/* ============================================================
   ChatQP shared stylesheet.
   Same design language as before (dark regulatory terminal,
   Fraunces serif plus IBM Plex Mono, grid-cell layouts), now
   lifted further so long reading sections are easier on screen.
   Nav, hero and terminal cards stay dark. Reading sections
   use lighter panels and higher-contrast body text.
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Lighter slate base so structure and body copy read clearly. */
  --bg:      #202838;
  --bg2:     #2a3447;
  --bg3:     #344056;
  --term-bg: #161d29;          /* terminal cards stay darker for contrast */
  --panel:   rgba(255,255,255,0.055); /* lighter reading panel */
  --border:  rgba(255,255,255,0.18);
  --border2: rgba(255,255,255,0.28);
  --text:    #f8fafc;
  --muted:   #c9d3e3;          /* lifted for readability */
  --muted2:  #a5b0c2;
  --accent:  #2dd4bf;          /* teal */
  --accent2: #5eead4;
  --warn:    #fbbf24;
  --danger:  #f87171;
  --success: #4ade80;
  --violet:  #c4b5fd;
  --orange:  #fb923c;
  --serif:   'Fraunces', Georgia, serif;
  --mono:    'IBM Plex Mono', 'Courier New', monospace;
  --maxw:    1100px;
}

html { scroll-behavior: smooth; background: var(--bg); }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

/* subtle grid texture, kept low so long pages are not tiring */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none; z-index: 0;
}

.glow {
  position: fixed; width: 720px; height: 720px; border-radius: 50%;
  background: radial-gradient(circle, rgba(45,212,191,0.13) 0%, transparent 70%);
  top: -200px; left: -220px; pointer-events: none; z-index: 0;
  animation: driftGlow 20s ease-in-out infinite alternate;
}
.glow.two {
  top: auto; bottom: -260px; left: auto; right: -240px;
  background: radial-gradient(circle, rgba(96,165,250,0.10) 0%, transparent 70%);
  animation-duration: 26s;
}
@keyframes driftGlow { from { transform: translate(0,0); } to { transform: translate(180px,120px); } }

section { position: relative; z-index: 1; }

a { color: inherit; }

/* ---------------- NAV ---------------- */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 40px;
  border-bottom: 1px solid var(--border);
  background: rgba(32,40,56,0.90);
  backdrop-filter: blur(14px);
}
.nav-logo { font-family: var(--serif); font-size: 20px; letter-spacing: -0.02em; color: var(--text); text-decoration: none; }
.nav-logo span { color: var(--accent); }
.nav-mid { display: flex; gap: 20px; align-items: center; }
.nav-mid a {
  font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--muted); text-decoration: none; transition: color 0.2s; white-space: nowrap;
}
.nav-mid a:hover, .nav-mid a.active { color: var(--accent); }
.nav-right { display: flex; align-items: center; gap: 12px; }
.nav-tag { font-size: 10px; letter-spacing: 0.15em; text-transform: uppercase; color: var(--muted); border: 1px solid var(--border); padding: 4px 10px; }
.nav-toggle { display: none; background: none; border: 1px solid var(--border); color: var(--text); font-family: var(--mono); font-size: 18px; padding: 4px 10px; cursor: pointer; }

/* ---------------- shared bits ---------------- */
.section-label { font-size: 10px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); margin-bottom: 40px; }
.section-label::before { content: '[ '; }
.section-label::after  { content: ' ]'; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding-left: 48px; padding-right: 48px; }

