/* ============================================================
   CONNECTING LAB — MAIN STYLESHEET
   Futuristic Dark Theme | IT·AI Community
   ============================================================ */

/* ---------- CSS VARIABLES ---------- */
:root {
  --bg-primary: #060810;
  --bg-secondary: #0a0d1a;
  --bg-card: #0d1120;
  --bg-card-hover: #111828;

  --accent: #00d4ff;
  --accent-dim: rgba(0, 212, 255, 0.12);
  --accent-glow: rgba(0, 212, 255, 0.4);
  --accent2: #7c3aed;
  --accent2-dim: rgba(124, 58, 237, 0.15);
  --accent2-glow: rgba(124, 58, 237, 0.4);
  --accent3: #06b6d4;

  --text-primary: #f0f4ff;
  --text-secondary: #8892a4;
  --text-muted: #4a5568;
  --border: rgba(255, 255, 255, 0.07);
  --border-accent: rgba(0, 212, 255, 0.25);

  --font-display: 'Orbitron', sans-serif;
  --font-body: 'Noto Sans KR', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-glow: 0 0 40px rgba(0, 212, 255, 0.15);
  --shadow-card: 0 4px 32px rgba(0, 0, 0, 0.4);
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { border: none; background: none; cursor: pointer; font-family: inherit; }

/* ---------- SCROLLBAR ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 3px; }

/* ---------- SELECTION ---------- */
::selection { background: var(--accent); color: var(--bg-primary); }

/* ============================================================
   CURSOR GLOW
   ============================================================ */
.cursor-glow {
  position: fixed;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.06) 0%, transparent 70%);
  pointer-events: none;
  z-index: 9999;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s;
}

/* ============================================================
   PARTICLE CANVAS
   ============================================================ */
#particleCanvas {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.5;
}

/* ============================================================
   SECTION COMMON
   ============================================================ */
section { position: relative; z-index: 1; }

.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 100px 40px;
}

.section-header {
  text-align: center;
  margin-bottom: 70px;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  letter-spacing: 0.2em;
  margin-bottom: 16px;
  opacity: 0.8;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0 40px;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(6, 8, 16, 0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 2px;
}

.logo-bracket { color: var(--accent); opacity: 0.6; }
.logo-text { color: var(--text-primary); }
.logo-accent { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 8px 14px;
  border-radius: 8px;
  transition: var(--transition);
  letter-spacing: 0.02em;
}

.nav-link:hover {
  color: var(--text-primary);
  background: var(--accent-dim);
}

.nav-cta {
  background: linear-gradient(135deg, var(--accent), #0099cc);
  color: var(--bg-primary) !important;
  font-weight: 700;
  padding: 9px 20px !important;
  border-radius: 8px;
  font-size: 0.85rem;
  transition: var(--transition);
}

.nav-cta:hover {
  box-shadow: 0 0 20px var(--accent-glow);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
  display: block;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
}

.hero-orbs {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  animation: orbFloat 8s ease-in-out infinite;
}

.orb-1 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.12), transparent 70%);
  top: -10%; left: -5%;
  animation-duration: 10s;
}

.orb-2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.12), transparent 70%);
  bottom: -10%; right: -5%;
  animation-duration: 12s;
  animation-delay: -3s;
}

.orb-3 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.08), transparent 70%);
  top: 40%; right: 20%;
  animation-duration: 15s;
  animation-delay: -6s;
}

@keyframes orbFloat {
  0%, 100% { transform: translateY(0) scale(1); }
  33% { transform: translateY(-30px) scale(1.05); }
  66% { transform: translateY(20px) scale(0.97); }
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 120px 40px 80px;
  max-width: 900px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: 100px;
  padding: 8px 18px;
  font-size: 0.82rem;
  font-family: var(--font-mono);
  color: var(--accent);
  margin-bottom: 32px;
  letter-spacing: 0.05em;
}

.badge-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: pulseDot 2s ease-in-out infinite;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.8); }
}

.hero-title {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin-bottom: 24px;
}

.title-line { display: block; }

.title-word {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 7rem);
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1;
  display: inline-block;
  color: var(--text-primary);
}

.accent-word {
  color: transparent;
  -webkit-text-stroke: 2px var(--accent);
  text-shadow: 0 0 60px var(--accent-glow);
}

