:root {
  --color-bg-primary: #0a0e1a;
  --color-bg-secondary: #111827;
  --color-accent: #d4af37;
  --color-text-primary: #f5f5f5;
  --color-text-secondary: #a0a0a0;
  --color-text-muted: #6b7280;
  --color-border: rgba(212, 175, 55, 0.15);

  --font-serif: 'Noto Serif JP', serif;
  --font-sans: 'Noto Sans JP', sans-serif;

  --max-width: 1080px;
  --section-padding-y: 120px;
}

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

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

body {
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  word-break: keep-all;
  overflow-wrap: break-word;
  line-break: strict;
}

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

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== Hero ========== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 80px 0 40px;
}

.hero .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 48px;
  width: 100%;
}

.hero-text {
  text-align: center;
}

.hero-label {
  font-family: var(--font-serif);
  font-size: 16px;
  color: var(--color-accent);
  margin-bottom: 0;
}

.hero-subtitle {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--color-text-secondary);
  letter-spacing: 0.15em;
  margin-top: 8px;
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 16px;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  background-color: var(--color-accent);
  color: var(--color-bg-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 700;
  padding: 16px 40px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: opacity 0.2s;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  opacity: 0.85;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  background-color: transparent;
  color: var(--color-accent);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 700;
  padding: 16px 40px;
  border-radius: 6px;
  border: 1.5px solid var(--color-accent);
  cursor: pointer;
  transition: background-color 0.2s, color 0.2s;
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  background-color: var(--color-accent);
  color: var(--color-bg-primary);
}

.hero-image {
  max-height: 50vh;
  transition: transform 0.3s;
}

.hero-image:hover {
  transform: translateY(-4px);
}

/* ========== Problem ========== */
.problem {
  padding: var(--section-padding-y) 0;
}

.problem-list {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.problem-item {
  border-left: 2px solid var(--color-accent);
  padding-left: 24px;
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.6;
  word-break: auto-phrase;
}

/* ========== About ========== */
.about {
  padding: var(--section-padding-y) 0;
}

.about .container {
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.about-image {
  max-width: 280px;
  margin: 0 auto;
}

.about-label {
  font-size: 14px;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.about-heading {
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 24px;
}

.about-body p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  font-size: 15px;
}

/* ========== Metrics ========== */
.metrics {
  padding: var(--section-padding-y) 0;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-label {
  display: block;
  font-size: 14px;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 20px;
}

.section-lead {
  font-size: 16px;
  color: var(--color-text-secondary);
  max-width: 640px;
  margin: 0 auto;
  line-height: 1.8;
}

.metrics-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.metric-card {
  background-color: var(--color-bg-secondary);
  border: 0.5px solid var(--color-border);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
}

.metric-mark {
  font-family: var(--font-serif);
  font-size: 24px;
  color: var(--color-accent);
  margin-bottom: 4px;
}

.metric-label {
  font-size: 13px;
  color: var(--color-text-secondary);
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.metric-value {
  font-family: var(--font-serif);
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 8px;
}

.metric-note {
  font-size: 13px;
  color: var(--color-text-muted);
}

.metrics-footnote {
  text-align: center;
  margin-top: 48px;
}

.footnote-highlight {
  font-family: var(--font-serif);
  font-size: 18px;
  color: var(--color-accent);
  margin-bottom: 16px;
  line-height: 1.8;
}

.footnote-source {
  font-size: 12px;
  color: var(--color-text-muted);
}

.marks-glossary {
  max-width: 720px;
  margin: 80px auto 0;
}

.glossary-title {
  font-family: var(--font-serif);
  font-size: 20px;
  text-align: center;
  margin-bottom: 24px;
}

.glossary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.glossary-list > div {
  display: flex;
  gap: 16px;
}

.glossary-list dt {
  font-family: var(--font-serif);
  font-size: 16px;
  color: var(--color-accent);
  min-width: 100px;
  flex-shrink: 0;
}

.glossary-list dd {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ========== Showcase ========== */
.showcase {
  padding: var(--section-padding-y) 0;
  background-color: var(--color-bg-primary);
}

.showcase-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 48px;
}

.showcase-item {
  margin: 0;
  background-color: var(--color-bg-secondary);
  border: 0.5px solid var(--color-border);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s ease;
}

.showcase-item:hover {
  transform: translateY(-4px);
}

.showcase-image-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 1 / 1.414;
  overflow: hidden;
  background-color: var(--color-bg-primary);
}

