/* ==========================================================================
   Behavior Change Biology Hackathon 2027 - Editorial Academic Style
   Designed to be thoughtful, precise, academic, and distinctly non-generic.
   ========================================================================== */

/* --- Custom Properties & Design Tokens --- */
:root {
  /* Palette: Warm Academic Paper & Deep Bio-Slate */
  --bg-main: #FAF9F6;
  --bg-surface: #FFFFFF;
  --bg-surface-elevated: #FFFFFF;
  --bg-subtle: #F3F4F1;
  --bg-subtle-hover: #EBECE8;
  --bg-dark: #121824;
  --bg-dark-surface: #1B2333;

  --border-light: #E5E7EB;
  --border-medium: #D1D5DB;
  --border-dark: rgba(255, 255, 255, 0.12);

  --text-main: #1A202C;
  --text-muted: #5A6A80;
  --text-light: #8A99AD;
  --text-inverse: #F8FAFC;
  --text-inverse-muted: #94A3B8;

  --accent-primary: #1E3A8A; /* Academic Deep Royal */
  --accent-teal: #0D9488;    /* Biological Neural Teal */
  --accent-sage: #059669;    /* Bioscience Green */
  --accent-amber: #B45309;   /* Editorial Accent Warmth */
  --accent-light-blue: #EFF6FF;
  --accent-light-teal: #F0FDFA;

  /* Typography */
  --font-sans: 'Outfit', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Shippori Mincho', 'Noto Serif JP', serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Spacing */
  --section-pad: clamp(4rem, 7vw, 6.5rem);
  --container-max: 1200px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);

  /* Elevation */
  --shadow-subtle: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
  --shadow-card: 0 4px 20px -2px rgba(27, 35, 51, 0.05), 0 2px 6px -1px rgba(27, 35, 51, 0.03);
  --shadow-hover: 0 12px 28px -4px rgba(27, 35, 51, 0.08), 0 4px 10px -2px rgba(27, 35, 51, 0.04);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
  background-color: var(--bg-main);
  color: var(--text-main);
}

body {
  font-family: var(--font-sans);
  line-height: 1.7;
  letter-spacing: 0.015em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--bg-main);
  color: var(--text-main);
  overflow-x: hidden;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

button {
  cursor: pointer;
  font-family: inherit;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* --- Utility / Container --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1.25rem, 4vw, 2.5rem);
  padding-right: clamp(1.25rem, 4vw, 2.5rem);
}

.section {
  padding-top: var(--section-pad);
  padding-bottom: var(--section-pad);
  position: relative;
}

.section-divider {
  height: 1px;
  background: var(--border-light);
  width: 100%;
}

/* Section Header: Editorial & Scholarly */
.section-head {
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-teal);
  margin-bottom: 0.75rem;
}

.section-tag::before {
  content: '';
  display: inline-block;
  width: 18px;
  height: 1.5px;
  background-color: currentColor;
}

.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.section-lead {
  font-size: clamp(1rem, 1.3vw, 1.125rem);
  color: var(--text-muted);
  max-width: 760px;
  line-height: 1.8;
}

/* --- Global Header & Navigation --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(250, 249, 246, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  transition: all var(--transition-smooth);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
  gap: 1.5rem;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo-icon {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  display: block;
}

.brand-acronym {
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: 1.625rem;
  color: #111827;
  letter-spacing: -0.03em;
  line-height: 1;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.2;
}

.brand-jp {
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  font-weight: 700;
  color: #111827;
  letter-spacing: -0.01em;
  transition: color var(--transition-fast);
}

.brand-wrapper:hover .brand-jp {
  color: var(--accent-primary);
}

.brand-en {
  font-family: var(--font-sans);
  font-size: 0.625rem;
  font-weight: 600;
  color: #64748B;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Nav Links */
.site-nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: #4B5563;
  position: relative;
  padding: 0.35rem 0.1rem;
  transition: color var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: #1E3A8A;
  font-weight: 600;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0%;
  height: 2.5px;
  background-color: #2563EB;
  border-radius: 2px;
  transition: width var(--transition-fast);
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

.btn-header-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: #387B7A;
  color: #FFFFFF;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.55rem 1.35rem;
  border-radius: 9999px;
  box-shadow: 0 2px 8px rgba(56, 123, 122, 0.2);
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  white-space: nowrap;
  flex-shrink: 0;
}

.btn-header-pill:hover {
  background-color: #2b6362;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(56, 123, 122, 0.3);
  color: #FFFFFF;
}

.btn-header-pill .arrow {
  transition: transform var(--transition-fast);
}

.btn-header-pill:hover .arrow {
  transform: translateX(3px);
}

.header-cta-group {
  display: flex;
  align-items: center;
  gap: 0.875rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 0.6875rem 1.375rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  text-align: center;
  line-height: 1.4;
  box-sizing: border-box;
}

.btn-cta-main {
  font-size: 1.0625rem;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-md);
  flex-wrap: wrap;
}

.btn-hero-cta {
  font-size: 0.9375rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  flex-wrap: wrap;
}

.btn-main-text {
  display: inline-block;
  white-space: nowrap;
}

.btn-sub-text {
  display: inline-block;
  white-space: nowrap;
  font-size: 0.9em;
  opacity: 0.95;
}

.btn-primary {
  background-color: var(--text-main);
  color: #FFF;
  border: 1px solid var(--text-main);
}

.btn-primary:hover {
  background-color: var(--accent-primary);
  border-color: var(--accent-primary);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(27, 35, 51, 0.15);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-main);
  border: 1px solid var(--border-medium);
}

.btn-outline:hover {
  background-color: var(--bg-surface);
  border-color: var(--text-main);
}

.btn-teal {
  background-color: var(--accent-teal);
  color: #FFF;
  border: 1px solid var(--accent-teal);
}

.btn-teal:hover {
  background-color: #0b7a70;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.25);
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 0;
  z-index: 101;
}

.mobile-nav-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--text-main);
  transition: all var(--transition-fast);
}

/* --- Hero Section --- */
.hero {
  position: relative;
  overflow: hidden;
  background-color: #FFFFFF;
  background-image: radial-gradient(circle at 75% 35%, rgba(220, 240, 255, 0.45) 0%, rgba(240, 249, 255, 0.2) 45%, #FFFFFF 85%);
  padding-top: clamp(2.5rem, 5vw, 4.5rem);
  padding-bottom: clamp(3.25rem, 6vw, 5.25rem);
  border-bottom: 1px solid var(--border-light);
}

.hero-particles-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
  opacity: 0.7;
}

/* Ambient Watermarks */
.hero-watermark {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: #94A3B8;
  opacity: 0.45;
  line-height: 1.55;
  pointer-events: none;
  z-index: 1;
  display: flex;
  flex-direction: column;
}

.hero-watermark-left {
  bottom: 1.75rem;
  left: clamp(1.25rem, 4vw, 3rem);
}

.hero-watermark-right {
  bottom: 1.75rem;
  right: clamp(1.25rem, 4vw, 3rem);
  text-align: right;
}

.hero-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: clamp(2rem, 4vw, 3.5rem);
  align-items: center;
}

.hero-left {
  display: flex;
  flex-direction: column;
}

.hero-kicker {
  font-size: 0.9375rem;
  font-weight: 600;
  color: #4A6B82;
  letter-spacing: 0.08em;
  margin-bottom: 0.875rem;
}

.hero-heading {
  font-size: clamp(2.2rem, 3.6vw, 3.1rem);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.018em;
  color: #0F172A;
  margin-bottom: 1.25rem;
  word-break: keep-all;
}

.hero-heading-line {
  display: block;
}

.hero-year-teal {
  color: #387B7A;
  font-weight: 800;
}

.hero-subhead {
  font-size: clamp(1rem, 1.3vw, 1.125rem);
  font-weight: 500;
  line-height: 1.75;
  color: #1E293B;
  margin-bottom: 1.75rem;
  max-width: 600px;
}

