:root {
  --bg: #f7fcff;
  --bg-strong: #dff5ff;
  --ink: #173744;
  --muted: #657b84;
  --line: rgba(65, 161, 196, 0.18);
  --card: rgba(255, 255, 255, 0.78);
  --card-strong: rgba(255, 255, 255, 0.94);
  --accent: #6dc8e8;
  --accent-deep: #147fa8;
  --shadow: 0 24px 70px rgba(80, 155, 190, 0.15);
  --radius: 28px;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Inter", "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 300;
  letter-spacing: 0.01em;
  line-height: 1.78;
  overflow-x: hidden;
}

body::selection { background: rgba(109, 200, 232, 0.32); }

.water-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(circle at 12% 16%, rgba(138, 217, 244, 0.34), transparent 32%),
    radial-gradient(circle at 82% 4%, rgba(201, 240, 252, 0.78), transparent 29%),
    linear-gradient(145deg, #ffffff 0%, #f6fcff 40%, #ebf9ff 100%);
}

.water-bg::after {
  content: "";
  position: absolute;
  inset: -12%;
  background-image:
    radial-gradient(circle, rgba(78, 174, 209, 0.06) 1px, transparent 1.2px),
    linear-gradient(115deg, transparent 0%, rgba(255,255,255,0.46) 48%, transparent 52%);
  background-size: 42px 42px, 100% 100%;
  transform: rotate(-6deg);
  opacity: 0.9;
}

.site-header {
  position: sticky;
  top: 18px;
  z-index: 20;
  width: min(calc(100% - 32px), var(--max));
  margin: 18px auto 0;
  padding: 10px 12px 10px 18px;
  border: 1px solid var(--line);
  border-radius: 999px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(22px);
  box-shadow: 0 12px 36px rgba(54, 132, 168, 0.11);
}

.logo {
  display: inline-flex;
  color: var(--ink);
  text-decoration: none;
  font-weight: 500;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.92rem;
}

.nav a,
.link-row a,
.publication a,
.profile-role a,
.cv-link {
  color: var(--accent-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  transition: color 180ms ease, opacity 180ms ease;
}

.nav a { color: var(--ink); text-decoration: none; }
.nav a:hover,
.link-row a:hover,
.publication a:hover,
.profile-role a:hover,
.cv-link:hover { color: #0d6589; }

.language-switcher {
  display: inline-flex;
  padding: 4px;
  gap: 2px;
  border-radius: 999px;
  background: rgba(223, 245, 255, 0.72);
}

.lang-button {
  border: 0;
  border-radius: 999px;
  padding: 7px 10px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.78rem;
  cursor: pointer;
}

.lang-button.is-active {
  background: #ffffff;
  color: var(--accent-deep);
  box-shadow: 0 5px 16px rgba(80, 155, 190, 0.14);
}

.section {
  width: min(calc(100% - 42px), var(--max));
  margin: 0 auto;
  padding: 78px 0;
}

.hero {
  min-height: min(700px, calc(100vh - 90px));
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 300px);
  align-items: center;
  gap: clamp(32px, 6vw, 72px);
  padding-top: 48px;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

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

h1 {
  max-width: 680px;
  margin-bottom: 18px;
  font-size: clamp(2.4rem, 5vw, 4.35rem);
  line-height: 1.04;
  letter-spacing: -0.055em;
  font-weight: 300;
}

.hero-name span { display: block; }
.name-secondary {
  margin-top: 6px;
  font-size: 0.52em;
  letter-spacing: -0.025em;
  color: var(--muted);
}
.name-secondary:empty { display: none; }

h2 {
  margin-bottom: 0;
  font-size: clamp(1.9rem, 4vw, 3.15rem);
  line-height: 1.15;
  letter-spacing: -0.055em;
  font-weight: 300;
}

h3 {
  margin-bottom: 12px;
  font-size: 1.2rem;
  line-height: 1.35;
  font-weight: 500;
}

.profile-role {
  margin-bottom: 20px;
  color: var(--accent-deep);
  font-size: clamp(1rem, 1.8vw, 1.12rem);
  font-weight: 400;
}

.hero-lead {
  max-width: 650px;
  color: var(--muted);
  font-size: clamp(1rem, 1.9vw, 1.16rem);
}

.profile-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 0;
  color: var(--ink);
  font-size: 0.96rem;
}

.hero-actions,
.link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.button,
.link-row a,
.cv-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 19px;
  border-radius: 999px;
  border: 1px solid var(--line);
  text-decoration: none;
  font-weight: 400;
  background: rgba(255,255,255,0.62);
}

.button { transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease; }
.button:hover { transform: translateY(-2px); }

.button.primary {
  color: #fff;
  background: linear-gradient(135deg, #54bddf, #1e91bf);
  box-shadow: 0 16px 32px rgba(31, 145, 191, 0.20);
}
.button.ghost { color: var(--ink); }

.hero-photo {
  position: relative;
  width: min(100%, 300px);
  justify-self: end;
  margin: 0;
  border-radius: 30px;
  overflow: hidden;
  border: 1px solid rgba(65, 161, 196, 0.2);
  background: rgba(255, 255, 255, 0.56);
  box-shadow: 0 24px 65px rgba(80, 155, 190, 0.18);
  aspect-ratio: 4 / 5;
}

.hero-photo::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(255,255,255,0.10), transparent 38%);
  pointer-events: none;
}

