/* ==========================================================================
   SpatialBrain Technologies — Design System
   ========================================================================== */

:root {
  /* Brand palette */
  --c-primary: #071a2d;
  --c-primary-800: #0b2743;
  --c-primary-700: #103656;
  --c-secondary: #5843c4;
  --c-secondary-600: #4735a3;
  --c-accent: #3bdea9;
  --c-accent-soft: #93c5fd;
  --c-blue: #3e9feb;
  --c-bg: #f8fafc;
  --c-bg-alt: #eef2f7;
  --c-surface: #ffffff;
  --c-text: #111827;
  --c-text-muted: #4b5566;
  --c-text-soft: #6b7688;
  --c-border: #e2e8f0;
  --c-border-strong: #cbd5e1;

  /* On-dark tones */
  --c-on-dark: #f1f5f9;
  --c-on-dark-muted: #93a3b8;
  --c-on-dark-border: rgba(241, 245, 249, 0.12);

  /* Gradients */
  --grad-hero: radial-gradient(120% 120% at 15% 0%, #103a5c 0%, #071a2d 45%, #050f1c 100%);
  --grad-accent: linear-gradient(120deg, var(--c-accent) 0%, var(--c-blue) 50%, var(--c-secondary) 100%);
  --grad-glow: radial-gradient(circle, rgba(59, 222, 169, 0.35) 0%, rgba(59, 222, 169, 0) 70%);
  --grad-surface: linear-gradient(180deg, #ffffff 0%, #f4f7fb 100%);

  /* Typography */
  --font-head: "Manrope", "Segoe UI", sans-serif;
  --font-body: "Inter", "Segoe UI", sans-serif;

  --fs-xs: clamp(0.75rem, 0.72rem + 0.1vw, 0.8125rem);
  --fs-sm: clamp(0.875rem, 0.84rem + 0.12vw, 0.9375rem);
  --fs-base: clamp(1rem, 0.96rem + 0.15vw, 1.0625rem);
  --fs-lg: clamp(1.125rem, 1.06rem + 0.25vw, 1.3125rem);
  --fs-xl: clamp(1.375rem, 1.25rem + 0.5vw, 1.75rem);
  --fs-2xl: clamp(1.75rem, 1.5rem + 1vw, 2.375rem);
  --fs-3xl: clamp(2.25rem, 1.8rem + 1.8vw, 3.375rem);
  --fs-4xl: clamp(2.75rem, 2.1rem + 2.8vw, 4.5rem);
  --fs-5xl: clamp(3.25rem, 2.3rem + 4vw, 5.75rem);

  /* Spacing */
  --space-section: clamp(5rem, 4rem + 4vw, 9rem);
  --space-section-sm: clamp(3.5rem, 3rem + 2vw, 6rem);
  --container-w: 1320px;
  --gutter: clamp(1.25rem, 3vw, 3rem);

  /* Radii & shadows */
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 24px;
  --r-xl: 32px;
  --r-pill: 999px;

  --shadow-sm: 0 2px 8px rgba(7, 26, 45, 0.06);
  --shadow-md: 0 12px 32px rgba(7, 26, 45, 0.10);
  --shadow-lg: 0 24px 64px rgba(7, 26, 45, 0.16);
  --shadow-glow: 0 0 0 1px rgba(59, 222, 169, 0.18), 0 20px 60px rgba(88, 67, 196, 0.18);

  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-soft: cubic-bezier(0.4, 0, 0.2, 1);
  --dur-fast: 0.2s;
  --dur-med: 0.45s;
  --dur-slow: 0.9s;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
html, body { height: 100%; }
body {
  font-family: var(--font-body);
  background: var(--c-bg);
  color: var(--c-text);
  font-size: var(--fs-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg, canvas, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--c-primary);
}
::selection { background: var(--c-accent); color: var(--c-primary); }