.hero-meta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.875rem 1.625rem;
  margin-bottom: 2rem;
}

.hero-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: #1E293B;
  white-space: nowrap;
}

.hero-meta-icon {
  color: #1E3A8A;
  flex-shrink: 0;
}

.hero-cta-wrap {
  display: flex;
  align-items: center;
  gap: 1.125rem;
  flex-wrap: wrap;
}

.hero-deadline {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.9375rem;
  font-weight: 500;
  color: #334155;
  background-color: #FFFFFF;
  border: 1px solid #CBD5E1;
  padding: 0.55rem 1.05rem;
  border-radius: 9999px;
  box-shadow: 0 1px 4px rgba(15, 23, 42, 0.05);
  line-height: 1;
}

.hero-deadline-icon {
  color: #B45309;
  flex-shrink: 0;
}

.hero-deadline-text {
  display: inline-flex;
  align-items: center;
  gap: 0.15rem;
}

.hero-deadline-date {
  font-family: var(--font-mono);
  font-weight: 700;
  color: #0F172A;
  letter-spacing: 0.01em;
}

.btn-hero-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.625rem;
  background-color: #387B7A;
  color: #FFFFFF;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  padding: 0.8125rem 2.25rem;
  border-radius: 9999px;
  box-shadow: 0 4px 14px rgba(56, 123, 122, 0.28);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn-hero-pill:hover {
  background-color: #2b6362;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 123, 122, 0.38);
  color: #FFFFFF;
}

.btn-hero-pill .arrow {
  transition: transform var(--transition-fast);
  font-size: 1.15em;
  line-height: 1;
}

.btn-hero-pill:hover .arrow {
  transform: translateX(4px);
}

/* Hero Right: Key Visual Card */
.hero-right {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.hero-visual-card-wrap {
  width: 100%;
  max-width: 580px;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: 0 16px 40px -8px rgba(15, 23, 42, 0.1), 0 4px 14px -2px rgba(15, 23, 42, 0.04);
  border: 1px solid rgba(226, 232, 240, 0.95);
  background-color: #FFFFFF;
  cursor: pointer;
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth);
}

.hero-visual-card-wrap:hover {
  transform: translateY(-3px);
  box-shadow: 0 22px 48px -6px rgba(15, 23, 42, 0.15), 0 8px 18px -2px rgba(15, 23, 42, 0.06);
}

.hero-visual-card-img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.hero-visual-card-wrap:hover .hero-visual-card-img {
  transform: scale(1.015);
}

/* --- Section: About & Mission --- */
.about-header-divider {
  border-bottom: 1px solid #E2E8F0;
  margin-bottom: clamp(2rem, 4vw, 3rem);
  padding-bottom: 1.25rem;
}

.about-section-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: #387B7A;
  text-transform: uppercase;
  margin-bottom: 0.65rem;
}

.about-section-title {
  font-size: clamp(2rem, 3.4vw, 2.5rem);
  font-weight: 800;
  color: #0F172A;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin: 0;
}

.about-grid {
  display: grid;
  grid-template-columns: 1.45fr 1fr;
  gap: clamp(2.5rem, 5vw, 4.5rem);
  align-items: flex-start;
}

.about-prose-column {
  display: flex;
  flex-direction: column;
}

.about-prose-body {
  font-size: 1.0625rem;
  line-height: 1.95;
  color: #334155;
}

.about-prose-body p {
  margin-bottom: 1.85rem;
}

.about-prose-body p:last-child {
  margin-bottom: 0;
}

.about-prose-body strong {
  font-weight: 700;
  color: #0F172A;
}

.about-organizer-block {
  margin-top: 2.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid #E2E8F0;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.about-organizer-item {
  display: flex;
  flex-direction: column;
}

.about-organizer-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: #64748B;
  margin-bottom: 0.35rem;
}

.about-organizer-name {
  font-size: 1rem;
  font-weight: 700;
  color: #0F172A;
  line-height: 1.5;
}

.about-organizer-link {
  color: inherit;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color var(--transition-fast);
}

.about-organizer-link:hover {
  color: var(--accent-teal);
}

.about-organizer-link .external-icon-sm {
  flex-shrink: 0;
  stroke: var(--accent-teal);
}

/* Right Column: Overview Card */
.about-overview-card {
  background-color: #F1F5F7;
  border-top: 4px solid #387B7A;
  border-radius: 4px 4px 8px 8px;
  padding: clamp(1.75rem, 3.5vw, 2.5rem) clamp(1.5rem, 3vw, 2.25rem);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
}

.overview-card-title {
  font-size: 1.375rem;
  font-weight: 800;
  color: #0F172A;
  margin-bottom: 1.75rem;
  letter-spacing: -0.01em;
}

.overview-items-list {
  display: flex;
  flex-direction: column;
}

.overview-item {
  border-bottom: 1px solid #DCE3E8;
  padding-bottom: 1.15rem;
  margin-bottom: 1.15rem;
}

.overview-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
  margin-bottom: 0;
}

.overview-item-label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: #64748B;
  margin-bottom: 0.35rem;
  letter-spacing: 0.02em;
}

.overview-item-value {
  font-size: 1.0625rem;
  font-weight: 700;
  color: #0F172A;
  line-height: 1.45;
}

.overview-item-sub {
  font-size: 0.9375rem;
  font-weight: 500;
  color: #334155;
  margin-top: 0.25rem;
  line-height: 1.4;
}

.overview-item-sub.fee-note {
  font-size: 0.875rem;
  color: #64748B;
  font-weight: 500;
  margin-top: 0.35rem;
}


.quote-box {
  margin-top: 2.5rem;
  padding: 1.5rem 1.75rem;
  background-color: var(--bg-subtle);
  border-left: 3px solid var(--text-main);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.quote-box p {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.9375rem;
  color: var(--text-main);
  line-height: 1.7;
}

/* --- Hackathon Activities & Analytical Themes Block --- */
.activities-block {
  margin-top: clamp(3.5rem, 6vw, 5rem);
  padding-top: clamp(2.5rem, 5vw, 3.5rem);
  border-top: 1px solid var(--border-light);
}

.activities-header-divider {
  border-bottom: 1px solid #E2E8F0;
  margin-bottom: clamp(1.75rem, 3.5vw, 2.5rem);
  padding-bottom: 1.25rem;
}

.activities-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: #387B7A;
  text-transform: uppercase;
  margin-bottom: 0.65rem;
}

.activities-title {
  font-size: clamp(2rem, 3.4vw, 2.5rem);
  font-weight: 800;
  color: #0F172A;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin: 0;
}

.activities-intro {
  font-size: 1.03125rem;
  line-height: 1.9;
  color: #334155;
  margin-bottom: 2.25rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid #E2E8F0;
}

.activities-intro p {
  margin: 0;
  letter-spacing: 0.01em;
}

.activities-intro-link {
  color: #387B7A;
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition-fast);
}

.activities-intro-link:hover {
  color: #245857;
}

/* Steps List (Mockup Layout Reproduction) */
.activities-steps-list {
  position: relative;
  display: flex;
  flex-direction: column;
  background-color: #FFFFFF;
  border-radius: 18px;
  border: 1px solid #E2E8F0;
  box-shadow: 0 4px 24px -4px rgba(15, 23, 42, 0.05);
  overflow: hidden;
}

.activity-step-row {
  display: flex;
  align-items: center;
  border-bottom: 1px solid #EEF2F6;
  padding: clamp(1.5rem, 2.8vw, 2.25rem) clamp(1.5rem, 3vw, 2.5rem);
  transition: background-color var(--transition-fast);
  position: relative;
}

.activity-step-row:last-child {
  border-bottom: none;
}

.activity-step-row:hover {
  background-color: #FAFCFD;
}

/* Left block: Illustration + Step Headings */
.activity-step-left {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2vw, 1.5rem);
  width: clamp(260px, 32vw, 320px);
  flex-shrink: 0;
  padding-left: 0;
}