/* GLITCH EFFECT */
.glitch {
  position: relative;
}

.glitch::before,
.glitch::after {
  content: attr(data-text);
  position: absolute;
  top: 0; left: 0;
  font-family: var(--font-display);
  font-size: inherit;
  font-weight: inherit;
  letter-spacing: inherit;
  color: var(--text-primary);
  clip-path: polygon(0 0, 100% 0, 100% 33%, 0 33%);
}

.glitch::before {
  left: 2px;
  color: var(--accent);
  animation: glitch1 4s infinite;
  opacity: 0;
}

.glitch::after {
  left: -2px;
  color: var(--accent2);
  animation: glitch2 4s infinite;
  opacity: 0;
}

@keyframes glitch1 {
  0%, 90%, 100% { opacity: 0; transform: translate(0); clip-path: polygon(0 0, 100% 0, 100% 0, 0 0); }
  92% { opacity: 0.6; transform: translate(-3px, 0); clip-path: polygon(0 20%, 100% 20%, 100% 40%, 0 40%); }
  94% { opacity: 0.3; transform: translate(3px, 0); clip-path: polygon(0 60%, 100% 60%, 100% 80%, 0 80%); }
  96% { opacity: 0; transform: translate(0); }
}

@keyframes glitch2 {
  0%, 91%, 100% { opacity: 0; transform: translate(0); clip-path: polygon(0 0, 100% 0, 100% 0, 0 0); }
  93% { opacity: 0.5; transform: translate(3px, 0); clip-path: polygon(0 40%, 100% 40%, 100% 60%, 0 60%); }
  95% { opacity: 0.3; transform: translate(-3px, 0); clip-path: polygon(0 10%, 100% 10%, 100% 30%, 0 30%); }
  97% { opacity: 0; transform: translate(0); }
}

.hero-subtitle {
  font-family: var(--font-mono);
  font-size: clamp(0.95rem, 1.8vw, 1.15rem);
  color: var(--accent);
  margin-bottom: 24px;
  min-height: 2em;
  letter-spacing: 0.05em;
}

.cursor-blink {
  animation: blink 1s step-end infinite;
  color: var(--accent);
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.hero-desc {
  font-size: clamp(0.95rem, 1.5vw, 1.05rem);
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 60px;
  flex-wrap: wrap;
}

/* ---------- BUTTONS ---------- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: linear-gradient(135deg, var(--accent) 0%, #0099bb 100%);
  color: var(--bg-primary);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 14px 30px;
  border-radius: var(--radius);
  transition: var(--transition);
  letter-spacing: 0.02em;
  position: relative;
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #00eeff, #0077aa);
  opacity: 0;
  transition: var(--transition);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px var(--accent-glow);
}

.btn-primary:hover::before { opacity: 1; }
.btn-primary span, .btn-primary i { position: relative; z-index: 1; }

.btn-primary.large { padding: 16px 38px; font-size: 1rem; }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.95rem;
  padding: 13px 30px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.btn-ghost:hover {
  color: var(--text-primary);
  border-color: var(--border-accent);
  background: var(--accent-dim);
}

/* ---------- HERO STATS ---------- */
.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px 40px;
  backdrop-filter: blur(10px);
}

.hero-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 0 32px;
}

.stat-num {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
}

.stat-unit {
  font-family: var(--font-display);
  font-size: 0.9rem;
  color: var(--accent);
  margin-left: 2px;
}

.stat-num + .stat-unit { display: inline; }
.hero-stat { flex-direction: row; flex-wrap: wrap; justify-content: center; align-items: baseline; gap: 4px; }
.hero-stat .stat-label { width: 100%; text-align: center; font-size: 0.78rem; color: var(--text-muted); font-family: var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; margin-top: 2px; }

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}

/* ---------- HERO SCROLL ---------- */
.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  letter-spacing: 0.15em;
  animation: scrollBounce 2s ease-in-out infinite;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, transparent, var(--accent));
  border-radius: 1px;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ============================================================
   ABOUT
   ============================================================ */
.about { background: var(--bg-secondary); }

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 80px;
  align-items: start;
}

.about-lead {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.85;
}

.highlight {
  color: var(--accent);
  font-weight: 600;
}

.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 28px;
}

.tag {
  display: inline-block;
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  color: var(--accent);
  font-size: 0.8rem;
  padding: 5px 14px;
  border-radius: 100px;
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  transition: var(--transition);
}

