/* ============================================
   QGTM IT School — Design System & Base
   ============================================ */

:root {
  /* Brand */
  --forest: #0B3328;
  --forest-hover: #0A2920;
  --forest-soft: #0B33280D;
  --forest-border: #0B332820;
  --lime: #C5F135;
  --lime-hover: #B0D82C;
  --lime-soft: #F4FCDA;

  /* Neutrals */
  --ink: #09090B;
  --ink-80: #27272A;
  --ink-60: #52525B;
  --ink-40: #71717A;
  --ink-20: #A1A1AA;
  --ink-10: #D4D4D8;
  --border: #E4E4E7;
  --border-strong: #D4D4D8;
  --surface: #FFFFFF;
  --surface-raised: #FAFAFA;
  --surface-sunken: #F4F4F5;
  --surface-tint: #F8FAFC;

  /* Semantic */
  --success: #16A34A;
  --success-bg: #F0FDF4;
  --warning: #D97706;
  --error: #DC2626;

  /* Spacing */
  --sp-1: 4px; --sp-2: 8px; --sp-3: 12px; --sp-4: 16px;
  --sp-5: 20px; --sp-6: 24px; --sp-8: 32px; --sp-10: 40px;
  --sp-12: 48px; --sp-16: 64px; --sp-20: 80px; --sp-24: 96px;
  --sp-32: 128px;

  /* Radius */
  --r-sm: 6px; --r-md: 10px; --r-lg: 14px; --r-xl: 20px; --r-2xl: 28px;
  --r-pill: 999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(9,9,11,.04);
  --shadow-sm: 0 1px 3px rgba(9,9,11,.06), 0 1px 2px rgba(9,9,11,.04);
  --shadow-md: 0 4px 12px rgba(9,9,11,.06), 0 2px 6px rgba(9,9,11,.04);
  --shadow-lg: 0 16px 40px rgba(9,9,11,.08), 0 4px 12px rgba(9,9,11,.04);
  --shadow-xl: 0 28px 72px rgba(9,9,11,.12), 0 8px 24px rgba(9,9,11,.06);
  --shadow-forest: 0 12px 32px rgba(11,51,40,.18);

  /* Layout */
  --container: 1200px;
  --container-wide: 1320px;
  --container-narrow: 880px;
  --nav-h: 60px; /* default mobile; overridden at wider breakpoints */

  /* Motion */
  --ease: cubic-bezier(.16,1,.3,1);
  --t-fast: 150ms;
  --t-base: 240ms;
  --t-slow: 480ms;
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  font-family: 'Geist', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea, select { font-family: inherit; font-size: inherit; color: inherit; }
ul, ol { list-style: none; }
::selection { background: var(--lime); color: var(--forest); }

/* Skip link */
.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--forest); color: #fff; padding: 12px 16px;
  z-index: 9999; border-radius: 0 0 var(--r-md) 0;
}
.skip-link:focus { left: 0; }

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  line-height: 1.15;
}
h1 { font-size: clamp(2.25rem, 1.4rem + 3.6vw, 4rem); font-weight: 800; letter-spacing: -0.035em; }
h2 { font-size: clamp(1.75rem, 1.2rem + 2.4vw, 2.75rem); letter-spacing: -0.03em; }
h3 { font-size: clamp(1.25rem, 1rem + 1vw, 1.625rem); }
h4 { font-size: 1.125rem; }
p { color: var(--ink-60); }
.lead { font-size: clamp(1.0625rem, 1rem + .35vw, 1.25rem); color: var(--ink-60); line-height: 1.6; }

code, .mono { font-family: 'Geist Mono', ui-monospace, SFMono-Regular, Menlo, monospace; }

/* ── Layout helpers ── */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: 16px; }
.container-wide { max-width: var(--container-wide); }
.container-narrow { max-width: var(--container-narrow); }

.section { padding-block: clamp(64px, 4vw + 40px, 120px); }
.section-sm { padding-block: clamp(48px, 3vw + 24px, 80px); }
.section-tint { background: var(--surface-raised); }
.section-sunken { background: var(--surface-sunken); }
.section-forest { background: var(--forest); color: #fff; }
.section-forest h1,
.section-forest h2,
.section-forest h3 { color: #fff; }
.section-forest p { color: rgba(255,255,255,.75); }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: 'Geist Mono', monospace;
  font-size: .75rem; font-weight: 500;
  text-transform: uppercase; letter-spacing: .12em;
  color: var(--forest);
  padding: 6px 12px;
  background: var(--lime-soft);
  border: 1px solid var(--forest-border);
  border-radius: var(--r-pill);
}
.section-forest .eyebrow {
  background: rgba(197,241,53,.15);
  border-color: rgba(197,241,53,.3);
  color: var(--lime);
}

.section-head { max-width: 760px; margin-bottom: var(--sp-12); }
.section-head.center { margin-inline: auto; text-align: center; }
.section-head .eyebrow { margin-bottom: var(--sp-4); }
.section-head h2 { margin-bottom: var(--sp-4); }
.section-head p { font-size: 1.0625rem; }

/* ── Utility ── */
.grid { display: grid; gap: var(--sp-6); }
/* Base grid definitions are single-column; responsive.css adds columns */
.grid-2 { grid-template-columns: 1fr; }
.grid-3 { grid-template-columns: 1fr; }
.grid-4 { grid-template-columns: 1fr; }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-2 { gap: var(--sp-2); } .gap-3 { gap: var(--sp-3); } .gap-4 { gap: var(--sp-4); }
.mt-4 { margin-top: var(--sp-4); } .mt-6 { margin-top: var(--sp-6); } .mt-8 { margin-top: var(--sp-8); }
.text-center { text-align: center; }

/* Scroll reveal */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal-delay-1 { transition-delay: 80ms; }
.reveal-delay-2 { transition-delay: 160ms; }
.reveal-delay-3 { transition-delay: 240ms; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}