: 6px; }
.legal h3 {
  font-size: 15px;
  margin: 16px 0 6px;
  color: var(--color-muted);
}
.legal-company-info {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 8px 24px;
  margin: 16px 0 0;
  padding: 20px 24px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}
.legal-company-info dt {
  font-size: 13px;
  font-weight: 700;
  color: var(--color-muted);
}
.legal-company-info dd {
  margin: 0;
  font-size: 14px;
}
@media (max-width: 600px) {
  .legal-company-info {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .legal-company-info dt { margin-top: 12px; }
  .legal-company-info dt:first-of-type { margin-top: 0; }
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 24px 0;
  background: #fff;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.copyright { margin: 0; color: var(--color-muted); font-size: 13px; }
.footer-nav { display: flex; gap: 20px; }
.footer-nav a { color: var(--color-muted); font-size: 13px; }
.footer-nav a:hover { color: var(--color-primary); }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero { padding: 56px 0 40px; }
  .hero-inner { grid-template-columns: 1fr; gap: 32px; }
  .hero h1 { font-size: 30px; }
  .feature-grid, .steps { grid-template-columns: 1fr; }
  .site-nav { display: none; }
  .section { padding: 56px 0; }
  .science-block,
  .science-block.reverse {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .science-block.reverse .science-text { order: 2; }
  .science-block.reverse .science-visual { order: 1; }
  .screen-grid { grid-template-columns: repeat(2, 1fr); }
  .company-info {
    grid-template-columns: 1fr;
    gap: 0;
    padding: 20px;
  }
  .company-info dt { margin-top: 12px; }
  .company-info dt:first-of-type { margin-top: 0; }
}