.activity-step-ill-wrap {
  width: 120px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.activity-step-ill {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  display: block;
  filter: drop-shadow(0 2px 4px rgba(15, 23, 42, 0.04));
  transition: transform var(--transition-smooth);
}

.activity-step-row:hover .activity-step-ill {
  transform: translateY(-2px) scale(1.03);
}

.activity-step-heading {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.35rem;
  flex-shrink: 0;
}

.activity-step-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: #0F172A;
  margin: 0;
  line-height: 1.25;
  letter-spacing: -0.015em;
}

.activity-step-sub {
  display: block;
  font-size: 0.875rem;
  font-weight: 700;
  color: #387B7A;
  margin: 0;
  line-height: 1.3;
  letter-spacing: 0.01em;
}

/* Subtle vertical divider */
.activity-step-divider {
  width: 1px;
  height: 58px;
  background-color: #E2E8F0;
  margin: 0 clamp(1rem, 2vw, 1.75rem);
  flex-shrink: 0;
  align-self: center;
}

/* Right block: Description paragraph */
.activity-step-content {
  flex: 1;
  display: flex;
  align-items: center;
}

.activity-step-content p {
  font-size: 0.96875rem;
  line-height: 1.9;
  color: #334155;
  margin: 0;
  letter-spacing: 0.01em;
}

.activity-step-content strong {
  font-weight: 700;
  color: #0F172A;
}

/* Welcome Box */
.activities-welcome-box {
  background-color: #F1F7F6;
  border-left: 4px solid #387B7A;
  padding: 1.25rem 1.75rem;
  margin-top: 2.25rem;
  border-radius: 0 4px 4px 0;
}

.activities-welcome-box p {
  font-size: 1rem;
  color: #1E293B;
  font-weight: 500;
  line-height: 1.75;
  margin: 0;
}

/* --- Past Event Highlights Showcase --- */
.past-event-block {
  margin-top: 4.5rem;
  padding-top: 3.5rem;
  border-top: 1px solid var(--border-light);
}

.past-event-head {
  max-width: 680px;
  margin-bottom: 2rem;
}

.past-event-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.01em;
  margin-bottom: 0.6rem;
}

.past-event-subtitle {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.past-event-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.25rem, 2.5vw, 1.75rem);
  align-items: stretch;
}

.past-photo-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.past-photo-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-medium);
}

.past-photo-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 11;
  overflow: hidden;
  cursor: pointer;
  background: #0F172A;
}

.past-photo-card-group .past-photo-wrap {
  aspect-ratio: 16 / 11;
}

.past-photo-img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.past-photo-wrap:hover .past-photo-img {
  transform: scale(1.03);
}

.past-photo-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 65%, rgba(15, 23, 42, 0.35) 100%);
  pointer-events: none;
}

.past-photo-tag {
  position: absolute;
  bottom: 0.75rem;
  left: 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: #FFFFFF;
  background: rgba(15, 23, 42, 0.78);
  backdrop-filter: blur(4px);
  padding: 0.25rem 0.65rem;
  border-radius: 4px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  z-index: 2;
}

.past-photo-info {
  padding: 1rem 1.25rem 1.15rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.past-photo-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 0;
  line-height: 1.45;
}

/* --- Section: Data & Tech Tools --- */
.tech-section {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.75rem;
}

.tech-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem 2rem 2rem;
  position: relative;
  transition: all var(--transition-smooth);
  display: flex;
  flex-direction: column;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
}

.tech-card:hover {
  border-color: rgba(13, 148, 136, 0.4);
  box-shadow: 0 12px 28px -4px rgba(27, 35, 51, 0.08), 0 4px 12px -2px rgba(13, 148, 136, 0.08);
  transform: translateY(-3px);
}

.tech-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-teal);
  background-color: rgba(13, 148, 136, 0.08);
  border: 1px solid rgba(13, 148, 136, 0.2);
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
  width: fit-content;
  margin-bottom: 1.125rem;
}

.tech-name {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 0.875rem;
  letter-spacing: -0.01em;
}

.tech-sub {
  font-size: 0.84375rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.tech-desc {
  font-size: 0.9375rem;
  color: #374151;
  line-height: 1.75;
  margin-bottom: 1.75rem;
}

.tech-action {
  margin-top: auto;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-light);
}

.tech-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0.875rem 1.25rem;
  background-color: var(--bg-main);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-size: 0.9375rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  text-decoration: none;
  box-sizing: border-box;
}

.tech-btn-text {
  letter-spacing: 0.01em;
}

.tech-btn-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background-color: rgba(13, 148, 136, 0.1);
  color: var(--accent-teal);
  font-size: 0.9375rem;
  font-weight: 700;
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

.tech-btn:hover {
  background-color: var(--accent-teal);
  border-color: var(--accent-teal);
  color: #FFF;
  box-shadow: 0 4px 14px rgba(13, 148, 136, 0.25);
  transform: translateY(-1px);
}

.tech-btn:hover .tech-btn-arrow {
  background-color: rgba(255, 255, 255, 0.25);
  color: #FFF;
  transform: translate(2px, -2px);
}

/* --- Section: Schedule / Timetable (Visual Header Cards Stack) --- */
.section-lead-catch {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--accent-teal);
  margin-top: 0.5rem;
  margin-bottom: 0.35rem;
  letter-spacing: -0.01em;
}

.section-lead-sub {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.sched-cards-stack {
  max-width: 880px;
  margin: 2.75rem auto 0;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.sched-card {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 24px;
  box-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.02);
  overflow: hidden;
  position: relative;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.sched-card:hover {
  box-shadow: 0 12px 32px -4px rgba(13, 148, 136, 0.1), 0 4px 12px -2px rgba(15, 23, 42, 0.04);
}

/* Card Header with Photo & Accent Ribbon */
.sched-card-header {
  position: relative;
  min-height: 180px;
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  background: linear-gradient(135deg, #F8FAFC 0%, #F0FDFA 60%, #E6FFFA 100%);
  border-bottom: 1px solid #E2E8F0;
  overflow: hidden;
}

/* Diagonal Accent Ribbon */
.sched-ribbon {
  position: absolute;
  top: 0;
  left: 0;
  width: 90px;
  height: 90px;
  overflow: hidden;
  pointer-events: none;
  z-index: 3;
}

.sched-ribbon::before {
  content: '';
  position: absolute;
  top: 14px;
  left: -32px;
  width: 120px;
  height: 6px;
  background: linear-gradient(90deg, #0D9488 0%, #14B8A6 100%);
  transform: rotate(-45deg);
  box-shadow: 0 2px 6px rgba(13, 148, 136, 0.3);
}

.sched-header-left {
  position: relative;
  z-index: 2;
  padding: 2.25rem 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.75rem;
  max-width: 58%;
}

.sched-badge-prep {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 800;
  color: #0F766E;
  background: #CCFBF1;
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  letter-spacing: 0.06em;
  width: fit-content;
}

.sched-card-name {
  font-size: 1.85rem;
  font-weight: 800;
  color: #0F172A;
  margin: 0;
  letter-spacing: -0.02em;
}

.sched-day-callout {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
}

.sched-day-callout .day-word {
  font-family: var(--font-sans);
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  color: #0D9488;
}

.sched-day-callout .day-digit {
  font-family: var(--font-sans);
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1;
  color: #0F766E;
}

.sched-header-meta {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  margin-top: 0.25rem;
}

.sched-meta-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: #475569;
}

.sched-meta-svg {
  width: 16px;
  height: 16px;
  color: #0D9488;
  flex-shrink: 0;
}

/* Header Visual (Photo & Script Text) */
.sched-header-visual {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 52%;
  overflow: hidden;
  pointer-events: none;
  z-index: 1;
}

.sched-header-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 18%;
  mask-image: linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.25) 20%, rgba(0, 0, 0, 1) 55%);
  -webkit-mask-image: linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.25) 20%, rgba(0, 0, 0, 1) 55%);
}