.tag:hover {
  background: var(--accent);
  color: var(--bg-primary);
  transform: translateY(-2px);
}

.about-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.value-card {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 16px;
  align-items: start;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.value-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--accent2));
  opacity: 0;
  transition: var(--transition);
}

.value-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.value-card:hover::before { opacity: 1; }

.card-icon {
  width: 52px; height: 52px;
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: var(--accent);
  flex-shrink: 0;
}

.value-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.card-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  background: var(--accent);
  color: var(--bg-primary);
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
}

.value-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================================
   HISTORY / TIMELINE
   ============================================================ */
.history { background: var(--bg-primary); }

.timeline {
  position: relative;
  padding: 20px 0;
}

.timeline-line {
  position: absolute;
  left: 50%;
  top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, transparent, var(--accent) 10%, var(--accent) 90%, transparent);
  transform: translateX(-50%);
  opacity: 0.3;
}

.timeline-item {
  display: grid;
  grid-template-columns: 1fr 60px 1fr;
  gap: 0;
  margin-bottom: 60px;
  align-items: start;
  position: relative;
}

.timeline-item > * {
  min-width: 0;
}

.timeline-dot {
  width: 48px; height: 48px;
  background: var(--bg-card);
  border: 2px solid var(--accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  position: relative;
  z-index: 2;
  margin: 0 auto;
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.2);
  transition: var(--transition);
}

.timeline-dot.active {
  background: var(--accent);
  color: var(--bg-primary);
  box-shadow: 0 0 30px var(--accent-glow);
  animation: dotPulse 2s ease-in-out infinite;
}

@keyframes dotPulse {
  0%, 100% { box-shadow: 0 0 20px var(--accent-glow); }
  50% { box-shadow: 0 0 40px var(--accent-glow), 0 0 80px rgba(0, 212, 255, 0.2); }
}

.timeline-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.timeline-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--accent-dim) 0%, transparent 60%);
  opacity: 0;
  transition: var(--transition);
}

.timeline-card:hover, .timeline-card.active {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.timeline-card:hover::after { opacity: 1; }

.timeline-card.active {
  border-color: rgba(0, 212, 255, 0.4);
  box-shadow: var(--shadow-glow);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.timeline-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.4;
}

.timeline-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 14px;
}

.timeline-tag {
  display: inline-block;
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 100px;
  letter-spacing: 0.1em;
}

.timeline-tag.current {
  background: var(--accent);
  color: var(--bg-primary);
  font-weight: 700;
}

/* LEFT/RIGHT positioning */
.timeline-item[data-side="left"] {
  grid-template-areas: "card dot empty";
}
.timeline-item[data-side="right"] {
  grid-template-areas: "empty dot card";
}

.timeline-item[data-side="left"] .timeline-dot  { grid-area: dot;   }
.timeline-item[data-side="left"] .timeline-card  { grid-area: card;  margin-right: 30px; }
.timeline-item[data-side="right"] .timeline-dot  { grid-area: dot;   }
.timeline-item[data-side="right"] .timeline-card { grid-area: card;  margin-left: 30px; }

/* ============================================================
   ACTIVITIES
   ============================================================ */
.activities { background: var(--bg-secondary); }

.activities-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.activity-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.activity-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  opacity: 0;
  transition: var(--transition);
}

.activity-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.activity-card:hover::before { opacity: 1; }

.activity-card.featured {
  grid-column: span 2;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.06), rgba(124, 58, 237, 0.06));
  border-color: rgba(0, 212, 255, 0.2);
  display: flex;
  gap: 28px;
  align-items: flex-start;
}

.activity-card.featured::before { opacity: 1; }

.activity-glow {
  position: absolute;
  bottom: -40px; right: -40px;
  width: 180px; height: 180px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.12), transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

/* ---------- BOOK CARD ---------- */
.activity-card.book-card {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  overflow: hidden;
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.06), rgba(124, 58, 237, 0.06));
  border-color: rgba(0, 212, 255, 0.25);
}

.book-card-top {
  display: flex;
  align-items: flex-start;
  gap: 28px;
  padding: 32px 32px 24px;
  position: relative;
}

