/* ===========================================================
   Kazue Suzuki — Researcher Site
   Design concept: ice-core stratigraphy meets a field notebook.
   =========================================================== */

@import url('https://fonts.googleapis.com/css2?family=Zen+Old+Mincho:wght@400;500;700;900&family=Zen+Kaku+Gothic+New:wght@400;500;700;900&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  --bg: #f5f9fb;
  --surface: #e9f1f5;
  --surface-2: #dbe8ee;
  --ink: #0e2430;
  --ink-muted: #4d6675;
  --ink-faint: #7b8f9b;
  --accent: #196f8e;
  --accent-strong: #0e5470;
  --accent-2: #2f9b83;
  --line: #c3d6de;
  --line-strong: #a9c2cc;
  --card-shadow: 0 1px 0 rgba(14, 36, 48, 0.04);
  --radius: 3px;

  --font-display: "Zen Old Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --font-body: "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", "Yu Gothic", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Menlo, monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #081420;
    --surface: #0f202b;
    --surface-2: #142a36;
    --ink: #e7f2f6;
    --ink-muted: #9db6c3;
    --ink-faint: #6d8794;
    --accent: #6cc9ea;
    --accent-strong: #93dcf4;
    --accent-2: #5fe0bd;
    --line: #1f3b48;
    --line-strong: #2b4c5a;
    --card-shadow: 0 1px 0 rgba(0, 0, 0, 0.2);
  }
}

:root[data-theme="dark"] {
  --bg: #081420;
  --surface: #0f202b;
  --surface-2: #142a36;
  --ink: #e7f2f6;
  --ink-muted: #9db6c3;
  --ink-faint: #6d8794;
  --accent: #6cc9ea;
  --accent-strong: #93dcf4;
  --accent-2: #5fe0bd;
  --line: #1f3b48;
  --line-strong: #2b4c5a;
  --card-shadow: 0 1px 0 rgba(0, 0, 0, 0.2);
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

a { color: var(--accent-strong); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

img { max-width: 100%; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--ink);
  text-wrap: balance;
  margin: 0;
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.wrap {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 28px;
}

.wrap--narrow {
  max-width: 760px;
}

/* ---------- Snow-crystal facet mark ---------- */
.facet {
  display: inline-block;
  width: 12px;
  height: 12px;
  flex-shrink: 0;
}
.facet svg { display: block; width: 100%; height: 100%; }
.facet path, .facet line { stroke: var(--accent); stroke-width: 1.4; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-header__inner {
  max-width: 1040px;
  margin: 0 auto;
  padding: 16px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  color: var(--ink);
  white-space: nowrap;
}
.brand__logo {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  flex-shrink: 0;
  display: block;
}
.brand small {
  display: block;
  font-family: var(--font-mono);
  font-weight: 400;
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  margin-top: 2px;
  white-space: normal;
}
@media (max-width: 900px) {
  .brand small { display: none; }
}
.nav {
  display: flex;
  gap: 26px;
  font-size: 14.5px;
}
.nav a {
  color: var(--ink-muted);
  padding: 4px 0;
  border-bottom: 1px solid transparent;
}
.nav a:hover, .nav a[aria-current="page"] {
  color: var(--ink);
  text-decoration: none;
  border-bottom-color: var(--accent);
}
.nav-toggle { display: none; }

@media (max-width: 720px) {
  .nav { display: none; }
  .nav-toggle {
    display: inline-flex;
    background: none;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius);
    color: var(--ink);
    padding: 6px 10px;
    font-family: var(--font-mono);
    font-size: 12px;
    cursor: pointer;
  }
  .nav.is-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 12px 28px 20px;
    gap: 14px;
  }
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}
.hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.55;
}
.hero__inner {
  position: relative;
  max-width: 1040px;
  margin: 0 auto;
  padding: 96px 28px 76px;
}
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-strong);
  margin-bottom: 22px;
}
.hero h1 {
  font-size: clamp(34px, 5vw, 52px);
  line-height: 1.35;
  max-width: 22ch;
}
.hero__name {
  font-size: clamp(15px, 2vw, 17px);
  color: var(--ink-muted);
  margin-top: 22px;
  font-family: var(--font-body);
}
.hero__name .mono { color: var(--ink-faint); }
.hero__lede {
  max-width: 60ch;
  font-size: 17px;
  color: var(--ink-muted);
  margin-top: 22px;
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 36px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--radius);
  font-size: 14.5px;
  font-weight: 500;
  border: 1px solid var(--line-strong);
  color: var(--ink);
  transition: border-color 0.15s ease, background 0.15s ease;
}
.btn:hover { text-decoration: none; border-color: var(--accent); background: var(--surface); }
.btn--primary {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: #f5fbfd;
}
.btn--primary:hover { background: var(--accent); border-color: var(--accent); }