.sched-script-text {
  position: absolute;
  bottom: 1.25rem;
  right: 1.75rem;
  font-family: 'Caveat', cursive, sans-serif;
  font-size: 1.85rem;
  font-weight: 700;
  color: #FFFFFF;
  text-shadow: 0 2px 10px rgba(15, 23, 42, 0.75), 0 1px 3px rgba(15, 23, 42, 0.95);
  transform: rotate(-5deg);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

/* Timeline Body */
.sched-timeline {
  padding: 2.5rem 2.75rem 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
}

/* タイムラインを貫く一本の美しい直線（コンテナ基準で1pxの狂いもなく完全一直線） */
.sched-timeline::before {
  content: '';
  position: absolute;
  left: calc(2.75rem + 15px); /* パディング 2.75rem + .sched-axisの幅30pxの半分 */
  top: 3.25rem; /* 最初のドットの中心 */
  bottom: 3.75rem; /* 最後のドットの中心 */
  width: 2px;
  background-color: #E2E8F0;
  z-index: 1;
}

.sched-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  position: relative;
}

/* 軸カラム（幅30pxでドットを完全センタリング） */
.sched-axis {
  width: 30px;
  flex-shrink: 0;
  display: flex;
  justify-content: center;
  padding-top: 4px; /* 時間ラベルのテキスト行の中心と完全一致 */
  position: relative;
  z-index: 2;
}

.sched-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #FFFFFF;
  border: 3px solid #0D9488;
  box-shadow: 0 0 0 2px rgba(13, 148, 136, 0.15);
}

.sched-dot.dot-party {
  border-color: #E11D48;
  box-shadow: 0 0 0 2px rgba(225, 29, 72, 0.15);
}

.sched-dot.dot-seminar {
  border-color: #D97706;
  box-shadow: 0 0 0 2px rgba(217, 119, 6, 0.15);
}

.sched-dot.dot-presentation {
  border-color: #0D9488;
  box-shadow: 0 0 0 2px rgba(13, 148, 136, 0.18);
}

.sched-dot.dot-break {
  border-color: #94A3B8;
  box-shadow: none;
  width: 10px;
  height: 10px;
}

/* 右側コンテンツエリア */
.sched-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.sched-time-row {
  display: flex;
  align-items: center;
  line-height: 1.4;
}

.sched-time-label {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  color: #1E293B;
  letter-spacing: 0.02em;
}

.sched-time-label.text-party {
  color: #9F1239;
}

.sched-time-label.text-seminar {
  color: #92400E;
}

.sched-time-label.text-presentation {
  color: #115E59;
}

/* イベントカード */
.sched-event-card {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 0.35rem 0.5rem;
  border-radius: 12px;
  background: transparent;
  transition: background-color 0.2s ease;
}

.sched-icon-badge {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: #F0FDFA;
  color: #0D9488;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border: 1px solid #CCFBF1;
  box-shadow: 0 1px 3px rgba(13, 148, 136, 0.08);
}

.sched-icon-badge svg {
  width: 18px;
  height: 18px;
}

.sched-event-body {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.sched-event-title {
  font-size: 0.975rem;
  font-weight: 700;
  color: #0F172A;
  line-height: 1.4;
  margin: 0;
}

.sched-speaker-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: #0D9488;
  background: #F0FDFA;
  padding: 0.15rem 0.55rem;
  border-radius: 4px;
  border: 1px solid #CCFBF1;
  width: fit-content;
  text-decoration: none;
}

a.sched-speaker-tag {
  cursor: pointer;
  transition: all var(--transition-fast, 0.2s ease);
}

a.sched-speaker-tag:hover {
  background: #CCFBF1;
  border-color: #99F6E4;
  color: #0F766E;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.sched-speaker-link-icon {
  width: 0.75rem;
  height: 0.75rem;
  stroke: currentColor;
  flex-shrink: 0;
  opacity: 0.85;
}


.sched-event-desc {
  font-size: 0.84rem;
  color: #64748B;
  line-height: 1.55;
  margin: 0;
}

/* Break Row */
.badge-break {
  background: #F1F5F9;
  border-color: #E2E8F0;
  color: #64748B;
}

/* Highlight Cards（懇親会、セミナー昼食会、ハッカソン発表会） */
.sched-event-card.card-party {
  background: linear-gradient(135deg, #FFF1F2 0%, #FFE4E6 100%);
  border: 1px solid #FECDD3;
  padding: 0.85rem 1.15rem;
}

.badge-party {
  background: #FFE4E6;
  border-color: #FECDD3;
  color: #E11D48;
}

.title-party {
  color: #9F1239;
}

.desc-party {
  color: #881337;
}

.sched-event-card.card-seminar {
  background: linear-gradient(135deg, #FFFBEB 0%, #FEF3C7 100%);
  border: 1px solid #FDE68A;
  padding: 0.85rem 1.15rem;
}

.badge-seminar {
  background: #FEF3C7;
  border-color: #FDE68A;
  color: #D97706;
}

.title-seminar {
  color: #92400E;
}

.desc-seminar {
  color: #78350F;
}

.sched-event-card.card-presentation {
  background: linear-gradient(135deg, #F0FDFA 0%, #CCFBF1 100%);
  border: 1px solid #99F6E4;
  padding: 0.85rem 1.15rem;
}

.badge-presentation {
  background: #CCFBF1;
  border-color: #99F6E4;
  color: #0F766E;
}

.title-presentation {
  color: #115E59;
}

.desc-presentation {
  color: #134E4A;
}

/* --- Section: Application / Guidelines --- */
.guide-header-divider {
  border-bottom: 1px solid #E2E8F0;
  margin-bottom: clamp(2rem, 4vw, 3rem);
  padding-bottom: 1.25rem;
}

.guide-section-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: #387B7A;
  text-transform: uppercase;
  margin-bottom: 0.65rem;
}

.guide-section-title {
  font-size: clamp(2rem, 3.4vw, 2.5rem);
  font-weight: 800;
  color: #0F172A;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin: 0;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(1.25rem, 2.5vw, 1.75rem);
  align-items: stretch;
}

.guide-card {
  background-color: #FFFFFF;
  border: 1px solid #E2E8F0;
  border-radius: 8px;
  padding: clamp(1.75rem, 2.8vw, 2.25rem) clamp(1.5rem, 2.5vw, 2rem);
  display: flex;
  flex-direction: column;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.guide-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px -4px rgba(15, 23, 42, 0.06);
  border-color: #CBD5E1;
}

.guide-card-visual {
  width: 100%;
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.guide-card-img {
  max-width: 175px;
  max-height: 95px;
  width: auto;
  height: auto;
  object-fit: contain;
  display: block;
  margin: 0 auto;
}

.guide-card-body {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.guide-card-title {
  font-size: 1.45rem;
  font-weight: 800;
  color: #0F172A;
  margin-bottom: 1.15rem;
  letter-spacing: -0.01em;
}

.guide-card-text {
  font-size: 0.95rem;
  color: #334155;
  line-height: 1.85;
  margin-bottom: 1.25rem;
}

.guide-os-note {
  font-size: 0.875rem;
  color: #475569;
  margin-top: -0.5rem;
  margin-bottom: 1.25rem;
}

.guide-meta-footer {
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid #E2E8F0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.guide-meta-row {
  display: flex;
  align-items: center;
  font-size: 0.90625rem;
  font-weight: 700;
  color: #387B7A;
  line-height: 1.5;
}

.guide-slash {
  color: #94A3B8;
  font-weight: 400;
  margin: 0 0.5rem;
}

/* 参加費・実費 リスト */
.guide-fee-list {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
  margin-bottom: 1.5rem;
}

.guide-fee-row {
  display: flex;
  align-items: flex-start;
  gap: 1.15rem;
}

.guide-fee-label {
  font-size: 0.9375rem;
  font-weight: 700;
  color: #0F172A;
  min-width: 60px;
  flex-shrink: 0;
  padding-top: 0.15rem;
}

