/* ========================================
   Design Tokens
   ======================================== */
:root {
  --bg-primary: #111111;
  --bg-section: #0A0A0A;
  --bg-card: #1A1A1A;
  --bg-card-hover: #222222;
  --bg-modal: #1A1A1A;
  --accent: #FCE000;
  --accent-hover: #FFD700;
  --accent-dark: #C4AD00;
  --text-primary: #FFFFFF;
  --text-secondary: #9CA3AF;
  --text-muted: #6B7280;
  --border: #2A2A2A;
  --border-hover: #3A3A3A;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

body.modal-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

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

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

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 48px;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font);
  font-weight: 600;
  font-size: 1rem;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn--primary {
  background: var(--accent);
  color: #111;
}

.btn--primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(252, 224, 0, 0.3);
}

.btn--primary:active {
  transform: translateY(0);
}

.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

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

.btn--outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}

.btn--outline:hover {
  background: rgba(252, 224, 0, 0.1);
}

.btn--lg {
  padding: 16px 36px;
  font-size: 1.125rem;
  border-radius: var(--radius-md);
}

.btn--full {
  width: 100%;
  padding: 14px 28px;
}

/* ========================================
   Header
   ======================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: all var(--transition);
}

.header.scrolled {
  background: rgba(17, 17, 17, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

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

.header__logo {
  display: flex;
  align-items: center;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-secondary);
  gap: 0;
}

.header__logo-accent {
  font-weight: 900;
  color: var(--accent);
  margin-right: 6px;
  font-size: 1.25rem;
  letter-spacing: 0.05em;
}

.header__nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.header__link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
}

.header__link:hover {
  color: var(--text-primary);
}

.header__link--cta {
  background: var(--accent);
  color: #111;
  padding: 8px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.header__link--cta:hover {
  color: #111;
  background: var(--accent-hover);
}

.header__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

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

.header__burger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.header__burger.active span:nth-child(2) {
  opacity: 0;
}

.header__burger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ========================================
   Hero
   ======================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  background:
    radial-gradient(ellipse at 20% 50%, rgba(252, 224, 0, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(252, 224, 0, 0.03) 0%, transparent 50%),
    var(--bg-primary);
}

.hero__inner {
  text-align: center;
}

.hero__badges {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.hero__badge--accent {
  background: rgba(252, 224, 0, 0.1);
  border-color: rgba(252, 224, 0, 0.3);
  color: var(--accent);
}

.hero__overtitle {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: 16px;
}

.hero__title {
  font-size: clamp(2.5rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero__title br {
  display: none;
}

.hero__subtitle {
  font-size: clamp(1.125rem, 2.5vw, 1.375rem);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 48px;
  line-height: 1.5;
}

.hero__stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-bottom: 48px;
}

.hero__stat {
  text-align: center;
}

.hero__stat-number {
  display: block;
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  color: var(--accent);
  line-height: 1.1;
}

.hero__stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 500;
}

.hero__actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
}

/* ========================================
   About
   ======================================== */
.about {
  padding: 100px 0;
  background: var(--bg-section);
}

.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about__desc {
  font-size: 1.125rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-top: 16px;
}

.about__cards {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.info-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.info-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
}

.info-card__icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(252, 224, 0, 0.1);
  border-radius: var(--radius-sm);
  color: var(--accent);
}

.info-card__title {
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 2px;
}

.info-card__text {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* ========================================
   Program
   ======================================== */
.program {
  padding: 100px 0;
}

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

.program-card {
  padding: 28px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--accent);
  transition: all var(--transition);
}

.program-card:hover {
  border-color: var(--border-hover);
  border-left-color: var(--accent);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.program-card__num {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--accent);
  background: rgba(252, 224, 0, 0.1);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 16px;
}

.program-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.program-card__list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.program-card__list li {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  padding-left: 16px;
  position: relative;
}

.program-card__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 10px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.6;
}

/* ========================================
   Speakers
   ======================================== */
.speakers {
  padding: 100px 0;
  background: var(--bg-section);
}

.speakers__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.speaker-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.speaker-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.speaker-card__avatar {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--avatar-color, #666);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: #111;
}

.speaker-card__org {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 2px;
}

.speaker-card__topic {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.speakers__note {
  text-align: center;
  margin-top: 32px;
  color: var(--text-muted);
  font-size: 0.9375rem;
  font-style: italic;
}

/* ========================================
   Why Attend
   ======================================== */
.why-attend {
  padding: 100px 0;
}

.why-attend__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.why-card {
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.why-card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.why-card__icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(252, 224, 0, 0.1);
  border-radius: var(--radius-md);
  color: var(--accent);
  margin-bottom: 20px;
}

.why-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.why-card__text {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ========================================
   CTA
   ======================================== */
.cta {
  padding: 100px 0;
  background: var(--bg-section);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.cta__inner {
  text-align: center;
}

.cta__title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  color: var(--accent);
  margin-bottom: 8px;
}

.cta__subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.cta__actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
}

/* ========================================
   Footer
   ======================================== */
.footer {
  padding: 48px 0;
  border-top: 1px solid var(--border);
}

