/* ═══════════════════════════════════════════════
   化学生態学研究会 2026  —  styles.css
   ═══════════════════════════════════════════════ */

/* ── Variables ── */
:root {
  --bg:          #020E1A;
  --bg-mid:      #061D33;
  --bg-accent:   #0A3D6B;
  --blue-deep:   #1565C0;
  --blue-main:   #29B6F6;
  --blue-light:  #81D4FA;
  --blue-faint:  #E1F5FE;
  --text:        #E1F5FE;
  --text-muted:  rgba(129,212,250,0.65);
  --text-dim:    rgba(225,245,254,0.40);
  --border:      rgba(41,182,246,0.22);
  --border-mid:  rgba(21,101,192,0.30);

  --font-sans:    'Noto Sans JP', sans-serif;
  --font-display: 'Shippori Mincho', serif;

  --hero-bg: url('https://images.unsplash.com/photo-1559825481-12a05cc00344?auto=format&fit=crop&w=1920&q=80');
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  line-height: 1.75;
}
a { text-decoration: none; color: inherit; }
table { border-collapse: collapse; width: 100%; }

/* ── Molecule float animations ── */
@keyframes floatA {
  0%,100% { transform: translate(0,0); }
  25%     { transform: translate(10px,-22px); }
  50%     { transform: translate(-6px,-12px); }
  75%     { transform: translate(14px,-5px); }
}
@keyframes floatB {
  0%,100% { transform: translate(0,0); }
  33%     { transform: translate(-14px,-26px); }
  66%     { transform: translate(8px,-14px); }
}
@keyframes floatC {
  0%,100% { transform: translate(0,0); }
  50%     { transform: translate(-10px,-30px); }
}
@keyframes floatD {
  0%,100% { transform: translate(0,0); }
  40%     { transform: translate(18px,-18px); }
  80%     { transform: translate(-8px,-8px); }
}
@keyframes floatE {
  0%,100% { transform: translate(0,0); }
  30%     { transform: translate(-12px,-24px); }
  60%     { transform: translate(6px,-32px); }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes bounce {
  0%,100% { transform: translateY(0); }
  50%     { transform: translateY(-8px); }
}

.mol-a { animation: floatA 10s ease-in-out infinite; }
.mol-b { animation: floatB 14s ease-in-out infinite; animation-delay:-5s; }
.mol-c { animation: floatC 12s ease-in-out infinite; animation-delay:-3s; }
.mol-d { animation: floatD 16s ease-in-out infinite; animation-delay:-8s; }
.mol-e { animation: floatE 11s ease-in-out infinite; animation-delay:-2s; }
.mol-f { animation: floatA  9s ease-in-out infinite; animation-delay:-6s; }

.fade-up { animation: fadeInUp 0.9s ease-out both; }
.fade-in { animation: fadeIn   1.2s ease-out both; }
.d1 { animation-delay:0.1s; }
.d2 { animation-delay:0.3s; }
.d3 { animation-delay:0.5s; }
.d4 { animation-delay:0.7s; }
.d5 { animation-delay:0.9s; }
.d6 { animation-delay:1.1s; }
.d7 { animation-delay:1.3s; }

/* ── Navigation ── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2.5rem;
  height: 64px;
  background: rgba(6,29,51,0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(41,182,246,0.14);
}
.nav-brand {
  font-family: var(--font-display);
  font-size: 0.875rem;
  color: var(--blue-light);
  letter-spacing: 0.05em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}
.nav-links a {
  font-size: 0.875rem;
  color: var(--text-muted);
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--blue-light); }
.btn-nav {
  font-size: 0.8rem;
  font-weight: 700;
  background: var(--blue-main);
  color: #fff !important;
  padding: 0.45rem 1rem;
  border-radius: 9999px;
  transition: background 0.2s;
}
.btn-nav:hover { background: var(--blue-light); color: #fff !important; }

