:root {
  --bg: #f7f0e6;
  --bg-surface: #ede4d6;
  --ink: #2a1f14;
  --ink-muted: #7a6655;
  --accent: #8b4513;
  --accent-soft: #c9a882;
  --line: rgba(42, 31, 20, 0.12);

  --font-display: 'Noto Serif JP', 'Shippori Mincho', serif;
  --font-body: 'Noto Sans JP', sans-serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 8rem;
  --space-section: clamp(80px, 12vw, 160px);

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-full: 100px;

  --transition-slow: 0.9s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-medium: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  letter-spacing: 0.02em;
  overflow-x: hidden;
}

::selection {
  background: var(--accent);
  color: var(--bg);
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--space-sm);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--space-lg);
  max-width: 600px;
}

.line-wrap {
  display: block;
  overflow: hidden;
  padding-top: 0.15em;
  margin-top: -0.15em;
}

.line-inner {
  display: block;
}

.texture-kyoto {
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='200' height='200' filter='url(%23n)' opacity='0.045'/%3E%3C/svg%3E"),
    repeating-linear-gradient(45deg, transparent, transparent 18px, rgba(42,31,20,0.018) 18px, rgba(42,31,20,0.018) 19px),
    repeating-linear-gradient(-45deg, transparent, transparent 18px, rgba(42,31,20,0.018) 18px, rgba(42,31,20,0.018) 19px);
}

.clip-round-bottom {
  border-radius: 0 0 50% 50% / 0 0 5vw 5vw;
  overflow: hidden;
  padding-bottom: calc(var(--space-section) + 6vw);
}

.section-dissolve {
  position: relative;
  z-index: 2;
  margin-top: -120px;
  padding-top: calc(120px + var(--space-section));
}
.section-dissolve::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 140px;
  background: linear-gradient(to bottom, transparent, var(--bg));
  pointer-events: none;
  z-index: -1;
}

.section-rule {
  position: relative;
  padding-top: calc(var(--space-section) + 32px);
}
.section-rule::before {
  content: '';
  position: absolute;
  top: 0;
  left: 10%;
  right: 10%;
  height: 1px;
  background: linear-gradient(
    to right,
    transparent,
    var(--accent) 25%,
    var(--accent) 75%,
    transparent
  );
  opacity: 0.3;
}

.side-nav {
  position: fixed;
  left: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
}

.side-nav a {
  writing-mode: vertical-lr;
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ink-muted);
  transition: color var(--transition-medium);
  padding: 8px 4px;
}

.side-nav a:hover,
.side-nav a.active {
  color: var(--accent);
}

.nav-progress {
  position: absolute;
  left: 50%;
  top: 0;
  width: 1px;
  height: 100%;
  background: var(--line);
  transform: translateX(-50%);
}

.nav-progress::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--scroll-progress, 0%);
  background: var(--accent);
  transition: height 0.1s linear;
}

.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg) var(--space-md);
  overflow: hidden;
}

.hero-bg-element {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 20%, rgba(139, 69, 19, 0.06) 0%, transparent 50%),
              radial-gradient(ellipse at 70% 80%, rgba(201, 168, 130, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
}

.hero-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  background: rgba(139, 69, 19, 0.08);
  padding: 8px 20px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-md);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 6rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: var(--space-md);
  color: var(--ink);
}

.hero-subtitle {
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  color: var(--ink-muted);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.05em;
}

.hero-actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-block;
  padding: 14px 32px;
  background: var(--accent);
  color: var(--bg);
  font-weight: 500;
  border-radius: var(--radius-full);
  transition: all var(--transition-medium);
  font-size: 0.95rem;
}

.btn-primary:hover {
  background: var(--ink);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-block;
  padding: 14px 32px;
  background: transparent;
  color: var(--ink);
  font-weight: 500;
  border: 1px solid var(--line);
  border-radius: var(--radius-full);
  transition: all var(--transition-medium);
  font-size: 0.95rem;
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.hero-visual {
  position: absolute;
  right: 10%;
  top: 50%;
  transform: translateY(-50%);
  width: 40vw;
  height: 40vw;
  max-width: 500px;
  max-height: 500px;
  pointer-events: none;
}

.hero-orb {
  position: absolute;
  inset: 20%;
  background: radial-gradient(circle, rgba(139, 69, 19, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  animation: pulse 4s ease-in-out infinite;
}

.hero-ring {
  position: absolute;
  inset: 0;
  border: 1px solid var(--accent-soft);
  border-radius: 50%;
  opacity: 0.3;
  animation: ring-rotate 20s linear infinite;
}

.hero-ring-2 {
  inset: 15%;
  animation-duration: 15s;
  animation-direction: reverse;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(1.1); opacity: 0.8; }
}

@keyframes ring-rotate {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.intro {
  padding: var(--space-section) 0;
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.intro-card {
  background: var(--bg-surface);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
  transition: all var(--transition-medium);
}

.intro-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(42, 31, 20, 0.08);
}

.intro-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(139, 69, 19, 0.08);
  border-radius: var(--radius-md);
  color: var(--accent);
  margin-bottom: var(--space-md);
}