.guide-fee-val-block {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.guide-badge-free {
  display: inline-block;
  background-color: #E6F4EA;
  color: #137333;
  font-weight: 700;
  font-size: 0.8125rem;
  padding: 0.2rem 0.65rem;
  border-radius: 4px;
}

.guide-fee-amount {
  font-size: 1.125rem;
  font-weight: 800;
  color: #0F172A;
  line-height: 1.2;
}

.guide-fee-sub {
  font-size: 0.775rem;
  color: #64748B;
  margin-top: 0.35rem;
  line-height: 1.5;
}

.guide-subnote {
  margin-top: auto;
  font-size: 0.775rem;
  color: #64748B;
  line-height: 1.6;
}



.financial-callout {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  background-color: var(--accent-light-blue);
  border: 1px solid #BFDBFE;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.financial-callout-icon {
  color: var(--accent-primary);
  flex-shrink: 0;
  margin-top: 2px;
}

.financial-callout-text {
  font-size: 0.875rem;
  color: #1E3A8A;
  line-height: 1.65;
}

/* --- Section: Venue & Access --- */
.venue-section {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.venue-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: stretch;
}

.venue-details {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.venue-name {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.venue-room {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--accent-teal);
  margin-bottom: 1.25rem;
}

.venue-address {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.access-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
}

.access-item {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: var(--text-main);
}

.access-line {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.125rem 0.5rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-light);
  color: var(--text-muted);
  white-space: nowrap;
}

.venue-card-visual {
  background-color: var(--bg-main);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.visual-map-placeholder {
  height: 240px;
  background: linear-gradient(135deg, #EEF2F6 0%, #E2E8F0 100%);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}

.visual-map-placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(var(--border-medium) 1px, transparent 1px);
  background-size: 20px 20px;
  opacity: 0.5;
}

.pin-badge {
  position: relative;
  z-index: 2;
  background-color: var(--text-main);
  color: #FFF;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  font-size: 0.8125rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.venue-amenities {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.amenity-chip {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 0.625rem;
  text-align: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
}

/* --- Section: Committee & Organizers --- */
.committee-wrapper {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.host-banners {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.host-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.host-box:hover {
  border-color: var(--border-medium);
}

.host-role {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-teal);
  text-transform: uppercase;
  margin-bottom: 0.375rem;
}

.host-name {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
}

.host-link {
  color: inherit;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color var(--transition-fast);
}

.host-link:hover {
  color: var(--accent-teal);
}

.host-external-icon {
  flex-shrink: 0;
  stroke: var(--accent-teal);
  transition: transform var(--transition-fast);
}

.host-link:hover .host-external-icon {
  transform: translate(2px, -2px);
}

.host-logo-wrap {
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--border-light);
  display: flex;
  align-items: center;
}

.host-logo-link {
  display: inline-block;
  line-height: 0;
}

.host-logo-img {
  max-height: 38px;
  width: auto;
  object-fit: contain;
  opacity: 0.9;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.host-logo-img:hover {
  opacity: 1;
  transform: scale(1.02);
}

.members-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.25rem;
}

.member-card {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
}

.member-card:hover {
  border-color: var(--accent-teal);
  box-shadow: 0 4px 16px rgba(13, 148, 136, 0.08);
  transform: translateY(-2px);
}

.member-role {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--text-light);
  text-transform: uppercase;
  margin-bottom: 0.375rem;
}

.member-name {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.25rem;
  transition: color var(--transition-fast);
}

.member-card:hover .member-name {
  color: var(--accent-teal);
}

.member-affil {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.member-rm-footer {
  margin-top: 0.875rem;
  padding-top: 0.625rem;
  border-top: 1px dashed var(--border-light);
  display: flex;
  align-items: center;
}

.member-rm-badge {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--accent-teal);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: color var(--transition-fast);
}

.member-rm-icon {
  flex-shrink: 0;
  stroke: var(--accent-teal);
  transition: transform var(--transition-fast);
}

.member-card:hover .member-rm-icon {
  transform: translate(2px, -2px);
}

/* --- Contact Form Embed --- */
.contact-embed-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.04);
  scroll-margin-top: 90px;
}

.contact-embed-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 2rem;
}

.contact-embed-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--accent-teal);
  background-color: rgba(13, 148, 136, 0.08);
  border: 1px solid rgba(13, 148, 136, 0.2);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  display: inline-block;
  margin-bottom: 0.75rem;
}

.contact-embed-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.contact-embed-desc {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.contact-embed-external {
  font-size: 0.875rem;
}

.contact-iframe-wrap {
  max-width: 720px;
  margin: 0 auto;
  background-color: #FFFFFF;
  border-radius: 12px;
  border: 1px solid var(--border-light);
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(15, 23, 42, 0.03);
}

.contact-iframe-wrap iframe {
  display: block;
  width: 100%;
  border: none;
  min-height: 860px;
}

@media (max-width: 640px) {
  .contact-embed-card {
    padding: 1.75rem 0.75rem;
    scroll-margin-top: 80px;
  }
  .contact-iframe-wrap {
    border-radius: 8px;
  }
  .contact-iframe-wrap iframe {
    min-height: 980px;
  }
}

/* --- Section: FAQ (Accordion) --- */
.faq-grid {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.faq-item {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-medium);
}

.faq-question {
  width: 100%;
  padding: 1.25rem 1.5rem;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  background: none;
}

.faq-icon {
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text-light);
  transition: transform var(--transition-fast);
  font-size: 1.25rem;
  line-height: 1;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  color: var(--accent-teal);
}

.faq-answer {
  display: none;
  padding: 0 1.5rem 1.25rem 1.5rem;
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.75;
  border-top: 1px dashed var(--border-light);
  margin-top: 0.25rem;
  padding-top: 1rem;
}

.faq-item.active .faq-answer {
  display: block;
}

/* --- Global CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, #121824 0%, #1E293B 100%);
  color: #FFF;
  border-radius: var(--radius-lg);
  padding: clamp(2.5rem, 5vw, 4rem);
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 50%, rgba(13, 148, 136, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.cta-title {
  font-size: clamp(1.875rem, 3.5vw, 2.5rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
}

.cta-subtitle {
  font-size: 1.0625rem;
  color: var(--text-inverse-muted);
  max-width: 600px;
  margin: 0 auto 2rem auto;
  position: relative;
  z-index: 1;
}

.cta-buttons {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

/* --- Site Footer --- */
.site-footer {
  background-color: var(--bg-main);
  border-top: 1px solid var(--border-light);
  padding: 4rem 0 3rem 0;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.footer-brand p {
  line-height: 1.7;
  max-width: 440px;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-main);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-links a:hover {
  color: var(--text-main);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-light);
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.75rem;
  color: var(--text-light);
}

/* --- Registration Modal --- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(18, 24, 36, 0.7);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-smooth);
}

.modal-backdrop.active {
  opacity: 1;
  visibility: visible;
}

.modal-card {
  background-color: var(--bg-surface);
  border-radius: var(--radius-md);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
  width: 100%;
  max-width: 720px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  transform: translateY(20px);
  transition: transform var(--transition-smooth);
  padding: clamp(1.5rem, 3vw, 2.25rem);
}

.modal-backdrop.active .modal-card {
  transform: translateY(0);
}

.form-iframe-container {
  width: 100%;
  height: 680px;
  max-height: 70vh;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border-light);
  background-color: #FAF9F6;
  margin-top: 1rem;
}

.form-iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.form-external-link {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.8125rem;
  color: var(--accent-teal);
  margin-top: 0.75rem;
  font-weight: 500;
}

.form-external-link:hover {
  text-decoration: underline;
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--bg-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all var(--transition-fast);
  font-size: 1.25rem;
}

.modal-close-btn:hover {
  background-color: var(--bg-subtle-hover);
  color: var(--text-main);
}

.modal-title {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.375rem;
}

.modal-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  line-height: 1.6;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.375rem;
}

