:root {
  --ink: #16191d;
  --muted: #606a73;
  --line: #d9e0e6;
  --paper: #f7f8f8;
  --white: #ffffff;
  --accent: #1f6f7d;
  --accent-dark: #134952;
  --soft: #eaf2f3;
  --shadow: 0 18px 60px rgba(20, 28, 35, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.75;
}

a {
  color: var(--accent);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--accent-dark);
}

.site-header {
  background: #1e252b;
}

.nav {
  position: fixed;
  z-index: 10;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  padding: 0 44px;
  color: var(--white);
  background: rgba(20, 26, 31, 0.78);
  backdrop-filter: blur(16px);
}

.brand {
  color: var(--white);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.82);
  font-size: 0.92rem;
  text-decoration: none;
}

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

.hero {
  min-height: 72vh;
  display: flex;
  align-items: center;
  padding: 112px 7vw 88px;
  color: var(--white);
  background-image:
    linear-gradient(90deg, rgba(13, 18, 23, 0.82) 0%, rgba(13, 18, 23, 0.54) 52%, rgba(13, 18, 23, 0.72) 100%),
    url("assets/hero-cosmology.png"),
    url("assets/hero-cosmology.svg");
  background-position: center, center, center;
  background-size: cover, cover, cover;
  background-repeat: no-repeat, no-repeat, no-repeat;
}

.hero-copy {
  width: min(900px, 100%);
}

.eyebrow {
  margin: 0 0 18px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 20px;
  font-size: clamp(4rem, 11vw, 8.5rem);
  line-height: 0.88;
  letter-spacing: 0;
}

.hero-subtitle {
  max-width: 720px;
  margin: 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(1.05rem, 2vw, 1.4rem);
}

.section {
  width: min(1140px, calc(100% - 48px));
  margin: 0 auto;
  padding: 96px 0;
}

.section-label {
  margin-bottom: 28px;
  color: var(--accent);
  font-size: 1.4rem;
  font-weight: 700;
  text-align: center;
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 48px;
  align-items: start;
  padding: 38px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.contact-block h2 {
  margin-bottom: 12px;
  font-size: 1.35rem;
  line-height: 1.2;
}

.contact-block p {
  margin-bottom: 8px;
}

.profile-links {
  display: grid;
  gap: 12px;
}

.profile-links a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 48px;
  padding: 0 16px;
  color: var(--accent-dark);
  background: var(--soft);
  border: 1px solid #cfe0e4;
  font-weight: 700;
  text-decoration: none;
}

.profile-links a::after {
  content: "↗";
  color: var(--accent);
}

.keywords {
  margin-top: 34px;
  display: flex;
  gap: 22px;
  align-items: baseline;
  color: var(--muted);
}

.keywords span {
  color: var(--ink);
  font-weight: 800;
}

.keywords p {
  margin-bottom: 0;
}

.split-section {
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: 64px;
  border-top: 1px solid var(--line);
}

.split-section > h2 {
  position: sticky;
  top: 96px;
  align-self: start;
  font-size: clamp(2.1rem, 4vw, 3.2rem);
  line-height: 1.05;
  text-decoration: underline;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.12em;
}

.timeline {
  display: grid;
  gap: 20px;
  padding-top: 10px;
}

.timeline-item {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 24px;
  align-items: baseline;
}

.timeline-item time {
  color: var(--accent-dark);
  font-weight: 800;
}

.timeline-item p {
  margin-bottom: 0;
}

.work-content {
  display: grid;
  gap: 42px;
}

.work-group {
  padding: 34px;
  background: var(--white);
  border: 1px solid var(--line);
}

.work-group h3 {
  margin-bottom: 22px;
  font-size: 1.35rem;
  line-height: 1.2;
}

.work-group h4 {
  margin-bottom: 12px;
  color: var(--accent-dark);
  font-size: 1rem;
}

.publication + .publication,
.entry + .entry,
.year-block + .year-block {
  margin-top: 28px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.publication h4 {
  color: var(--ink);
  font-size: 1.08rem;
}

.publication p,
.entry p {
  margin-bottom: 4px;
}

.note {
  margin: -14px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.plain-list {
  margin: 0;
  padding-left: 1.2rem;
}

.footer {
  padding: 36px 7vw;
  color: rgba(255, 255, 255, 0.84);
  background: #20272d;
}

.footer p {
  margin-bottom: 0;
}

@media (max-width: 820px) {
  .nav {
    min-height: 56px;
    padding: 0 24px;
  }

  .nav-links {
    gap: 18px;
  }

  .hero {
    min-height: 62vh;
    padding: 96px 24px 64px;
  }

  h1 {
    font-size: clamp(3.6rem, 18vw, 5.6rem);
  }

  .section {
    width: min(100% - 40px, 720px);
    padding: 70px 0;
  }

  .intro-grid,
  .split-section {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .intro-grid,
  .work-group {
    padding: 26px;
  }

  .split-section > h2 {
    position: static;
  }
}

@media (max-width: 560px) {
  .nav-links {
    display: none;
  }

  .hero {
    min-height: 58vh;
  }

  .eyebrow {
    font-size: 0.72rem;
  }

  .section {
    width: min(100% - 32px, 560px);
  }

  .keywords,
  .timeline-item {
    display: block;
  }

  .timeline-item time {
    display: block;
    margin-bottom: 4px;
  }

  .profile-links a {
    min-height: 44px;
  }
}