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

:root {
  --purple: #7c3aed;
  --purple-light: #a855f7;
  --cyan: #06b6d4;
  --cyan-light: #22d3ee;
  --dark: #050811;
  --dark2: #0d1117;
  --dark3: #161b27;
  --card: rgba(255,255,255,0.04);
  --border: rgba(255,255,255,0.08);
  --text: #e2e8f0;
  --muted: #94a3b8;
  --white: #ffffff;
  --gradient: linear-gradient(135deg, var(--purple), var(--cyan));
  --gradient-text: linear-gradient(90deg, #a855f7, #22d3ee);
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 20px 60px rgba(124,58,237,0.15);
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Be Vietnam Pro', sans-serif;
  background: var(--dark);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* =====================
   TYPOGRAPHY
======================== */
.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--cyan);
  background: rgba(6,182,212,0.1);
  border: 1px solid rgba(6,182,212,0.3);
  border-radius: 100px;
  padding: 4px 16px;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  color: var(--white);
  line-height: 1.25;
  margin-bottom: 48px;
  text-align: center;
}

/* =====================
   NAVBAR
======================== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 18px 0;
  transition: all 0.3s ease;
}

.navbar.scrolled {
  background: rgba(5,8,17,0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--white);
  letter-spacing: -1px;
}
.logo span { color: var(--purple-light); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--white); }

.btn-nav {
  background: var(--gradient) !important;
  color: var(--white) !important;
  padding: 8px 22px !important;
  border-radius: 100px !important;
  font-weight: 700 !important;
  font-size: 0.9rem !important;
  transition: opacity 0.2s, transform 0.2s !important;
}
.btn-nav:hover { opacity: 0.85; transform: translateY(-1px); }

.hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--white);
  font-size: 1.5rem;
  cursor: pointer;
}

/* =====================
   HERO
======================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 90px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 60% 40%, rgba(124,58,237,0.2) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(6,182,212,0.15) 0%, transparent 60%),
    var(--dark);
}

.particles {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.particle {
  position: absolute;
  border-radius: 50%;
  animation: float linear infinite;
  opacity: 0.5;
}

@keyframes float {
  0%   { transform: translateY(100vh) scale(0); opacity: 0; }
  10%  { opacity: 0.5; }
  90%  { opacity: 0.3; }
  100% { transform: translateY(-10vh) scale(1); opacity: 0; }
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 640px;
  padding: 60px 24px;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(124,58,237,0.15);
  border: 1px solid rgba(168,85,247,0.3);
  border-radius: 100px;
  padding: 6px 18px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--purple-light);
  margin-bottom: 24px;
  animation: fadeUp 0.6s ease both;
}

.hero h1 {
  font-size: clamp(3.5rem, 8vw, 6.5rem);
  font-weight: 900;
  line-height: 1;
  color: var(--white);
  letter-spacing: -3px;
  margin-bottom: 20px;
  animation: fadeUp 0.7s 0.1s ease both;
}

.hero-sub {
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  color: var(--muted);
  margin-bottom: 36px;
  animation: fadeUp 0.7s 0.2s ease both;
  line-height: 1.8;
}
.hero-sub strong { color: var(--white); }

.hero-cta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 56px;
  animation: fadeUp 0.7s 0.3s ease both;
}

.btn-primary {
  display: inline-block;
  background: var(--gradient);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 100px;
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  box-shadow: 0 8px 30px rgba(124,58,237,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(124,58,237,0.55);
}

.btn-ghost {
  display: inline-block;
  background: transparent;
  color: var(--white);
  padding: 14px 28px;
  border-radius: 100px;
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  border: 1px solid var(--border);
  transition: border-color 0.2s, background 0.2s;
}
.btn-ghost:hover {
  border-color: rgba(168,85,247,0.5);
  background: rgba(168,85,247,0.07);
}

.btn-full { width: 100%; text-align: center; font-size: 1.05rem; padding: 16px; }

.hero-stats {
  display: flex;
  align-items: center;
  gap: 28px;
  animation: fadeUp 0.7s 0.4s ease both;
}

.stat { display: flex; flex-direction: column; }
.stat .num { font-size: 1.4rem; font-weight: 800; color: var(--white); }
.stat .lbl { font-size: 0.75rem; color: var(--muted); }
.stat-divider { width: 1px; height: 36px; background: var(--border); }

.hero-img-wrap {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 48%;
  max-width: 620px;
  z-index: 1;
  animation: fadeIn 1s 0.4s ease both;
}
.hero-img {
  width: 100%;
  object-fit: cover;
  border-radius: 24px 0 0 24px;
  mask-image: linear-gradient(to right, transparent 0%, black 25%, black 80%, transparent 100%);
  -webkit-mask-image: linear-gradient(to right, transparent 0%, black 25%, black 80%, transparent 100%);
}

/* =====================
   AGENDA
======================== */
.agenda {
  padding: 100px 0;
  text-align: center;
  background: var(--dark2);
  position: relative;
}

