:root {
  --bg: #05070b;
  --text: #eaf6ff;
  --muted: rgba(234, 246, 255, 0.7);
  --cyan: #35d8ff;
  --card: rgba(14, 18, 24, 0.6);
  --stroke: rgba(53, 216, 255, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

#scene {
  position: fixed;
  inset: 0;
  z-index: 0;
}

#scene canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  padding: 18px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  pointer-events: none;
}

.brand {
  font-weight: 700;
  letter-spacing: 0.14em;
  opacity: 0.95;
  pointer-events: auto;
}

.nav {
  display: flex;
  gap: 18px;
  pointer-events: auto;
}

.nav-btn {
  background: transparent;
  border: 0;
  color: rgba(234, 246, 255, 0.55);
  font-size: 12px;
  letter-spacing: 0.12em;
  padding: 6px 8px;
  cursor: pointer;
  border-bottom: 1px solid transparent;
  transition: 180ms ease;
}

.nav-btn:hover {
  color: rgba(234, 246, 255, 0.9);
}

.nav-btn.active {
  color: var(--cyan);
  border-bottom-color: rgba(53, 216, 255, 0.8);
}

.top-actions {
  display: flex;
  gap: 10px;
  pointer-events: auto;
}

.chip {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: rgba(234, 246, 255, 0.7);
  padding: 6px 10px;
  border-radius: 10px;
  cursor: pointer;
}

.btn {
  border: 1px solid var(--stroke);
  color: var(--cyan);
  background: rgba(53, 216, 255, 0.05);
  padding: 10px 14px;
  border-radius: 12px;
  letter-spacing: 0.12em;
  cursor: pointer;
}

#scroll {
  position: relative;
  z-index: 1;
}

.panel {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 96px 18px 40px;
}

.hero {
  text-align: center;
  max-width: 980px;
}

.hero h1 {
  margin: 0;
  font-size: clamp(56px, 8vw, 92px);
  letter-spacing: 0.08em;
}

.tagline {
  margin-top: 14px;
  color: rgba(234, 246, 255, 0.7);
  letter-spacing: 0.22em;
  font-size: 12px;
  line-height: 1.6;
}

.hint {
  margin-top: 26px;
  color: rgba(234, 246, 255, 0.45);
  font-size: 12px;
  letter-spacing: 0.2em;
}

.card {
  width: min(720px, 92vw);
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 18px;
  padding: 26px 26px;
  backdrop-filter: blur(8px);
}

.card h2 {
  margin: 0 0 12px;
  letter-spacing: 0.08em;
}

.sub {
  margin: 0 0 14px;
  color: var(--muted);
}

.card ul {
  margin: 0;
  padding-left: 18px;
  color: rgba(234, 246, 255, 0.82);
}

.grid {
  width: min(980px, 92vw);
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.tile {
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 18px;
  backdrop-filter: blur(8px);
}

.tile h3 {
  margin: 0 0 6px;
  color: var(--cyan);
  letter-spacing: 0.08em;
  font-size: 13px;
}

.tile p {
  margin: 0;
  color: rgba(234, 246, 255, 0.75);
}

.steps {
  margin: 0;
  padding-left: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.steps li {
  display: flex;
  gap: 12px;
  align-items: center;
  color: rgba(234, 246, 255, 0.8);
  letter-spacing: 0.06em;
}

.steps span {
  color: var(--cyan);
  font-weight: 700;
  width: 34px;
  display: inline-block;
}

.cta {
  display: inline-block;
  margin-top: 14px;
  padding: 12px 18px;
  border-radius: 14px;
  background: rgba(53, 216, 255, 0.14);
  border: 1px solid rgba(53, 216, 255, 0.5);
  color: var(--cyan);
  text-decoration: none;
  letter-spacing: 0.12em;
}

.mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  opacity: 0.85;
}

@media (max-width: 820px) {
  .nav {
    display: none; /* mobile: nav sparisce, scroll naturale */
  }
  .grid {
    grid-template-columns: 1fr;
  }
  .topbar {
    padding: 14px 14px;
  }
}