.hero-photo img,
.research-image img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.section-heading { margin-bottom: 32px; }

.text-card,
.contact-card,
.publication-list,
.timeline,
.research-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow);
}

.research-list {
  display: grid;
  gap: 22px;
}

.research-card {
  display: grid;
  grid-template-columns: minmax(220px, 0.42fr) minmax(0, 0.58fr);
  overflow: hidden;
  min-height: 260px;
}

.research-image {
  margin: 0;
  min-height: 260px;
  background: rgba(255,255,255,0.42);
}

.research-copy {
  padding: clamp(24px, 4vw, 38px);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.card-number {
  display: block;
  margin-bottom: 18px;
  color: rgba(20, 127, 168, 0.46);
  font-size: 0.92rem;
  font-weight: 500;
}

.publication-list,
.timeline,
.contact-card {
  padding: clamp(24px, 4vw, 38px);
}

.publication {
  display: grid;
  grid-template-columns: 82px 1fr;
  gap: 22px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}
.publication:first-child { padding-top: 0; }
.publication:last-child { padding-bottom: 0; border-bottom: 0; }
.publication h3 a { color: var(--ink); }
.pub-year { color: var(--accent-deep); font-weight: 500; }
.micro { color: var(--muted); font-size: 0.92rem; }

.split {
  display: grid;
  grid-template-columns: 0.78fr 1.22fr;
  gap: 42px;
  align-items: start;
}

.cv-link { margin-top: 24px; color: var(--accent-deep); }

.timeline-item {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 18px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}
.timeline-item:first-child { padding-top: 0; }
.timeline-item:last-child { padding-bottom: 0; border-bottom: 0; }
.timeline-item span { color: var(--accent-deep); font-weight: 500; }
.timeline-item p { margin: 0; }

.contact { padding-bottom: 56px; }
.contact-card { display: flex; justify-content: flex-start; }
.contact-card .link-row { margin-top: 0; }

.site-footer {
  width: min(calc(100% - 42px), var(--max));
  margin: 0 auto 26px;
  padding: 24px 0 38px;
  display: flex;
  justify-content: center;
  gap: 20px;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--line);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 700ms ease, transform 700ms ease;
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 920px) {
  .site-header {
    align-items: stretch;
    border-radius: 26px;
    flex-wrap: wrap;
  }
  .nav {
    order: 3;
    width: 100%;
    justify-content: space-around;
    gap: 10px;
    padding: 4px 8px 8px;
  }
  .hero,
  .split,
  .research-card {
    grid-template-columns: 1fr;
  }
  .hero { min-height: auto; }
  .hero-photo {
    justify-self: start;
    width: min(100%, 280px);
  }
  .research-image { min-height: 230px; }
}

@media (max-width: 560px) {
  .section {
    width: min(calc(100% - 26px), var(--max));
    padding: 62px 0;
  }
  .site-header { width: min(calc(100% - 22px), var(--max)); }
  .nav { font-size: 0.82rem; }
  .publication,
  .timeline-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  h1 { font-size: clamp(2.05rem, 10vw, 3rem); }
  .hero-photo { width: min(100%, 240px); }
  .research-image { min-height: 210px; }
  .site-footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { transition: none; transform: none; opacity: 1; }
}

.water-refraction {
  position: fixed;
  left: 0;
  top: 0;
  width: 100vw;
  height: 100vh;
  width: 100dvw;
  height: 100dvh;
  z-index: 9999;
  pointer-events: none;
  opacity: 1;
  background: transparent;
  mix-blend-mode: normal;
  will-change: contents;
  touch-action: none;
}

@media (prefers-reduced-motion: reduce) {
  .water-refraction { display: none; }
}

/* Compact horizontal Research interests cards */
#research .research-list-horizontal {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.1rem;
  align-items: stretch;
}

#research .research-list-horizontal .research-card-compact {
  display: block;
  padding: 0;
  overflow: hidden;
  min-height: 0;
  border-radius: 24px;
}

#research .research-list-horizontal .research-image {
  width: 100%;
  height: 145px;
  min-height: 0;
  margin: 0;
  overflow: hidden;
}

#research .research-list-horizontal .research-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

#research .research-list-horizontal .research-copy {
  padding: 1rem 1.05rem 1.15rem;
  display: block;
}

#research .research-list-horizontal .card-number {
  margin-bottom: 0.35rem;
  font-size: 0.72rem;
  letter-spacing: 0.12em;
}

#research .research-list-horizontal h3 {
  font-size: 1.02rem;
  line-height: 1.35;
  margin: 0.35rem 0 0.5rem;
}

#research .research-list-horizontal p {
  font-size: 0.86rem;
  line-height: 1.65;
  margin: 0;
}

.timeline-text p {
  margin: 0 0 0.35rem;
}

.timeline-text p:last-child {
  margin-bottom: 0;
}

.contact-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
}

.contact-message {
  margin: 0 0 1.1rem;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.contact-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 19px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--accent-deep);
  text-decoration: none;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  font-weight: 400;
  background: rgba(255,255,255,0.62);
  transition: color 180ms ease, opacity 180ms ease;
}

.contact-links a:hover {
  color: #0d6589;
}

@media (max-width: 900px) {
  #research .research-list-horizontal {
    grid-template-columns: 1fr;
  }

  #research .research-list-horizontal .research-image {
    height: 180px;
  }
}