/* ============================================
   TiP Lab — brand refresh inspired by the original site
   Blue #006AD1 · gradient #31C0FD → #A634FE · "Play with TiP!"
   ============================================ */

:root {
  --color-text: #1c2333;
  --color-text-light: #4b5565;
  --color-text-muted: #8a93a2;
  --color-bg: #ffffff;
  --color-bg-alt: #f4f7fb;
  --color-brand: #006ad1;            /* TiPラボ logo blue */
  --color-brand-hover: #0058ad;
  --color-grad-start: #31c0fd;       /* signature ring gradient */
  --color-grad-end: #a634fe;
  --color-brand-soft: #e8f2fd;
  --color-border: #e4e8f0;
  --color-ink: #141e30;              /* deep navy (hero overlay / footer) */
  --gradient-brand: linear-gradient(135deg, var(--color-grad-start), var(--color-grad-end));

  --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Poppins', 'Noto Sans JP', sans-serif;
  --max-width: 1120px;
  --header-height: 64px;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

a {
  color: var(--color-brand);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: var(--color-brand-hover); }

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

::selection { background: var(--color-grad-start); color: #fff; }

/* ---- Header ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.site-logo { display: flex; align-items: center; }
.site-logo img { height: 30px; width: auto; }

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.site-nav a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text-light);
  text-decoration: none;
  transition: color 0.2s;
}
.site-nav a:hover,
.site-nav a.active { color: var(--color-brand); }

.lang-switch {
  font-size: 0.8rem !important;
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  color: var(--color-text-muted) !important;
}
.lang-switch:hover {
  border-color: var(--color-brand);
  color: var(--color-brand) !important;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: 0.3s;
}

/* ---- Hero: duotone slideshow ---- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 130px 0 110px;
  background: var(--color-ink);
  color: #fff;
}

.hero-slides { position: absolute; inset: 0; }
.hero-slides .slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  animation: heroFade 28s infinite;
}
.hero-slides .slide:nth-child(1) { animation-delay: 0s; }
.hero-slides .slide:nth-child(2) { animation-delay: 7s; }
.hero-slides .slide:nth-child(3) { animation-delay: 14s; }
.hero-slides .slide:nth-child(4) { animation-delay: 21s; }

@keyframes heroFade {
  0%   { opacity: 0; }
  4%   { opacity: 1; }
  25%  { opacity: 1; }
  32%  { opacity: 0; }
  100% { opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .hero-slides .slide { animation: none; }
  .hero-slides .slide:first-child { opacity: 1; }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(20, 30, 48, 0.72) 0%, rgba(20, 30, 48, 0.45) 45%, rgba(99, 52, 190, 0.28) 100%);
}

.hero-content { position: relative; z-index: 1; }

.hero .tagline {
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 14px;
}

.hero .slogan {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 600;
  font-size: 4rem;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: #fff;
  margin-bottom: 14px;
  text-shadow: 0 2px 24px rgba(10, 15, 30, 0.35);
}

.hero .hero-labname {
  font-size: 1.15rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.92);
  margin-bottom: 18px;
}

.hero .subtitle {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.82);
  max-width: 640px;
  line-height: 1.8;
}

/* ---- Section ---- */
.section { padding: 72px 0; }
.section-alt { background: var(--color-bg-alt); }

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 36px;
  letter-spacing: -0.01em;
}
.section-title::after {
  content: '';
  display: block;
  width: 56px;
  height: 4px;
  background: var(--gradient-brand);
  border-radius: 2px;
  margin-top: 10px;
}

.eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 8px;
}

/* ---- Research circles (signature gradient rings) ---- */
.research-circles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
  text-align: center;
}

.research-circle {
  display: block;
  color: inherit;
  text-decoration: none;
}

.research-circle img {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 18px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.research-circle:hover img {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 14px 36px rgba(72, 90, 220, 0.25);
}

.research-circle h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--color-text);
  transition: color 0.2s;
}
.research-circle:hover h3 { color: var(--color-brand); }

