:root {
  --bg-dark: #020617;
  --bg-alt: #020617;
  --bg-card: #02091f;
  --text-main: #e5e7eb;
  --text-muted: #9ca3af;
  --accent: #3b82f6;
  --accent-soft: #1d4ed8;
  --accent-gradient-start: #4f46e5;
  --accent-gradient-end: #22c1c3;
  --border-subtle: rgba(148, 163, 184, 0.25);
  --radius-lg: 18px;
  --radius-md: 12px;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.75);
}

/* RESET / BAZA */

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

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top, #0b1120 0, #020617 55%, #000 100%);
  color: var(--text-main);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

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

/* LAYOUT */

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* HEADER */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: linear-gradient(
    to bottom,
    rgba(2, 6, 23, 0.92),
    rgba(2, 6, 23, 0.82),
    transparent
  );
  border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0;
}

.logo {
  font-weight: 700;
  letter-spacing: 0.06em;
  font-size: 0.98rem;
  text-transform: uppercase;
  color: #e5e7eb;
}

.logo span {
  background: linear-gradient(120deg, var(--accent-gradient-start), var(--accent-gradient-end));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav {
  display: flex;
  gap: 1.3rem;
  font-size: 0.86rem;
}

.nav a {
  color: var(--text-muted);
  padding: 0.3rem 0;
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.3rem;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-gradient-end));
  transition: width 0.2s ease-out;
}

.nav a:hover {
  color: var(--text-main);
}

.nav a:hover::after {
  width: 100%;
}

/* HERO */

.hero {
  padding: 4.5rem 0 3.5rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
  gap: 2.75rem;
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(1.9rem, 3.1vw, 2.35rem);
  line-height: 1.15;
  margin: 0 0 1rem;
}

.hero-text p {
  margin: 0 0 1.7rem;
  color: var(--text-muted);
  font-size: 0.98rem;
  max-width: 34rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
}

.btn-primary,
.btn-ghost {
  border-radius: 999px;
  font-size: 0.9rem;
  padding: 0.65rem 1.4rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}

.btn-primary {
  background: radial-gradient(circle at 0 0, var(--accent-gradient-end), var(--accent));
  color: #0b1120;
  font-weight: 600;
  box-shadow: 0 12px 28px rgba(37, 99, 235, 0.45);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 40px rgba(37, 99, 235, 0.6);
}

.btn-ghost {
  border-color: rgba(148, 163, 184, 0.6);
  color: var(--text-main);
  background: rgba(15, 23, 42, 0.75);
}

.btn-ghost:hover {
  background: rgba(15, 23, 42, 0.98);
  transform: translateY(-1px);
}

/* HERO VISUAL */

.hero-visual {
  position: relative;
  padding: 1.6rem 1.3rem;
  border-radius: var(--radius-lg);
  background: radial-gradient(circle at 10% 0, rgba(56, 189, 248, 0.2), transparent 50%),
              radial-gradient(circle at 100% 20%, rgba(79, 70, 229, 0.2), transparent 55%),
              rgba(15, 23, 42, 0.96);
  border: 1px solid rgba(129, 140, 248, 0.4);
  box-shadow: var(--shadow-soft);
}

.ai-orbit {
  position: relative;
  width: 100%;
  max-width: 260px;
  margin: 0 auto 1.3rem;
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  border: 1px dashed rgba(148, 163, 184, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at center, rgba(15, 23, 42, 0.4), transparent 70%);
}

.ai-core {
  width: 90px;
  height: 90px;
  border-radius: 999px;
  background: conic-gradient(from 220deg, var(--accent-gradient-start), var(--accent-gradient-end), var(--accent-gradient-start));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0b1120;
  font-weight: 700;
  font-size: 1.1rem;
  box-shadow: 0 0 0 1px rgba(15, 23, 42, 0.9), 0 18px 35px rgba(15, 23, 42, 0.95);
}

.orbit-node {
  position: absolute;
  padding: 0.35rem 0.6rem;
  border-radius: 999px;
  font-size: 0.72rem;
  background: rgba(15, 23, 42, 0.88);
  border: 1px solid rgba(148, 163, 184, 0.55);
  color: var(--text-muted);
}

.node-1 { top: 8%; left: 50%; transform: translateX(-50%); }
.node-2 { bottom: 10%; left: 12%; }
.node-3 { bottom: 10%; right: 8%; }
.node-4 { top: 42%; right: -6%; }

.hero-caption {
  margin: 0;
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* SECTIONS */

.section {
  padding: 3.5rem 0;
}

.section-alt {
  background: radial-gradient(circle at top, rgba(15, 23, 42, 0.85), #020617 70%);
}

.section-label {
  font-size: 0.76rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.section h2 {
  margin: 0 0 1.5rem;
  font-size: 1.4rem;
}

/* GRIDY */

.grid-2 {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.4rem;
  margin-top: 1.4rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.3rem;
  margin-top: 1.4rem;
}

/* CARDY */

.card {
  background: radial-gradient(circle at top, rgba(31, 41, 55, 0.9), rgba(15, 23, 42, 0.98));
  border-radius: var(--radius-md);
  padding: 1.2rem 1.1rem;
  border: 1px solid var(--border-subtle);
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.65);
}

.card h3 {
  margin: 0 0 0.6rem;
  font-size: 1.02rem;
}

.card p {
  margin: 0 0 0.6rem;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.card-icon {
  font-size: 1.4rem;
  margin-bottom: 0.3rem;
}

/* BENEFITY */

.benefits-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 1.3rem;
  margin-top: 1.8rem;
}

.benefit h4 {
  margin: 0 0 0.4rem;
  font-size: 0.98rem;
}

.benefit p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* KROKI */

.steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.6rem;
}

.step {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
  padding: 0.85rem 1rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(55, 65, 81, 0.9);
}

.step-number {
  width: 30px;
  height: 30px;
  border-radius: 999px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 0 0, var(--accent), var(--accent-gradient-end));
  color: #020617;
  font-weight: 700;
  font-size: 0.85rem;
}

.step h3 {
  margin: 0 0 0.25rem;
  font-size: 0.95rem;
}

.step p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* FOOTER */

.site-footer {
  border-top: 1px solid rgba(30, 64, 175, 0.7);
  padding: 1.6rem 0 1.8rem;
  background: radial-gradient(circle at top, #020617, #000 70%);
}

.footer-inner {
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-note {
  margin-top: 0.3rem;
  font-size: 0.8rem;
}

/* FADE-IN NA SCROLL (JS + CSS) */

.fade-in-section {
  opacity: 0;
  transform: translateY(30px);
  visibility: hidden;
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  will-change: opacity, transform;
}

.fade-in-section.is-visible {
  opacity: 1;
  transform: none;
  visibility: visible;
}

/* RESPONSYWNOŚĆ */

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-visual {
    order: -1;
  }

  .grid-3 {
    grid-template-columns: minmax(0, 1fr);
  }

  .grid-2,
  .benefits-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .step {
    border-radius: var(--radius-md);
  }
}

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.4rem;
  }

  .nav {
    flex-wrap: wrap;
    gap: 0.8rem;
  }

  .hero {
    padding-top: 3.5rem;
  }

  .hero-text h1 {
    font-size: 1.6rem;
  }
}