.book-covers {
  width: 100%;
  overflow: hidden;
  border-top: 1px solid rgba(0, 212, 255, 0.15);
  background: rgba(0, 0, 0, 0.2);
}

.book-covers img {
  width: 100%;
  height: auto;
  max-height: 300px;
  object-fit: contain;
  object-position: center;
  display: block;
  filter: brightness(0.95) saturate(0.9);
  transition: var(--transition);
}

.activity-card.book-card:hover .book-covers img {
  filter: brightness(1) saturate(1.05);
}

/* ---------- CONFERENCE CARD ---------- */
.activity-card.conference-card {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 28px;
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.06), rgba(0, 212, 255, 0.06));
  border-color: rgba(124, 58, 237, 0.25);
  position: relative;
  overflow: hidden;
}

.activity-card.conference-card::before { opacity: 1; }
.activity-card.conference-card .activity-glow {
  position: absolute;
  bottom: -40px; right: -40px;
  width: 200px; height: 200px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.15), transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.activity-icon {
  width: 56px; height: 56px;
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: var(--accent);
  flex-shrink: 0;
  transition: var(--transition);
}

.activity-card:hover .activity-icon {
  background: var(--accent);
  color: var(--bg-primary);
  box-shadow: 0 0 20px var(--accent-glow);
}

.activity-cat {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  letter-spacing: 0.15em;
  margin-bottom: 8px;
  opacity: 0.8;
}

.activity-content h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.activity-content p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 16px;
}

.activity-meta {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.activity-meta span {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  display: flex;
  align-items: center;
  gap: 5px;
}

.activity-meta i { color: var(--accent); font-size: 0.72rem; }

/* ============================================================
   COMMUNITY
   ============================================================ */
.community { background: var(--bg-primary); }

/* ---------- TOPICS WRAPPER ---------- */
.topics-wrapper {
  display: flex;
  flex-direction: column;
  gap: 56px;
}

.topics-year-block {}

.topics-year-label {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 28px;
}

.year-badge {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--bg-primary);
  background: var(--text-muted);
  padding: 6px 20px;
  border-radius: 100px;
  letter-spacing: 0.1em;
  white-space: nowrap;
  flex-shrink: 0;
}

.year-badge.current {
  background: linear-gradient(135deg, var(--accent), #0099bb);
  color: var(--bg-primary);
  box-shadow: 0 0 20px var(--accent-glow);
}

.year-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(to right, var(--border-accent), transparent);
}

/* ---------- TOPICS GRID ---------- */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  position: relative;
}

.topic-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-5px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.4);
}

.topic-card.upcoming {
  opacity: 0.65;
}

.topic-card.upcoming:hover {
  opacity: 1;
}

.topic-img-wrap {
  position: relative;
  width: 100%;
  height: 160px;
  overflow: hidden;
}

.topic-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: brightness(0.6) saturate(0.8);
  transition: var(--transition);
}

.topic-card:hover .topic-img-wrap img {
  filter: brightness(0.75) saturate(1);
  transform: scale(1.05);
}

.topic-month {
  position: absolute;
  top: 12px;
  left: 12px;
  background: rgba(6, 8, 16, 0.75);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-accent);
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 100px;
  letter-spacing: 0.1em;
}

.topic-quarter {
  position: absolute;
  bottom: 12px;
  right: 12px;
  background: rgba(124, 58, 237, 0.7);
  backdrop-filter: blur(8px);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: 100px;
  letter-spacing: 0.1em;
}

.upcoming-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(124, 58, 237, 0.85);
  backdrop-filter: blur(8px);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 100px;
  letter-spacing: 0.08em;
}

.topic-body {
  padding: 16px 18px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.topic-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent);
  letter-spacing: 0.12em;
  opacity: 0.8;
}

.topic-body h4 {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.45;
}

.values-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.value-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.value-num {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  opacity: 0.5;
  letter-spacing: 0.1em;
  flex-shrink: 0;
  margin-top: 2px;
}

.value-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.value-text strong {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-weight: 600;
}

.value-text span {
  font-size: 0.83rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ============================================================
   STATS
   ============================================================ */
.stats {
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
}

.stats-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.stats-grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
}

.stats .section-container { position: relative; z-index: 1; }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 50px;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: var(--transition);
}

.stat-card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
  transform: translateY(-6px);
  box-shadow: var(--shadow-glow);
}

