:root {
  --blue: #2456a6;
  --teal: #14a6a2;
  --green: #7fbe3a;
  --ink: #15293a;
  --ink-soft: #4c606c;
  --ink-faint: #7a8b94;
  --bg: #f3f7f6;
  --paper: #ffffff;
  --line: rgba(21, 41, 58, 0.13);
  --line-strong: rgba(21, 41, 58, 0.24);
  --grad: linear-gradient(90deg, #2456a6 0%, #14a6a2 52%, #7fbe3a 100%);
  --grad-v: linear-gradient(180deg, #2456a6 0%, #14a6a2 52%, #7fbe3a 100%);
  --serif: "Hiragino Mincho ProN", "Yu Mincho", "YuMincho", "Noto Serif JP", serif;
  --sans: "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", "Yu Gothic", "YuGothic", Meiryo, system-ui, sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", ui-monospace, monospace;
  --maxw: 1120px;
  --shadow: 0 24px 64px rgba(21, 41, 58, 0.13);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.85;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
}

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

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

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

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 760;
  line-height: 1.34;
}

.wrap {
  width: min(var(--maxw), calc(100vw - 52px));
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  top: 10px;
  left: -999px;
  z-index: 80;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--ink);
  color: #fff;
  font-weight: 800;
}

.skip-link:focus {
  left: 10px;
}

.grad-text {
  background: var(--grad);
  background-clip: text;
  color: transparent;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.72em;
  margin-bottom: 14px;
  color: var(--teal);
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  border-radius: 999px;
  background: var(--grad);
}

.site-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  border-bottom: 1px solid var(--line);
  background: rgba(243, 247, 246, 0.88);
  backdrop-filter: saturate(1.25) blur(14px);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand img {
  width: 82px;
  height: auto;
}

.brand span {
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0;
}

.nav-links {
  display: flex;
  gap: 26px;
  font-size: 0.88rem;
  font-weight: 700;
}

.nav-links a {
  position: relative;
  color: var(--ink-soft);
  padding: 4px 0;
  transition: color 160ms ease;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background: var(--grad);
  transition: width 180ms ease;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a.is-active {
  color: var(--ink);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after,
.nav-links a.is-active::after {
  width: 100%;
}

.hero {
  min-height: 60svh;
  padding: 34px 0 30px;
  display: flex;
  align-items: center;
  background:
    linear-gradient(90deg, rgba(243, 247, 246, 0.98) 0%, rgba(243, 247, 246, 0.84) 42%, rgba(243, 247, 246, 0.18) 72%),
    url("assets/hero-network-abstract.jpg") center / cover no-repeat;
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  max-width: var(--maxw);
}

.logo-lockup {
  width: min(230px, 66vw);
  margin-bottom: 10px;
}

.logo-lockup img {
  width: 100%;
}

.logo-lockup span {
  display: block;
  margin-top: -6px;
  background: var(--grad);
  background-clip: text;
  color: transparent;
  font-family: var(--sans);
  font-size: 2.18rem;
  font-weight: 900;
  letter-spacing: 0;
  line-height: 1;
}

h1 {
  max-width: 820px;
  margin-bottom: 18px;
  font-size: 3.45rem;
}

.h1-line {
  display: block;
}

.keep-line {
  white-space: nowrap;
}

.lede {
  max-width: 690px;
  margin-bottom: 24px;
  color: var(--ink-soft);
  font-size: 1rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 21px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 800;
  line-height: 1.25;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease, color 160ms ease;
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-2px);
}

.btn-grad {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 14px 34px rgba(20, 166, 162, 0.22);
}

.btn-outline {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.78);
  color: var(--ink);
}

.btn-outline:hover,
.btn-outline:focus-visible {
  border-color: var(--teal);
  color: var(--teal);
  box-shadow: 0 12px 28px rgba(21, 41, 58, 0.08);
}

.stats {
  background: var(--ink);
  color: #e7efec;
}

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

.stat {
  padding: 28px 22px;
  border-right: 1px solid rgba(255, 255, 255, 0.1);
}

