/* ===== Base ===== */
:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --bg-tint: #eef3f9;
  --line: #e3e8ef;
  --line-strong: #c9d3df;
  --ink: #1a2332;
  --ink-soft: #4a5568;
  --ink-mute: #7a8699;
  --accent: oklch(0.52 0.09 240);
  --accent-soft: oklch(0.92 0.04 240);
  --accent-ink: oklch(0.32 0.08 240);
  --warn: oklch(0.65 0.12 50);
  --radius: 4px;
  --maxw: 1080px;
  --pad: 24px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", YuGothic, "Meiryo", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  max-width: 100vw;
}

img { max-width: 100%; display: block; }
a { color: var(--accent-ink); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== Layout ===== */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--pad);
}

section {
  padding: 88px 0;
  border-top: 1px solid var(--line);
}
section:first-of-type { border-top: none; }

.section-head {
  margin-bottom: 48px;
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}
.section-num {
  font-family: "Cormorant Garamond", "Times New Roman", serif;
  font-size: 22px;
  font-weight: 400;
  color: var(--accent);
  letter-spacing: 0.05em;
}
.section-title-en {
  font-family: "Cormorant Garamond", "Times New Roman", serif;
  font-size: 40px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ink);
  margin: 0;
  line-height: 1.1;
  word-break: keep-all;
}
.section-title-jp {
  font-size: 14px;
  color: var(--ink-mute);
  letter-spacing: 0.15em;
  margin-left: 4px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.site-header .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px var(--pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.logo-mark {
  display: flex;
  align-items: center;
  gap: 12px;
}
.logo-icon {
  width: 32px;
  height: 32px;
  border: 1.5px solid var(--accent);
  border-radius: 50%;
  display: grid;
  place-items: center;
  color: var(--accent);
  font-family: "Cormorant Garamond", serif;
  font-size: 18px;
  font-weight: 500;
}
.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.logo-text .ja { font-size: 14px; font-weight: 600; color: var(--ink); letter-spacing: 0.05em; }
.logo-text .en { font-size: 10px; color: var(--ink-mute); letter-spacing: 0.2em; text-transform: uppercase; }

.nav { display: flex; gap: 28px; align-items: center; }
.nav a {
  font-size: 13px;
  color: var(--ink-soft);
  letter-spacing: 0.08em;
}
.nav a:hover { color: var(--accent); text-decoration: none; }
.nav .cta {
  background: var(--accent);
  color: #fff;
  padding: 9px 18px;
  border-radius: var(--radius);
  font-size: 13px;
  letter-spacing: 0.05em;
}
.nav .cta:hover { background: var(--accent-ink); text-decoration: none; }

@media (max-width: 720px) {
  .nav .nav-links { display: none; }
  :root { --pad: 16px; }
  .site-header .inner { gap: 12px; padding: 12px var(--pad); }
  .logo-text .ja { font-size: 12px; }
  .logo-text .en { font-size: 9px; letter-spacing: 0.15em; }
  .nav { gap: 12px; }
  .nav .cta { padding: 8px 14px; font-size: 12px; }
}

/* ===== Hero ===== */
.hero {
  padding: 96px 0 88px;
  border-top: none;
  position: relative;
  overflow: hidden;
}
.hero .grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}
.hero .eyebrow {
  font-family: "Cormorant Garamond", serif;
  color: var(--accent);
  font-size: 18px;
  letter-spacing: 0.15em;
  margin-bottom: 20px;
}
.hero h1 {
  font-size: 44px;
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: 0.02em;
  margin: 0 0 24px;
  color: var(--ink);
  text-wrap: pretty;
}
.hero h1 .accent { color: var(--accent); }
.hero p.lead {
  font-size: 16px;
  line-height: 2.0;
  color: var(--ink-soft);
  margin: 0 0 36px;
  max-width: 28em;
}
.hero .cta-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: var(--radius);
  font-size: 14px;
  letter-spacing: 0.08em;
  font-weight: 500;
  border: 1px solid transparent;
  transition: all 0.15s ease;
  cursor: pointer;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-ink); text-decoration: none; }
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn .arrow { transition: transform 0.15s; }
.btn:hover .arrow { transform: translateX(3px); }

.hero-visual {
  position: relative;
  aspect-ratio: 4 / 5;
  background: var(--bg-tint);
  border: 1px solid var(--line);
  border-radius: 2px;
  overflow: hidden;
}
.placeholder {
  width: 100%;
  height: 100%;
  background-image: repeating-linear-gradient(
    135deg,
    transparent 0,
    transparent 12px,
    rgba(26,35,50,0.04) 12px,
    rgba(26,35,50,0.04) 13px
  );
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
}
.placeholder .label {
  font-family: "JetBrains Mono", "Menlo", monospace;
  font-size: 11px;
  color: var(--ink-mute);
  background: rgba(255,255,255,0.92);
  padding: 6px 12px;
  letter-spacing: 0.05em;
  border: 1px solid var(--line);
}

