:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #0e0e18;
  --bg-card: #14141f;
  --border-subtle: #1a1a25;
  --text-primary: #f0f0f5;
  --text-secondary: #8a8a9a;
  --text-muted: #555566;
  --accent-green: #1a8a6b;
  --accent-green-light: #22b88a;
  --accent-navy: #2b3a5c;
  --accent-navy-light: #3d5280;
  --gradient-root: linear-gradient(135deg, #1a8a6b 0%, #2b3a5c 100%);
  --gradient-wave: linear-gradient(90deg, #2b3a5c 0%, #1a8a6b 50%, #22b88a 100%);
  --font-en: 'Outfit', sans-serif;
  --font-kr: 'Noto Sans KR', sans-serif;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
}

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-kr);
  background: var(--bg-primary);
  color: var(--text-primary);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--accent-green);
  color: #fff;
}

#wave-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

#nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 48px;
  transition: background 0.5s, backdrop-filter 0.5s;
}

#nav.scrolled {
  background: rgba(10, 10, 15, 0.88);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom: 1px solid rgba(255,255,255,0.03);
}

.nav-ci {
  height: 34px;
  width: auto;
  opacity: 0;
  transition: opacity 0.6s;
}

#nav.scrolled .nav-ci {
  opacity: 1;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 101;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  transition: transform 0.3s, opacity 0.3s;
  border-radius: 1px;
}

.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); }

.nav-links {
  display: flex;
  list-style: none;
  gap: 36px;
}

.nav-links a {
  font-family: var(--font-en);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--text-muted);
  transition: color 0.3s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent-green-light);
  transition: width 0.4s var(--ease-out-expo);
}

.nav-links a:hover, .nav-links a.active { color: var(--text-primary); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

.lang-switch {
  font-family: var(--font-en);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-decoration: none;
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
  padding: 6px 14px;
  transition: all 0.3s;
  margin-left: 12px;
}

.lang-switch:hover {
  color: var(--accent-green-light);
  border-color: var(--accent-green-light);
  background: rgba(34, 184, 138, 0.06);
}

.scroll-indicator {
  position: fixed;
  right: 32px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.scroll-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  border: 1px solid var(--text-muted);
  transition: all 0.5s var(--ease-out-expo);
  cursor: pointer;
}

.scroll-dot.active {
  background: var(--accent-green-light);
  border-color: var(--accent-green-light);
  transform: scale(1.6);
  box-shadow: 0 0 16px rgba(34, 184, 138, 0.5);
}

#main-container {
  position: relative;
  z-index: 1;
}

.section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.section-inner {
  width: 100%;
  max-width: 1200px;
  padding: 120px 60px;
  display: flex;
  align-items: center;
  gap: 80px;
}

.section-inner--split {
  display: flex;
  gap: 80px;
}

.section-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.section-content-right {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.section-visual {
  flex: 0 0 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  min-height: 300px;
}

.section-num {
  font-family: var(--font-en);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--accent-green-light);
}

.section-title {
  font-size: clamp(32px, 4.5vw, 48px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.section-title-em {
  font-size: clamp(32px, 4.5vw, 48px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
  background: var(--gradient-wave);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-divider {
  width: 60px;
  height: 3px;
  background: var(--gradient-root);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 1s var(--ease-out-expo) 0.3s;
}

.reveal-block.visible .section-divider { transform: scaleX(1); }

.section-desc {
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: var(--text-secondary);
  font-weight: 300;
}

.reveal-text {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.9s var(--ease-out-expo), transform 0.9s var(--ease-out-expo);
}

.reveal-block.visible .reveal-text { opacity: 1; transform: translateY(0); }
.reveal-block.visible .reveal-text:nth-child(2) { transition-delay: 0.08s; }
.reveal-block.visible .reveal-text:nth-child(3) { transition-delay: 0.14s; }
.reveal-block.visible .reveal-text:nth-child(4) { transition-delay: 0.2s; }
.reveal-block.visible .reveal-text:nth-child(5) { transition-delay: 0.26s; }

/* HERO */
.section--hero {
  flex-direction: column;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
}

.hero-glow--1 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(26, 138, 107, 0.08) 0%, transparent 70%);
  top: 20%;
  left: 30%;
}

.hero-glow--2 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(43, 58, 92, 0.1) 0%, transparent 70%);
  bottom: 10%;
  right: 20%;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 36px;
  text-align: center;
  position: relative;
  z-index: 2;
}

