:root {
    --size: 25mm;       /* Cube face size */
    --half: calc(var(--size) / 2);
    --bg: #0a0a0a;       /* Dark background */

    --bg: #0a0a0a;
    --surface: #111315;
    --text: #e9eef2;
    --muted: #b9c4cc;
    --accent: #ff6a00;   /* ember orange */
    --accent-2: #ff2d00; /* hot core red */
    --glow: 0 0 24px rgba(255, 72, 0, 0.35);

    /* Coal tones */
    --coal-1: #0d0f12;
    --coal-2: #121417;
    --coal-3: #1a1d21;

    /* Sizing */
    --radius: 14px;
    --pad: 20px;
}

* { box-sizing: border-box; }
html, body { height: 100%; background: var(--bg); color: var(--text); font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; }
a { color: var(--text); text-decoration: none; }
a:focus { outline: 2px solid var(--accent); outline-offset: 2px; }
img { max-width: 100%; display: block; }

.site-header {
  position: sticky; top: 0; z-index: 10;
  background: linear-gradient(to bottom, rgba(0,0,0,0.7), transparent);
  backdrop-filter: blur(6px);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 20px;
}
.logo { font-weight: 800; letter-spacing: 0.5px; }
.logo span { color: var(--accent); text-shadow: var(--glow); }
.nav-list { display: flex; gap: 18px; list-style: none; margin: 0; padding: 0; }
.nav-list a { color: var(--muted); }
.nav-list a:hover { color: var(--text); text-shadow: 0 0 6px rgba(255,255,255,0.12); }

.hero {
  position: relative;
  min-height: 58vh;
  display: grid;
  place-items: center;
  overflow: hidden;
  background:
    radial-gradient(110% 80% at 50% 110%, #000 20%, #0b0c0e 55%, #121417 100%);
}

/* Dim overlay for contrast */
.hero__overlay {
  position: absolute; inset: 0;
  background: radial-gradient(80% 60% at 50% 80%, rgba(255, 64, 0, 0.08), transparent 70%),
              radial-gradient(60% 40% at 50% 100%, rgba(255, 64, 0, 0.12), transparent 70%);
  pointer-events: none;
}

/* Ember particles via layered radial-gradients */
.hero__embers {
  position: absolute; inset: 0;
  background:
    radial-gradient(6px 6px at 20% 85%, rgba(255,110,0,0.9), transparent 60%),
    radial-gradient(4px 4px at 40% 88%, rgba(255,80,0,0.8), transparent 60%),
    radial-gradient(5px 5px at 60% 83%, rgba(255,60,0,0.85), transparent 60%),
    radial-gradient(3px 3px at 70% 86%, rgba(255,150,0,0.85), transparent 60%),
    radial-gradient(4px 4px at 30% 82%, rgba(255,60,0,0.75), transparent 60%);
  animation: rise 9s linear infinite;
  mix-blend-mode: screen;
  filter: blur(0.6px) saturate(1.2);
}
@keyframes rise {
  0%   { transform: translateY(10px); opacity: 0.65; }
  50%  { transform: translateY(-8px); opacity: 0.90; }
  100% { transform: translateY(-18px); opacity: 0.60; }
}

/* Soft smoke ribbon using conic-gradient shift */
.hero__smoke {
  position: absolute; inset: 0;
  background:
    conic-gradient(from 180deg at 50% 90%, rgba(180,180,180,0.08), rgba(0,0,0,0.0), rgba(180,180,180,0.05));
  filter: blur(12px);
  animation: drift 24s linear infinite;
  opacity: 0.6;
}
@keyframes drift {
  0% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-6px) rotate(6deg); }
  100% { transform: translateY(0) rotate(0deg); }
}

/* Heat shimmer (subtle vertical refractive distortion) */
.hero__heat {
  position: absolute; inset: 0;
  background:
    repeating-linear-gradient(
      to bottom,
      rgba(255, 120, 0, 0.05) 0px,
      rgba(255, 120, 0, 0.05) 2px,
      transparent 3px,
      transparent 8px
    );
  mix-blend-mode: overlay;
  animation: shimmer 2.8s ease-in-out infinite;
  opacity: 0.5;
}
@keyframes shimmer {
  0% { transform: translateY(0); }
  50% { transform: translateY(-3px); }
  100% { transform: translateY(0); }
}

/* Respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  .hero__embers, .hero__smoke, .hero__heat { animation: none; }
}

