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

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
}

body {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: #0c1f17;
  color: #f5f8f6;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

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

.intro {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #000;
  transition: opacity 1s ease-out, visibility 1s ease-out;
  z-index: 10;
}

.intro-logo {
  width: clamp(160px, 18vw, 240px);
  filter: drop-shadow(0 12px 30px rgba(0, 0, 0, 0.4));
  animation: logoPulse 2s ease-in-out infinite alternate;
}

.intro.fade-out {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.particles {
  position: fixed;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 2;
}

.particle {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  box-shadow: 0 0 12px rgba(138, 224, 194, 0.2);
  animation-name: particleDrift;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
  will-change: transform, opacity;
}

.color-overlay {
  position: fixed;
  inset: 0;
  background: radial-gradient(circle at center, rgba(25, 63, 49, 0.85), #0c1f17 70%);
  opacity: 0;
  transition: opacity 1.2s ease-in;
  pointer-events: none;
  z-index: 5;
}

.color-overlay.visible {
  opacity: 1;
}

.main {
  position: relative;
  width: min(760px, 90vw);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(28px, 4vw, 40px);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 1s ease-in, transform 1s ease-in;
  min-height: 100vh;
  padding: clamp(24px, 5vw, 48px);
  margin-top: -60px;
}

.main.fade-in,
.main.visible {
  opacity: 1;
  transform: translateY(0);
}

.main.skip-intro {
  transition: none;
  opacity: 1;
  transform: translateY(0);
}

.hero-header {
  margin-bottom: clamp(20px, 4vh, 40px);
}

.hero-header .logo {
  width: clamp(60px, 8vw, 90px);
  animation: floaty 3.4s ease-in-out infinite;
  transition: transform 0.4s ease, filter 0.4s ease;
}

.hero-header .logo:hover {
  transform: scale(1.04);
  filter: drop-shadow(0 8px 20px rgba(58, 134, 255, 0.22));
}

.content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding-top: 0;
}

.content h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 600;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0;
  max-width: 560px;
  font-size: clamp(1rem, 2vw, 1.2rem);
  font-weight: 400;
  line-height: 1.6;
  color: rgba(245, 248, 246, 0.78);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-top: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 180px;
  padding: 14px 32px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
  color: #f5f8f6;
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform 0.3s ease, background 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease, color 0.3s ease;
  backdrop-filter: blur(14px);
}

.btn.primary {
  background: rgba(58, 134, 255, 0.12);
  border-color: rgba(58, 134, 255, 0.4);
}

.btn:hover {
  transform: scale(1.05);
  background: #3a86ff;
  border-color: rgba(255, 255, 255, 0.4);
  color: #ffffff;
  box-shadow: 0 0 16px rgba(58, 134, 255, 0.35);
}

.btn:focus-visible {
  outline: 2px solid rgba(58, 134, 255, 0.8);
  outline-offset: 3px;
}

@media (max-width: 540px) {
  .hero-header {
    margin-bottom: clamp(18px, 6vh, 32px);
  }

  .content {
    padding-top: 0;
  }

  .actions {
    gap: 14px;
  }

  .btn {
    width: 100%;
    min-width: unset;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@keyframes logoPulse {
  from {
    transform: scale(1);
    opacity: 0.92;
  }

  to {
    transform: scale(1.04);
    opacity: 1;
  }
}

@keyframes floaty {
  0% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-10px);
  }

  100% {
    transform: translateY(0);
  }
}

@keyframes particleDrift {
  0% {
    transform: translate3d(var(--start-x, 0), 110vh, 0) scale(var(--scale, 1));
    opacity: 0;
  }

  15% {
    opacity: 0.45;
  }

  75% {
    opacity: 0.3;
  }

  100% {
    transform: translate3d(var(--end-x, 0), -10vh, 0) scale(var(--scale, 1));
    opacity: 0;
  }
}