/* ── Hero ── */
.hero {
  position: relative;
  height: 100vh;
  min-height: 640px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: var(--hero-bg);
  background-size: cover;
  background-position: center;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom,
    rgba(2,14,26,.80) 0%,
    rgba(10,61,107,.45) 50%,
    rgba(2,14,26,.90) 100%);
}
.hero-molecules {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}
.hero-molecules svg { width: 100%; height: 100%; }
.hero-content {
  position: relative;
  z-index: 10;
  text-align: center;
  padding: 0 1.5rem;
  max-width: 820px;
  width: 100%;
}
.hero-badge {
  display: inline-block;
  margin-bottom: 1.5rem;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--blue-main);
  border: 1px solid rgba(41,182,246,.38);
  padding: 0.375rem 1.25rem;
  border-radius: 9999px;
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 600;
  line-height: 1.15;
  color: #fff;
  margin-bottom: 0.75rem;
}
.hero-title span { color: var(--blue-main); }
.hero-subtitle {
  font-size: 1.1rem;
  font-weight: 300;
  letter-spacing: 0.25em;
  color: var(--blue-light);
  margin-bottom: 2rem;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: .625rem 1.5rem;
  color: rgba(255,255,255,.75);
  font-size: .9rem;
  margin-bottom: 2.5rem;
}
.hero-meta-item { display: flex; align-items: center; gap: .5rem; }
.hero-meta-item svg { color: var(--blue-main); flex-shrink: 0; }
.hero-sep { color: rgba(41,182,246,.3); }
.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: var(--blue-main);
  color: #020E1A;
  font-weight: 700;
  font-size: .9375rem;
  padding: .875rem 2rem;
  border-radius: 9999px;
  transition: background .3s, box-shadow .3s;
}
.btn-primary:hover {
  background: var(--blue-light);
  box-shadow: 0 0 28px rgba(41,182,246,.4), 0 0 56px rgba(41,182,246,.15);
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  border: 1px solid rgba(41,182,246,.45);
  color: var(--blue-light);
  font-weight: 500;
  font-size: .9375rem;
  padding: .875rem 2rem;
  border-radius: 9999px;
  transition: background .3s;
}
.btn-outline:hover { background: rgba(41,182,246,.1); }
.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .375rem;
  color: rgba(41,182,246,.55);
  font-size: .625rem;
  letter-spacing: .3em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color .2s;
}
.hero-scroll:hover { color: var(--blue-main); }
.hero-scroll svg { animation: bounce 2s ease-in-out infinite; }

/* ── Section commons ── */
.section { padding: 5rem 1.5rem; }
.section-inner { max-width: 920px; margin: 0 auto; }
.section-header { margin-bottom: 3.5rem; }
.section-eyebrow {
  font-size: .7rem;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--blue-main);
  margin-bottom: .5rem;
}
.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  color: #fff;
  margin-bottom: 1rem;
}
.section-divider {
  width: 48px;
  height: 2px;
  background: linear-gradient(90deg, var(--blue-main), transparent);
}

