:root {
  --ink: #172126;
  --muted-ink: #526267;
  --paper: #fbfcfb;
  --soft: #eef3f1;
  --line: #d7e1dc;
  --teal: #16666b;
  --teal-dark: #0e474b;
  --coral: #c65f45;
  --gold: #b18728;
  --green: #4d7c45;
  --white: #ffffff;
  --shadow: 0 18px 45px rgba(23, 33, 38, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Yu Gothic", "Hiragino Kaku Gothic ProN", Meiryo, system-ui, sans-serif;
  line-height: 1.7;
}

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 4vw, 56px);
  color: var(--white);
  background: rgba(14, 28, 30, 0.74);
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
}

.brand {
  font-weight: 700;
  white-space: nowrap;
}

.nav {
  display: flex;
  gap: clamp(12px, 2vw, 28px);
  font-size: 0.92rem;
}

.nav a {
  color: rgba(255, 255, 255, 0.86);
}

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

.hero {
  position: relative;
  min-height: 78vh;
  display: grid;
  align-items: center;
  padding: 112px clamp(22px, 6vw, 86px) 72px;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(12, 23, 25, 0.84), rgba(12, 23, 25, 0.56), rgba(12, 23, 25, 0.22)),
    url("assets/experiment-dashboard-02.png") center / cover no-repeat;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(12, 23, 25, 0.22), rgba(12, 23, 25, 0));
  pointer-events: none;
}

.hero-content {
  position: relative;
  width: min(780px, 100%);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--coral);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #f0b08d;
}

h1,
h2,
h3,
p {
  margin-top: 0;
  overflow-wrap: anywhere;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(2.8rem, 5.2vw, 4.8rem);
  line-height: 1.02;
  letter-spacing: 0;
  overflow-wrap: anywhere;
  word-break: normal;
}

h1 span {
  display: inline;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(1.9rem, 3vw, 3rem);
  line-height: 1.22;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 8px;
  font-size: 1.08rem;
  line-height: 1.35;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 690px;
  margin-bottom: 30px;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(1.02rem, 2vw, 1.28rem);
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 10px 18px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-weight: 700;
}

.button.primary {
  color: var(--white);
  background: var(--coral);
}

.button.secondary {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.08);
}

.button.outline {
  color: var(--teal-dark);
  border-color: var(--line);
  background: var(--white);
}

.inline-action {
  margin-top: 6px;
}

.text-link {
  display: inline-flex;
  margin-top: 16px;
  color: var(--teal-dark);
  font-weight: 700;
}

.text-link:hover {
  color: var(--coral);
}

.section {
  padding: clamp(64px, 9vw, 108px) clamp(20px, 5vw, 72px);
}

.section-inner {
  width: min(1160px, 100%);
  margin: 0 auto;
}

.section-heading {
  max-width: 780px;
  margin-bottom: 34px;
}

.section-heading p:not(.eyebrow) {
  color: var(--muted-ink);
  font-size: 1.03rem;
}

.section-heading.compact {
  max-width: 640px;
}

.intro {
  padding-top: clamp(48px, 7vw, 82px);
}

.metric-grid,
.pillar-grid,
.article-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.metric-card,
.pillar-card,
.article-list article {
  min-height: 210px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 10px 28px rgba(23, 33, 38, 0.06);
}

.metric-label,
.number {
  display: block;
  margin-bottom: 14px;
  color: var(--teal);
  font-size: 0.84rem;
  font-weight: 700;
}

.metric-card strong {
  display: block;
  margin-bottom: 12px;
  color: var(--teal-dark);
  font-size: clamp(1.45rem, 2.5vw, 2.25rem);
  line-height: 1.18;
}

.metric-card p,
.pillar-card p,
.article-list p {
  margin-bottom: 0;
  color: var(--muted-ink);
}

.bands {
  background: var(--soft);
}

.pillar-card {
  border-top: 4px solid var(--teal);
}

.pillar-card:nth-child(2) {
  border-top-color: var(--coral);
}

.pillar-card:nth-child(3) {
  border-top-color: var(--gold);
}

.timeline {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.timeline li {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 24px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
}

.timeline li:last-child {
  border-bottom: 1px solid var(--line);
}

.timeline span {
  color: var(--coral);
  font-weight: 700;
}

.timeline p {
  margin-bottom: 0;
  color: var(--muted-ink);
}

.muted {
  background: #f4f6f5;
}

.article-list {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.article-list article {
  min-height: 188px;
}

.section-action {
  margin-top: 24px;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1.1fr);
  gap: clamp(28px, 6vw, 70px);
  align-items: start;
}

.tool-table {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.tool-table [role="row"] {
  display: grid;
  grid-template-columns: 190px 1fr;
  min-height: 72px;
  border-bottom: 1px solid var(--line);
}

.tool-table [role="row"]:last-child {
  border-bottom: 0;
}

.tool-table [role="cell"] {
  display: flex;
  align-items: center;
  padding: 18px 20px;
}

.tool-table [role="cell"]:first-child {
  color: var(--teal-dark);
  font-weight: 700;
  background: var(--soft);
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.link-grid a {
  display: flex;
  min-height: 88px;
  align-items: center;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--teal-dark);
  background: var(--white);
  font-weight: 700;
  box-shadow: 0 10px 28px rgba(23, 33, 38, 0.05);
}

.site-footer {
  padding: 28px clamp(20px, 5vw, 72px);
  color: rgba(255, 255, 255, 0.78);
  background: var(--ink);
}

.site-footer p {
  width: min(1160px, 100%);
  margin: 0 auto;
  font-size: 0.92rem;
}

@media (max-width: 880px) {
  .site-header {
    position: absolute;
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero {
    min-height: 74vh;
    padding-top: 150px;
    background:
      linear-gradient(90deg, rgba(12, 23, 25, 0.86), rgba(12, 23, 25, 0.58)),
      url("assets/experiment-dashboard-02.png") center / cover no-repeat;
  }

  .metric-grid,
  .pillar-grid,
  .article-list,
  .link-grid,
  .split {
    grid-template-columns: 1fr;
  }

  .timeline li {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .tool-table [role="row"] {
    grid-template-columns: 1fr;
  }

  .tool-table [role="cell"] {
    min-height: 52px;
  }
}

@media (max-width: 520px) {
  .site-header {
    padding-inline: 20px;
  }

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

  .button {
    width: 100%;
  }

  h1 {
    font-size: 2rem;
    line-height: 1.14;
  }

  .hero h1 span {
    display: block;
  }

  .hero-copy {
    font-size: 1rem;
  }
}