/* ==========================================================================
   Personal academic homepage — base stylesheet
   Edit the custom properties below to restyle the whole site.
   ========================================================================== */

:root {
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    "Hiragino Sans", "Noto Sans JP", Meiryo, sans-serif;
  --font-serif: ui-serif, Georgia, "Times New Roman", "Hiragino Mincho ProN", serif;

  --bg: #ffffff;
  --bg-subtle: #f6f8fa;
  --bg-inset: #eef1f5;
  --text: #1c2024;
  --text-muted: #5a6472;
  --border: #d8dee6;
  --accent: #0b5cad;
  --accent-soft: #e7f0fa;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 8px 24px rgba(16, 24, 40, 0.06);

  --measure: 50rem;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216;
    --bg-subtle: #161b22;
    --bg-inset: #1c232c;
    --text: #e6edf3;
    --text-muted: #9aa7b4;
    --border: #2a323c;
    --accent: #6cb2ff;
    --accent-soft: #14273c;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.5), 0 8px 24px rgba(0, 0, 0, 0.4);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover,
a:focus-visible {
  text-decoration: underline;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

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

/* --------------------------------------------------------- layout helpers */

.wrap {
  width: 100%;
  max-width: var(--measure);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 0.6rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0;
}

/* ----------------------------------------------------------------- header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 3.75rem;
}

.brand {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--text);
}

.brand:hover {
  text-decoration: none;
  color: var(--accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 0.35rem 0.6rem;
  font-size: 1rem;
  cursor: pointer;
}

.site-nav ul {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  color: var(--text-muted);
  font-size: 0.94rem;
  font-weight: 500;
  padding-block: 0.25rem;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover {
  color: var(--text);
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  color: var(--text);
  border-bottom-color: var(--accent);
}

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    width: 100%;
  }

  .site-header .wrap {
    flex-wrap: wrap;
    padding-block: 0.6rem;
  }

  .site-nav.open {
    display: block;
  }

  .site-nav ul {
    flex-direction: column;
    gap: 0.25rem;
    padding-block: 0.5rem;
  }

  .site-nav a {
    display: block;
    padding: 0.4rem 0;
    border-bottom: none;
  }
}

/* ------------------------------------------------------------------- main */

main {
  padding-block: 3rem 4rem;
}

section + section {
  margin-top: 3.25rem;
}

h1,
h2,
h3 {
  font-family: var(--font-serif);
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin: 0 0 0.6rem;
}

h1 {
  font-size: clamp(1.9rem, 1.4rem + 1.8vw, 2.6rem);
}

h2 {
  font-size: 1.45rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.25rem;
}

h3 {
  font-size: 1.1rem;
}

p {
  margin: 0 0 1rem;
}

.lead {
  font-size: 1.08rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------------- hero */

.hero {
  display: grid;
  grid-template-columns: 168px 1fr;
  gap: 2rem;
  align-items: start;
}

.hero-photo {
  width: 168px;
  height: 168px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--border);
  background: var(--bg-subtle);
}

.hero h1 {
  margin-bottom: 0.25rem;
}

.hero .title {
  font-size: 1.05rem;
  color: var(--text);
  margin: 0 0 0.15rem;
}

.hero .affil {
  color: var(--text-muted);
  margin: 0 0 1rem;
}

@media (max-width: 640px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 1.25rem;
    text-align: center;
  }

  .hero-photo {
    margin-inline: auto;
  }

  .links {
    justify-content: center;
  }
}

/* ------------------------------------------------------------ link chips */

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text);
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.links a:hover {
  text-decoration: none;
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

/* ------------------------------------------------------------------- tags */

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.tags li {
  font-size: 0.85rem;
  color: var(--text-muted);
  background: var(--bg-inset);
  border-radius: 6px;
  padding: 0.2rem 0.65rem;
}

/* ------------------------------------------------------------------- news */

.news {
  list-style: none;
  margin: 0;
  padding: 0;
}

.news li {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  gap: 1rem;
  padding: 0.55rem 0;
  border-bottom: 1px dashed var(--border);
}

.news li:last-child {
  border-bottom: none;
}

.news time {
  color: var(--text-muted);
  font-size: 0.86rem;
  font-variant-numeric: tabular-nums;
  padding-top: 0.15rem;
}

@media (max-width: 560px) {
  .news li {
    grid-template-columns: 1fr;
    gap: 0.1rem;
  }
}

/* ----------------------------------------------------------- publications */

.pub-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1.5rem;
}

.pub-search {
  flex: 1 1 16rem;
  font: inherit;
  font-size: 0.95rem;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.8rem;
}

.pub-search::placeholder {
  color: var(--text-muted);
}

.pub-count {
  font-size: 0.86rem;
  color: var(--text-muted);
}

.year-group {
  margin-bottom: 2rem;
}

.year-group h2 {
  font-size: 1.2rem;
  font-variant-numeric: tabular-nums;
}

.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.05rem;
}

.pub {
  display: grid;
  gap: 0.2rem;
  padding-left: 0.9rem;
  border-left: 2px solid var(--border);
}

.pub:hover {
  border-left-color: var(--accent);
}

.pub-title {
  font-weight: 600;
  line-height: 1.45;
  color: var(--text);
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.pub-authors .me {
  color: var(--text);
  font-weight: 600;
}

.pub-meta {
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.badge {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 5px;
  padding: 0.05rem 0.45rem;
}

.pub-links a {
  font-size: 0.82rem;
}

.pub-links a + a::before {
  content: "·";
  color: var(--border);
  margin-inline: 0.4rem;
}

.empty-state {
  color: var(--text-muted);
  font-style: italic;
  padding: 1.5rem 0;
}

/* --------------------------------------------------------------- cv lists */

.cv-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.cv-list > li {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 1rem;
}

.cv-list .when {
  color: var(--text-muted);
  font-size: 0.88rem;
  font-variant-numeric: tabular-nums;
}

.cv-list .what strong {
  display: block;
}

.cv-list .where {
  color: var(--text-muted);
  font-size: 0.92rem;
}

@media (max-width: 560px) {
  .cv-list > li {
    grid-template-columns: 1fr;
    gap: 0.1rem;
  }
}

/* ------------------------------------------------------------------ cards */

.card {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
}

.card + .card {
  margin-top: 1rem;
}

.card h3 {
  margin-bottom: 0.25rem;
}

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

/* ----------------------------------------------------------------- footer */

.site-footer {
  border-top: 1px solid var(--border);
  padding-block: 1.75rem;
  color: var(--text-muted);
  font-size: 0.86rem;
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  justify-content: space-between;
}

/* ------------------------------------------------------------------ misc */

.note {
  font-size: 0.88rem;
  color: var(--text-muted);
  background: var(--bg-subtle);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 0.75rem 1rem;
}

@media print {
  .site-header,
  .site-footer,
  .pub-tools {
    display: none;
  }

  body {
    font-size: 11pt;
  }
}