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

:root {
  --bg: #000;
  --bg-card: rgba(255, 255, 255, 0.04);
  --bg-card-hover: rgba(255, 255, 255, 0.08);
  --border-card: rgba(255, 255, 255, 0.08);
  --text-primary: #fff;
  --text-secondary: rgba(255, 255, 255, 0.55);
  --text-tertiary: rgba(255, 255, 255, 0.3);
  --accent: #3182f6;
  --accent-hover: #1b64da;
  --radius: 16px;
  --radius-sm: 12px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  overflow: hidden;
  height: 100%;
}

body {
  font-family: 'Pretendard Variable', Pretendard, -apple-system, BlinkMacSystemFont,
    'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  overflow: hidden;
  height: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Sections Container ===== */
.section {
  width: 100%;
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
  transform: translateY(40px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
  pointer-events: none;
  overflow: hidden;
}

.section.active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
  z-index: 1;
}

.section.exit-up {
  opacity: 0;
  transform: translateY(-60px);
}

.section.exit-down {
  opacity: 0;
  transform: translateY(60px);
}

.section-inner {
  width: 100%;
  max-width: 1120px;
  padding: 0 32px;
  text-align: center;
}

/* ===== Dot Navigation ===== */
.dot-nav {
  position: fixed;
  right: 28px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, 0.3);
  background: transparent;
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
}

.dot:hover {
  border-color: rgba(255, 255, 255, 0.6);
}

.dot.active {
  background: var(--text-primary);
  border-color: var(--text-primary);
  transform: scale(1.3);
}

/* ===== Typography ===== */
.section-label {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.section-desc {
  font-size: clamp(16px, 2vw, 20px);
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto 48px;
}

/* ===== Buttons ===== */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 36px;
  background: var(--accent);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
  letter-spacing: -0.01em;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(49, 130, 246, 0.3);
}

.btn-primary.btn-large {
  padding: 18px 48px;
  font-size: 18px;
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 36px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 16px;
  font-weight: 500;
  border: 1.5px solid rgba(255, 255, 255, 0.15);
  border-radius: 50px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-ghost:hover {
  color: var(--text-primary);
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-2px);
}

/* ===== Hero Section ===== */
.section-hero {
  background: radial-gradient(ellipse at 50% 30%, rgba(49, 130, 246, 0.06) 0%, transparent 60%);
}

.hero-content {
  text-align: center;
}

.hero-logo {
  margin-bottom: 32px;
}

.hero-logo img {
  width: min(320px, 70vw);
  height: auto;
}

.hero-subtitle {
  font-size: clamp(18px, 2.5vw, 24px);
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 48px;
  letter-spacing: -0.01em;
}

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

.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
}

.scroll-line {
  width: 1px;
  height: 48px;
  background: linear-gradient(to bottom, rgba(255,255,255,0.4), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.6); transform-origin: top; }
  50% { opacity: 1; transform: scaleY(1); }
}

/* ===== Video Section ===== */
.video-wrapper {
  position: relative;
  width: 100%;
  max-width: 900px;
  margin: 40px auto 0;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-card);
}

.video-wrapper video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.video-play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(10px);
  border: none;
  border-radius: 50%;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  z-index: 2;
}

.video-play-btn:hover {
  background: rgba(0, 0, 0, 0.7);
  transform: translate(-50%, -50%) scale(1.1);
}

.video-play-btn.hidden {
  opacity: 0;
  pointer-events: none;
}

.video-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  color: var(--text-tertiary);
  font-size: 14px;
  display: none;
}

.video-wrapper.no-video .video-placeholder {
  display: flex;
}

.video-wrapper.no-video video,
.video-wrapper.no-video .video-play-btn {
  display: none;
}

/* ===== Features Section ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.floating-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: left;
  transition: var(--transition);
  backdrop-filter: blur(20px);
}

.floating-card:hover {
  background: var(--bg-card-hover);
  transform: translateY(-6px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
  border-color: rgba(255, 255, 255, 0.12);
}

.feature-icon {
  margin-bottom: 24px;
  opacity: 0.8;
}

.feature-card h4,
.dcc-card h4 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.feature-card p,
.dcc-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ===== DCC Section ===== */
.section-dcc {
  justify-content: flex-start;
  padding-top: 10vh;
}