/* ---------- Section scaffolding ---------- */
section { padding: 72px 0; }
.section-tight { padding: 52px 0; }
.hairline {
  border: none;
  border-top: 1px solid var(--line);
  margin: 0;
}
.section-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 40px;
}
.section-head .facet { transform: translateY(-1px); }
.section-head h2 {
  font-size: clamp(22px, 3vw, 28px);
}
.section-num {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-faint);
  letter-spacing: 0.08em;
}
.section-sub {
  color: var(--ink-muted);
  font-size: 15.5px;
  max-width: 62ch;
  margin: -24px 0 40px;
}

/* ---------- Theme cards (research specimens) ---------- */
.theme-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
@media (max-width: 720px) { .theme-grid { grid-template-columns: 1fr; } }

.theme-card {
  background: var(--bg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.theme-card__head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}
.theme-card__id {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  letter-spacing: 0.06em;
}
.theme-card h3 {
  font-size: 19px;
  line-height: 1.5;
  margin-top: 6px;
}
.theme-icon {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  color: var(--accent);
}
.theme-icon svg { width: 100%; height: 100%; }
.theme-card p {
  color: var(--ink-muted);
  font-size: 14.8px;
  margin: 0;
}
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  padding-top: 6px;
}
.chip {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--accent-strong);
  background: var(--surface);
  border: 1px solid var(--line);
  padding: 4px 9px;
  border-radius: 999px;
  letter-spacing: 0.01em;
}
.theme-card__link {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--accent-strong);
}

/* ---------- Stratigraphy timeline (career / publications) ---------- */
.strata {
  position: relative;
  padding-left: 28px;
  border-left: 1px solid var(--line);
}
.strata__item {
  position: relative;
  padding-bottom: 30px;
}
.strata__item:last-child { padding-bottom: 0; }
.strata__item::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 2px solid var(--accent);
  border-radius: 1px;
  transform: rotate(45deg);
}
.strata__date {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--accent-strong);
  display: block;
  margin-bottom: 6px;
}
.strata__title {
  font-weight: 700;
  font-size: 15.5px;
  color: var(--ink);
}
.strata__meta {
  color: var(--ink-muted);
  font-size: 14px;
  margin-top: 4px;
}
.strata__tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--accent-2);
  border: 1px solid var(--line);
  padding: 1px 7px;
  border-radius: 999px;
  margin-top: 8px;
}

/* ---------- Publication log ---------- */
.pub-list { list-style: none; margin: 0; padding: 0; }
.pub-item {
  padding: 22px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 20px;
}
.pub-item:last-child { border-bottom: 1px solid var(--line); }
.pub-year {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--ink-faint);
  padding-top: 2px;
}
.pub-title { font-size: 15.5px; font-weight: 500; line-height: 1.6; }
.pub-authors { color: var(--ink-muted); font-size: 13.8px; margin-top: 6px; }
.pub-venue { color: var(--ink-faint); font-size: 13.2px; margin-top: 4px; font-style: normal; }
.pub-badges { margin-top: 8px; display: flex; gap: 6px; flex-wrap: wrap; }
.badge {
  font-family: var(--font-mono);
  font-size: 10.5px;
  padding: 2px 7px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--ink-muted);
}
.badge--accent { color: var(--accent-strong); border-color: var(--accent); }
@media (max-width: 560px) {
  .pub-item { grid-template-columns: 1fr; gap: 6px; }
}

/* ---------- Grants table ---------- */
.grant-list { list-style: none; margin: 0; padding: 0; }
.grant-item {
  padding: 18px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: baseline;
}
.grant-item:last-child { border-bottom: 1px solid var(--line); }
.grant-title { font-size: 14.8px; font-weight: 500; }
.grant-meta { color: var(--ink-muted); font-size: 13px; margin-top: 4px; }
.grant-period { font-family: var(--font-mono); font-size: 12.5px; color: var(--ink-faint); white-space: nowrap; }

