:root {
  --bg: #f7f8fa;
  --bg-alt: #eef1f5;
  --fg: #1b2430;
  --fg-muted: #4d5a6b;
  --border: #dde2e8;
  --card-bg: #ffffff;
  --navy: #163049;
  --navy-deep: #0e2036;
  --accent: #c97a1c;
  --accent-contrast: #ffffff;
  --badge-bg: #fdeed9;
  --badge-fg: #8a5313;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #10151c;
    --bg-alt: #161d26;
    --fg: #e7ecf2;
    --fg-muted: #a9b4c2;
    --border: #2a3441;
    --card-bg: #171f29;
    --navy: #1c3a58;
    --navy-deep: #0c1826;
    --accent: #e8a33d;
    --accent-contrast: #1b1200;
    --badge-bg: #3a2b12;
    --badge-fg: #f0c581;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--navy);
  color: #fff;
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.02em;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.brand-text strong {
  font-size: 1rem;
}

.brand-text small {
  color: var(--fg-muted);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
}

.site-nav {
  display: flex;
  gap: 28px;
}

.site-nav a {
  color: var(--fg-muted);
  text-decoration: none;
  font-size: 0.92rem;
  white-space: nowrap;
}

.site-nav a:hover {
  color: var(--fg);
}

/* Hero */
.hero {
  background: linear-gradient(160deg, var(--navy-deep), var(--navy));
  color: #f2f5f8;
  padding: 96px 0 88px;
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  margin: 0 0 18px;
}

.hero h1 {
  font-size: clamp(1.9rem, 4vw, 2.9rem);
  line-height: 1.45;
  margin: 0 0 24px;
}

.hero-lead {
  max-width: 620px;
  color: #cbd6e3;
  font-size: 1.02rem;
  margin: 0 0 36px;
}

.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 13px 26px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

.btn:hover { opacity: 0.9; }

.btn-primary {
  background: var(--accent);
  color: var(--accent-contrast);
}

.btn-ghost {
  border-color: rgba(255,255,255,0.35);
  color: #f2f5f8;
}

/* Sections */
.section {
  padding: 76px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 1.55rem;
  margin: 0 0 16px;
}

.section-lead {
  color: var(--fg-muted);
  max-width: 680px;
  margin: 0 0 40px;
}

/* Concept */
.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
}

.concept-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 26px;
}

.concept-card h3 {
  margin: 0 0 12px;
  font-size: 1.05rem;
  color: var(--navy);
}

@media (prefers-color-scheme: dark) {
  .concept-card h3 { color: var(--accent); }
}

.concept-card p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 0.94rem;
}

/* Tools */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.tool-card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 30px 26px 26px;
  display: flex;
  flex-direction: column;
}

.tool-badge {
  position: absolute;
  top: 20px;
  right: 20px;
  background: var(--badge-bg);
  color: var(--badge-fg);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  letter-spacing: 0.03em;
}

.tool-icon {
  width: 48px;
  height: 48px;
  color: var(--navy);
  margin-bottom: 18px;
}

@media (prefers-color-scheme: dark) {
  .tool-icon { color: var(--accent); }
}

.tool-icon svg {
  width: 100%;
  height: 100%;
}

.tool-card h3 {
  margin: 0 0 10px;
  font-size: 1.08rem;
}

.tool-card p {
  color: var(--fg-muted);
  font-size: 0.92rem;
  margin: 0 0 22px;
  flex-grow: 1;
}

.tool-link-disabled {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--fg-muted);
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 10px 16px;
  text-align: center;
  cursor: not-allowed;
}

/* Business model steps */
.model-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.model-steps li {
  display: flex;
  flex-direction: column;
  gap: 14px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 26px;
}

.step-no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--navy);
  color: #fff;
  font-weight: 700;
  font-size: 0.95rem;
}

.model-steps h3 {
  margin: 0 0 8px;
  font-size: 1.02rem;
}

.model-steps p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 0.92rem;
}

/* Company */
.company-list {
  display: grid;
  gap: 20px;
  margin: 0;
}

.company-list > div {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 12px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 16px;
}

.company-list dt {
  color: var(--fg-muted);
  font-size: 0.88rem;
  font-weight: 600;
}

.company-list dd {
  margin: 0;
}

/* Contact */
.contact-wrap {
  text-align: left;
}

/* Footer */
.site-footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  color: var(--fg-muted);
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 860px) {
  .header-inner {
    height: auto;
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 0;
    gap: 10px;
  }
  .site-nav {
    gap: 16px;
    overflow-x: auto;
    width: 100%;
    padding-bottom: 2px;
  }
  .concept-grid,
  .tool-grid,
  .model-steps {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 72px 0 60px;
  }
  .section {
    padding: 56px 0;
  }
  .company-list > div {
    grid-template-columns: 1fr;
  }
}