.hero-logo-wrap {
  position: relative;
}

.hero-logo {
  width: clamp(180px, 26vw, 320px);
  height: auto;
  animation: logoFloat 7s ease-in-out infinite;
  filter: drop-shadow(0 16px 48px rgba(26, 138, 107, 0.25));
}

.logo-glow {
  position: absolute;
  width: 200%;
  height: 200%;
  top: -50%;
  left: -50%;
  background: radial-gradient(circle, rgba(26, 138, 107, 0.06) 0%, transparent 60%);
  pointer-events: none;
  animation: logoFloat 7s ease-in-out infinite reverse;
}

@keyframes logoFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}

.hero-title {
  font-family: var(--font-en);
  font-size: clamp(48px, 9vw, 96px);
  font-weight: 900;
  letter-spacing: -3px;
  line-height: 1.05;
  display: flex;
  gap: 0.18em;
  flex-wrap: wrap;
  justify-content: center;
}

.hero-title .word {
  display: inline-block;
  opacity: 0;
  transform: translateY(50px) rotateX(-12deg);
  animation: wordReveal 1.1s var(--ease-out-expo) forwards;
}

.hero-title .word:nth-child(1) { animation-delay: 0.3s; }
.hero-title .word.accent-green { animation-delay: 0.5s; color: var(--accent-green-light); }
.hero-title .word.light { animation-delay: 0.7s; color: var(--text-muted); font-weight: 300; }
.hero-title .word.accent-navy { animation-delay: 0.9s; color: var(--accent-navy-light); }

@keyframes wordReveal {
  to { opacity: 1; transform: translateY(0) rotateX(0); }
}

.hero-sub {
  font-size: clamp(15px, 1.8vw, 20px);
  color: var(--text-secondary);
  font-weight: 300;
  letter-spacing: 0.15em;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out-expo) 1.2s forwards;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero-divider {
  width: 60px;
  height: 2px;
  background: var(--gradient-root);
  opacity: 0;
  animation: fadeUp 1s var(--ease-out-expo) 1.5s forwards;
}

.scroll-cue {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out-expo) 1.8s forwards;
}

.scroll-cue span {
  font-family: var(--font-en);
  font-size: 10px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.scroll-cue-line {
  width: 1px;
  height: 36px;
  background: linear-gradient(to bottom, var(--accent-green-light), transparent);
  animation: scrollPulse 2.5s ease-in-out infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.2; transform: scaleY(0.5); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* PHILOSOPHY */
.root-lines {
  display: flex;
  gap: 20px;
  align-items: center;
  justify-content: center;
  height: 100%;
}

.root-line {
  width: 2px;
  height: 0;
  background: var(--gradient-root);
  border-radius: 1px;
  transform: rotate(var(--rotate));
  transition: height 1.4s var(--ease-out-expo) var(--delay);
}

.reveal-block.visible .root-line {
  height: var(--h);
}

/* DEVELOPMENT */
.dev-visual {
  flex-direction: column;
  gap: 16px;
}

.glass-card {
  background: rgba(20, 20, 31, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 24px 32px;
  display: flex;
  align-items: center;
  gap: 16px;
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateX(40px);
  transition: all 0.9s var(--ease-out-expo);
  width: 100%;
}

.glass-card[data-float="1"] { transition-delay: 0.2s; }
.glass-card[data-float="2"] { transition-delay: 0.4s; }
.glass-card[data-float="3"] { transition-delay: 0.6s; }

.reveal-block.visible .glass-card {
  opacity: 1;
  transform: translateX(0);
}

.glass-card:hover {
  border-color: rgba(26, 138, 107, 0.2);
  transform: translateX(6px);
}

.glass-card:hover .card-glow {
  opacity: 1;
}

.card-glow {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(26, 138, 107, 0.03), transparent);
  opacity: 0;
  transition: opacity 0.4s;
  pointer-events: none;
}

.card-icon {
  font-size: 26px;
  line-height: 1;
}

.card-label {
  font-family: var(--font-en);
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

/* FUN & PRACTICAL */
.section--funpractical {
  background: var(--bg-secondary);
}

.tag-row {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-top: 16px;
}

.tag-word {
  font-family: var(--font-en);
  font-size: clamp(32px, 4vw, 44px);
  font-weight: 800;
  background: linear-gradient(90deg, #2b3a5c, #22b88a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tag-word--alt {
  background: linear-gradient(90deg, #1a8a6b, #3d5280);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tag-x {
  font-family: var(--font-en);
  font-size: 22px;
  color: var(--text-muted);
}