.dcc-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 40px;
}

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

.cta-area {
  margin-top: 56px;
}

/* ===== Mobile Footer Section ===== */
.section-mobile-footer {
  display: none;
}

.mobile-only {
  display: none;
}

/* ===== Footer ===== */
.site-footer {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 32px 0;
}

.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.footer-logo img {
  opacity: 0.4;
  transition: var(--transition);
}

.footer-logo img:hover {
  opacity: 0.7;
}

.footer-info {
  text-align: center;
  flex: 1;
}

.footer-company {
  font-weight: 600;
  margin-bottom: 4px;
  font-size: 14px;
}

.footer-info p {
  font-size: 13px;
  color: var(--text-tertiary);
  line-height: 1.7;
}

.footer-copy {
  text-align: right;
}

.footer-copy p {
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ===== Animations ===== */
.anim-fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.anim-scale-in {
  opacity: 0;
  transform: scale(0.95);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.section.active .anim-fade-up,
.section.active .anim-scale-in {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.delay-1 { transition-delay: 0.15s; }
.delay-2 { transition-delay: 0.3s; }
.delay-3 { transition-delay: 0.45s; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .dot-nav {
    right: 14px;
    gap: 12px;
  }

  .dot {
    width: 8px;
    height: 8px;
  }

  .mobile-only {
    display: block;
  }

  .desktop-footer {
    display: none;
  }

  .section-mobile-footer {
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .section-mobile-footer .site-footer {
    position: static;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: auto;
    border-top: none;
    padding: 0;
  }

  .section-mobile-footer .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: 24px;
    padding: 0 24px;
  }

  .section-mobile-footer .footer-logo img {
    opacity: 0.6;
    width: 160px;
  }

  .section-mobile-footer .footer-info {
    text-align: center;
  }

  .section-mobile-footer .footer-copy {
    text-align: center;
  }

  .section-inner {
    padding: 0 20px;
  }

  .hero-logo img {
    width: min(240px, 65vw);
  }

  .hero-subtitle {
    font-size: 17px;
    margin-bottom: 36px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }

  .btn-primary, .btn-ghost {
    width: 100%;
    max-width: 280px;
  }

  .section-features,
  .section-dcc {
    justify-content: flex-start;
    padding-top: 12vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .section-dcc {
    padding-top: 10vh;
  }

  .features-grid,
  .dcc-grid {
    grid-template-columns: 1fr;
    gap: 10px;
    margin-top: 20px;
  }

  .floating-card {
    padding: 16px 18px;
    display: flex;
    align-items: flex-start;
    gap: 14px;
  }

  .floating-card:hover {
    transform: none;
    box-shadow: none;
  }

  .feature-icon,
  .dcc-icon {
    margin-bottom: 0;
    flex-shrink: 0;
  }

  .feature-icon svg,
  .dcc-icon svg {
    width: 32px;
    height: 32px;
  }

  .feature-card h4,
  .dcc-card h4 {
    font-size: 15px;
    margin-bottom: 4px;
  }

  .feature-card p,
  .dcc-card p {
    font-size: 13px;
    line-height: 1.5;
  }

  .section-title {
    margin-bottom: 8px;
  }

  .section-desc {
    margin-bottom: 20px;
    font-size: 14px;
  }

  .section-label {
    margin-bottom: 10px;
  }

  .cta-area {
    margin-top: 24px;
    padding-bottom: 20px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: 20px;
    padding: 0 20px;
  }

  .footer-info {
    text-align: center;
  }

  .footer-copy {
    text-align: center;
  }

  .video-wrapper {
    margin-top: 28px;
    border-radius: var(--radius-sm);
  }

  .scroll-indicator {
    bottom: 24px;
  }
}

@media (max-width: 480px) {
  .section-label {
    font-size: 11px;
    letter-spacing: 2px;
  }

  .section-features,
  .section-dcc {
    padding-top: 10vh;
  }

  .floating-card {
    padding: 14px 16px;
    gap: 12px;
  }

  .feature-icon svg,
  .dcc-icon svg {
    width: 28px;
    height: 28px;
  }

  .feature-card h4,
  .dcc-card h4 {
    font-size: 14px;
  }

  .feature-card p,
  .dcc-card p {
    font-size: 12px;
  }

  .btn-primary.btn-large {
    padding: 14px 32px;
    font-size: 15px;
  }

  .site-footer {
    padding: 24px 0;
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}