.stat-card:hover::before { opacity: 1; }

.stat-icon {
  font-size: 1.4rem;
  color: var(--accent);
  margin-bottom: 16px;
  opacity: 0.7;
}

.stat-counter {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
  display: inline;
}

.stat-unit {
  font-family: var(--font-display);
  font-size: 1.2rem;
  color: var(--accent);
  font-weight: 600;
}

.stat-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 8px;
  display: block;
}

.stat-bar {
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  margin-top: 20px;
  overflow: hidden;
}

.stat-bar-fill {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 2px;
  transition: width 1.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- AI BANNER ---------- */
.ai-banner {
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.06), rgba(124, 58, 237, 0.08));
  border: 1px solid rgba(0, 212, 255, 0.25);
  border-radius: var(--radius-lg);
  padding: 40px 48px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 32px;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.ai-banner::before {
  content: '';
  position: absolute;
  top: -50%; left: -10%;
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.1), transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.ai-banner-icon {
  width: 70px; height: 70px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  color: var(--bg-primary);
  flex-shrink: 0;
  box-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
}

.ai-banner-label {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--accent);
  letter-spacing: 0.2em;
  margin-bottom: 8px;
  background: var(--accent-dim);
  border: 1px solid var(--border-accent);
  padding: 2px 10px;
  border-radius: 100px;
}

.ai-banner-text h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.ai-banner-text p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.ai-banner-chips {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex-shrink: 0;
}

.ai-banner-chips span {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 5px 14px;
  border-radius: 100px;
  text-align: center;
  transition: var(--transition);
  cursor: default;
}

.ai-banner-chips span:hover {
  background: var(--accent-dim);
  border-color: var(--border-accent);
  color: var(--accent);
}

/* ============================================================
   JOIN
   ============================================================ */
.join {
  background: var(--bg-primary);
  position: relative;
  overflow: hidden;
}

.join-bg { position: absolute; inset: 0; z-index: 0; }

.join-orb-1 {
  position: absolute;
  width: 600px; height: 600px;
  top: -20%; left: -10%;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.08), transparent 70%);
  border-radius: 50%;
  filter: blur(40px);
}

.join-orb-2 {
  position: absolute;
  width: 500px; height: 500px;
  bottom: -20%; right: -5%;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.1), transparent 70%);
  border-radius: 50%;
  filter: blur(40px);
}

.join .section-container { position: relative; z-index: 1; }

.join-content {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
  padding: 100px 0;
}

.join-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: 100px;
  padding: 8px 18px;
  font-size: 0.82rem;
  font-family: var(--font-mono);
  color: var(--accent);
  margin-bottom: 32px;
  letter-spacing: 0.05em;
}

.badge-dot.pulse {
  animation: pulseAnim 1.5s ease-in-out infinite;
}

@keyframes pulseAnim {
  0%, 100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(0, 212, 255, 0.4); }
  50% { transform: scale(1.1); box-shadow: 0 0 0 6px rgba(0, 212, 255, 0); }
}

.join-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.join-title .accent { color: var(--accent); }

.join-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.85;
  margin-bottom: 40px;
}

.join-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 48px;
  text-align: left;
}

.join-feature.card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.join-feature.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  opacity: 0;
  transition: var(--transition);
}

.join-feature.card:hover {
  border-color: var(--border-accent);
  background: var(--bg-card-hover);
}

.join-feature.card:hover::before { opacity: 1; }

.join-feature-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.join-feature-title i {
  color: var(--accent);
  font-size: 0.95rem;
  flex-shrink: 0;
}

.join-feature.card p {
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin: 0;
}

.join-feature:hover {
  border-color: var(--border-accent);
  color: var(--text-primary);
}

.join-feature i { color: var(--accent); font-size: 0.9rem; flex-shrink: 0; }

.join-actions {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.social-links {
  display: flex;
  gap: 12px;
}

.social-btn {
  width: 46px; height: 46px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.social-btn:hover {
  background: var(--accent-dim);
  border-color: var(--border-accent);
  color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 212, 255, 0.15);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  position: relative;
  z-index: 1;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 40px 30px;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 60px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 28px;
}

.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-top: 16px;
}

.footer-est {
  font-family: var(--font-mono) !important;
  font-size: 0.75rem !important;
  color: var(--text-muted) !important;
  margin-top: 8px !important;
  letter-spacing: 0.1em;
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 2px;
}

