:root {
  color-scheme: light;
  --ink: #17211d;
  --muted: #5b6862;
  --paper: #f7f5ef;
  --white: #ffffff;
  --line: #d8d4ca;
  --teal: #0f766e;
  --teal-dark: #0b4f4a;
  --blue: #2563eb;
  --amber: #d97706;
  --coral: #c2410c;
  --green: #2f7d32;
  --shadow: 0 18px 48px rgba(23, 33, 29, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

a {
  color: inherit;
}

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

.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, 48px);
  border-bottom: 1px solid rgba(216, 212, 202, 0.9);
  background: rgba(247, 245, 239, 0.92);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  min-width: 220px;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: var(--white);
  font-weight: 800;
  letter-spacing: 0;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: var(--muted);
  font-size: 0.78rem;
}

nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
}

nav a {
  border-radius: 999px;
  padding: 8px 12px;
  color: var(--muted);
  font-size: 0.92rem;
  text-decoration: none;
}

nav a:hover {
  background: rgba(15, 118, 110, 0.1);
  color: var(--teal-dark);
}

.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  grid-template-columns: minmax(360px, 0.78fr) minmax(0, 1.22fr);
  align-items: center;
  gap: clamp(30px, 5vw, 84px);
  min-height: min(780px, calc(100vh - 74px));
  overflow: hidden;
  padding: clamp(52px, 7vw, 94px) clamp(18px, 5vw, 72px);
  background:
    linear-gradient(90deg, rgba(5, 8, 22, 0.94) 0%, rgba(5, 8, 22, 0.86) 40%, rgba(8, 13, 35, 0.56) 68%, rgba(8, 13, 35, 0.3) 100%),
    url("./assets/hero-quantum-universe-bg.svg") center / cover no-repeat;
  color: var(--white);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(circle at 18% 40%, rgba(255, 255, 255, 0.08), transparent 30%);
}

.hero-copy {
  max-width: 660px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--teal-dark);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  margin: 0;
  font-size: clamp(2.25rem, 5.3vw, 5.1rem);
  line-height: 1.05;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: clamp(1.8rem, 3vw, 3.1rem);
  line-height: 1.18;
  letter-spacing: 0;
}

h3 {
  margin: 0;
  font-size: 1.16rem;
  line-height: 1.35;
  letter-spacing: 0;
}

.lead {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.4vw, 1.18rem);
}

.hero .eyebrow {
  color: #c7d2fe;
  text-shadow: 0 0 22px rgba(124, 140, 255, 0.42);
}

.hero h1 {
  max-width: 820px;
  color: var(--white);
  text-shadow: 0 18px 42px rgba(0, 0, 0, 0.32);
}

.hero .lead {
  max-width: 760px;
  color: rgba(255, 255, 255, 0.78);
  text-shadow: 0 10px 26px rgba(0, 0, 0, 0.28);
}

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

.hero-actions a {
  display: inline-flex;
  min-height: 46px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ink);
  border-radius: 8px;
  padding: 10px 18px;
  font-weight: 700;
  text-decoration: none;
}

.hero .hero-actions a {
  border-color: rgba(255, 255, 255, 0.46);
  background: rgba(255, 255, 255, 0.08);
  color: var(--white);
  backdrop-filter: blur(10px);
}

.hero-actions a:first-child {
  background: var(--ink);
  color: var(--white);
}

.hero .hero-actions a:first-child {
  background: var(--white);
  color: #101525;
}

.hero-project-title {
  min-width: 0;
  justify-self: start;
  width: min(100%, 1180px);
  color: var(--white);
}

.hero-project-title p,
.hero-project-title h2 {
  display: block;
  margin: 0;
}

.hero-project-title p {
  color: #c7d2fe;
  font-size: clamp(0.92rem, 1vw, 1.08rem);
  font-weight: 800;
  text-shadow: 0 0 22px rgba(124, 140, 255, 0.44);
}

.hero-project-title h2 {
  margin-top: 10px;
  color: var(--white);
  font-size: clamp(1.35rem, 2vw, 3rem);
  font-weight: 760;
  line-height: 1.18;
  overflow-wrap: normal;
  text-shadow: 0 18px 46px rgba(0, 0, 0, 0.45);
  white-space: nowrap;
}

.hero-project-title h2 span {
  display: block;
}

.concept-showcase {
  padding: clamp(24px, 5vw, 64px) clamp(16px, 4vw, 48px) clamp(42px, 7vw, 88px);
  background: #101525;
}

.concept-showcase .hero-visual {
  width: 100%;
  max-width: 1480px;
  margin: 0 auto;
}