.footer__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.footer__logo {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.footer__logo-accent {
  font-weight: 900;
  color: var(--accent);
  margin-right: 4px;
  letter-spacing: 0.05em;
}

.footer__org {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.footer__right {
  text-align: right;
}

.footer__date {
  font-weight: 600;
  font-size: 0.9375rem;
}

.footer__venue {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

.footer__bottom {
  grid-column: 1 / -1;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ========================================
   Modal
   ======================================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

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

.modal__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.modal__content {
  position: relative;
  background: var(--bg-modal);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 40px;
  max-width: 520px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  transform: translateY(20px) scale(0.98);
  transition: transform 0.3s ease;
}

.modal.active .modal__content {
  transform: translateY(0) scale(1);
}

.modal__close {
  position: absolute;
  top: 16px;
  right: 20px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.75rem;
  cursor: pointer;
  line-height: 1;
  transition: color var(--transition);
  padding: 4px;
}

.modal__close:hover {
  color: var(--text-primary);
}

.modal__title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.modal__subtitle {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* ========================================
   Form
   ======================================== */
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.required {
  color: var(--accent);
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font);
  font-size: 1rem;
  color: var(--text-primary);
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition);
  appearance: none;
  -webkit-appearance: none;
}

.form-group input::placeholder {
  color: var(--text-muted);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(252, 224, 0, 0.1);
}

.form-group select {
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%236B7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
}

.form-group select option {
  background: var(--bg-primary);
  color: var(--text-primary);
}

.form-hint {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.form-group input.error,
.form-group select.error {
  border-color: #EF4444;
}

/* ========================================
   Success State
   ======================================== */
.modal__success {
  text-align: center;
  padding: 20px 0;
}

.modal__success-icon {
  margin-bottom: 20px;
}

.modal__success-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.modal__success-text {
  color: var(--text-secondary);
  margin-bottom: 28px;
  line-height: 1.6;
}

/* ========================================
   Scroll Animations
   ======================================== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger animation delay for grid items */
.program__grid .animate-on-scroll:nth-child(2),
.speakers__grid .animate-on-scroll:nth-child(2),
.why-attend__grid .animate-on-scroll:nth-child(2) {
  transition-delay: 0.1s;
}

.program__grid .animate-on-scroll:nth-child(3),
.speakers__grid .animate-on-scroll:nth-child(3),
.why-attend__grid .animate-on-scroll:nth-child(3) {
  transition-delay: 0.2s;
}

.program__grid .animate-on-scroll:nth-child(4),
.speakers__grid .animate-on-scroll:nth-child(4),
.why-attend__grid .animate-on-scroll:nth-child(4) {
  transition-delay: 0.3s;
}

.program__grid .animate-on-scroll:nth-child(5),
.speakers__grid .animate-on-scroll:nth-child(5) {
  transition-delay: 0.4s;
}

.program__grid .animate-on-scroll:nth-child(6),
.speakers__grid .animate-on-scroll:nth-child(6) {
  transition-delay: 0.5s;
}

.speakers__grid .animate-on-scroll:nth-child(7) {
  transition-delay: 0.6s;
}

.speakers__grid .animate-on-scroll:nth-child(8) {
  transition-delay: 0.7s;
}

/* ========================================
   Responsive: Tablet (768px)
   ======================================== */
@media (max-width: 1024px) {
  .program__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .speakers__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .header__nav {
    position: fixed;
    top: 0;
    right: 0;
    width: 280px;
    height: 100vh;
    background: var(--bg-primary);
    border-left: 1px solid var(--border);
    flex-direction: column;
    align-items: flex-start;
    padding: 80px 32px 32px;
    gap: 0;
    transform: translateX(100%);
    transition: transform var(--transition);
    z-index: 999;
  }

  .header__nav.active {
    transform: translateX(0);
  }

  .header__nav .header__link {
    padding: 12px 0;
    font-size: 1.125rem;
    width: 100%;
    border-bottom: 1px solid var(--border);
  }

  .header__nav .header__link--cta {
    margin-top: 16px;
    text-align: center;
    border-bottom: none;
  }

  .header__burger {
    display: flex;
    z-index: 1001;
  }

  .hero {
    padding: 100px 0 60px;
  }

  .hero__title br {
    display: block;
  }

  .hero__stats {
    gap: 24px;
  }

  .about__grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

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

  .why-attend__grid {
    grid-template-columns: 1fr;
  }

  .footer__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer__right {
    text-align: center;
  }

  .modal__content {
    padding: 28px 20px;
    border-radius: var(--radius-lg);
  }

  .form-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero__stats {
    flex-direction: column;
    gap: 16px;
  }

  .hero__actions {
    flex-direction: column;
    align-items: center;
  }

  .hero__actions .btn {
    width: 100%;
  }

  .cta__actions {
    flex-direction: column;
    align-items: center;
  }

  .cta__actions .btn {
    width: 100%;
  }

  .hero__badges {
    flex-direction: column;
    align-items: center;
  }
}