@media (max-width: 820px) {
  .hero { padding: 56px 0; }
  .hero .grid { grid-template-columns: 1fr; gap: 40px; }
  .hero h1 { font-size: 30px; }
  .hero-visual { aspect-ratio: 3 / 2; }
}

/* ===== About ===== */
.about-text p {
  font-size: 16px;
  line-height: 2.1;
  color: var(--ink-soft);
  max-width: 38em;
  margin: 0 0 1.6em;
}
.values {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  margin-top: 56px;
  border: 1px solid var(--line);
}
.value-item {
  background: var(--bg);
  padding: 36px 28px;
}
.value-num {
  font-family: "Cormorant Garamond", serif;
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--accent);
  margin-bottom: 16px;
}
.value-title {
  font-size: 17px;
  font-weight: 600;
  margin: 0 0 12px;
  color: var(--ink);
  letter-spacing: 0.02em;
}
.value-desc {
  font-size: 14px;
  line-height: 1.9;
  color: var(--ink-soft);
  margin: 0;
}
@media (max-width: 720px) {
  .values { grid-template-columns: 1fr; }
}

/* ===== Activities ===== */
.activity-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 56px;
  margin-bottom: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--line);
}
.activity-grid:last-child { border-bottom: none; padding-bottom: 0; margin-bottom: 0; }
.activity-label {
  font-family: "Cormorant Garamond", serif;
  font-size: 22px;
  color: var(--accent);
  letter-spacing: 0.05em;
}
.activity-label small {
  display: block;
  font-family: inherit;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink-mute);
  margin-top: 6px;
  text-transform: uppercase;
}
.activity-body h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 16px;
  letter-spacing: 0.02em;
}
.activity-body p {
  font-size: 15px;
  line-height: 2.0;
  color: var(--ink-soft);
  margin: 0 0 0.8em;
}
.meta-list {
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
  display: grid;
  gap: 8px;
}
.meta-list li {
  display: grid;
  grid-template-columns: 110px 1fr;
  font-size: 14px;
  padding: 8px 0;
  border-top: 1px dashed var(--line);
}
.meta-list li:last-child { border-bottom: 1px dashed var(--line); }
.meta-list .key { color: var(--ink-mute); letter-spacing: 0.1em; font-size: 12px; padding-top: 2px; }
.meta-list .val { color: var(--ink); }

@media (max-width: 720px) {
  .activity-grid { grid-template-columns: 1fr; gap: 16px; }
  .meta-list li { grid-template-columns: 90px 1fr; }
}

/* ===== Next event ===== */
.next-event {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  padding: 48px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
}
.event-tag {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.2em;
  background: var(--accent);
  color: #fff;
  padding: 4px 10px;
  margin-bottom: 20px;
  text-transform: uppercase;
}
.event-date {
  font-family: "Cormorant Garamond", serif;
  font-size: 56px;
  font-weight: 400;
  line-height: 1;
  color: var(--ink);
  margin: 0 0 12px;
  letter-spacing: 0.02em;
}
.event-date small {
  font-family: "Noto Sans JP", sans-serif;
  font-size: 14px;
  color: var(--ink-mute);
  letter-spacing: 0.1em;
  margin-left: 8px;
}
.event-time {
  font-size: 14px;
  color: var(--ink-soft);
  letter-spacing: 0.05em;
  margin-bottom: 28px;
}
.event-theme {
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--ink-mute);
  text-transform: uppercase;
  margin-bottom: 8px;
}
.event-title {
  font-size: 22px;
  font-weight: 600;
  line-height: 1.6;
  margin: 0 0 16px;
}
.event-desc {
  font-size: 14px;
  line-height: 2.0;
  color: var(--ink-soft);
  margin: 0 0 24px;
}
.event-track {
  padding-left: 16px;
  border-left: 2px solid var(--accent-soft);
  margin-bottom: 20px;
}
.event-track .event-desc {
  margin: 0;
}
.event-track-title {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--accent);
  margin: 0 0 8px;
}
@media (max-width: 720px) {
  .next-event { grid-template-columns: 1fr; padding: 28px; gap: 28px; }
  .event-date { font-size: 42px; }
}

