/* ============================================================
   Green-labs AI Training — shared stylesheet
   Minimalist design system. Edit the variables below to rebrand.
   ============================================================ */

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f6f5f1;     /* warm off-white for alternating sections */
  --color-ink: #1a1f24;        /* near-black body text */
  --color-muted: #5c6770;      /* secondary text */
  --color-accent: #2f5d62;     /* deep teal — calm, academic */
  --color-accent-dark: #21464a;
  --color-line: #e4e2db;       /* hairline borders */

  --font-serif: Georgia, "Times New Roman", serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;

  --maxw: 1080px;
  --space: 1.5rem;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--color-ink);
  background: var(--color-bg);
  line-height: 1.65;
  font-size: 18px;
}
img { max-width: 100%; display: block; }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 { font-family: var(--font-serif); font-weight: 600; line-height: 1.2; color: var(--color-ink); }
h1 { font-size: clamp(2.2rem, 5vw, 3.4rem); letter-spacing: -0.01em; }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-top: 0; }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1rem; }
.lead { font-size: 1.2rem; color: var(--color-muted); }

/* ---------- layout ---------- */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--space); }
section { padding: 5rem 0; }
.section-alt { background: var(--color-bg-alt); }
.center { text-align: center; }
.narrow { max-width: 680px; margin-left: auto; margin-right: auto; }

/* ---------- header / nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.9);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-line);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1rem var(--space); max-width: var(--maxw); margin: 0 auto;
}
.brand { font-family: var(--font-serif); font-size: 1.25rem; font-weight: 600; color: var(--color-ink); }
.brand:hover { text-decoration: none; }
.nav-links { display: flex; gap: 1.75rem; align-items: center; list-style: none; margin: 0; padding: 0; }
.nav-links a { color: var(--color-ink); font-size: 0.95rem; }
.nav-links a:hover { color: var(--color-accent); text-decoration: none; }

/* ---------- buttons ---------- */
.btn {
  display: inline-block; padding: 0.85rem 1.6rem; border-radius: 4px;
  font-size: 1rem; font-weight: 600; cursor: pointer; border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease;
}
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-dark); text-decoration: none; }
.btn-outline { background: transparent; color: var(--color-accent); border-color: var(--color-accent); }
.btn-outline:hover { background: var(--color-accent); color: #fff; text-decoration: none; }
.btn-row { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn-row.center { justify-content: center; }

/* ---------- hero ---------- */
.hero { padding: 6rem 0 5rem; }
.hero h1 { max-width: 16ch; }
.hero .lead { max-width: 52ch; margin-top: 1.25rem; margin-bottom: 2rem; }
.eyebrow {
  text-transform: uppercase; letter-spacing: 0.12em; font-size: 0.8rem;
  font-weight: 700; color: var(--color-accent); margin-bottom: 1rem;
}

/* ---------- grid of cards ---------- */
.grid { display: grid; gap: 1.5rem; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--color-bg); border: 1px solid var(--color-line);
  border-radius: 6px; padding: 2rem;
}
.section-alt .card { background: #fff; }
.card h3 { margin-top: 0; }
.card .price { color: var(--color-muted); font-size: 0.95rem; }

/* ---------- feature list ---------- */
.features { list-style: none; padding: 0; margin: 0; display: grid; gap: 1.5rem; }
.features li { padding-left: 1.75rem; position: relative; }
.features li::before {
  content: "—"; position: absolute; left: 0; color: var(--color-accent); font-weight: 700;
}
.features strong { display: block; }

/* ---------- CTA band ---------- */
.cta-band { background: var(--color-accent); color: #fff; }
.cta-band h2, .cta-band p { color: #fff; }
.cta-band .btn-primary { background: #fff; color: var(--color-accent); }
.cta-band .btn-primary:hover { background: var(--color-bg-alt); }

/* ---------- forms ---------- */
form { display: grid; gap: 1.1rem; max-width: 560px; }
label { font-size: 0.95rem; font-weight: 600; display: block; margin-bottom: 0.35rem; }
input, select, textarea {
  width: 100%; padding: 0.75rem 0.9rem; font-size: 1rem; font-family: inherit;
  border: 1px solid var(--color-line); border-radius: 4px; background: #fff;
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--color-accent); border-color: transparent; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--color-line); padding: 3rem 0; font-size: 0.9rem;
  color: var(--color-muted); background: var(--color-bg-alt);
}
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1.5rem; }
.footer-inner a { color: var(--color-muted); }

/* ---------- utilities ---------- */
.mt-0 { margin-top: 0; } .mb-0 { margin-bottom: 0; }
hr { border: none; border-top: 1px solid var(--color-line); margin: 3rem 0; }

/* ---------- responsive ---------- */
@media (max-width: 820px) {
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .nav-links { gap: 1rem; font-size: 0.9rem; }
  .nav-links .nav-cta { display: none; }
  section { padding: 3.5rem 0; }
}