@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; }
}

/* ---------- Layout helpers ---------- */
.container {
  width: 100%;
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: var(--space-section); position: relative; }
.section-sm { padding-block: var(--space-section-sm); position: relative; }
.section-dark { background: var(--grad-hero); color: var(--c-on-dark); }
.section-alt { background: var(--c-bg-alt); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-head);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-secondary-600);
  margin-bottom: 1.25rem;
}
.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--grad-accent);
  border-radius: 2px;
}
.section-dark .eyebrow { color: var(--c-accent-soft); }

.section-head {
  max-width: 760px;
  margin-bottom: clamp(2.5rem, 2rem + 2vw, 4.5rem);
}
.section-head.center { margin-inline: auto; text-align: center; }
.section-head h2 { font-size: var(--fs-3xl); margin-bottom: 1rem; }
.section-dark .section-head h2 { color: var(--c-on-dark); }
.section-head p { font-size: var(--fs-lg); color: var(--c-text-muted); font-weight: 400; }
.section-dark .section-head p { color: var(--c-on-dark-muted); }

.eyebrow-icon { width: 16px; height: 16px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: var(--fs-sm);
  letter-spacing: 0.01em;
  padding: 0.95rem 1.75rem;
  border-radius: var(--r-pill);
  transition: transform var(--dur-fast) var(--ease-soft), box-shadow var(--dur-fast) var(--ease-soft), background var(--dur-fast) var(--ease-soft), color var(--dur-fast) var(--ease-soft), border-color var(--dur-fast) var(--ease-soft);
  white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; transition: transform var(--dur-fast) var(--ease-soft); }
.btn:hover svg { transform: translateX(3px); }

.btn-primary {
  background: var(--grad-accent);
  color: var(--c-primary);
  box-shadow: var(--shadow-glow);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 0 0 1px rgba(59,222,169,0.3), 0 28px 70px rgba(88,67,196,0.28); }

.btn-outline {
  background: transparent;
  border: 1.5px solid var(--c-on-dark-border);
  color: var(--c-on-dark);
  backdrop-filter: blur(6px);
}
.btn-outline:hover { border-color: var(--c-accent); background: rgba(59,222,169,0.08); transform: translateY(-2px); }

.btn-dark {
  background: var(--c-primary);
  color: var(--c-on-dark);
}
.btn-dark:hover { background: var(--c-primary-700); transform: translateY(-2px); }

.btn-ghost {
  background: transparent;
  border: 1.5px solid var(--c-border-strong);
  color: var(--c-primary);
}
.btn-ghost:hover { border-color: var(--c-secondary); color: var(--c-secondary-600); background: rgba(88,67,196,0.05); }

.btn-sm { padding: 0.7rem 1.3rem; font-size: var(--fs-xs); }

/* ---------- Glass ---------- */
.glass {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}
.glass-light {
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

/* ---------- Reveal / scroll animation hooks ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.9s var(--ease-out), transform 0.9s var(--ease-out);
}
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }
[data-reveal="scale"] { transform: translateY(0) scale(0.94); }
[data-reveal="scale"].is-visible { transform: translateY(0) scale(1); }
[data-reveal="left"] { transform: translateX(-36px); }
[data-reveal="left"].is-visible { transform: translateX(0); }
[data-reveal="right"] { transform: translateX(36px); }
[data-reveal="right"].is-visible { transform: translateX(0); }

[data-reveal-group] > * { transition-delay: calc(var(--i, 0) * 90ms); }

/* ---------- Utility ---------- */
.text-gradient {
  background: var(--grad-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.muted { color: var(--c-text-muted); }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0; padding: 0; margin: -1px;
}
.skip-link {
  position: absolute; top: -60px; left: 1rem; z-index: 999;
  background: var(--c-primary); color: #fff; padding: 0.8rem 1.4rem; border-radius: var(--r-sm);
  transition: top var(--dur-fast) var(--ease-soft);
}
.skip-link:focus { top: 1rem; }

:focus-visible { outline: 2px solid var(--c-accent); outline-offset: 3px; border-radius: 4px; }