.stat:last-child {
  border-right: 0;
}

.key {
  color: #83b7b3;
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.stat strong {
  display: block;
  margin-top: 8px;
  background: linear-gradient(90deg, #6fa9e6, #3ed0c4, #b7e05a);
  background-clip: text;
  color: transparent;
  font-family: var(--serif);
  font-size: 2.5rem;
  line-height: 1.05;
}

.stat strong span {
  margin-left: 0.24em;
  color: #c3d6d2;
  font-family: var(--sans);
  font-size: 0.38em;
  font-weight: 600;
}

.stat p {
  margin: 7px 0 0;
  color: #9fbab6;
  font-size: 0.82rem;
}

.section {
  padding: 76px 0;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  gap: 72px;
  align-items: start;
}

.section-head h2 {
  margin-bottom: 0;
  font-size: 2.45rem;
}

.section-head p:not(.eyebrow) {
  margin: 15px 0 0;
  color: var(--ink-soft);
}

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

.body-copy p {
  color: var(--ink-soft);
}

.body-copy p + p {
  margin-top: 18px;
}

.overview {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.contact {
  background: var(--ink);
  color: #dce7e4;
}

.contact .eyebrow {
  color: #7ed0c9;
}

.contact .section-head h2 {
  color: #fff;
}

.contact .section-head p {
  color: #a9c3bf;
}

.contact-page-inner {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 56px;
  align-items: start;
}

.contact-page {
  min-height: calc(100svh - 64px);
  display: flex;
  align-items: center;
}

.contact-form {
  position: relative;
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 28px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.04);
}

.contact-field {
  display: grid;
  gap: 7px;
}

.contact-field label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: #d5e4e1;
  font-size: 0.88rem;
  font-weight: 800;
}

.contact-field label span {
  color: #8fd3cc;
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 800;
  text-transform: uppercase;
}

.contact-field input,
.contact-field textarea {
  width: 100%;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font: inherit;
  line-height: 1.55;
  outline: none;
  transition: border-color 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.contact-field input {
  min-height: 46px;
  padding: 10px 13px;
}

.contact-field textarea {
  min-height: 150px;
  padding: 12px 13px;
  resize: vertical;
}

.contact-field input:focus,
.contact-field textarea:focus {
  border-color: rgba(143, 211, 204, 0.82);
  background: rgba(255, 255, 255, 0.11);
  box-shadow: 0 0 0 3px rgba(143, 211, 204, 0.14);
}

.contact-form .btn {
  width: fit-content;
  min-width: 148px;
}

.contact-form .btn:disabled {
  cursor: progress;
  opacity: 0.64;
  transform: none;
}

.form-status {
  min-height: 1.6em;
  margin: 0;
  color: #a9c3bf;
  font-size: 0.88rem;
}

.hp-field {
  position: absolute;
  left: -10000px;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.publication-hero {
  padding: 46px 0 42px;
  background:
    linear-gradient(90deg, rgba(243, 247, 246, 0.99) 0%, rgba(243, 247, 246, 0.86) 48%, rgba(243, 247, 246, 0.22) 78%),
    url("assets/hero-network-abstract.jpg") center / cover no-repeat;
  border-bottom: 1px solid var(--line);
}

.publication-hero-inner {
  max-width: var(--maxw);
}

.publication-hero h1 {
  margin-bottom: 14px;
  font-size: 3rem;
}

.publication-section {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.publication-list {
  display: grid;
  gap: 18px;
}

.publication-card {
  position: relative;
  overflow: hidden;
  padding: 30px 32px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.publication-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--grad-v);
}

.publication-card:hover {
  border-color: var(--line-strong);
  box-shadow: 0 18px 38px rgba(21, 41, 58, 0.09);
  transform: translateY(-3px);
}

.publication-kind {
  display: inline-flex;
  align-items: center;
  padding: 6px 11px;
  border-radius: 999px;
  background: var(--grad);
  color: #fff;
  font-family: var(--mono);
  font-size: 0.64rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.publication-card h3 {
  max-width: 840px;
  margin: 16px 0 11px;
  font-size: 1.34rem;
  line-height: 1.55;
}