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

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

.agenda-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: left;
  transition: transform 0.25s, border-color 0.25s, background 0.25s;
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.agenda-card:hover {
  transform: translateY(-4px);
  border-color: rgba(168,85,247,0.35);
  background: rgba(168,85,247,0.07);
}

.agenda-card--highlight {
  background: linear-gradient(135deg, rgba(124,58,237,0.18), rgba(6,182,212,0.1));
  border-color: rgba(168,85,247,0.4);
}

.agenda-icon {
  font-size: 1.6rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.agenda-card p { font-size: 0.95rem; color: var(--muted); line-height: 1.6; }
.agenda-card p strong { color: var(--white); }

/* =====================
   SESSIONS
======================== */
.sessions {
  padding: 100px 0;
  text-align: center;
  background: var(--dark);
}

.timeline {
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: relative;
  margin-top: 8px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 52px;
  top: 0; bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--purple), var(--cyan), transparent);
  border-radius: 2px;
}

.session-card {
  display: flex;
  gap: 28px;
  text-align: left;
  padding: 28px 32px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative;
  transition: border-color 0.25s, background 0.25s, transform 0.25s;
  opacity: 0;
  transform: translateX(-20px);
}

.session-card.visible {
  opacity: 1;
  transform: translateX(0);
  transition: opacity 0.5s ease, transform 0.5s ease, border-color 0.25s, background 0.25s;
}

.session-card:hover {
  border-color: rgba(168,85,247,0.4);
  background: rgba(168,85,247,0.06);
  transform: translateX(4px);
}

.session-num {
  font-size: 2.8rem;
  font-weight: 900;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  flex-shrink: 0;
  width: 64px;
  line-height: 1;
}

.session-body { flex: 1; }

.session-body h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 14px;
}

.session-body ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.session-body ul li {
  font-size: 0.93rem;
  color: var(--muted);
  padding-left: 20px;
  position: relative;
  line-height: 1.6;
}

.session-body ul li::before {
  content: '✿';
  position: absolute;
  left: 0;
  color: var(--purple-light);
  font-size: 0.75rem;
  top: 3px;
}

.session-body ul li strong { color: var(--text); }

/* =====================
   REGISTER
======================== */
.register {
  padding: 100px 0;
  background: var(--dark2);
  position: relative;
  overflow: hidden;
}

.register::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 80% at 80% 50%, rgba(124,58,237,0.12) 0%, transparent 70%);
  pointer-events: none;
}

.register-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.info-list { display: flex; flex-direction: column; gap: 24px; }

.info-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
}

.info-icon { font-size: 1.5rem; flex-shrink: 0; }

.info-item strong {
  display: block;
  color: var(--white);
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.info-item p { color: var(--muted); font-size: 0.9rem; line-height: 1.6; }
.info-item p strong { display: inline; color: var(--white); }

.register-form-wrap {
  position: sticky;
  top: 100px;
}

.register-form {
  background: var(--dark3);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 36px 32px;
  box-shadow: var(--shadow);
}

.register-form h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--white);
  margin-bottom: 24px;
  text-align: center;
}

.form-group { margin-bottom: 14px; }

.form-group input,
.form-group select {
  width: 100%;
  padding: 13px 18px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--white);
  font-family: 'Be Vietnam Pro', sans-serif;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s;
}

.form-group input::placeholder { color: var(--muted); }
.form-group select option { background: var(--dark3); color: var(--white); }

.form-group input:focus,
.form-group select:focus {
  border-color: var(--purple-light);
  background: rgba(168,85,247,0.06);
}

.form-note {
  text-align: center;
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 12px;
}

.success-msg {
  display: none;
  text-align: center;
  color: #4ade80;
  font-weight: 600;
  padding: 16px;
  background: rgba(74,222,128,0.08);
  border: 1px solid rgba(74,222,128,0.2);
  border-radius: var(--radius-sm);
  margin-top: 16px;
}

/* =====================
   FOOTER
======================== */
.footer {
  padding: 36px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-logo {
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--white);
  margin-bottom: 8px;
}
.footer-logo span { color: var(--purple-light); }

.footer p { font-size: 0.82rem; color: var(--muted); }

/* =====================
   ANIMATIONS
======================== */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* =====================
   RESPONSIVE
======================== */
@media (max-width: 1024px) {
  .hero-img-wrap { width: 44%; }
  .agenda-grid { grid-template-columns: repeat(2, 1fr); }
  .register-inner { grid-template-columns: 1fr; gap: 40px; }
  .register-form-wrap { position: static; }
  .timeline::before { left: 44px; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .hamburger { display: block; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 64px; left: 0; right: 0;
    background: rgba(5,8,17,0.97);
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border);
  }

  .hero { padding-top: 80px; }
  .hero-content { max-width: 100%; }
  .hero-img-wrap { display: none; }
  .hero h1 { letter-spacing: -1px; }
  .hero-stats { gap: 16px; flex-wrap: wrap; }

  .agenda-grid { grid-template-columns: 1fr; }

  .timeline::before { display: none; }
  .session-card { flex-direction: column; gap: 8px; }
  .session-num { font-size: 1.8rem; width: auto; }

  .register-form { padding: 24px 20px; }
}