/* QLoF Primer — Foundational Knowledge for Anyone */
/* Laws of Form made accessible across all disciplines */

:root {
  --bg: #fdfcfa;
  --text: #1a1a1a;
  --muted: #5e5e5e;
  --accent: #b0562a;
  --accent2: #2a6e4f;
  --border: #e0ddd5;
  --warm-bg: #faf6f0;
  --code-bg: #f5f2ec;
  --highlight: #fff3e0;
  --sans: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --serif: Georgia, "Times New Roman", Times, serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 18px; scroll-behavior: smooth; }
body { font-family: var(--serif); color: var(--text); background: var(--bg); line-height: 1.75; -webkit-font-smoothing: antialiased; }
.container { max-width: 720px; margin: 0 auto; padding: 2rem 1.5rem 4rem; }

/* Navigation */
.site-header { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--border); display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; }
.site-title { font-family: var(--sans); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); }
.site-title a { color: var(--muted); text-decoration: none; }
.site-title a:hover { color: var(--accent); }
.site-subtitle { font-family: var(--sans); font-size: 0.7rem; color: var(--muted); }

.chapter-nav { font-family: var(--sans); font-size: 0.8rem; display: flex; justify-content: space-between; align-items: center; padding: 0.75rem 0; margin: 1.5rem 0; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.chapter-nav a { color: var(--accent); text-decoration: none; }
.chapter-nav a:hover { text-decoration: underline; }
.chapter-nav .current { color: var(--muted); font-style: italic; }

/* Headings */
h1 { font-family: var(--sans); font-size: 1.8rem; font-weight: 600; line-height: 1.3; margin: 2rem 0 0.75rem; }
h2 { font-family: var(--sans); font-size: 1.2rem; font-weight: 600; margin: 2rem 0 0.75rem; padding-top: 0.5rem; }
h3 { font-family: var(--sans); font-size: 1rem; font-weight: 600; margin: 1.5rem 0 0.5rem; }
h4 { font-family: var(--sans); font-size: 0.9rem; font-weight: 600; margin: 1.25rem 0 0.5rem; color: var(--muted); }

p { margin: 0 0 1.2rem; }
strong { font-weight: 600; }
em { font-style: italic; }
ul, ol { margin: 0 0 1.2rem 2rem; }
li { margin-bottom: 0.5rem; }

blockquote { margin: 1.5rem 0; padding: 1rem 1.5rem; border-left: 3px solid var(--accent); background: var(--warm-bg); }
blockquote p:last-child { margin: 0; }

code { font-family: var(--mono); font-size: 0.85rem; background: var(--code-bg); padding: 0.1rem 0.3rem; border-radius: 2px; }
pre { background: var(--code-bg); border: 1px solid var(--border); padding: 1rem 1.25rem; overflow-x: auto; font-size: 0.8rem; line-height: 1.5; margin: 1rem 0 1.5rem; border-radius: 4px; }
pre code { background: none; padding: 0; font-size: inherit; }

hr { border: none; border-top: 1px solid var(--border); margin: 2.5rem 0; }
a { color: var(--accent); }
a:hover { text-decoration: underline; }

/* Hero */
.hero { text-align: center; padding: 3rem 0 2.5rem; }
.hero h1 { font-size: 2.2rem; margin: 0 0 1rem; }
.hero .tagline { font-family: var(--sans); font-size: 1rem; color: var(--muted); line-height: 1.6; max-width: 540px; margin: 0 auto 1.5rem; }
.hero .callout { display: inline-block; font-family: var(--sans); font-size: 0.8rem; color: var(--accent2); border: 1px solid var(--accent2); padding: 0.35rem 1rem; }
.hero .start-btn { display: inline-block; font-family: var(--sans); font-size: 0.95rem; color: #fff; background: var(--accent); padding: 0.6rem 2rem; text-decoration: none; margin-top: 1.5rem; }
.hero .start-btn:hover { background: #933f19; text-decoration: none; }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 1rem; margin: 2rem 0; }
.card { background: var(--warm-bg); border: 1px solid var(--border); padding: 1.25rem; text-decoration: none; transition: transform 0.1s; }
.card:hover { transform: translateY(-1px); }
.card h3 { font-family: var(--sans); font-size: 0.9rem; margin: 0 0 0.5rem; color: var(--text); }
.card p { font-size: 0.85rem; color: var(--muted); margin: 0; }
.card .icon { font-size: 1.5rem; margin-bottom: 0.5rem; }

/* Insight box */
.insight { background: var(--highlight); border: 1px solid #e0d0b0; padding: 1.25rem 1.5rem; margin: 1.5rem 0; }
.insight strong { font-family: var(--sans); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--accent); display: block; margin-bottom: 0.5rem; }
.insight p { margin: 0; }

/* Pattern visual */
.pattern-demo { background: var(--code-bg); border: 1px solid var(--border); padding: 1.5rem; margin: 1.5rem 0; text-align: center; font-family: var(--mono); font-size: 1.1rem; }
.pattern-demo .token { display: inline-block; padding: 0.3rem 0.6rem; margin: 0.2rem; background: #e8e4dc; border: 1px solid #d0ccc4; }
.pattern-demo .token.mark { background: #f0e0d0; border-color: #c0a080; }
.pattern-demo .token.enclose { background: #d0e0f0; border-color: #8090c0; }
.pattern-demo .rule { font-size: 0.9rem; color: var(--muted); margin-top: 0.75rem; }

/* Step */
.step { margin: 1.5rem 0; padding-left: 2rem; border-left: 2px solid var(--accent2); }
.step-num { font-family: var(--sans); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--accent2); margin-bottom: 0.3rem; }
.step p { margin: 0 0 0.5rem; }

/* Footer */
.site-footer { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border); font-family: var(--sans); font-size: 0.75rem; color: var(--muted); text-align: center; line-height: 1.7; }
.site-footer a { color: var(--muted); }

/* Tables */
table { width: 100%; border-collapse: collapse; margin: 1.5rem 0; font-family: var(--sans); font-size: 0.85rem; }
th, td { padding: 0.5rem 0.75rem; border: 1px solid var(--border); text-align: left; vertical-align: top; }
th { background: var(--warm-bg); font-weight: 600; }

/* Cross-discipline badge */
.discipline-badge { display: inline-block; font-family: var(--sans); font-size: 0.7rem; padding: 0.15rem 0.5rem; margin: 0.15rem; border: 1px solid var(--border); }
.discipline-badge.math { border-color: #4a90d9; color: #4a90d9; }
.discipline-badge.physics { border-color: #d94a4a; color: #d94a4a; }
.discipline-badge.chemistry { border-color: #4ad94a; color: #4ad94a; }
.discipline-badge.biology { border-color: #4ad9b0; color: #4ad9b0; }
.discipline-badge.psychology { border-color: #d9a04a; color: #d9a04a; }
.discipline-badge.engineering { border-color: #8a4ad9; color: #8a4ad9; }

/* Warm callout */
.warm-callout { background: linear-gradient(135deg, #fff8f0, #fef5e7); border: 1px solid #e8d5b0; padding: 1.5rem; margin: 2rem 0; text-align: center; }
.warm-callout p { margin: 0.5rem 0; }

/* Responsive */
@media (max-width: 600px) {
  html { font-size: 16px; }
  .container { padding: 1.5rem 1rem 3rem; }
  .hero h1 { font-size: 1.6rem; }
  .card-grid { grid-template-columns: 1fr; }
}