/* ============================================
   BASE — Reset, Typography, Layout
   ============================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font: inherit; color: inherit; }
ul, ol { list-style: none; }
input, textarea, select { font: inherit; color: inherit; }
h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  line-height: 1.15;
  color: var(--text);
  font-weight: 500;
}
h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
p { color: var(--text-secondary); line-height: 1.7; }

/* Layout */
.container { width: var(--container); margin: 0 auto; }
.grid { display: grid; gap: var(--space-lg); }
.flex { display: flex; gap: var(--space-md); }
.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;
}

/* Section spacing */
.section { padding: 5rem 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; margin-bottom: 3rem; }
.section-label {
  font-size: 0.65rem; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--green); font-weight: 600; margin-bottom: 0.5rem;
}
.section-title { margin-bottom: 0.5rem; }
.section-desc { font-size: 0.95rem; max-width: 480px; margin: 0 auto; }

/* Scroll progress */
.scroll-progress {
  position: fixed; top: 0; left: 0; height: 2px;
  background: var(--green); z-index: var(--z-progress); width: 0;
}

/* Overlay backdrop */
.overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: var(--z-overlay);
  opacity: 0; visibility: hidden;
  transition: opacity 0.3s, visibility 0.3s;
}
.overlay.active { opacity: 1; visibility: visible; }