/* ===== Past topics ===== */
.topic-list {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--line);
}
.topic-row {
  display: grid;
  grid-template-columns: 100px 110px 1fr 80px;
  gap: 24px;
  padding: 22px 4px;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
  transition: background 0.15s;
}
.topic-row:hover { background: var(--bg-soft); }
.topic-num {
  font-family: "Cormorant Garamond", serif;
  font-size: 18px;
  color: var(--accent);
  letter-spacing: 0.05em;
}
.topic-date {
  font-size: 12px;
  color: var(--ink-mute);
  letter-spacing: 0.1em;
}
.topic-title {
  font-size: 15px;
  color: var(--ink);
  font-weight: 500;
}
.topic-tag {
  font-size: 11px;
  color: var(--ink-mute);
  border: 1px solid var(--line-strong);
  padding: 3px 8px;
  letter-spacing: 0.1em;
  justify-self: end;
  text-align: center;
}
@media (max-width: 720px) {
  .topic-row { grid-template-columns: 60px 1fr; }
  .topic-date, .topic-tag { display: none; }
}

/* ===== Organizers ===== */
.org-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}
.org-card {
  border: 1px solid var(--line);
  padding: 24px;
  background: var(--bg);
}
.org-photo {
  aspect-ratio: 1 / 1;
  background: var(--bg-tint);
  margin-bottom: 20px;
}
.org-name {
  font-size: 17px;
  font-weight: 600;
  margin: 0 0 4px;
}
.org-name-en {
  font-family: "Cormorant Garamond", serif;
  font-size: 13px;
  color: var(--ink-mute);
  letter-spacing: 0.1em;
  margin-bottom: 14px;
}
.org-affil {
  font-size: 12px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin: 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}
@media (max-width: 720px) {
  .org-grid { grid-template-columns: 1fr; }
  .org-grid[style*="repeat(2"] { grid-template-columns: 1fr !important; }
}

/* ===== Join ===== */
.join-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-bottom: 48px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.step {
  padding: 32px 24px;
  border-right: 1px solid var(--line);
  position: relative;
}
.step:last-child { border-right: none; }
.step-num {
  font-family: "Cormorant Garamond", serif;
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--accent);
  margin-bottom: 14px;
}
.step h4 {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 10px;
}
.step p {
  font-size: 13px;
  line-height: 1.9;
  color: var(--ink-soft);
  margin: 0;
}
@media (max-width: 720px) {
  .join-steps { grid-template-columns: 1fr; }
  .step { border-right: none; border-bottom: 1px solid var(--line); }
  .step:last-child { border-bottom: none; }
}

.cta-band {
  text-align: center;
  padding: 48px 24px;
  background: var(--bg-soft);
  border: 1px solid var(--line);
}
.cta-band p {
  font-size: 14px;
  color: var(--ink-soft);
  margin: 0 0 20px;
}

/* ===== FAQ ===== */
.faq-list { border-top: 1px solid var(--line); }
.faq-item {
  border-bottom: 1px solid var(--line);
  padding: 20px 4px;
}
.faq-q {
  display: grid;
  grid-template-columns: 32px 1fr 24px;
  gap: 12px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink);
  align-items: baseline;
  list-style: none;
}
.faq-q::-webkit-details-marker { display: none; }
.faq-q .q-mark {
  font-family: "Cormorant Garamond", serif;
  color: var(--accent);
  font-size: 18px;
}
.faq-q .toggle {
  color: var(--ink-mute);
  text-align: right;
  font-size: 16px;
  transition: transform 0.2s;
}
details[open] .faq-q .toggle { transform: rotate(45deg); }
.faq-a {
  display: grid;
  grid-template-columns: 32px 1fr 24px;
  gap: 12px;
  margin-top: 14px;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 2.0;
}
.faq-a .a-mark {
  font-family: "Cormorant Garamond", serif;
  color: var(--ink-mute);
  font-size: 18px;
}

/* ===== Footer ===== */
.site-footer {
  background: var(--ink);
  color: #c8d1de;
  padding: 64px 0 28px;
  margin-top: 0;
}
.site-footer .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--pad);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer-brand .logo-icon { border-color: #fff; color: #fff; }
.footer-brand .ja { color: #fff; }
.footer-brand .en { color: #8a99b0; }
.footer-brand p {
  font-size: 12px;
  color: #8a99b0;
  line-height: 1.9;
  margin: 20px 0 0;
}
.footer-col h5 {
  font-family: "Cormorant Garamond", serif;
  font-size: 13px;
  font-weight: 400;
  letter-spacing: 0.2em;
  color: #fff;
  margin: 0 0 18px;
  text-transform: uppercase;
}
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { color: #c8d1de; font-size: 13px; }
.footer-col a:hover { color: #fff; text-decoration: none; }
.footer-bot {
  border-top: 1px solid #2a3548;
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: #6a778c;
  letter-spacing: 0.1em;
  flex-wrap: wrap;
  gap: 12px;
}
@media (max-width: 720px) {
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
}

/* ===== Utility ===== */
.muted { color: var(--ink-mute); }
.divider {
  width: 32px;
  height: 1px;
  background: var(--accent);
  margin: 0 0 20px;
}