/* ─── Reset ─────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
img, svg, video, canvas { max-width: 100%; display: block; }
button, input, textarea { font: inherit; color: inherit; }
ul { list-style: none; }
a { color: inherit; text-decoration: none; }

/* ─── Base typography ───────────────────────────────────────────────────── */
html { font-size: 16px; }
body {
  font-family: var(--sans);
  font-weight: 400;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  position: relative;
}

/* Subtle ambient backdrop on every page */
body::before {
  content: '';
  position: fixed; inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 18% -5%, rgba(139,92,246,0.12), transparent 60%),
    radial-gradient(ellipse 60% 50% at 95% 20%, rgba(34,211,238,0.08), transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* Faint grid texture */
body::after {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(to right, rgba(255,255,255,0.025) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, #000 30%, transparent 75%);
  pointer-events: none;
  z-index: 0;
}

main, header, footer, section { position: relative; z-index: 1; }

p { color: var(--text-soft); }

h1, h2, h3, h4 { font-family: var(--serif); color: #f4f5fb; line-height: 1.12; letter-spacing: -0.02em; font-weight: 700; }
h1 { font-size: clamp(2.6rem, 6vw, 4.6rem); }
h2 { font-size: clamp(2rem, 3.6vw, 2.9rem); }
h3 { font-size: clamp(1.4rem, 2vw, 1.8rem); }
h4 { font-size: 1.05rem; font-family: var(--sans); font-weight: 600; }

em.grad,
h1 em,
h2 em,
.gradient {
  font-style: italic;
  background: linear-gradient(115deg, var(--primary) 0%, var(--cyan) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

code, pre, .mono { font-family: var(--mono); font-size: 0.85em; }

/* ─── Layout primitives ─────────────────────────────────────────────────── */
.container { max-width: var(--container); margin: 0 auto; padding: 0 28px; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--sans); font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--primary-soft);
}
.eyebrow::before {
  content: ''; width: 22px; height: 1px;
  background: linear-gradient(to right, transparent, var(--primary));
}

.section-head { max-width: 720px; margin: 0 auto var(--space-section) auto; text-align: center; padding-bottom: 0; margin-bottom: clamp(48px, 6vw, 72px); }
.section-head h2 { margin-top: 12px; }
.section-head p { margin-top: 18px; font-size: 1.05rem; max-width: 56ch; margin-left: auto; margin-right: auto; }

/* ─── Buttons ───────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--sans); font-weight: 600; font-size: 0.95rem;
  padding: 13px 24px;
  border: 1px solid transparent;
  border-radius: var(--r);
  cursor: pointer;
  transition: transform 0.18s var(--ease-out), background 0.18s, border-color 0.18s, box-shadow 0.18s;
  white-space: nowrap;
}
.btn-lg { padding: 15px 30px; font-size: 1rem; }
.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: var(--primary-glow);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 0 72px rgba(139,92,246,0.4); }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-bright);
}
.btn-ghost:hover { border-color: var(--primary); background: var(--primary-dim); transform: translateY(-1px); }

/* ─── Skip link / a11y ──────────────────────────────────────────────────── */
.skip-link {
  position: absolute; top: -100px; left: 12px;
  background: var(--primary); color: #fff;
  padding: 10px 16px; border-radius: var(--r);
  z-index: 1000; font-weight: 600;
}
.skip-link:focus { top: 12px; }

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