.publication-authors,
.publication-note {
  max-width: 840px;
  color: var(--ink-soft);
  font-size: 0.94rem;
}

.publication-meta {
  margin: 11px 0 0;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.82rem;
}

.publication-note {
  margin-top: 13px;
}

.publication-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.plink {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 9px 16px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1.2;
  transition: border-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.plink:hover,
.plink:focus-visible {
  border-color: var(--teal);
  color: var(--teal);
  transform: translateY(-2px);
}

.publication-contact {
  background: var(--bg);
}

.publication-contact-inner {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
}

.site-footer {
  padding: 34px 0;
  background: #0f2130;
  color: #a9c3bf;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  font-size: 0.78rem;
}

.footer-inner img {
  width: 92px;
  opacity: 0.92;
  filter: drop-shadow(0 6px 18px rgba(0, 0, 0, 0.16));
}

.footer-inner p {
  margin: 0;
}

.reveal {
  opacity: 1;
  transform: none;
  transition: opacity 560ms ease, transform 560ms ease;
}

.has-js .reveal {
  opacity: 0;
  transform: translateY(18px);
}

.has-js .reveal.in {
  opacity: 1;
  transform: none;
}

@media (max-width: 980px) {
  .wrap {
    width: min(100vw - 42px, 780px);
  }

  h1 {
    font-size: 2.55rem;
  }

  .section-head h2 {
    font-size: 2.08rem;
  }

  .stat strong {
    font-size: 2.12rem;
  }

  .hero {
    min-height: 60svh;
    background:
      linear-gradient(90deg, rgba(243, 247, 246, 0.98) 0%, rgba(243, 247, 246, 0.86) 58%, rgba(243, 247, 246, 0.38)),
      url("assets/hero-network-abstract.jpg") 58% center / cover no-repeat;
  }

  .two-column,
  .contact-page-inner,
  .publication-contact-inner {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .publication-contact-inner {
    display: grid;
  }

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

  .stat:nth-child(2) {
    border-right: 0;
  }

  .stat:nth-child(-n + 2) {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
}

@media (max-width: 680px) {
  .wrap {
    width: min(100vw - 30px, 620px);
  }

  .nav-inner {
    min-height: 58px;
    flex-wrap: wrap;
    gap: 8px;
    padding: 10px 0;
  }

  .brand img {
    width: 68px;
  }

  .brand span {
    font-size: 0.76rem;
  }

  .nav-links {
    display: flex;
    width: 100%;
    gap: 18px;
    overflow-x: auto;
    padding: 2px 1px 4px;
    font-size: 0.82rem;
    scrollbar-width: none;
  }

  .nav-links::-webkit-scrollbar {
    display: none;
  }

  .hero {
    min-height: 72svh;
    padding: 34px 0 36px;
    background:
      linear-gradient(90deg, rgba(243, 247, 246, 0.99) 0%, rgba(243, 247, 246, 0.9) 70%, rgba(243, 247, 246, 0.58)),
      url("assets/hero-network-abstract.jpg") 66% center / cover no-repeat;
  }

  .logo-lockup {
    width: min(185px, 68vw);
  }

  .logo-lockup span {
    font-size: 1.75rem;
  }

  h1 {
    font-size: 1.95rem;
  }

  .publication-hero h1 {
    font-size: 2.08rem;
  }

  .section-head h2 {
    font-size: 1.72rem;
  }

  .stat strong {
    font-size: 2rem;
  }

  .lede {
    font-size: 0.96rem;
  }

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

  .stats-inner {
    grid-template-columns: 1fr;
  }

  .stat {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .stat:last-child {
    border-bottom: 0;
  }

  .section {
    padding: 58px 0;
  }

  .contact-form,
  .publication-card {
    padding: 22px;
  }

  .contact-form .btn {
    width: 100%;
  }

  .footer-inner {
    display: grid;
    justify-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    scroll-behavior: auto !important;
    transition: none !important;
  }

  .has-js .reveal,
  .reveal {
    opacity: 1;
    transform: none;
  }
}