.hero-visual {
  margin: 0;
  filter: drop-shadow(var(--shadow));
}

.concept-system {
  position: relative;
  isolation: isolate;
  display: grid;
  gap: clamp(18px, 2.4vw, 28px);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  padding: clamp(22px, 3vw, 36px);
  background:
    radial-gradient(circle at 12% 18%, rgba(246, 198, 106, 0.46), transparent 18%),
    radial-gradient(circle at 86% 16%, rgba(125, 211, 252, 0.38), transparent 20%),
    radial-gradient(circle at 78% 86%, rgba(248, 113, 113, 0.26), transparent 18%),
    linear-gradient(145deg, #111827 0%, #12312e 48%, #1f2937 100%);
  color: var(--white);
}

.concept-system::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    radial-gradient(circle, rgba(255, 255, 255, 0.88) 0 1px, transparent 1.4px),
    radial-gradient(circle, rgba(255, 255, 255, 0.58) 0 1px, transparent 1.2px);
  background-position: 12px 16px, 48px 60px;
  background-size: 86px 92px, 124px 132px;
  opacity: 0.5;
}

.concept-heading,
.concept-map,
.concept-core,
.concept-stars {
  position: relative;
  z-index: 1;
}

.concept-heading {
  max-width: 1180px;
}

.concept-heading strong,
.concept-heading span {
  display: block;
  overflow-wrap: anywhere;
}

.concept-heading strong {
  font-size: clamp(2rem, 4.5vw, 4.05rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: 0;
}

.concept-heading span {
  margin-top: 8px;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(1.02rem, 1.8vw, 1.24rem);
  line-height: 1.55;
}

.concept-map {
  display: grid;
  grid-template-columns: 1fr;
  grid-template-areas:
    "core"
    "stars";
  gap: 14px;
  align-items: stretch;
}

.concept-nebula {
  position: absolute;
  inset: 12% 0 8%;
  z-index: 0;
  border-radius: 999px;
  background:
    radial-gradient(circle at 18% 42%, rgba(255, 255, 255, 0.24), transparent 18%),
    radial-gradient(circle at 42% 44%, rgba(45, 212, 191, 0.28), transparent 32%),
    radial-gradient(circle at 72% 58%, rgba(59, 130, 246, 0.22), transparent 35%),
    radial-gradient(circle at 86% 30%, rgba(217, 119, 6, 0.14), transparent 32%);
  filter: blur(2px);
  opacity: 0.82;
}

.concept-core {
  grid-area: core;
  display: grid;
  grid-template-columns: minmax(220px, 0.34fr) minmax(0, 1fr);
  gap: 18px;
  width: 100%;
  align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 8px;
  padding: clamp(18px, 2.5vw, 28px);
  background: rgba(9, 24, 27, 0.72);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.24);
  backdrop-filter: blur(14px);
}

.concept-core h2 {
  margin: 0;
  font-size: clamp(1.25rem, 2.4vw, 2rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: 0;
}

.concept-core-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
}

.concept-core-item {
  min-width: 0;
}

.concept-core-item h3 {
  margin: 0;
  color: #f6c66a;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
}

.concept-core-item + .concept-core-item {
  border-left: 1px solid rgba(255, 255, 255, 0.14);
  padding-left: 12px;
}

.concept-core-item p {
  margin: 6px 0 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: clamp(1rem, 1.45vw, 1.12rem);
  line-height: 1.65;
  overflow-wrap: anywhere;
}

.concept-stars {
  grid-area: stars;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(178px, 1fr));
  gap: 12px;
}

.concept-star {
  position: relative;
  min-width: 0;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  padding: 14px 15px 16px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
}

.concept-star::before {
  content: "";
  display: block;
  width: 12px;
  height: 12px;
  margin-bottom: 10px;
  border-radius: 50%;
  background: #f6c66a;
  box-shadow: 0 0 18px rgba(246, 198, 106, 0.9);
}

.concept-star h3 {
  color: var(--white);
  font-size: clamp(1rem, 1.45vw, 1.18rem);
  font-weight: 700;
  line-height: 1.35;
}

.concept-star p {
  margin: 7px 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(0.92rem, 1.15vw, 1rem);
  line-height: 1.55;
}

.summary-band {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border-block: 1px solid var(--line);
}

.summary-band div {
  min-height: 124px;
  padding: 26px clamp(18px, 3vw, 34px);
  background: var(--white);
}

.summary-band strong,
.summary-band span {
  display: block;
}

.summary-band strong {
  font-size: clamp(1.45rem, 2.2vw, 2.4rem);
  line-height: 1.15;
}