/* ── Overview ── */
.overview { background: rgba(6,29,51,.6); }
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}
.card {
  background: rgba(2,14,26,.6);
  border: 1px solid var(--border);
  border-radius: 1rem;
  padding: 1.75rem;
}
.card-header {
  display: flex;
  align-items: center;
  gap: .75rem;
  margin-bottom: 1.25rem;
}
.card-icon {
  width: 2rem; height: 2rem;
  background: rgba(21,101,192,.3);
  border-radius: .5rem;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  color: var(--blue-main);
}
.card-label {
  font-size: .7rem;
  letter-spacing: .25em;
  text-transform: uppercase;
  color: var(--blue-light);
  font-weight: 500;
}
.venue-name {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  color: #fff;
  margin-bottom: .25rem;
}
.venue-address, .venue-tel {
  font-size: 1rem;
  color: var(--text-muted);
}
.access-block {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(41,182,246,.12);
}
.access-eyebrow {
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--blue-main);
  margin-bottom: .75rem;
}
.access-item {
  display: flex;
  align-items: flex-start;
  gap: .625rem;
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: .5rem;
}
.access-item svg { color: var(--blue-main); flex-shrink: 0; margin-top: 3px; }
.fee-table { margin-top: .25rem; }
.fee-table thead th {
  font-size: .7rem;
  font-weight: 400;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: rgba(41,182,246,.58);
  padding-bottom: .75rem;
  text-align: center;
  border-bottom: 1px solid rgba(41,182,246,.18);
}
.fee-table thead th:first-child { text-align: left; }
.fee-table td {
  padding: .875rem 0;
  font-size: 1rem;
  color: var(--text-muted);
  text-align: center;
  border-bottom: 1px solid rgba(21,101,192,.1);
}
.fee-table td:first-child { text-align: left; color: rgba(225,245,254,.9); }
.fee-student { color: var(--blue-light) !important; font-weight: 500; }
.fee-general { color: #fff !important; font-weight: 500; }
.fee-note {
  margin-top: 1.25rem;
  font-size: .7rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ── Program ── */
.program-section { background: rgba(2,14,26,.4); }
.day-header {
  display: flex;
  align-items: baseline;
  gap: .75rem;
  margin-bottom: 1.5rem;
}
.day-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--blue-main);
}
.day-date { font-size: .875rem; color: var(--text-muted); }
.prog-items { display: flex; flex-direction: column; gap: .75rem; }
.session-card {
  background: rgba(2,14,26,.6);
  border: 1px solid rgba(41,182,246,.18);
  border-radius: .75rem;
  overflow: hidden;
}
.session-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .625rem 1rem;
  background: rgba(10,61,107,.2);
  border-bottom: 1px solid rgba(41,182,246,.13);
}
.session-name {
  font-size: .875rem;
  font-weight: 500;
  letter-spacing: .15em;
  color: var(--blue-main);
}
.session-chair { font-size: .875rem; color: var(--text-dim); }
.talk-item {
  display: flex;
  gap: .75rem;
  padding: .75rem 1rem;
  border-bottom: 1px solid rgba(21,101,192,.1);
}
.talk-item:last-child { border-bottom: none; }
.talk-time {
  font-size: .875rem;
  font-family: monospace;
  color: rgba(41,182,246,.7);
  margin-top: 2px;
  width: 3.25rem;
  flex-shrink: 0;
}
.talk-title { font-size: 1rem; font-weight: 500; color: rgba(255,255,255,.9); }
.talk-speaker { font-size: 1rem; color: var(--text-muted); margin-top: .2rem; }
.talk-empty {
  padding: 1rem;
  font-size: .8rem;
  font-style: italic;
  color: var(--text-dim);
}
.special-card {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .75rem 1rem;
  border-radius: .75rem;
  border: 1px solid;
  font-size: .9rem;
  font-weight: 500;
}
.special-note { margin-left: auto; font-size: .75rem; opacity: .6; }
.sp-break   { background:rgba(6,29,51,.5);   border-color:rgba(21,101,192,.15); color:rgba(129,212,250,.7); }
.sp-poster  { background:rgba(10,61,107,.2);  border-color:rgba(41,182,246,.28); color:var(--blue-light); }
.sp-banquet { background:rgba(21,101,192,.12);border-color:rgba(41,182,246,.28); color:var(--blue-light); }
.prog-note {
  margin-top: 2rem;
  text-align: center;
  font-size: .75rem;
  color: var(--text-dim);
}

/* ── Poster ── */
.poster-section { background: rgba(6,29,51,.6); }
.poster-datetime {
  margin-bottom: 1.5rem;
  font-size: .875rem;
  color: var(--text-muted);
}
.poster-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.poster-item {
  background: rgba(2,14,26,.6);
  border: 1px solid rgba(41,182,246,.18);
  border-radius: .75rem;
  padding: 1rem;
}
.poster-title { font-size: 1rem; font-weight: 500; color: rgba(255,255,255,.9); }
.poster-authors { font-size: .9rem; color: var(--text-muted); margin-top: .5rem; }
.poster-authors sup { color: var(--blue-main); font-size: .7em; }
.poster-affil { font-size: .8rem; color: var(--text-dim); margin-top: .35rem; }