.intro-card h3 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.intro-card p {
  color: var(--ink-muted);
  font-size: 0.95rem;
  line-height: 1.8;
}

.scenarios {
  padding: var(--space-section) 0;
}

.scenario-block {
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--line);
}

.scenario-block:last-child {
  border-bottom: none;
}

.scenario-header {
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.scenario-num {
  font-family: var(--font-display);
  font-size: clamp(3rem, 6vw, 5rem);
  font-weight: 700;
  color: var(--accent-soft);
  line-height: 1;
  opacity: 0.6;
}

.scenario-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  font-weight: 600;
}

.scenario-content {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.scenario-desc p {
  color: var(--ink-muted);
  font-size: 1.05rem;
  line-height: 1.9;
  margin-bottom: var(--space-md);
}

.scenario-tags {
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

.tag {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(139, 69, 19, 0.06);
  color: var(--accent);
  font-size: 0.8rem;
  border-radius: var(--radius-full);
  font-weight: 500;
}

.scenario-cases {
  display: grid;
  gap: var(--space-md);
}

.case-card {
  background: var(--bg-surface);
  padding: var(--space-md);
  border-radius: var(--radius-lg);
}

.case-card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--accent);
}

.case-metrics {
  display: flex;
  gap: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.metric {
  display: flex;
  flex-direction: column;
}

.metric-value {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--ink);
}

.metric-label {
  font-size: 0.75rem;
  color: var(--ink-muted);
  letter-spacing: 0.05em;
}

.case-desc {
  font-size: 0.9rem;
  color: var(--ink-muted);
  line-height: 1.7;
}

.scenario-tech {
  background: rgba(139, 69, 19, 0.03);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--accent);
}

.scenario-tech h4 {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--space-sm);
}

.tech-steps {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.tech-step {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 0.9rem;
  color: var(--ink-muted);
}

.step-dot {
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
}

.comparison {
  padding: var(--space-section) 0;
  background: var(--bg-surface);
}

.comparison-table-wrapper {
  overflow-x: auto;
  margin-bottom: var(--space-lg);
  border-radius: var(--radius-lg);
  background: var(--bg);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 700px;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--line);
}

.comparison-table th {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  background: rgba(139, 69, 19, 0.03);
}

.comparison-table td {
  font-size: 0.95rem;
}

.comparison-table td.highlight {
  color: var(--accent);
  font-weight: 600;
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
}

.compare-card {
  text-align: center;
  padding: var(--space-lg);
  background: var(--bg);
  border-radius: var(--radius-lg);
}

.compare-value {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.compare-unit {
  font-size: 0.85rem;
  color: var(--ink-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 4px;
}

.compare-label {
  font-size: 0.9rem;
  color: var(--ink-muted);
  margin-top: var(--space-sm);
}

.cases {
  padding: var(--space-section) 0;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.case-full {
  grid-column: 1 / -1;
  background: var(--bg-surface);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
}

.case-half {
  background: var(--bg-surface);
  padding: var(--space-lg);
  border-radius: var(--radius-lg);
}

.case-dark {
  background: var(--ink);
  color: var(--bg);
}

.case-dark .case-brand {
  color: var(--accent-soft);
}

.case-brand {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--space-xs);
}

.case-title {
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 2vw, 1.8rem);
  font-weight: 600;
  margin-bottom: var(--space-md);
}

.case-data {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
}

.data-item {
  display: flex;
  flex-direction: column;
}

.data-value {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 700;
}

.data-label {
  font-size: 0.75rem;
  opacity: 0.7;
}

.case-story {
  color: var(--ink-muted);
  line-height: 1.8;
  max-width: 700px;
}

.case-dark .case-story {
  color: rgba(247, 240, 230, 0.7);
}

.footer {
  padding: var(--space-xl) 0 var(--space-lg);
  border-top: 1px solid var(--line);
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.footer-brand h3 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.footer-brand p {
  color: var(--ink-muted);
  font-size: 0.9rem;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.footer-col h4 {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
  color: var(--accent);
}

.footer-col a {
  display: block;
  font-size: 0.9rem;
  color: var(--ink-muted);
  padding: 6px 0;
  transition: color var(--transition-medium);
}

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

.footer-bottom {
  padding-top: var(--space-md);
  border-top: 1px solid var(--line);
}

.footer-bottom p {
  font-size: 0.85rem;
  color: var(--ink-muted);
}

@media (max-width: 1024px) {
  .side-nav {
    display: none;
  }

  .hero-visual {
    display: none;
  }

  .scenario-content {
    grid-template-columns: 1fr;
  }

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

  .footer-content {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 768px) {
  :root {
    --space-section: 60px;
  }

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

  .comparison-cards {
    grid-template-columns: 1fr 1fr;
  }

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

  .case-full {
    grid-column: 1;
  }

  .footer-links {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    text-align: center;
  }

  .comparison-cards {
    grid-template-columns: 1fr;
  }

  .case-metrics {
    flex-direction: column;
    gap: var(--space-sm);
  }
}