.summary-band span {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.95rem;
}

.section {
  padding: clamp(64px, 9vw, 116px) clamp(18px, 5vw, 72px);
}

.section.alt {
  background: #ece9df;
}

.section-heading {
  max-width: 920px;
  margin-bottom: 36px;
}

.section-heading p:not(.eyebrow) {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.section-heading h2 span {
  display: block;
}

.vision-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.feature-card,
.impact-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  padding: 24px;
}

.card-number {
  display: block;
  margin-bottom: 42px;
  color: var(--amber);
  font-size: 0.86rem;
  font-weight: 900;
}

.feature-card p,
.impact-grid p,
.program-list p {
  margin: 12px 0 0;
  color: var(--muted);
}

.program-list {
  display: grid;
  gap: 12px;
}

.program-list article {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  border: 1px solid rgba(23, 33, 29, 0.12);
  border-radius: 8px;
  background: var(--white);
  padding: 22px;
}

.program-icon {
  display: grid;
  width: 58px;
  height: 58px;
  place-items: center;
  border-radius: 8px;
  color: var(--white);
  font-weight: 900;
}

.program-icon.physics {
  background: var(--coral);
}

.program-icon.info {
  background: var(--blue);
}

.program-icon.math {
  background: var(--teal);
}

.program-icon.tour {
  background: var(--green);
}

.program-icon.stage {
  background: var(--amber);
}

.wide-visual {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  padding: clamp(16px, 3vw, 28px);
  box-shadow: var(--shadow);
}

.wide-visual figcaption {
  margin-top: 14px;
  color: var(--muted);
  font-size: 0.92rem;
}

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 18px;
}

.evidence-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  padding: 22px;
}

.evidence-grid p {
  margin: 10px 0 0;
  color: var(--muted);
}

.impact {
  background: #f4f0e5;
}

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

.closing-band {
  padding: clamp(54px, 7vw, 84px) clamp(18px, 5vw, 72px);
  background: var(--ink);
  color: var(--white);
}

.closing-band .eyebrow {
  color: #f6c66a;
}

.closing-band h2 {
  max-width: 980px;
}

.closing-band h2 span {
  display: block;
}

.closing-band p:last-child {
  margin: 20px 0 0;
  color: rgba(255, 255, 255, 0.72);
}

.site-footer {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: clamp(32px, 5vw, 56px) clamp(18px, 5vw, 72px);
  background: var(--ink);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.site-footer a {
  display: inline-block;
  opacity: 0.8;
  transition: opacity 0.2s;
}

.site-footer a:hover {
  opacity: 1;
}

.site-footer img {
  height: 80px;
  width: auto;
}

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

  nav {
    justify-content: flex-start;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    background:
      linear-gradient(180deg, rgba(5, 8, 22, 0.94) 0%, rgba(5, 8, 22, 0.82) 58%, rgba(8, 13, 35, 0.46) 100%),
      url("./assets/hero-quantum-universe-bg.svg") center / cover no-repeat;
  }

  .hero-project-title {
    width: min(100%, 680px);
    justify-self: start;
  }

  .hero-project-title h2 {
    font-size: clamp(1rem, 2.7vw, 1.55rem);
  }

  .concept-core {
    grid-template-columns: 1fr;
  }

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

  .hero-visual {
    order: -1;
  }

  .summary-band,
  .vision-grid,
  .impact-grid,
  .evidence-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .site-header {
    position: static;
  }

  .brand {
    min-width: 0;
  }

  .hero {
    padding-top: 38px;
  }

  .hero h1 {
    font-size: clamp(2.1rem, 11vw, 3.25rem);
  }

  .hero-project-title h2 {
    font-size: clamp(0.74rem, 3.35vw, 1.08rem);
  }

  .concept-map {
    grid-template-columns: 1fr;
    grid-template-areas:
      "core"
      "stars";
  }

  .concept-nebula {
    inset: 0 0 auto;
    height: 340px;
  }

  .concept-stars {
    grid-template-columns: 1fr;
  }

  .concept-core-list {
    grid-template-columns: 1fr;
  }

  .concept-core-item + .concept-core-item {
    border-top: 1px solid rgba(255, 255, 255, 0.14);
    border-left: 0;
    padding-top: 12px;
    padding-left: 0;
  }

  .summary-band,
  .vision-grid,
  .impact-grid,
  .evidence-grid {
    grid-template-columns: 1fr;
  }

  .summary-band div {
    min-height: 104px;
  }

  .program-list article {
    grid-template-columns: 1fr;
  }

  .program-icon {
    width: 48px;
    height: 48px;
  }
}