/* ==========================================================
   Seiya Kawano — personal academic site
   Modern minimal stylesheet (2026 redesign)
   ========================================================== */

:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --ink: #1b2430;
  --muted: #5b6675;
  --line: #e4e8ef;
  --brand: #14406e;
  --brand-2: #1e5fa8;
  --accent: #c99b2d;
  --award: #b4231f;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 35, 60, .05), 0 8px 24px rgba(20, 35, 60, .06);
  --maxw: 960px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Inter", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand-2); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

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

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.site-header .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: .65rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .4rem 1rem;
}

.brand {
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--ink);
  letter-spacing: .01em;
  white-space: nowrap;
}
.brand:hover { text-decoration: none; color: var(--brand); }
.brand small { font-weight: 500; color: var(--muted); margin-left: .5em; font-size: .8em; }

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: .1rem;
  margin: 0;
  padding: 0;
}

.site-nav a {
  display: inline-block;
  padding: .35rem .7rem;
  border-radius: 8px;
  color: var(--ink);
  font-size: .92rem;
  font-weight: 500;
}
.site-nav a:hover { background: #eef2f8; text-decoration: none; }
.site-nav a.active { color: var(--brand); font-weight: 700; }
.site-nav a.lang {
  border: 1px solid var(--line);
  color: var(--muted);
  margin-left: .35rem;
  font-size: .82rem;
}

/* ---------- Hero ---------- */
.hero {
  background:
    radial-gradient(1100px 420px at 85% -10%, rgba(201, 155, 45, .18), transparent 60%),
    linear-gradient(135deg, #12325a 0%, #14406e 55%, #1e5fa8 100%);
  color: #fff;
  padding: 3.6rem 1.25rem 3.2rem;
}

.hero .inner { max-width: var(--maxw); margin: 0 auto; }

.hero .kicker {
  margin: 0 0 .6rem;
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: #bcd3ef;
}

.hero h1 {
  margin: 0 0 .4rem;
  font-size: clamp(1.9rem, 5vw, 2.7rem);
  line-height: 1.25;
  letter-spacing: .02em;
}
.hero h1 .romaji {
  display: block;
  font-size: .5em;
  font-weight: 500;
  color: #c9dcf4;
  letter-spacing: .06em;
  margin-top: .3rem;
}

.hero .lead {
  max-width: 46em;
  margin: .9rem 0 0;
  color: #e3edf9;
  font-size: .98rem;
}
.hero .lead a { color: #ffd98a; }

.chips { margin: 1.3rem 0 0; display: flex; flex-wrap: wrap; gap: .5rem; }
.chip {
  display: inline-block;
  padding: .22rem .8rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, .35);
  background: rgba(255, 255, 255, .08);
  color: #eaf2fc;
  font-size: .82rem;
}

.hero .cta { margin-top: 1.6rem; display: flex; flex-wrap: wrap; gap: .6rem; }
.btn {
  display: inline-block;
  padding: .5rem 1.1rem;
  border-radius: 10px;
  font-size: .9rem;
  font-weight: 600;
  border: 1px solid rgba(255, 255, 255, .45);
  color: #fff;
}
.btn:hover { background: rgba(255, 255, 255, .12); text-decoration: none; }
.btn.primary { background: #fff; color: var(--brand); border-color: #fff; }
.btn.primary:hover { background: #eef4fb; }

/* ---------- Page title band (subpages) ---------- */
.page-title {
  background: linear-gradient(135deg, #12325a 0%, #1e5fa8 100%);
  color: #fff;
  padding: 2.2rem 1.25rem;
}
.page-title .inner { max-width: var(--maxw); margin: 0 auto; }
.page-title h1 { margin: 0; font-size: clamp(1.5rem, 4vw, 2rem); letter-spacing: .03em; }
.page-title p { margin: .3rem 0 0; color: #c9dcf4; font-size: .9rem; }