.btn-primary { background: var(--accent); color: #06231f; padding: 13px 28px; font-family: var(--mono); font-size: 12px; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase; text-decoration: none; border: none; cursor: pointer; display: inline-block; transition: background 0.2s, transform 0.15s; }
.btn-primary:hover { background: var(--accent2); transform: translateY(-1px); }
.btn-ghost { color: var(--text); font-family: var(--mono); font-size: 12px; letter-spacing: 0.08em; text-decoration: none; border: 1px solid var(--border2); padding: 13px 24px; display: inline-block; transition: color 0.2s, border-color 0.2s, background 0.2s; }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* page hero used by sub-pages */
.page-hero { padding: 150px 0 50px; }
.page-hero .eyebrow { font-size: 10px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); margin-bottom: 22px; }
.page-hero .eyebrow::before { content: '// '; opacity: 0.5; }
.page-hero h1 { font-family: var(--serif); font-size: clamp(38px,6vw,72px); font-weight: 300; line-height: 1.02; letter-spacing: -0.03em; margin-bottom: 22px; }
.page-hero h1 em { font-style: italic; color: var(--accent); }
.page-hero .lead { font-size: 16px; color: var(--text); max-width: 640px; line-height: 1.7; }
.page-hero .lead.muted { color: var(--muted); font-size: 14px; margin-top: 14px; }

/* generic content prose for sub-pages */
.prose { max-width: 760px; }
.prose h2 { font-family: var(--serif); font-size: clamp(26px,3.2vw,40px); font-weight: 300; letter-spacing: -0.02em; line-height: 1.15; margin: 0 0 20px; }
.prose h2 em { font-style: italic; color: var(--accent); }
.prose h3 { font-family: var(--serif); font-size: 22px; font-weight: 300; margin: 0 0 12px; }
.prose p { font-size: 15px; color: var(--muted); line-height: 1.9; margin-bottom: 20px; }
.prose p strong, .prose strong { color: var(--text); font-weight: 500; }
.block { padding: 76px 0; border-top: 1px solid var(--border); }
.block:first-of-type { border-top: none; }

/* lighter reading panel for long text sections */
.reading-panel { background: var(--panel); border: 1px solid var(--border); padding: 34px 36px; }
@media (max-width: 640px) { .reading-panel { padding: 26px 22px; } }

/* callout / disclaimer card */
.callout { border-left: 2px solid var(--accent); background: rgba(45,212,191,0.06); padding: 18px 22px; margin: 8px 0 24px; }
.callout.warn { border-left-color: var(--warn); background: rgba(251,191,36,0.06); }
.callout.danger { border-left-color: var(--danger); background: rgba(248,113,113,0.06); }
.callout p { margin: 0; font-size: 13px; color: var(--text); line-height: 1.75; }
.callout .label { font-size: 9px; letter-spacing: 0.2em; text-transform: uppercase; color: var(--accent); display: block; margin-bottom: 8px; }
.callout.warn .label { color: var(--warn); }
.callout.danger .label { color: var(--danger); }

/* comparison table */
.tbl { width: 100%; border-collapse: collapse; border: 1px solid var(--border); font-size: 12.5px; margin: 8px 0 24px; }
.tbl th, .tbl td { text-align: left; padding: 14px 18px; border: 1px solid var(--border); vertical-align: top; line-height: 1.6; }
.tbl th { background: var(--bg3); color: var(--text); font-weight: 500; letter-spacing: 0.04em; text-transform: uppercase; font-size: 10px; }
.tbl td { color: var(--muted); background: var(--bg2); }
.tbl td:first-child { color: var(--text); }
.tbl tr:hover td { background: var(--bg3); }

/* card grids reused */
.grid-1px { display: grid; gap: 1px; background: var(--border); border: 1px solid var(--border); }
.cols-2 { grid-template-columns: 1fr 1fr; }
.cols-auto { grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); }
.cell { background: var(--bg2); padding: 32px 30px; transition: background 0.25s; }
.cell:hover { background: var(--bg3); }
.cell .num { font-size: 10px; color: var(--muted2); letter-spacing: 0.1em; margin-bottom: 16px; }
.cell .icon { font-size: 22px; margin-bottom: 14px; }
.cell h3 { font-family: var(--serif); font-size: 21px; font-weight: 300; margin-bottom: 10px; line-height: 1.2; }
.cell p { font-size: 13.5px; color: var(--muted); line-height: 1.75; }
.cell .tag { display: inline-block; margin-top: 18px; font-size: 10px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); border: 1px solid rgba(45,212,191,0.4); padding: 3px 8px; }