.research-circle p {
  font-size: 0.85rem;
  color: var(--color-text-light);
  line-height: 1.6;
  max-width: 260px;
  margin: 0 auto;
}

/* ---- Feature bands (lab / international) ---- */
.feature-band {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.feature-band-reverse .feature-image { order: 2; }
.feature-band-reverse .feature-text { order: 1; }

.feature-image img {
  border-radius: 14px;
  box-shadow: 0 18px 44px rgba(20, 30, 48, 0.16);
  width: 100%;
  object-fit: cover;
}

.feature-text h2 {
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
}

.feature-text p {
  color: var(--color-text-light);
  margin-bottom: 22px;
}

.btn-gradient {
  display: inline-block;
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-brand);
  padding: 11px 26px;
  border-radius: 999px;
  box-shadow: 0 6px 18px rgba(120, 80, 250, 0.3);
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-gradient:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(120, 80, 250, 0.4);
}

/* ---- Cards (still used elsewhere) ---- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 22px;
}

.card {
  position: relative;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 28px;
  overflow: hidden;
  transition: box-shadow 0.2s, border-color 0.2s, transform 0.2s;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--gradient-brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}
.card:hover {
  box-shadow: 0 10px 30px rgba(20, 30, 48, 0.1);
  border-color: transparent;
  transform: translateY(-2px);
}
.card:hover::before { transform: scaleX(1); }

.card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 8px; }
.card p { font-size: 0.92rem; color: var(--color-text-light); line-height: 1.65; }

.card .card-link {
  display: inline-block;
  margin-top: 14px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-brand);
}

/* ---- Member Cards ---- */
.member-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px;
}

.member-card {
  text-align: center;
  padding: 32px 24px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  transition: box-shadow 0.2s;
}
.member-card:hover { box-shadow: 0 10px 28px rgba(20, 30, 48, 0.1); }

.member-card img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 16px;
  padding: 3px;
  background: var(--gradient-brand);
}

a.member-card {
  display: block;
  color: inherit;
  text-decoration: none;
  transition: box-shadow 0.2s, border-color 0.2s, transform 0.2s;
}
a.member-card:hover {
  color: inherit;
  border-color: var(--color-grad-start);
  transform: translateY(-2px);
}
a.member-card:hover h3 { color: var(--color-brand); }

.member-placeholder {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 2.4rem;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-brand);
}

.member-card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 4px; }
.member-card .role {
  font-size: 0.82rem;
  color: var(--color-brand);
  font-weight: 600;
  margin-bottom: 8px;
}
.member-card .bio { font-size: 0.88rem; color: var(--color-text-light); }

/* ---- Publications ---- */
.pub-year {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 36px 0 12px;
  color: var(--color-brand);
}

.pub-item {
  padding: 14px 0 14px 16px;
  border-bottom: 1px solid var(--color-border);
  border-left: 3px solid transparent;
  font-size: 0.92rem;
  line-height: 1.6;
  transition: border-color 0.2s, background 0.2s;
}
.pub-item:hover { border-left-color: var(--color-grad-start); background: var(--color-bg-alt); }

.pub-item .pub-title { font-weight: 600; }
.pub-item .pub-authors { color: var(--color-text-light); }
.pub-item .pub-venue { font-style: italic; color: var(--color-text-muted); }

/* ---- News List ---- */
.news-item {
  display: flex;
  gap: 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
  align-items: baseline;
}

.news-date {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  font-weight: 500;
  white-space: nowrap;
  min-width: 100px;
}

.news-title { font-size: 0.95rem; font-weight: 500; color: var(--color-text); }
.news-title:hover { color: var(--color-brand); }

/* ---- Highlights strip ---- */
.highlights {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  padding: 28px 0;
  text-align: center;
}
.highlight-item { padding: 20px 16px; }
.highlight-item + .highlight-item { border-left: 1px solid var(--color-border); }

