:root {
  color-scheme: light;
  --ink: #17211f;
  --muted: #5d6b67;
  --line: #dce4df;
  --paper: #fbfcf8;
  --soft: #eef4ef;
  --mint: #4aa986;
  --teal: #167f83;
  --coral: #e56f51;
  --gold: #d8a02d;
  --blue: #3e72c7;
  --shadow: 0 18px 50px rgba(22, 48, 43, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Hiragino Sans", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.75;
}

a {
  color: inherit;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(18px, 4vw, 56px);
  background: rgba(251, 252, 248, 0.9);
  border-bottom: 1px solid rgba(220, 228, 223, 0.78);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--ink);
  color: #fff;
  font-weight: 900;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.88rem;
}

.nav a {
  padding: 6px 10px;
  border-radius: 8px;
  text-decoration: none;
}

.nav a:hover {
  background: var(--soft);
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
  align-items: center;
  min-height: calc(100vh - 62px);
  padding: clamp(36px, 6vw, 84px) clamp(18px, 5vw, 72px) clamp(24px, 4vw, 56px);
  gap: clamp(28px, 5vw, 72px);
  overflow: hidden;
}

.hero-copy {
  max-width: 680px;
}

.eyebrow,
.section-kicker,
.prompt-label {
  margin: 0 0 12px;
  color: var(--teal);
  font-size: 0.77rem;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

h1 {
  margin: 0;
  font-size: clamp(3.3rem, 8vw, 7.5rem);
  line-height: 0.94;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 4rem);
  line-height: 1.08;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  line-height: 1.45;
}

p {
  margin: 0;
}

.lead {
  max-width: 620px;
  margin-top: 24px;
  color: #34413e;
  font-size: clamp(1.04rem, 1.7vw, 1.28rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 10px 18px;
  border: 1px solid var(--ink);
  border-radius: 8px;
  text-decoration: none;
  font-weight: 800;
  line-height: 1.25;
}

.button.primary {
  background: var(--ink);
  color: #fff;
}

.button.secondary {
  background: #fff;
  color: var(--ink);
}

.hero-art {
  position: relative;
  min-height: 400px;
}

.hero-art img {
  width: min(780px, 60vw);
  min-width: 430px;
  border-radius: 8px;
  box-shadow: var(--shadow);
  transform: rotate(1deg);
}

.section {
  padding: clamp(58px, 8vw, 112px) clamp(18px, 5vw, 72px);
}

.intro,
.split,
.feature,
.mcp {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(26px, 5vw, 76px);
}

.intro {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.intro-text {
  display: grid;
  gap: 18px;
  color: #33413d;
  font-size: 1.05rem;
}

.section-heading {
  max-width: 860px;
  margin-bottom: 30px;
}

.section-heading.narrow {
  max-width: 840px;
}

.section-heading.narrow p:not(.section-kicker) {
  margin-top: 18px;
  color: var(--muted);
  font-size: 1.05rem;
}

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

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

.steps article,
.panel,
.workflow article,
.checklist article {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px;
}

.steps span {
  display: inline-block;
  margin-bottom: 18px;
  color: var(--coral);
  font-weight: 900;
}

.steps p,
.panel p,
.workflow p,
.checklist p,
.feature-copy p,
.mcp-copy p,
.closing p {
  color: var(--muted);
}

.content-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.panel {
  min-height: 230px;
}

.panel.accent {
  background: #fff7f1;
  border-color: #f2cdbf;
}

.feature {
  background: #17312f;
  color: #fff;
}

.feature .section-kicker,
.feature .prompt-label {
  color: #7bd4b6;
}

.feature-copy {
  display: grid;
  align-content: center;
  gap: 18px;
  max-width: 720px;
}

.feature-copy p {
  color: rgba(255, 255, 255, 0.78);
}

.prompt-card {
  align-self: center;
  background: #0c1d1b;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  padding: clamp(18px, 3vw, 28px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.24);
}

pre {
  margin: 0;
  white-space: pre-wrap;
}

code {
  color: #f4fbf7;
  font-family:
    "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: clamp(0.92rem, 1.45vw, 1.08rem);
  line-height: 1.7;
}

.tetris {
  background: #fff;
}

.practice-layout {
  display: grid;
  grid-template-columns: minmax(250px, 360px) minmax(0, 1fr);
  gap: clamp(24px, 5vw, 70px);
  align-items: center;
}

.board-preview {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  grid-auto-rows: 1fr;
  gap: 6px;
  aspect-ratio: 6 / 8;
  padding: 16px;
  background: #16211f;
  border: 10px solid #263b37;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.block {
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.1);
}

.block.cyan {
  background: #50c4ca;
}

.block.red {
  background: #e05f58;
}

.block.yellow {
  background: #e3b947;
}

.block.green {
  background: #61b86d;
}

.block.purple {
  background: #8b6bd7;
}

.checklist {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.workflow {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.mcp {
  background: #f6f0e7;
  align-items: center;
}

.mcp-copy {
  display: grid;
  gap: 18px;
  max-width: 760px;
}

.connection-map {
  display: grid;
  grid-template-columns: 1fr 54px 1fr 54px 1fr;
  align-items: center;
  min-height: 180px;
}

.connection-map span {
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  border-radius: 50%;
  background: #fff;
  border: 1px solid #e0d4c3;
  box-shadow: 0 12px 30px rgba(83, 59, 35, 0.1);
  font-weight: 900;
}