/* terminal output block (shared with samples + how-it-works) */
.term { background: var(--term-bg); border: 1px solid var(--border); font-family: var(--mono); font-size: 11.5px; line-height: 1.65; }
.term-header { display: flex; align-items: center; gap: 8px; padding: 10px 16px; border-bottom: 1px solid var(--border); background: #1a2230; }
.term-dot { width: 10px; height: 10px; border-radius: 50%; }
.term-dot.r { background: #f87171; } .term-dot.y { background: #fbbf24; } .term-dot.g { background: #4ade80; }
.term-title { font-size: 10px; color: var(--muted); margin-left: 8px; letter-spacing: 0.05em; }
.term-body { padding: 20px 24px; overflow-x: auto; }
.t-dim{color:var(--muted2);} .t-muted{color:var(--muted);} .t-text{color:var(--text);}
.t-accent{color:var(--accent);} .t-warn{color:var(--warn);} .t-danger{color:var(--danger);}
.t-success{color:var(--success);} .t-label{color:var(--violet);} .t-rule{color:var(--orange);}
.term-line { display: block; white-space: pre; }
.term-sep  { display: block; color: var(--muted2); white-space: pre; margin: 2px 0; }
.summary-box { margin-top: 4px; padding: 12px 16px; border-left: 2px solid var(--accent); background: rgba(45,212,191,0.06); }
.summary-box.danger  { border-left-color: var(--danger);  background: rgba(248,113,113,0.07); }
.summary-box.warn    { border-left-color: var(--warn);    background: rgba(251,191,36,0.07); }
.summary-box.success { border-left-color: var(--success); background: rgba(74,222,128,0.07); }

/* ---------------- FOOTER ---------------- */
footer { position: relative; z-index: 1; border-top: 1px solid var(--border); margin-top: 30px; }
.footer-inner { max-width: var(--maxw); margin: 0 auto; padding: 44px 48px; display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
.footer-logo { font-family: var(--serif); font-size: 20px; color: var(--text); margin-bottom: 12px; }
.footer-logo span { color: var(--accent); }
.footer-blurb { font-size: 12px; color: var(--muted); line-height: 1.7; max-width: 300px; }
.footer-col h4 { font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--muted2); margin-bottom: 14px; }
.footer-col a { display: block; font-size: 12px; color: var(--muted); text-decoration: none; padding: 4px 0; letter-spacing: 0.04em; transition: color 0.2s; }
.footer-col a:hover { color: var(--accent); }
.footer-bar { border-top: 1px solid var(--border); }
.footer-bar-inner { max-width: var(--maxw); margin: 0 auto; padding: 16px 48px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 11px; color: var(--muted2); letter-spacing: 0.05em; }
.footer-disclaimer { color: var(--muted); }

/* ---------------- animation ---------------- */
@keyframes fadeUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ---------------- responsive ---------------- */
@media (max-width: 900px) {
  .nav-mid { display: none; }
  .nav-toggle { display: inline-block; }
  nav.open .nav-mid {
    display: flex; flex-direction: column; gap: 0;
    position: absolute; top: 100%; left: 0; right: 0;
    background: rgba(32,40,56,0.98); border-bottom: 1px solid var(--border); padding: 8px 40px 16px;
  }
  nav.open .nav-mid a { padding: 12px 0; border-bottom: 1px solid var(--border); }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
}
@media (max-width: 768px) {
  .cols-2 { grid-template-columns: 1fr; }
  .tbl, .tbl tbody, .tbl tr { display: block; }
  .tbl thead { display: none; }
  .tbl td { display: block; border-top: none; }
  .tbl tr { border: 1px solid var(--border); margin-bottom: 1px; }
}
@media (max-width: 640px) {
  nav { padding: 16px 24px; }
  .wrap { padding-left: 24px; padding-right: 24px; }
  .footer-inner, .footer-bar-inner { padding-left: 24px; padding-right: 24px; }
  nav.open .nav-mid { padding-left: 24px; padding-right: 24px; }
}