/* ---------- Main layout ---------- */
main { max-width: var(--maxw); margin: 0 auto; padding: 2.2rem 1.25rem 3.5rem; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.6rem 1.8rem;
  margin-bottom: 1.6rem;
}

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

h2 {
  font-size: 1.25rem;
  margin: 0 0 1rem;
  padding-left: .75rem;
  border-left: 4px solid var(--accent);
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--brand);
}

h3 {
  font-size: 1.02rem;
  margin: 1.6rem 0 .5rem;
  color: var(--ink);
}
h3:first-of-type { margin-top: 0; }

/* ---------- Timeline lists (education / experience) ---------- */
.timeline { list-style: none; margin: 0; padding: 0 0 0 .2rem; }
.timeline li {
  position: relative;
  padding: 0 0 1rem 1.4rem;
  border-left: 2px solid var(--line);
}
.timeline li:last-child { padding-bottom: .1rem; }
.timeline li::before {
  content: "";
  position: absolute;
  left: -6px;
  top: .5em;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--brand-2);
  border: 2px solid #fff;
  box-shadow: 0 0 0 1px var(--line);
}
.timeline .when {
  display: block;
  font-size: .8rem;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: .04em;
}
.timeline .what { display: block; }
.timeline .note { display: block; font-size: .88rem; color: var(--muted); }

/* ---------- News ---------- */
.news { list-style: none; margin: 0; padding: 0; }
.news li {
  display: flex;
  gap: 1rem;
  padding: .55rem 0;
  border-bottom: 1px dashed var(--line);
  align-items: baseline;
}
.news li:last-child { border-bottom: 0; }
.news time {
  flex: 0 0 6.2em;
  font-size: .82rem;
  font-weight: 700;
  color: var(--brand-2);
  letter-spacing: .02em;
}

/* ---------- Publications ---------- */
.pubs { margin: 0 0 1.2rem; padding-left: 1.4rem; }
.pubs li { margin-bottom: .7rem; }
.pubs li::marker { color: var(--brand-2); font-weight: 600; }

.award {
  display: inline-block;
  color: var(--award);
  font-weight: 700;
  font-size: .88em;
}

.tag {
  display: inline-block;
  font-size: .72rem;
  font-weight: 700;
  color: var(--brand);
  background: #e8eef7;
  border-radius: 6px;
  padding: .05rem .5rem;
  margin-left: .3rem;
  vertical-align: .08em;
  white-space: nowrap;
}

/* plain lists (awards, funds) */
.plain { margin: 0; padding-left: 1.4rem; }
.plain li { margin-bottom: .45rem; }

/* ---------- Contact ---------- */
.contact-mail {
  font-size: 1.15rem;
  font-weight: 600;
  background: #eef2f8;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: .8rem 1.2rem;
  display: inline-block;
}

.map-embed {
  width: 100%;
  border: 0;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  aspect-ratio: 4 / 3;
  max-height: 460px;
}

/* ---------- Links list ---------- */
.link-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: .6rem;
}
.link-grid a {
  display: block;
  padding: .6rem .9rem;
  background: #f2f5fa;
  border: 1px solid var(--line);
  border-radius: 10px;
  font-size: .9rem;
  color: var(--ink);
}
.link-grid a:hover { border-color: var(--brand-2); color: var(--brand-2); text-decoration: none; }

/* ---------- Footer ---------- */
.site-footer {
  background: #12233c;
  color: #9fb3cd;
  padding: 1.6rem 1.25rem;
  font-size: .84rem;
}
.site-footer .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: .5rem;
}
.site-footer a { color: #cfe0f2; }

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
  body { font-size: 15px; }
  .card { padding: 1.2rem 1.1rem; }
  .news li { flex-direction: column; gap: 0; }
  .news time { flex-basis: auto; }
  .hero { padding: 2.6rem 1.1rem 2.4rem; }
}

@media print {
  .site-header, .site-footer, .hero .cta { display: none; }
  body { background: #fff; }
  .card { box-shadow: none; border: 0; padding: 0; margin-bottom: 1.2rem; }
}