.footer-links {
  display: flex;
  gap: 60px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.footer-col a {
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.footer-col a:hover { color: var(--accent); padding-left: 4px; }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.footer-tag {
  letter-spacing: 0.15em;
  color: var(--accent);
  opacity: 0.5;
}

/* ============================================================
   BOTTOM BAR
   ============================================================ */
.bottom-bar {
  width: 100%;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 18px 40px;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-family: 'Noto Sans KR', sans-serif;
  letter-spacing: 0.02em;
}
.bottom-bar i {
  color: var(--accent);
  margin-right: 6px;
}
.bottom-bar a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}
.bottom-bar a:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top {
  position: fixed;
  bottom: 36px; right: 36px;
  width: 46px; height: 46px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text-secondary);
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: var(--transition);
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: all;
}

.back-to-top:hover {
  background: var(--accent-dim);
  border-color: var(--border-accent);
  color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(0, 212, 255, 0.2);
}

/* ============================================================
   SCROLL REVEAL ANIMATIONS
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.reveal-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* ============================================================
   RESPONSIVE — TABLET (≤1024px)
   ============================================================ */
@media (max-width: 1024px) {
  .about-grid { grid-template-columns: 1fr; gap: 50px; }
  .activities-grid { grid-template-columns: repeat(2, 1fr); }
  .activity-card.featured { grid-column: span 2; }
  .topics-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .ai-banner { grid-template-columns: auto 1fr; }
  .ai-banner-chips { display: flex; flex-direction: row; flex-wrap: wrap; grid-column: span 2; justify-content: flex-start; }
}

/* ============================================================
   RESPONSIVE — MOBILE (≤768px)
   ============================================================ */
@media (max-width: 768px) {
  .section-container { padding: 70px 24px; }
  .section-title { font-size: 1.6rem; }

  /* NAVBAR */
  .navbar { padding: 0 20px; }
  .nav-links {
    position: fixed;
    top: 0; right: -100%;
    width: 280px; height: 100vh;
    background: rgba(6, 8, 16, 0.97);
    backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    padding: 40px;
    gap: 6px;
    border-left: 1px solid var(--border);
    transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 999;
  }
  .nav-links.open { right: 0; }
  .nav-link { font-size: 1rem; padding: 12px 20px; }
  .nav-toggle { display: flex; z-index: 1000; position: relative; }
  .nav-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .nav-toggle.active span:nth-child(2) { opacity: 0; }
  .nav-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

  /* HERO */
  .hero-content { padding: 100px 24px 60px; }
  .hero-stats { flex-wrap: wrap; gap: 16px; padding: 20px 24px; }
  .hero-stat { flex: 0 0 auto; }
  .stat-divider { display: none; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions a { text-align: center; justify-content: center; }

  /* TIMELINE */
  .timeline-line { left: 24px; }
  .timeline-item {
    grid-template-columns: 48px 1fr;
    grid-template-areas: "dot card" !important;
    margin-bottom: 40px;
  }
  .timeline-item[data-side="left"],
  .timeline-item[data-side="right"] {
    grid-template-areas: "dot card" !important;
  }
  .timeline-dot { margin: 0; grid-area: dot !important; }
  .timeline-card { margin: 0 0 0 20px !important; grid-area: card !important; }

  /* ACTIVITIES */
  .activities-grid { grid-template-columns: 1fr; }
  .activity-card.featured { grid-column: span 1; flex-direction: column; }
  .activity-card.conference-card { flex-direction: column; }
  .book-covers img { max-height: none; height: auto; }

  /* COMMUNITY */
  .topics-grid { grid-template-columns: repeat(2, 1fr); }

  /* STATS */
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .ai-banner {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 24px;
    padding: 28px 24px;
  }
  .ai-banner-icon { margin: 0 auto; }
  .ai-banner-chips { flex-direction: row; flex-wrap: wrap; justify-content: center; }

  /* JOIN */
  .join-features { grid-template-columns: 1fr; }

  /* FOOTER */
  .footer-top { flex-direction: column; gap: 40px; }
  .footer-links { flex-direction: column; gap: 32px; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { padding: 16px; }
  .back-to-top { bottom: 20px; right: 20px; }
}