/* R5 Academy — Base reset + typography + global atmosphere */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--platinum);
  background: var(--carbon-1);
  background-image:
    radial-gradient(ellipse 90% 50% at 50% -10%, rgba(0,124,255,0.10) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 100% 100%, rgba(0,124,255,0.05) 0%, transparent 60%);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Carbon-grid texture overlay — barely perceptible blueprint */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.018) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.018) 1px, transparent 1px);
  background-size: 56px 56px;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse 100% 80% at 50% 30%, black 30%, transparent 90%);
  -webkit-mask-image: radial-gradient(ellipse 100% 80% at 50% 30%, black 30%, transparent 90%);
}

/* Subtle noise grain */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml;utf8,<svg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.6 0'/></filter><rect width='100%' height='100%' filter='url(%23n)' opacity='0.45'/></svg>");
  opacity: 0.025;
  pointer-events: none;
  z-index: 1;
  mix-blend-mode: overlay;
}

main, section, header, footer, nav { position: relative; z-index: 2; }

/* Typography */
h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--white-cold);
  margin: 0;
}

h1 { font-size: clamp(2.5rem, 6vw, var(--fs-5xl)); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4.5vw, var(--fs-3xl)); }
h3 { font-size: clamp(1.5rem, 3vw, var(--fs-2xl)); }
h4 { font-size: var(--fs-xl); }
h5 { font-size: var(--fs-lg); }

p { margin: 0 0 var(--sp-4); color: var(--chrome-bright); }
p:last-child { margin-bottom: 0; }

a {
  color: var(--cyber-bright);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out-strong);
}
a:hover { color: var(--cyber-electric); }

ul, ol { margin: 0; padding: 0; list-style: none; }

img, svg { display: block; max-width: 100%; height: auto; }

button { font-family: inherit; cursor: pointer; }

::selection {
  background: var(--cyber);
  color: var(--carbon-0);
}

/* Custom scrollbar */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--carbon-2); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--titanium) 0%, var(--carbon-3) 100%);
  border: 1px solid var(--titanium-border);
}
::-webkit-scrollbar-thumb:hover { background: var(--cyber); }

/* Container */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--sp-5);
}

.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 var(--sp-5);
}

/* Section spacing */
.section { padding: clamp(4rem, 10vw, 7rem) 0; }
.section-tight { padding: clamp(3rem, 7vw, 5rem) 0; }

/* Display utilities */
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyber-bright);
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
}
.eyebrow::before {
  content: '';
  display: inline-block;
  width: 28px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyber) 0%, transparent 100%);
}

.mono { font-family: var(--font-mono); }

.text-chrome {
  background: var(--grad-chrome);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.text-cyber { color: var(--cyber-bright); }
.text-dim { color: var(--chrome); }

/* Section eyebrow header */
.section-head {
  margin-bottom: var(--sp-7);
  max-width: 760px;
}
.section-head .eyebrow { margin-bottom: var(--sp-3); }
.section-head p { margin-top: var(--sp-4); font-size: var(--fs-md); }

/* Tag / chip */
.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 6px 12px;
  background: rgba(0,124,255,0.08);
  border: var(--bd-cyber);
  color: var(--cyber-bright);
  border-radius: var(--r-sm);
}

.tag-dim {
  background: var(--carbon-2);
  border: var(--bd-thin);
  color: var(--chrome-bright);
}

/* Skip link */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms var(--ease-out-strong), transform 700ms var(--ease-out-strong);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@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;
  }
}