.showcase-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
}

.showcase-image-wrapper::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 50%;
  background: linear-gradient(
    to bottom,
    transparent 0%,
    var(--color-bg-secondary) 100%
  );
  pointer-events: none;
}

.showcase-caption {
  padding: 20px 24px 24px;
  text-align: center;
}

.showcase-tag {
  display: inline-block;
  font-family: var(--font-serif);
  font-size: 14px;
  color: var(--color-accent);
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.showcase-desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin: 0;
  line-height: 1.6;
}

.showcase-footnote {
  text-align: center;
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 32px;
}

/* ========== Benefits ========== */
.benefits {
  padding: var(--section-padding-y) 0;
}

.benefits-list {
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.benefit-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.benefit-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
}

.benefit-icon svg {
  width: 40px;
  height: 40px;
  stroke: var(--color-accent);
  fill: none;
  stroke-width: 1.5;
}

.benefit-heading {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 6px;
}

.benefit-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
}

/* ========== CTA ========== */
.cta {
  padding: var(--section-padding-y) 0;
  text-align: center;
}

.cta-image {
  max-width: 240px;
  margin: 0 auto 32px;
}

.cta-heading {
  font-family: var(--font-serif);
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
}

.cta-sub {
  font-size: 18px;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
}

.btn-large {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  background-color: var(--color-accent);
  color: var(--color-bg-primary);
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 700;
  padding: 20px 56px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: opacity 0.2s;
}

.btn-large:hover,
.btn-large:focus-visible {
  opacity: 0.85;
}

/* ========== FAQ ========== */
.faq {
  padding: var(--section-padding-y) 0;
}

.faq-title {
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 48px;
  text-align: center;
}

.faq-list {
  max-width: 720px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item summary {
  padding: 24px 0;
  font-family: var(--font-serif);
  font-size: 18px;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 24px;
  color: var(--color-accent);
  transition: transform 0.2s;
}

.faq-item[open] summary::after {
  content: '-';
}

.faq-answer {
  padding: 0 0 24px;
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* ========== Footer ========== */
.footer {
  padding: 60px 0 32px;
  border-top: 1px solid var(--color-border);
}

.footer .container {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.footer-brand-name {
  font-family: var(--font-serif);
  font-size: 18px;
  margin-bottom: 4px;
}

.footer-brand-tagline {
  font-size: 13px;
  color: var(--color-text-muted);
}

.footer-nav {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 14px;
  color: var(--color-text-secondary);
  transition: color 0.2s;
}

.footer-nav a:hover,
.footer-nav a:focus-visible {
  color: var(--color-accent);
}

.footer-social {
  display: flex;
  gap: 20px;
}

.footer-social a {
  font-size: 14px;
  color: var(--color-text-secondary);
  transition: color 0.2s;
}

.footer-social a:hover,
.footer-social a:focus-visible {
  color: var(--color-accent);
}

.footer-copy {
  font-size: 12px;
  color: var(--color-text-muted);
  text-align: center;
  margin-top: 16px;
}

/* ========== Mobile adjustments ========== */
@media (max-width: 767px) {
  .problem-item,
  .section-lead {
    font-size: 16px;
    line-height: 1.9;
    letter-spacing: 0.02em;
    word-break: auto-phrase;
  }

  .cta {
    padding: 60px 0;
  }

  .cta-image {
    max-width: 200px;
  }

  .cta-heading {
    font-size: 36px;
    margin-top: 24px;
  }
}

/* ========== Responsive ========== */
@media (min-width: 768px) {
  .hero .container {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .hero-text {
    text-align: left;
    flex: 1;
    max-width: 540px;
  }

  .hero-title {
    font-size: 64px;
  }

  .hero-label {
    font-size: 18px;
  }

  .hero-sub {
    font-size: 18px;
  }

  .hero-cta {
    flex-direction: row;
    justify-content: flex-start;
  }

  .hero-image {
    max-height: 80vh;
    max-width: 360px;
  }

  .problem-item {
    font-size: 28px;
  }

  .about .container {
    flex-direction: row;
    align-items: center;
  }

  .about-image {
    max-width: 340px;
    margin: 0;
  }

  .about-heading {
    font-size: 36px;
  }

  .section-title {
    font-size: 36px;
  }

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

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

  .cta-heading {
    font-size: 48px;
  }

  .footer .container {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
  }

  .footer-copy {
    text-align: left;
  }
}

@media (min-width: 1024px) {
  .metrics-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}