.hero__content {
  z-index: 1;
  text-align: center;
  padding: 32px;
  max-width: 720px;
}
.hero__content h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  text-align: center;
  margin: 0 0 12px;
  text-shadow: 0 3px 24px rgba(255, 72, 0, 0.25);
}
.hero__content p {
  color: var(--muted);
  margin: 0 0 18px;
}

.cta-group { display: inline-flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  height: 42px; padding: 0 18px; border-radius: calc(var(--radius) - 4px);
  border: 1px solid #2a2f33;
  background: var(--surface);
  color: var(--text); font-weight: 600;
}
.btn--primary {
  border: 1px solid #3a2a20;
  background: linear-gradient(180deg, #1a1d21, #121417);
  box-shadow: inset 0 0 0 1px rgba(255, 72, 0, 0.18), var(--glow);
}
.btn--primary:hover { box-shadow: inset 0 0 0 1px rgba(255, 72, 0, 0.28), var(--glow); }
.btn--ghost { background: transparent; border-color: #383d42; color: var(--muted); }
.btn--ghost:hover { color: var(--text); }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
  padding: 28px 20px 48px;
}

.card {
  position: relative;
  background: linear-gradient(180deg, var(--coal-2), var(--coal-1));
  border: 1px solid #23262a;
  border-radius: var(--radius);
  padding: calc(var(--pad) + 2px);
  box-shadow: 0 6px 28px rgba(0,0,0,0.35);
}
.card h2 { margin: 0 0 8px; font-size: 1.25rem; }
.card p { margin: 0 0 14px; color: var(--muted); }
.link { color: #e4e9ed; font-weight: 600; }

.card__coalbed {
  height: 120px; border-radius: calc(var(--radius) - 6px); margin-bottom: 14px;
  background:
    radial-gradient(120px 24px at 50% 95%, rgba(255,80,0,0.25), transparent 60%),
    radial-gradient(80px 20px at 60% 92%, rgba(255,40,0,0.30), transparent 60%),
    linear-gradient(180deg, #0e0f12, #15181c 60%, #0e0f12),
    repeating-linear-gradient(90deg, #23262a 0 6px, #1a1d21 6px 12px);
  box-shadow: inset 0 -8px 24px rgba(255, 72, 0, 0.22), inset 0 6px 18px rgba(0,0,0,0.5);
}

.card__coalbed--bright {
  background:
    radial-gradient(140px 32px at 52% 96%, rgba(255,120,0,0.35), transparent 60%),
    radial-gradient(90px 24px at 62% 93%, rgba(255,60,0,0.40), transparent 60%),
    linear-gradient(180deg, #0e0f12, #181b20 60%, #0e0f12),
    repeating-linear-gradient(90deg, #262a2f 0 6px, #1c2025 6px 12px);
  box-shadow: inset 0 -10px 32px rgba(255, 72, 0, 0.28), inset 0 8px 22px rgba(0,0,0,0.55), var(--glow);
}

.scene {
    width: 300px;
    height: 300px;
    perspective: 800px;
    perspective-origin: 50% 50%;
    display: flex;
    align-items: center;
    justify-content: center;

    /* Box around the cube */
    border: 3px solid #444;       /* Dark border */
    border-radius: 8px;           /* Rounded corners (optional) */
    box-shadow: 0 0 20px rgba(0,0,0,0.6); /* Glow effect */
    }

    .cube {
    position: relative;
    width: var(--size);
    height: var(--size);
    transform-style: preserve-3d;
    animation: spin 10s linear infinite;
    }

    .cube:hover { animation-play-state: paused; }

    .face {
    position: absolute;
    width: var(--size);
    height: var(--size);
    display: grid;
    place-items: center;
    font-weight: 600;
    color: #eee;
    border: 1px solid #333;
    background: #1a1a1a;       /* Dark face color */
    }

    /* Position each face */
    .front  { transform: translateZ(var(--half)); }
    .back   { transform: rotateY(180deg) translateZ(var(--half)); }
    .right  { transform: rotateY(90deg)  translateZ(var(--half)); }
    .left   { transform: rotateY(-90deg) translateZ(var(--half)); }
    .top    { transform: rotateX(90deg)  translateZ(var(--half)); }
    .bottom { transform: rotateX(-90deg) translateZ(var(--half)); }

    @keyframes spin {
    0%   { transform: rotateX(0deg) rotateY(0deg); }
    50%  { transform: rotateX(180deg) rotateY(360deg); }
    100% { transform: rotateX(360deg) rotateY(720deg); }
    }