.form-label span.req {
  color: #DC2626;
  margin-left: 2px;
}

.form-input, .form-select, .form-textarea {
  width: 100%;
  padding: 0.6875rem 0.875rem;
  font-size: 0.875rem;
  font-family: inherit;
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface);
  color: var(--text-main);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus, .form-select:focus, .form-textarea:focus {
  outline: none;
  border-color: var(--accent-teal);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

.form-textarea {
  resize: vertical;
  min-height: 80px;
}

.form-hint {
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: 0.25rem;
}

/* Toast Notification */
.toast-msg {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: var(--bg-dark);
  color: #FFF;
  padding: 0.875rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  z-index: 2000;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-smooth);
}

.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}


/* --- Embedded Images & Enhancements --- */
.hero-image-wrap {
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border-light);
  background-color: var(--bg-subtle);
  cursor: pointer;
  position: relative;
}

.hero-img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  display: block;
  transition: transform var(--transition-fast);
}

.hero-image-wrap:hover .hero-img {
  transform: scale(1.015);
}

/* Tool Card Thumbnails */
.tech-card-img-wrap {
  width: 100%;
  height: 150px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border-light);
  background-color: #FAF9F6;
}

.tech-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform var(--transition-smooth);
}

.tech-card:hover .tech-card-img {
  transform: scale(1.03);
}

/* Venue Photo */
.venue-photo-wrap {
  position: relative;
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border-light);
  height: 260px;
  background-color: var(--bg-subtle);
  cursor: pointer;
}

.venue-photo-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 55%;
  display: block;
  transition: transform var(--transition-smooth);
}

.venue-photo-wrap:hover .venue-photo-img {
  transform: scale(1.02);
}

.venue-photo-tag {
  position: absolute;
  bottom: 0.75rem;
  left: 0.75rem;
  background: rgba(18, 24, 36, 0.85);
  backdrop-filter: blur(4px);
  color: #FFF;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.625rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

/* Lightbox Image Modal */
.image-lightbox {
  position: fixed;
  inset: 0;
  background-color: rgba(18, 24, 36, 0.88);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 2000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-smooth);
}

.image-lightbox.active {
  opacity: 1;
  visibility: visible;
}

.lightbox-content {
  position: relative;
  max-width: 95vw;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.lightbox-img {
  max-width: 100%;
  max-height: 80vh;
  border-radius: var(--radius-sm);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.lightbox-caption {
  color: var(--text-inverse);
  font-size: 0.875rem;
  margin-top: 0.75rem;
  text-align: center;
  background: rgba(0, 0, 0, 0.4);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
}

.lightbox-caption:empty {
  display: none !important;
}

.lightbox-close {
  position: absolute;
  top: -40px;
  right: 0;
  color: #FFF;
  font-size: 1.75rem;
  cursor: pointer;
  line-height: 1;
  background: none;
  border: none;
  padding: 0.25rem;
}


.diagram-img {
  width: 100%;
  height: auto;
  max-height: 480px;
  object-fit: contain;
  background-color: #FAF9F6;
  display: block;
}

.diagram-caption {
  padding: 0.875rem 1.25rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
  background-color: var(--bg-subtle);
  line-height: 1.6;
}

.quick-summary-box {
  margin-top: 1.75rem;
  padding: 1.25rem 1.5rem;
  background-color: #F8FAFC;
  border: 1px solid #E2E8F0;
  border-left: 4px solid var(--accent-teal);
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.summary-item {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-size: 0.875rem;
  color: #1E293B;
  line-height: 1.5;
}

.summary-icon {
  color: #0D9488;
  flex-shrink: 0;
}

.summary-item strong {
  color: #0F172A;
  font-weight: 700;
}

/* --- Responsive Media Queries --- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .work-days-grid {
    grid-template-columns: 1fr;
  }
  .tech-grid {
    grid-template-columns: 1fr;
  }
  .tech-card.primary-featured {
    grid-column: span 1;
  }
  .venue-grid {
    grid-template-columns: 1fr;
  }
  .guide-grid {
    grid-template-columns: 1fr;
  }
  .flow-steps {
    grid-template-columns: repeat(2, 1fr);
  }
  .members-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  /* Header & Mobile Menu */
  .header-inner {
    height: 4rem;
    gap: 0.5rem;
  }
  .brand-wrapper {
    gap: 0.5rem;
    min-width: 0;
    flex-shrink: 1;
  }
  .brand-logo-icon {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
  }
  .brand-acronym {
    font-size: 1.375rem;
  }
  .brand-jp {
    font-size: 0.875rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .brand-en {
    display: none;
  }
  .header-cta-group {
    gap: 0.45rem;
    flex-shrink: 0;
  }
  .btn-header-pill,
  .header-cta-group .btn {
    padding: 0.4rem 0.8rem;
    font-size: 0.8125rem;
    white-space: nowrap;
    flex-shrink: 0;
  }
  .btn-header-pill .arrow {
    display: none;
  }
  .site-nav {
    display: none;
    position: fixed;
    top: 4rem;
    left: 0;
    right: 0;
    background-color: var(--bg-main);
    border-bottom: 1px solid var(--border-medium);
    padding: 1.25rem 1.5rem 1.75rem 1.5rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
  }
  .site-nav.open {
    display: flex;
  }
  .site-nav .nav-link {
    padding: 0.625rem 0;
    font-size: 1rem;
    border-bottom: 1px solid var(--border-light);
  }
  .site-nav .nav-link:last-child {
    border-bottom: none;
  }
  .mobile-nav-toggle {
    display: flex;
  }

  /* Hero Section */
  .hero {
    padding-top: 2rem;
    padding-bottom: 2.5rem;
  }
  .hero-watermark {
    display: none;
  }
  .hero-heading {
    font-size: clamp(1.625rem, 5vw, 2.25rem);
    line-height: 1.3;
  }
  .hero-subhead {
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.75;
    color: #1F2937;
    margin-bottom: 1.5rem;
  }
  .hero-meta-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.625rem;
    margin-bottom: 1.5rem;
  }
  .btn-hero-pill {
    width: 100%;
  }
  .hero-deadline {
    width: 100%;
    justify-content: center;
    font-size: 0.875rem;
  }
  .hero-visual-card-wrap {
    max-width: 100%;
    border-radius: 14px;
  }

  /* About Overview Responsive */
  .about-grid {
    grid-template-columns: 1fr !important;
    gap: 1.75rem !important;
  }
  .about-header-divider {
    margin-bottom: 1.75rem;
    padding-bottom: 1rem;
  }
  .about-section-title {
    font-size: clamp(1.625rem, 6.5vw, 2.125rem);
  }
  .about-prose-body {
    font-size: 0.96875rem;
    line-height: 1.85;
  }
  .about-prose-body p {
    margin-bottom: 1.25rem;
  }
  .about-organizer-block {
    margin-top: 1.75rem;
    padding-top: 1.15rem;
  }
  .about-overview-card {
    margin-top: 0;
    width: 100%;
    box-sizing: border-box;
    padding: 1.5rem 1.25rem 1.65rem;
    border-radius: 6px;
  }
  .overview-card-title {
    font-size: 1.25rem;
    margin-bottom: 1.25rem;
  }
  .overview-item {
    padding-bottom: 0.85rem;
    margin-bottom: 0.85rem;
  }
  .overview-item-label {
    font-size: 0.775rem;
    margin-bottom: 0.25rem;
  }
  .overview-item-value {
    font-size: 0.96875rem;
    line-height: 1.4;
  }
  .overview-item-sub {
    font-size: 0.875rem;
  }
  .overview-item-sub.fee-note {
    font-size: 0.8125rem;
  }