.highlight-item .number {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 600;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.highlight-item .label {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ---- Page Content ---- */
.page-header {
  padding: 56px 0 32px;
  border-bottom: 1px solid var(--color-border);
}
.page-header h1 { font-size: 2.1rem; font-weight: 800; letter-spacing: -0.01em; }

.page-content { padding: 40px 0 60px; max-width: 780px; }

.page-content h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 44px 0 16px;
  padding-left: 14px;
  border-left: 4px solid;
  border-image: var(--gradient-brand) 1;
}
.page-content h3 { font-size: 1.12rem; font-weight: 600; margin: 28px 0 12px; }
.page-content p { margin-bottom: 16px; }
.page-content ul, .page-content ol { margin: 12px 0 16px 24px; }
.page-content li { margin-bottom: 6px; font-size: 0.95rem; }
.page-content a { font-weight: 500; }
.page-content a:hover { text-decoration: underline; }

/* ---- Member profile pages ---- */
.profile { padding: 40px 0 0; }

.back-link { font-size: 0.88rem; margin-bottom: 28px; }

.profile-header {
  display: flex;
  align-items: center;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--color-border);
}

.profile-photo img,
.profile-placeholder {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  padding: 4px;
  background: var(--gradient-brand);
}

.profile-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 600;
  color: #fff;
}

.profile-meta h1 {
  font-size: 1.9rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.profile-role {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-brand);
  margin-bottom: 8px;
}

.profile-sub {
  font-size: 0.88rem;
  color: var(--color-text-light);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.profile-content { padding-top: 16px; }

/* Collapsible per-year publication lists on profile pages */
.profile-content details {
  margin: 0 0 10px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 10px 16px;
}
.profile-content details[open] { padding-bottom: 4px; }
.profile-content summary {
  cursor: pointer;
  font-size: 0.95rem;
  color: var(--color-text-light);
  list-style-position: inside;
}
.profile-content summary:hover { color: var(--color-brand); }
.profile-content summary strong { color: var(--color-text); font-size: 1.02rem; }
.profile-content details ul { margin-top: 10px; }

@media (max-width: 600px) {
  .profile-header { flex-direction: column; text-align: center; gap: 20px; }
  .profile-sub { justify-content: center; }
}

/* ---- Research area tags ---- */
.tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 12px;
  border-radius: 999px;
  background: var(--color-brand-soft);
  color: var(--color-brand);
  margin-right: 6px;
  margin-bottom: 6px;
}

/* ---- Footer ---- */
.site-footer {
  background: var(--color-ink);
  color: rgba(226, 232, 240, 0.72);
  padding: 56px 0 32px;
  font-size: 0.88rem;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
}

.footer-col h4 {
  color: #fff;
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 14px;
}

.footer-col a {
  color: rgba(226, 232, 240, 0.6);
  display: block;
  margin-bottom: 7px;
  font-size: 0.85rem;
}
.footer-col a:hover { color: var(--color-grad-start); }

.footer-bottom {
  margin-top: 40px;
  padding-top: 22px;
  border-top: 1px solid rgba(148, 163, 184, 0.16);
  font-size: 0.8rem;
  color: rgba(148, 163, 184, 0.6);
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .nav-toggle { display: block; }

  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 24px;
    border-bottom: 1px solid var(--color-border);
    gap: 14px;
  }
  .site-nav.open { display: flex; }

  .hero { padding: 88px 0 72px; }
  .hero .slogan { font-size: 2.5rem; }
  .hero .hero-labname { font-size: 1rem; }

  .feature-band { grid-template-columns: 1fr; gap: 24px; }
  .feature-band-reverse .feature-image { order: 0; }
  .feature-band-reverse .feature-text { order: 1; }

  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
  .highlights { grid-template-columns: repeat(2, 1fr); }
  .highlight-item:nth-child(3) { border-left: none; }
  .card-grid { grid-template-columns: 1fr; }
  .research-circles { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .research-circle img { width: 140px; height: 140px; }
}