.connection-map i {
  height: 3px;
  background: var(--coral);
}

.resources {
  background: #fff;
  border-top: 1px solid var(--line);
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.resource-card {
  display: grid;
  grid-template-rows: auto 1fr;
  overflow: hidden;
  min-height: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  color: inherit;
  text-decoration: none;
  box-shadow: 0 12px 36px rgba(22, 48, 43, 0.08);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.resource-card:hover {
  border-color: rgba(22, 127, 131, 0.4);
  box-shadow: 0 18px 48px rgba(22, 48, 43, 0.14);
  transform: translateY(-3px);
}

.resource-card img {
  width: 100%;
  aspect-ratio: 2.1 / 1;
  object-fit: contain;
  background: #f2f5f3;
  border-bottom: 1px solid var(--line);
}

.resource-card div {
  display: grid;
  align-content: start;
  gap: 10px;
  padding: 18px;
}

.resource-card p {
  color: var(--teal);
  font-size: 0.76rem;
  font-weight: 900;
  text-transform: uppercase;
}

.resource-card h3 {
  margin: 0;
  font-size: 1rem;
}

.resource-card span {
  display: inline-flex;
  align-items: center;
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

.resource-card span::after {
  content: "";
  width: 7px;
  height: 7px;
  margin-left: 8px;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
}

.closing {
  max-width: 900px;
}

.closing p {
  margin: 18px 0 28px;
  font-size: 1.06rem;
}

.footer {
  padding: clamp(44px, 6vw, 72px) clamp(18px, 5vw, 72px) 34px;
  background: linear-gradient(180deg, rgba(20, 31, 29, 0.98) 0%, #0a1110 100%);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.72);
}

.footer-inner {
  max-width: 1180px;
  margin: 0 auto;
}

.footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(260px, 0.95fr) minmax(220px, 0.65fr);
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.footer-brand {
  max-width: 440px;
}

.footer-brand-heading {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.footer-brand-mark {
  display: grid;
  flex: 0 0 auto;
  place-items: center;
  width: 48px;
  height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-weight: 900;
}

.footer-kicker {
  margin-bottom: 3px;
  color: rgba(255, 255, 255, 0.52);
  font-size: 0.78rem;
  font-weight: 800;
}

.footer h2 {
  color: #fff;
  font-size: 1.25rem;
  line-height: 1.3;
}

.footer-brand p {
  font-size: 0.94rem;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.footer-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 7px 14px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  color: #fff;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 700;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.footer-nav a:hover {
  background: #fff;
  border-color: #fff;
  color: var(--ink);
}

.footer-links {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
}

.footer-social-links {
  display: flex;
  gap: 10px;
}

.footer-social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 50%;
  color: #fff;
  text-decoration: none;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.footer-social-link:hover {
  background: #fff;
  border-color: #fff;
  color: var(--ink);
}

.footer-social-link svg {
  width: 19px;
  height: 19px;
}

.footer-external-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #fff;
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 700;
}

.footer-external-link:hover {
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer-external-link svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.6;
}

.footer-related {
  display: grid;
  grid-template-columns: minmax(190px, 0.42fr) minmax(0, 1.58fr);
  gap: clamp(28px, 5vw, 64px);
  margin-top: clamp(38px, 6vw, 64px);
  padding-top: clamp(32px, 5vw, 48px);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-related-heading .footer-kicker {
  color: #7bd4b6;
}

.footer-related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.footer-related-grid a {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 13px;
  align-items: center;
  min-height: 88px;
  padding: 16px 18px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.035);
  color: #fff;
  text-decoration: none;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.footer-related-grid a:hover {
  background: rgba(255, 255, 255, 0.09);
  border-color: rgba(123, 212, 182, 0.5);
  transform: translateY(-2px);
}

.footer-related-grid a:focus-visible {
  outline: 3px solid #7bd4b6;
  outline-offset: 3px;
}

.footer-related-number {
  align-self: start;
  color: #7bd4b6;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.72rem;
  font-weight: 800;
}

.footer-related-copy {
  display: grid;
  gap: 3px;
}

.footer-related-copy strong {
  font-size: 0.94rem;
  line-height: 1.45;
}

.footer-related-copy small {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.78rem;
  line-height: 1.5;
}

.footer-related-arrow {
  color: rgba(255, 255, 255, 0.54);
  font-size: 1.05rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-related-grid a:hover .footer-related-arrow {
  color: #7bd4b6;
  transform: translate(2px, -2px);
}

.footer-divider {
  height: 1px;
  margin: clamp(28px, 5vw, 42px) 0 22px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, 0.32) 50%, rgba(255, 255, 255, 0) 100%);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  color: rgba(255, 255, 255, 0.56);
  font-size: 0.84rem;
}

@media (max-width: 980px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .nav {
    justify-content: flex-start;
  }

  .hero,
  .intro,
  .split,
  .feature,
  .mcp,
  .practice-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-art {
    min-height: 0;
  }

  .hero-art img {
    width: 100%;
    min-width: 0;
  }

  .steps,
  .workflow,
  .resource-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .footer-brand {
    max-width: 640px;
  }

  .footer-related {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .footer-bottom {
    flex-direction: column;
  }
}

@media (max-width: 680px) {
  .site-header {
    position: static;
  }

  .brand {
    font-size: 0.9rem;
  }

  .nav {
    font-size: 0.82rem;
  }

  h1 {
    font-size: clamp(3rem, 15vw, 4.5rem);
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .steps,
  .content-grid,
  .workflow,
  .checklist,
  .resource-grid,
  .footer-related-grid {
    grid-template-columns: 1fr;
  }

  .board-preview {
    max-width: 320px;
  }

  .connection-map {
    grid-template-columns: 1fr;
    gap: 12px;
    max-width: 220px;
  }

  .connection-map span {
    aspect-ratio: auto;
    min-height: 74px;
    border-radius: 8px;
  }

  .connection-map i {
    width: 3px;
    height: 34px;
    justify-self: center;
  }
}