  /* Activities Block Responsive */
  .activities-block {
    margin-top: 3rem;
    padding-top: 2rem;
  }
  .activities-header-divider {
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
  }
  .activities-title {
    font-size: clamp(1.625rem, 6.5vw, 2.125rem);
  }
  .activities-intro {
    font-size: 0.96875rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    padding-bottom: 1.35rem;
  }
  .activity-step-row {
    flex-wrap: wrap;
    padding: 1.35rem 1.25rem;
    gap: 0.85rem 0;
  }
  .activity-step-left {
    width: 100%;
    gap: 1rem;
    padding-left: 0;
  }
  .activity-step-ill-wrap {
    width: 95px;
    height: 65px;
  }
  .activity-step-title {
    font-size: 1.15rem;
  }
  .activity-step-sub {
    font-size: 0.8125rem;
  }
  .activity-step-divider {
    display: none;
  }
  .activity-step-content {
    width: 100%;
    padding: 0.35rem 0 0 0;
  }
  .activity-step-content p {
    font-size: 0.90625rem;
    line-height: 1.8;
  }
  .activities-welcome-box {
    margin-top: 1.75rem;
    padding: 1.15rem 1.15rem;
  }
  .activities-welcome-box p {
    font-size: 0.90625rem;
    line-height: 1.7;
  }

  /* Past Event Highlights Responsive */
  .past-event-block {
    margin-top: 3rem;
    padding-top: 2rem;
  }
  .past-event-head {
    margin-bottom: 1.5rem;
  }
  .past-event-title {
    font-size: 1.35rem;
  }
  .past-event-subtitle {
    font-size: 0.875rem;
    line-height: 1.6;
  }
  .past-event-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .past-photo-wrap {
    aspect-ratio: 16 / 10;
  }
  .past-photo-info {
    padding: 0.85rem 1rem 0.95rem;
  }
  .past-photo-name {
    font-size: 0.96875rem;
  }

  /* Vertical Schedule Cards Stack Responsive */
  .sched-cards-stack {
    margin-top: 1.5rem;
    gap: 1.5rem;
  }
  .sched-card {
    border-radius: 1.125rem;
  }
  .sched-card-header {
    min-height: 145px;
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    position: relative;
    overflow: hidden;
    background: #FFFFFF;
  }
  .sched-header-left {
    position: relative;
    z-index: 2;
    max-width: 62%;
    padding: 1.35rem 1rem 1.25rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0.45rem;
  }
  .sched-badge-prep {
    font-size: 0.6875rem;
    padding: 0.22rem 0.65rem;
  }
  .sched-day-callout .day-word {
    font-size: 1.15rem;
  }
  .sched-day-callout .day-digit {
    font-size: 2.25rem;
    line-height: 0.95;
  }
  .sched-card-name {
    font-size: 1.35rem;
  }
  .sched-header-meta {
    gap: 0.35rem;
    margin-top: 0.15rem;
  }
  .sched-meta-row {
    font-size: 0.775rem;
    gap: 0.4rem;
    line-height: 1.4;
  }
  .sched-meta-svg {
    width: 14px;
    height: 14px;
  }
  .sched-header-visual {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 50%;
    overflow: hidden;
    pointer-events: none;
    z-index: 1;
  }
  .sched-header-photo {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    mask-image: linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.25) 25%, rgba(0, 0, 0, 1) 65%);
    -webkit-mask-image: linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.25) 25%, rgba(0, 0, 0, 1) 65%);
  }
  .sched-script-text {
    bottom: 0.65rem;
    right: 0.85rem;
    font-size: 1.3rem;
  }
  .sched-timeline {
    padding: 1.5rem 1rem 1.85rem;
    gap: 1.15rem;
    position: relative;
  }
  .sched-timeline::before {
    left: calc(1rem + 13px);
    transform: translateX(-50%);
    top: 2rem;
    bottom: 2.35rem;
    width: 2px;
  }
  .sched-axis {
    width: 26px;
    padding-top: 2px;
  }
  .sched-dot {
    width: 11px;
    height: 11px;
    border-width: 2.5px;
  }
  .sched-item {
    gap: 0.65rem;
  }
  .sched-content {
    gap: 0.35rem;
  }
  .sched-time-label {
    font-size: 0.8125rem;
  }
  .sched-event-card {
    padding: 0.35rem 0.5rem;
    gap: 0.65rem;
    border-radius: 10px;
  }
  .sched-icon-badge {
    width: 28px;
    height: 28px;
    border-radius: 6px;
  }
  .sched-icon-badge svg {
    width: 15px;
    height: 15px;
  }
  .sched-event-title {
    font-size: 0.9375rem;
    line-height: 1.45;
  }
  .sched-speaker-tag {
    font-size: 0.75rem;
  }
  .sched-event-desc {
    font-size: 0.8125rem;
    line-height: 1.6;
  }
  .sched-event-card.card-party,
  .sched-event-card.card-seminar,
  .sched-event-card.card-presentation {
    padding: 0.65rem 0.75rem;
  }

  /* Data & Tech Cards */
  .tech-card {
    padding: 1.25rem;
  }
  .tech-card-img-wrap {
    height: 140px;
  }

  /* Guidelines */
  .guide-header-divider {
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
  }
  .guide-section-title {
    font-size: clamp(1.625rem, 6.5vw, 2.125rem);
  }
  .guide-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
    margin-bottom: 2rem;
  }
  .guide-card {
    padding: 1.5rem 1.25rem 1.65rem;
  }
  .guide-card-visual {
    height: 90px;
    margin-bottom: 1.15rem;
  }
  .guide-card-title {
    font-size: 1.25rem;
    margin-bottom: 0.85rem;
    text-align: center;
  }
  .guide-card-text {
    font-size: 0.90625rem;
    line-height: 1.75;
    margin-bottom: 1rem;
  }
  .guide-os-note {
    font-size: 0.8125rem;
    margin-top: -0.35rem;
    margin-bottom: 1rem;
  }
  .guide-meta-footer {
    padding-top: 1.15rem;
    gap: 0.35rem;
  }
  .guide-meta-row {
    font-size: 0.84375rem;
    flex-wrap: wrap;
  }
  .guide-fee-list {
    gap: 1rem;
    margin-bottom: 1.15rem;
  }
  .guide-fee-row {
    gap: 0.75rem;
  }
  .guide-fee-label {
    font-size: 0.875rem;
    min-width: 52px;
    padding-top: 0.1rem;
  }
  .guide-fee-amount {
    font-size: 1.03125rem;
  }
  .guide-fee-sub {
    font-size: 0.75rem;
    line-height: 1.45;
  }
  .guide-subnote {
    font-size: 0.75rem;
    line-height: 1.55;
  }

  /* Venue & Access */
  .venue-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .venue-card-visual {
    padding: 1.25rem;
  }
  .venue-photo-wrap {
    height: 200px;
  }
  .venue-amenities {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
  .venue-action .btn {
    width: 100%;
  }

  /* Committee & Organizers */
  .host-banners {
    grid-template-columns: 1fr;
  }
  .members-grid {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  .member-card {
    padding: 1rem 1.25rem;
  }

  /* FAQ */
  .faq-question {
    padding: 1rem 1.25rem;
    font-size: 0.9375rem;
  }
  .faq-answer {
    padding: 0 1.25rem 1rem 1.25rem;
    font-size: 0.875rem;
  }

  /* CTA Banner */
  .cta-banner {
    padding: 2.25rem 1.25rem;
    border-radius: var(--radius-md);
  }
  .cta-title {
    font-size: 1.5rem;
  }
  .cta-subtitle {
    font-size: 0.9375rem;
  }
  .cta-buttons {
    width: 100%;
    max-width: 440px;
    margin: 0 auto;
  }
  .cta-buttons .btn,
  .hero-actions .btn {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    padding: 0.8125rem 1rem;
    font-size: 0.9375rem;
  }

  /* Modal & Lightbox */
  .modal-card {
    padding: 1.5rem 1.25rem;
    max-height: 85vh;
  }
  .lightbox-close {
    top: -36px;
    font-size: 1.5rem;
  }
  .lightbox-caption {
    font-size: 0.75rem;
    padding: 0.2rem 0.6rem;
  }
}