/* ── Registration ── */
.registration {
  position: relative;
  padding: 6rem 1.5rem;
  overflow: hidden;
  background: linear-gradient(135deg, #061D33 0%, #0A3D6B 50%, #061D33 100%);
}
.reg-deco {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .07;
}
.reg-content {
  position: relative;
  z-index: 1;
  max-width: 680px;
  margin: 0 auto;
  text-align: center;
}
.reg-icon {
  width: 4rem; height: 4rem;
  margin: 0 auto 2rem;
  background: rgba(41,182,246,.12);
  border: 1px solid rgba(41,182,246,.28);
  border-radius: 1rem;
  display: flex; align-items: center; justify-content: center;
  color: var(--blue-main);
}
.divider-center { margin: 1rem auto; }
.reg-desc {
  color: var(--text-muted);
  font-size: .975rem;
  line-height: 1.8;
  margin-bottom: 2.5rem;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}
.reg-pills {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  max-width: 540px;
  margin: 0 auto 2.5rem;
  text-align: left;
}
.reg-pill {
  background: rgba(2,14,26,.6);
  border: 1px solid rgba(41,182,246,.18);
  border-radius: .75rem;
  padding: .75rem 1rem;
}
.reg-pill-label {
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--blue-main);
  margin-bottom: .25rem;
}
.reg-pill-value { font-size: .875rem; color: var(--blue-light); }
.reg-note {
  margin-top: 1.25rem;
  font-size: .75rem;
  color: var(--text-dim);
}

/* ── Payment block ── */
.payment-block {
  max-width: 480px;
  margin: 0 auto 2.5rem;
  background: rgba(2,14,26,.6);
  border: 1px solid rgba(41,182,246,.22);
  border-radius: .75rem;
  padding: 1.25rem 1.5rem;
  text-align: left;
}
.payment-title {
  font-size: .75rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--blue-main);
  margin-bottom: .5rem;
  font-weight: 500;
}
.payment-desc {
  font-size: .9rem;
  color: var(--blue-light);
  margin-bottom: .875rem;
  line-height: 1.7;
}
.payment-row {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  padding: .375rem 0;
  border-bottom: 1px solid rgba(41,182,246,.1);
}
.payment-row:last-of-type { border-bottom: none; }
.payment-label {
  font-size: .75rem;
  color: var(--text-dim);
  width: 5rem;
  flex-shrink: 0;
}
.payment-value {
  font-size: .9rem;
  color: var(--text);
  font-family: monospace;
  letter-spacing: .05em;
}
.payment-note {
  margin-top: .875rem;
  font-size: .75rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ── Footer ── */
footer {
  background: #020E1A;
  border-top: 1px solid rgba(21,101,192,.2);
  padding: 2rem 1.5rem;
  text-align: center;
}
.footer-title {
  font-family: var(--font-display);
  font-size: .9rem;
  color: var(--blue-light);
  margin-bottom: .375rem;
}
.footer-past { margin: .5rem 0 .75rem; }
.footer-past-link {
  font-size: .8rem;
  color: var(--blue-light);
  opacity: .8;
  transition: opacity .2s;
}
.footer-past-link:hover { opacity: 1; }
.footer-copy { font-size: .75rem; color: var(--text-dim); }

/* ── Responsive ── */
@media (max-width: 768px) {
  nav { padding: 0 1rem; }
  .nav-links { display: none; }
  .two-col { grid-template-columns: 1fr; }
  .poster-grid { grid-template-columns: 1fr; }
  .reg-pills { grid-template-columns: 1fr; }
  .hero-sep { display: none; }
}