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

:root {
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-border: #e2e6ea;
  --color-text: #1a1f2e;
  --color-text-muted: #6b7280;
  --color-accent: #1e4fad;
  --color-accent-hover: #163d8a;
  --color-badge-open: #16a34a;
  --color-badge-prep: #d97706;
  --color-badge-concept: #6b7280;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  font-size: 16px;
}

body {
  font-family: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP",
    "Yu Gothic", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
}

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

a:hover {
  text-decoration: underline;
}

/* ── Header ─────────────────────────────────── */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 32px;
}

.header-brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
  flex-shrink: 0;
}

.header-brand:hover {
  text-decoration: none;
  color: var(--color-accent);
}

.header-nav {
  display: flex;
  gap: 24px;
  list-style: none;
  flex: 1;
}

.header-nav a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.header-nav a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.btn {
  display: inline-block;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  line-height: 1.4;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border: 2px solid var(--color-accent);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  text-decoration: none;
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}

.btn-secondary:hover {
  background: var(--color-accent);
  color: #fff;
  text-decoration: none;
}

/* ── Hero ────────────────────────────────────── */
.hero {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 72px 24px 64px;
}

.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-kicker {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.hero-brand {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.15;
  color: var(--color-text);
  margin-bottom: 4px;
}

.hero-brand-en {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.hero-copy {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ── Product Preview Panel ───────────────────── */
.preview-panel {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.preview-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.preview-header-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-border);
}

.preview-title {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-left: 4px;
}

.preview-body {
  padding: 16px;
}

.preview-stat-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 16px;
}

.preview-stat {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 10px 12px;
}

.preview-stat-label {
  font-size: 0.68rem;
  color: var(--color-text-muted);
  margin-bottom: 2px;
}

.preview-stat-value {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
}

.preview-table {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.preview-table-row {
  display: grid;
  grid-template-columns: 2fr 1.2fr 1fr;
  padding: 8px 12px;
  font-size: 0.75rem;
  border-bottom: 1px solid var(--color-border);
  align-items: center;
}

.preview-table-row:last-child {
  border-bottom: none;
}

.preview-table-head {
  background: var(--color-bg);
  font-weight: 600;
  color: var(--color-text-muted);
  font-size: 0.7rem;
}

.preview-badge {
  display: inline-block;
  padding: 2px 7px;
  border-radius: 99px;
  font-size: 0.65rem;
  font-weight: 600;
}

.badge-sent {
  background: #dbeafe;
  color: #1d4ed8;
}

.badge-paid {
  background: #dcfce7;
  color: #15803d;
}

.badge-draft {
  background: #f3f4f6;
  color: #6b7280;
}

/* ── Sections shared ─────────────────────────── */
.section {
  padding: 72px 24px;
}

.section-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.section-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.section-subtitle {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 40px;
}

/* ── Series ──────────────────────────────────── */
.series-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.product-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.product-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
}

.product-name {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
}

.status-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 99px;
  font-size: 0.7rem;
  font-weight: 700;
  white-space: nowrap;
  flex-shrink: 0;
}

.status-open {
  background: #dcfce7;
  color: var(--color-badge-open);
}

.status-prep {
  background: #fef3c7;
  color: var(--color-badge-prep);
}

.status-concept {
  background: #f3f4f6;
  color: var(--color-badge-concept);
}

.product-desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

.product-features {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.product-features li {
  font-size: 0.75rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  color: var(--color-text-muted);
}

/* ── Features ────────────────────────────────── */
.features-bg {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}

.feature-item {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 18px;
}

.feature-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.feature-note {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* ── Roadmap ─────────────────────────────────── */
.roadmap-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.roadmap-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.roadmap-status {
  flex-shrink: 0;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 99px;
  white-space: nowrap;
  margin-top: 2px;
}

.roadmap-content-title {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 2px;
}

.roadmap-content-desc {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.roadmap-note {
  margin-top: 20px;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  padding: 12px 16px;
  background: var(--color-bg);
  border-left: 3px solid var(--color-border);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ── Footer ──────────────────────────────────── */
.site-footer {
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.6);
  padding: 32px 24px;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-brand {
  font-size: 0.9rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.85);
}

.footer-copy {
  font-size: 0.8rem;
}

.footer-link {
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.6);
}

.footer-link:hover {
  color: rgba(255, 255, 255, 0.9);
}

/* ── Responsive ──────────────────────────────── */
@media (max-width: 768px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-brand {
    font-size: 2rem;
  }

  .preview-panel {
    order: -1;
  }

  .header-nav {
    display: none;
  }

  .header-inner {
    justify-content: space-between;
  }

  .series-grid {
    grid-template-columns: 1fr;
  }

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

  .section {
    padding: 48px 16px;
  }

  .hero {
    padding: 48px 16px 40px;
  }
}

@media (max-width: 480px) {
  .features-grid {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    text-align: center;
  }
}