@media (max-width: 480px) {
  :root {
    --section-pad: 2.75rem;
  }
  .container {
    padding-left: 1.125rem;
    padding-right: 1.125rem;
  }
  .brand-wrapper {
    gap: 0.35rem;
  }
  .brand-logo-icon {
    width: 28px;
    height: 28px;
  }
  .brand-acronym {
    font-size: 1.25rem;
  }
  .brand-jp {
    font-size: 0.8125rem;
    letter-spacing: 0;
  }
  .brand-en {
    display: none;
  }
  .header-inner {
    gap: 0.35rem;
  }
  .header-cta-group {
    gap: 0.35rem;
  }
  .btn-header-pill,
  .header-cta-group .btn,
  .header-cta-group .btn-header-pill {
    padding: 0.35rem 0.65rem;
    font-size: 0.75rem;
    white-space: nowrap;
    flex-shrink: 0;
    letter-spacing: 0;
    line-height: 1.2;
  }
  .btn-header-pill .arrow {
    display: none;
  }
  .hero-heading {
    font-size: clamp(1.35rem, 6.2vw, 1.625rem);
    line-height: 1.35;
  }
  .hero-subhead {
    font-size: 0.9375rem;
    line-height: 1.7;
    margin-bottom: 1.25rem;
  }
  .hero-card {
    padding: 1rem;
  }
  .card-date-row {
    padding: 0.625rem 0.75rem;
  }
  .card-date-label {
    font-size: 0.75rem;
  }
  .card-date-val {
    font-size: 0.875rem;
  }
  .hero-key-facts {
    gap: 0.75rem;
  }
  .fact-label {
    font-size: 0.625rem;
  }
  .fact-val {
    font-size: 0.875rem;
    line-height: 1.45;
  }
  .section-head {
    margin-bottom: 1.75rem;
  }
  .section-title {
    font-size: 1.3125rem;
  }
  .section-tag {
    font-size: 0.75rem;
  }

  /* About on Small Mobile */
  .about-grid {
    gap: 1.35rem !important;
  }
  .about-overview-card {
    padding: 1.25rem 1rem 1.35rem;
  }
  .overview-card-title {
    font-size: 1.15rem;
    margin-bottom: 1rem;
  }
  .overview-item {
    padding-bottom: 0.75rem;
    margin-bottom: 0.75rem;
  }
  .overview-item-label {
    font-size: 0.75rem;
  }
  .overview-item-value {
    font-size: 0.90625rem;
  }

  /* Activities on Small Mobile */
  .activities-block {
    margin-top: 2.25rem;
    padding-top: 1.5rem;
  }
  .activity-step-row {
    padding: 1.15rem 1rem;
    gap: 0.75rem 0;
  }
  .activity-step-left {
    width: 100%;
    gap: 0.85rem;
    padding-left: 0;
  }
  .activity-step-ill-wrap {
    width: 78px;
    height: 54px;
  }
  .activity-step-title {
    font-size: 1.0625rem;
  }
  .activity-step-sub {
    font-size: 0.75rem;
  }
  .activity-step-content {
    width: 100%;
    padding: 0.25rem 0 0 0;
  }
  .activity-step-content p {
    font-size: 0.84375rem;
    line-height: 1.75;
  }
  .activities-welcome-box {
    margin-top: 1.35rem;
    padding: 1rem;
  }
  .activities-welcome-box p {
    font-size: 0.84375rem;
    line-height: 1.65;
  }

  /* Past Event Showcase on Small Mobile */
  .past-event-block {
    margin-top: 2.25rem;
    padding-top: 1.5rem;
  }
  .past-event-title {
    font-size: 1.2rem;
  }
  .past-event-grid {
    gap: 1rem;
  }
  /* Schedule Cards on Small Mobile */
  .sched-card-header {
    min-height: 135px;
  }
  .sched-header-left {
    max-width: 64%;
    padding: 1.15rem 0.75rem 1rem;
    gap: 0.35rem;
  }
  .sched-card-name {
    font-size: 1.2rem;
  }
  .sched-day-callout .day-digit {
    font-size: 2rem;
  }
  .sched-day-callout .day-word {
    font-size: 1.05rem;
  }
  .sched-meta-row {
    font-size: 0.725rem;
    gap: 0.35rem;
  }
  .sched-script-text {
    font-size: 1.15rem;
    bottom: 0.5rem;
    right: 0.65rem;
  }
  .sched-timeline {
    padding: 1.25rem 0.75rem 1.5rem;
    gap: 1rem;
  }
  .sched-timeline::before {
    left: calc(0.75rem + 12px);
    transform: translateX(-50%);
    top: 1.65rem;
    bottom: 2rem;
  }
  .sched-axis {
    width: 24px;
  }
  .sched-dot {
    width: 10px;
    height: 10px;
    border-width: 2px;
  }
  .sched-item {
    gap: 0.5rem;
  }
  .sched-event-card {
    padding: 0.3rem 0.45rem;
    gap: 0.55rem;
  }
  .sched-event-title {
    font-size: 0.875rem;
  }
  .sched-event-desc {
    font-size: 0.775rem;
  }

  /* Data & Tech */
  .tech-card {
    padding: 1rem;
  }
  .tech-name {
    font-size: 1.125rem;
  }
  .tech-desc {
    font-size: 0.875rem;
  }

  /* Guidelines */
  .guide-card {
    padding: 1.35rem 1.15rem 1.5rem;
  }
  .guide-card-visual {
    height: 80px;
    margin-bottom: 0.9rem;
  }
  .guide-card-img {
    max-width: 140px;
    max-height: 75px;
  }
  .guide-card-title {
    font-size: 1.1875rem;
    margin-bottom: 0.75rem;
    text-align: center;
  }
  .guide-card-text {
    font-size: 0.84375rem;
    line-height: 1.7;
    margin-bottom: 0.85rem;
  }
  .guide-meta-footer {
    padding-top: 1rem;
  }
  .guide-meta-row {
    font-size: 0.775rem;
  }
  .guide-slash {
    margin: 0 0.35rem;
  }
  .guide-fee-list {
    gap: 0.85rem;
    margin-bottom: 1rem;
  }
  .guide-fee-row {
    gap: 0.5rem;
  }
  .guide-fee-label {
    min-width: 48px;
    font-size: 0.8125rem;
  }
  .guide-badge-free {
    font-size: 0.75rem;
    padding: 0.15rem 0.5rem;
  }
  .guide-fee-amount {
    font-size: 0.9375rem;
  }
  .guide-fee-sub {
    font-size: 0.7rem;
    line-height: 1.4;
  }
  .guide-subnote {
    font-size: 0.7rem;
    line-height: 1.5;
  }
  .venue-card-visual {
    padding: 1rem;
  }
  .venue-photo-wrap {
    height: 180px;
  }
  .cta-banner {
    padding: 1.75rem 1rem;
  }
  .cta-title {
    font-size: 1.3125rem;
  }
  .cta-subtitle {
    font-size: 0.875rem;
  }
  .cta-buttons .btn,
  .hero-actions .btn {
    padding: 0.75rem 0.625rem;
    font-size: 0.875rem;
    gap: 0.25rem;
  }
  .btn-cta-main {
    font-size: 0.9375rem;
  }
  .btn-sub-text {
    font-size: 0.8125rem;
  }
  .modal-card {
    padding: 1.25rem 1rem;
    max-height: 90vh;
  }
  .modal-title {
    font-size: 1.1875rem;
  }
  .form-iframe-container {
    height: 520px;
  }
}

/* --- Print Styling --- */
@media print {
  .site-header, .site-nav, .hero-actions, .schedule-tabs-nav, .cta-banner, .site-footer, .modal-backdrop {
    display: none !important;
  }
  body {
    background: #FFF !important;
    color: #000 !important;
  }
  .section {
    padding: 2rem 0 !important;
  }
  .tab-panel {
    display: block !important;
    margin-bottom: 2rem;
    page-break-inside: avoid;
  }
}