/* ---------- Two-column layout ---------- */
.split {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 56px;
}
@media (max-width: 800px) { .split { grid-template-columns: 1fr; gap: 36px; } }

.field-log {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 26px;
}
.field-log h3 {
  font-size: 15px;
  font-family: var(--font-mono);
  letter-spacing: 0.03em;
  color: var(--ink-muted);
  text-transform: uppercase;
  margin-bottom: 16px;
}
.field-log ul { margin: 0; padding: 0; list-style: none; }
.field-log li {
  font-size: 13.8px;
  color: var(--ink-muted);
  padding: 7px 0;
  border-top: 1px dashed var(--line-strong);
  display: flex;
  gap: 10px;
}
.field-log li:first-child { border-top: none; }
.field-log .mono { color: var(--ink-faint); flex-shrink: 0; }

/* ---------- Pull quote / message ---------- */
.pull {
  font-family: var(--font-display);
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.75;
  color: var(--ink);
  border-left: 2px solid var(--accent);
  padding-left: 26px;
  max-width: 68ch;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 44px 0 56px;
  color: var(--ink-faint);
  font-size: 13.5px;
}
.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a { color: var(--ink-muted); }

/* ---------- CTA band ---------- */
.cta-band {
  background: var(--surface);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 56px 0;
  text-align: center;
}
.cta-band h2 { font-size: clamp(20px, 3vw, 26px); }
.cta-band p { color: var(--ink-muted); margin-top: 14px; max-width: 52ch; margin-left: auto; margin-right: auto; }
.cta-band .hero__actions { justify-content: center; margin-top: 28px; }

/* ---------- Page header (non-home) ---------- */
.page-head {
  position: relative;
  overflow: hidden;
  padding: 64px 0 44px;
  border-bottom: 1px solid var(--line);
}
.page-head .wrap { position: relative; }
.page-head .eyebrow { margin-bottom: 18px; }
.page-head h1 { font-size: clamp(28px, 4vw, 38px); max-width: 22ch; }
.page-head p { color: var(--ink-muted); margin-top: 18px; max-width: 60ch; font-size: 16px; }

/* ---------- Profile info blocks ---------- */
.info-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px 48px;
}
@media (max-width: 720px) { .info-grid { grid-template-columns: 1fr; } }
.info-block dt {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 6px;
}
.info-block dd { margin: 0 0 20px; font-size: 15px; }
.info-block dd:last-child { margin-bottom: 0; }

.tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 40px;
}
.contact-card {
  background: var(--bg);
  padding: 26px;
}
.contact-card .mono { display: block; font-size: 11.5px; color: var(--ink-faint); margin-bottom: 8px; letter-spacing: 0.06em; }
.contact-card a { font-size: 15px; font-weight: 500; }

/* ---------- Contact form ---------- */
.contact-form {
  margin-top: 56px;
  padding-top: 48px;
  border-top: 1px solid var(--line);
}
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 22px 24px;
}
.form-field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.form-field--full { grid-column: 1 / -1; }
.form-field label {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-faint);
}
.form-field label .required {
  color: var(--accent-2);
  margin-left: 4px;
}
.form-field input,
.form-field select,
.form-field textarea {
  font-family: var(--font-body);
  font-size: 15px;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 11px 13px;
  width: 100%;
}
.form-field textarea {
  resize: vertical;
  min-height: 160px;
  line-height: 1.7;
}
.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
}
.form-note {
  color: var(--ink-faint);
  font-size: 13px;
  margin-top: 4px;
}
.form-actions {
  margin-top: 8px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.form-submit {
  font-family: inherit;
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
}
/* honeypot field: hidden from sighted users and hidden from screen readers,
   but still present in the DOM for bots that blindly fill every input */
.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
@media (max-width: 640px) {
  .form-grid { grid-template-columns: 1fr; }
  .form-actions { flex-direction: column; align-items: flex-start; gap: 12px; }
}

/* ---------- Language switch ---------- */
.lang-switch {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ink-muted);
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 5px 12px;
  margin-left: 8px;
}
.lang-switch:hover {
  color: var(--ink);
  border-color: var(--accent);
  text-decoration: none;
  background: var(--surface);
}
@media (max-width: 720px) {
  .lang-switch { margin-left: 0; align-self: flex-start; }
}