/* TECHNOLOGY */
.section--technology {
  position: relative;
}

.tech-glow {
  position: absolute;
  width: 500px;
  height: 500px;
  right: 15%;
  top: 30%;
  background: radial-gradient(circle, rgba(26, 138, 107, 0.05) 0%, transparent 60%);
  filter: blur(60px);
  pointer-events: none;
}

.tech-visual {
  flex: 0 0 400px;
}

.orbit-system {
  position: relative;
  width: 300px;
  height: 300px;
  margin: 0 auto;
}

.orbit-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid;
}

.orbit-ring--1 {
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  border-color: rgba(26, 138, 107, 0.12);
  animation: orbitSpin 25s linear infinite;
}

.orbit-ring--2 {
  width: 70%;
  height: 70%;
  top: 15%;
  left: 15%;
  border-color: rgba(43, 58, 92, 0.2);
  animation: orbitSpin 18s linear infinite reverse;
}

.orbit-ring--3 {
  width: 40%;
  height: 40%;
  top: 30%;
  left: 30%;
  border-color: rgba(34, 184, 138, 0.15);
  animation: orbitSpin 12s linear infinite;
}

.orbit-center {
  position: absolute;
  width: 12px;
  height: 12px;
  background: var(--accent-green-light);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  box-shadow: 0 0 24px rgba(34, 184, 138, 0.6), 0 0 60px rgba(34, 184, 138, 0.2);
  animation: dotPulse 3s ease-in-out infinite;
}

.orbit-particle {
  position: absolute;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent-green-light);
}

.orbit-particle--1 {
  top: 0;
  left: 50%;
  animation: orbitSpin 25s linear infinite;
  transform-origin: 0 150px;
  opacity: 0.6;
}

.orbit-particle--2 {
  top: 15%;
  left: calc(50% + 52.5%);
  animation: orbitSpin 18s linear infinite reverse;
  transform-origin: -52.5% 105px;
  opacity: 0.4;
  background: var(--accent-navy-light);
}

.orbit-particle--3 {
  top: 30%;
  left: calc(50% + 20%);
  animation: orbitSpin 12s linear infinite;
  transform-origin: -20% 60px;
  opacity: 0.5;
}

@keyframes orbitSpin {
  to { transform: rotate(360deg); }
}

@keyframes dotPulse {
  0%, 100% { box-shadow: 0 0 24px rgba(34, 184, 138, 0.6), 0 0 60px rgba(34, 184, 138, 0.2); transform: translate(-50%, -50%) scale(1); }
  50% { box-shadow: 0 0 32px rgba(34, 184, 138, 0.8), 0 0 80px rgba(34, 184, 138, 0.3); transform: translate(-50%, -50%) scale(1.3); }
}

/* FOOTER */
.footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--border-subtle);
  padding: 48px 60px;
  background: var(--bg-primary);
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-ci {
  height: 32px;
  width: auto;
  opacity: 0.5;
  transition: opacity 0.3s;
}

.footer-ci:hover { opacity: 1; }

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

.footer-company {
  font-family: var(--font-en);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  margin-bottom: 4px;
}

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

/* RESPONSIVE */
@media (max-width: 768px) {
  #nav { padding: 16px 24px; }

  .nav-toggle { display: flex; }

  .nav-links {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(10, 10, 15, 0.97);
    backdrop-filter: blur(24px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s;
  }

  .nav-links.open { opacity: 1; pointer-events: auto; }
  .nav-links a { font-size: 16px; }

  .scroll-indicator { right: 14px; }

  .section-inner {
    flex-direction: column;
    padding: 80px 28px;
    gap: 48px;
  }

  .section-inner--split { flex-direction: column; }

  .section-visual {
    flex: none;
    width: 100%;
    min-height: 180px;
  }

  .orbit-system { width: 200px; height: 200px; }

  .footer { padding: 32px 28px; }
  .footer-inner { flex-direction: column; gap: 16px; text-align: center; }
  .footer-info { text-align: center; }
  .hero-glow { display: none; }
  .tech-glow { display: none; }
}

@media (max-width: 480px) {
  .section-inner { padding: 60px 20px; }
  .hero-logo { width: 160px; }
  .scroll-indicator { display: none; }
  .glass-card { padding: 16px 20px; }
  .hero-title { letter-spacing: -1px; }
}