:root {
  --primary-color: #1a1a2e;
  --secondary-color: #16213e;
  --accent-color: #0f3460;
  --highlight-color: #e94560;
  --text-light: #f5f5f5;
  --text-muted: #b8b8b8;
  --background: #0a0a0a;
  --card-background: rgba(255, 255, 255, 0.02);
  --border-color: rgba(255, 255, 255, 0.1);
  --gradient-primary: linear-gradient(135deg, #0f3460, #1a1a2e);
  --gradient-accent: linear-gradient(135deg, #e94560, #f27121);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  --shadow-light: 0 5px 15px rgba(0, 0, 0, 0.2);
}

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

/* Critical CSS for above-the-fold content */
.nav, .hero {
  contain: layout style paint;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--background);
  color: var(--text-light);
  line-height: 1.6;
  overflow-x: hidden;
}

.nav {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10, 10, 10, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
}

.nav-content {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-img {
  width: 32px;
  height: 32px;
  transition: transform 0.3s ease;
}

.logo-img:hover {
  transform: rotate(45deg) scale(1.1);
}

.tetra-symbol {
  font-size: 1.5rem;
  color: var(--highlight-color);
  transform: rotate(45deg);
  transition: transform 0.3s ease;
}

.tetra-symbol:hover {
  transform: rotate(90deg);
}

.company-name {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.025em;
}

.main {
  margin-top: 80px;
}

.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  padding: 1.5rem;
  background:
    radial-gradient(ellipse at top, rgba(15, 52, 96, 0.1), transparent 50%),
    radial-gradient(ellipse at bottom, rgba(233, 69, 96, 0.05), transparent 50%);
}

.hero-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 4rem;
  padding: 0 2rem;
}

.hero-text {
  max-width: 500px;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
}

.title-line {
  display: block;
  opacity: 0;
  transform: translateY(30px);
  animation: slideInUp 0.8s ease forwards;
}

.title-line:nth-child(1) { animation-delay: 0.1s; }
.title-line:nth-child(2) { animation-delay: 0.2s; }
.title-line:nth-child(3) { animation-delay: 0.3s; }
.title-line:nth-child(4) { animation-delay: 0.4s; }

.title-line.emphasis {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}


.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.tetra-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  width: 300px;
  height: 300px;
}

.tetra-element {
  background: var(--gradient-primary);
  border-radius: 8px;
  position: relative;
  opacity: 0;
  transform: scale(0.8) rotate(45deg);
  animation: elementAppear 1s ease forwards;
  transition: all 0.3s ease;
}

.tetra-element::before {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--background);
  border-radius: 6px;
  transition: all 0.3s ease;
}

.tetra-element:hover {
  transform: scale(1.1) rotate(45deg);
}

.tetra-element:hover::before {
  background: var(--gradient-accent);
}

.tetra-element[data-index="1"] { animation-delay: 0.8s; }
.tetra-element[data-index="2"] { animation-delay: 0.9s; }
.tetra-element[data-index="3"] { animation-delay: 1.0s; }
.tetra-element[data-index="4"] { animation-delay: 1.1s; }

.principles {
  padding: 8rem 2rem;
  background: linear-gradient(180deg, transparent, rgba(15, 52, 96, 0.05), transparent);
}

.principles-content {
  max-width: 1400px;
  margin: 0 auto;
}

.section-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 600;
  text-align: center;
  margin-bottom: 4rem;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -1rem;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--gradient-accent);
  border-radius: 2px;
}

.principles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.principle-card {
  background: var(--card-background);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 2rem;
  position: relative;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.principle-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow);
  border-color: var(--highlight-color);
}

.principle-number {
  font-size: 3rem;
  font-weight: 700;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
  line-height: 1;
}

.principle-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-light);
}


.about {
  padding: 6rem 2rem;
  background:
    radial-gradient(ellipse at center, rgba(233, 69, 96, 0.05), transparent 70%);
}

.about-content {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text {
  max-width: 600px;
}

.about-description {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

.about-description a {
  color: var(--highlight-color);
  text-decoration: none;
}

.about-description a:hover {
  text-decoration: underline;
}


.about-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.geometric-pattern {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  width: 200px;
  height: 200px;
  transform: rotate(45deg);
  will-change: transform;
}

.pattern-element {
  background: var(--gradient-primary);
  border-radius: 6px;
  animation: patternFloat 4s ease-in-out infinite;
}

.pattern-element:nth-child(1) {
  animation-delay: 0s;
}

.pattern-element:nth-child(2) {
  animation-delay: 1s;
}

.pattern-element:nth-child(3) {
  animation-delay: 2s;
}

.pattern-element:nth-child(4) {
  animation-delay: 3s;
}

.footer {
  background: var(--primary-color);
  border-top: 1px solid var(--border-color);
  padding: 2rem 2rem;
}

.footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.875rem;
}

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


@keyframes elementAppear {
  to {
    opacity: 1;
    transform: scale(1) rotate(45deg);
  }
}

@keyframes patternFloat {
  0%, 100% {
    transform: translateY(0) scale(1);
  }
  50% {
    transform: translateY(-10px) scale(1.05);
  }
}

@media (max-width: 768px) {
  .hero-content {
    flex-direction: column;
    justify-content: center;
    text-align: center;
    gap: 2rem;
  }

  .tetra-grid {
    width: 200px;
    height: 200px;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .geometric-pattern {
    width: 150px;
    height: 150px;
  }

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

  .nav-content {
    padding: 1rem;
  }

  .footer-content {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}