/* ============================================================
   VOLTLINE — tokens & base
   Dark canvas, one electric accent (volt yellow-green).
   Swiss discipline: hairlines, terse type, mono labels, grid.
   ============================================================ */
:root{
  --bg:#0a0c0b;
  --bg-2:#0e110f;
  --surface:#121614;
  --surface-2:#171c19;
  --panel:#151a17;
  --panel-lo:#0d100e;
  --panel-hi:#1d2420;
  --hairline:rgba(216,255,62,.14);
  --hairline-strong:rgba(216,255,62,.34);
  --text:#eef3ec;
  --text-muted:#9aa69a;
  --text-faint:#5f6b60;
  --accent:#d8ff3e;                 /* volt yellow-green */
  --accent-dim:rgba(216,255,62,.12);
  --accent-glow:rgba(216,255,62,.55);
  --warm:#ffb347;                   /* warm signal amber for LEDs */
  --warm-glow:rgba(255,179,71,.5);
  --red:#ff5d4d;
  --display:'IBM Plex Sans','Helvetica Neue',system-ui,sans-serif;
  --ui:'IBM Plex Sans','Helvetica Neue',system-ui,sans-serif;
  --mono:'IBM Plex Mono',ui-monospace,SFMono-Regular,monospace;
  --radius:2px;
  --ease:cubic-bezier(.2,0,0,1);
  --decel:cubic-bezier(.16,1,.3,1);
  --fast:120ms;
  --base:200ms;
  --slow:320ms;
  --maxw:1160px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:var(--ui);
  color:var(--text);
  background:var(--bg);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
::selection{background:var(--accent);color:#0a0c0b}
a{color:inherit;text-decoration:none}
img,svg{display:block}
button{font-family:inherit;cursor:pointer;color:inherit}
input,select{font-family:inherit}

/* Skip link */
.skip-link{
  position:absolute;left:-9999px;top:0;z-index:200;
  background:var(--accent);color:#0a0c0b;font-weight:700;
  padding:.7rem 1.2rem;border-radius:var(--radius);
}
.skip-link:focus{left:1rem;top:1rem}

/* Focus visibility everywhere */
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

/* ============================================================
   Layout helpers
   ============================================================ */
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 1.5rem}
section{padding:5rem 0;position:relative}
.eyebrow{
  font-family:var(--mono);
  font-size:.72rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--accent);
  margin:0 0 1rem;
  display:flex;align-items:center;gap:.6rem;
}
.eyebrow::before{content:"";width:1.4rem;height:1px;background:var(--accent)}
h2{
  font-family:var(--display);
  font-weight:800;
  font-size:clamp(1.9rem,4vw,3rem);
  letter-spacing:-.02em;
  line-height:1.05;
  margin:0 0 1.2rem;
}
.lede{color:var(--text-muted);font-size:1.08rem;max-width:46rem}

/* Buttons */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.55rem;
  font-family:var(--ui);font-weight:600;font-size:.95rem;
  padding:.8rem 1.4rem;border-radius:var(--radius);
  border:1px solid transparent;
  background:none;
  transition:background var(--base) var(--ease),color var(--base) var(--ease),
             border-color var(--base) var(--ease),transform var(--base) var(--ease);
}
.btn svg{width:1.05rem;height:1.05rem;flex:none}
.btn-primary{background:var(--accent);color:#0a0c0b}
.btn-primary:hover{background:#e6ff7a;transform:translateY(-1px)}
.btn-ghost{border-color:var(--hairline-strong);color:var(--text)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px)}
.btn-warm{border-color:rgba(255,179,71,.45);color:var(--warm)}
.btn-warm:hover{border-color:var(--warm);background:rgba(255,179,71,.08)}
.btn[aria-pressed="true"]{background:var(--accent-dim);border-color:var(--accent);color:var(--accent)}

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

/* ============================================================
   Header / nav
   ============================================================ */
header{
  position:sticky;top:0;z-index:50;
  background:rgba(10,12,11,.92);
  backdrop-filter:blur(10px) saturate(140%);
  -webkit-backdrop-filter:blur(10px) saturate(140%);
  border-bottom:1px solid var(--hairline);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:64px;gap:1rem}
.brand{display:flex;align-items:center;gap:.6rem;font-weight:800;letter-spacing:-.01em}
.brand svg{width:1.5rem;height:1.5rem}
.brand .volt{color:var(--accent)}
.nav-links{display:flex;gap:1.6rem;font-size:.9rem;color:var(--text-muted)}
.nav-links a{transition:color var(--fast) var(--ease);padding:.3rem 0}
.nav-links a:hover,.nav-links a[aria-current]{color:var(--text)}
.nav-links a[aria-current]{border-bottom:1px solid var(--accent)}
.nav-cta{font-size:.85rem;padding:.55rem 1rem}
@media(max-width:860px){.nav-links{display:none}}

/* ============================================================
   Hero
   ============================================================ */
.hero{padding:4.5rem 0 3.5rem;overflow:hidden;position:relative}
.hero-grid{
  position:absolute;inset:0;
  background-image:
    linear-gradient(var(--hairline) 1px,transparent 1px),
    linear-gradient(90deg,var(--hairline) 1px,transparent 1px);
  background-size:56px 56px;
  -webkit-mask-image:radial-gradient(ellipse 90% 70% at 50% 25%,#000 30%,transparent 78%);
  mask-image:radial-gradient(ellipse 90% 70% at 50% 25%,#000 30%,transparent 78%);
  opacity:.5;pointer-events:none;
}
.hero-inner{position:relative;z-index:2}
.hero-top{max-width:820px;margin-bottom:2.6rem}
.hero .eyebrow{margin-bottom:1.4rem}
.hero h1{
  font-family:var(--display);
  font-weight:800;
  font-size:clamp(2.4rem,6.4vw,4.4rem);
  letter-spacing:-.035em;
  line-height:.98;
  margin:0 0 1.2rem;
}
.hero h1 .accent{color:var(--accent)}
.hero .lede{font-size:1.12rem;max-width:40rem;margin-bottom:1.8rem}
.hero-ctas{display:flex;gap:.9rem;flex-wrap:wrap}
.hero-note{
  margin-top:1.6rem;
  font-family:var(--mono);
  font-size:.74rem;letter-spacing:.08em;
  color:var(--text-faint);
  display:flex;align-items:center;gap:.6rem;flex-wrap:wrap;
}
.hero-note::before{content:"";width:.5rem;height:.5rem;border-radius:50%;background:var(--accent);box-shadow:0 0 0 0 var(--accent-glow);animation:pulse 2.4s var(--ease) infinite}
@keyframes pulse{
  0%{box-shadow:0 0 0 0 var(--accent-glow)}
  70%{box-shadow:0 0 0 9px transparent}
  100%{box-shadow:0 0 0 0 transparent}
}