/* AviationGrade Guides — shared stylesheet for /guides/ (Contrail).
   Chrome (.hdr/.nav/.mnav/.phero/.ftr/.wrap/.btn) comes from ag-study-v3.css.
   This sheet only adds the guides index grid + the article layout. */

:root{
  --g-navy2:#0a2f73;
  --g-mono:ui-monospace,'SFMono-Regular','Menlo','Consolas',monospace;
}

/* ============================================================ shared ==== */
.g-wrap{max-width:1240px;margin:0 auto;padding:0 40px}
.g-main{background:#fff}
.g-main h2,.g-main h3,.g-main h4{font-family:'Outfit',-apple-system,'Segoe UI',sans-serif;font-weight:600;letter-spacing:-.02em;text-wrap:balance}
.phero .g-byline{display:flex;flex-wrap:wrap;gap:8px 14px;align-items:center;margin-top:18px;font-size:.82rem;color:#b9c8e6}
.phero .g-byline .who{color:#fff;font-weight:600}
.phero .g-byline .sep{width:3px;height:3px;border-radius:50%;background:#7f96c4;flex:none}
.phero .g-intro-note{margin-top:10px;font-size:.8rem;color:#9dc2f5}

/* ============================================================ index ===== */
.g-sec{padding:52px 0}
@media(max-width:767px){.g-sec{padding:36px 0}}
.g-kick{display:block;font-size:.68rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--sky)}
.g-sec>h2.g-blk{font-size:1.5rem;color:var(--navy);margin:6px 0 6px}
.g-sec .g-sub{color:var(--muted);margin:0 0 8px;max-width:64ch}

.g-pills{display:flex;flex-wrap:wrap;gap:8px;margin:22px 0 0}
.g-pills a{text-decoration:none;font-size:.82rem;font-weight:600;color:var(--navy);background:var(--wash);
  border:1px solid var(--line);padding:8px 14px;border-radius:999px}
.g-pills a:hover{border-color:var(--sky);color:var(--sky)}

.g-pillars{display:grid;grid-template-columns:repeat(auto-fit,minmax(258px,1fr));gap:16px;margin-top:16px}
.g-pillar{background:var(--navy);color:#fff;border-radius:16px;padding:24px 22px 22px;text-decoration:none;
  display:flex;flex-direction:column;gap:10px;position:relative;overflow:hidden}
.g-pillar::before{content:"";position:absolute;left:0;top:0;bottom:0;width:4px;background:var(--orange)}
.g-pillar .pk{font-size:.64rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:#8fb0ef}
.g-pillar h3{font-size:1.14rem}
.g-pillar p{margin:0;font-size:.88rem;color:#c6d3ec;line-height:1.6}
.g-pillar .go{margin-top:auto;font-size:.82rem;font-weight:700;color:#fff}
.g-pillar .go::after{content:" \2192"}
.g-pillar:hover{background:var(--g-navy2)}

.g-cluster{margin-top:40px;scroll-margin-top:96px}
.g-cluster>h2{font-size:1.28rem;color:var(--navy);display:flex;align-items:baseline;gap:12px;flex-wrap:wrap}
.g-cluster>h2 .ct{font-size:.72rem;font-weight:600;color:var(--muted);letter-spacing:.02em}
.g-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px;margin-top:16px}
.g-card{background:#fff;border:1px solid var(--line);border-radius:13px;padding:18px 18px 16px;text-decoration:none;
  display:flex;flex-direction:column;gap:8px;transition:border-color .15s,transform .15s}
.g-card:hover{border-color:var(--sky);transform:translateY(-2px)}
.g-card .ck{font-size:.62rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--sky)}
.g-card h3{font-size:1.02rem;color:var(--navy);line-height:1.35}
.g-card p{margin:0;font-size:.85rem;color:var(--muted);line-height:1.6;flex:1}
.g-card .upd{font-size:.7rem;color:#8a97ab;font-weight:500}

/* ============================================================ article === */
.g-artgrid{display:grid;grid-template-columns:minmax(0,1fr) 288px;gap:52px;padding:46px 0 10px}
@media(max-width:1000px){.g-artgrid{grid-template-columns:1fr;gap:6px}}

.prose{max-width:74ch;min-width:0}
.prose>p:first-of-type{font-size:1.05rem}
.prose h2{font-size:1.34rem;color:var(--navy);margin:38px 0 12px;scroll-margin-top:96px}
.prose h3{font-size:1.06rem;color:var(--navy);margin:24px 0 8px}
.prose p{margin:0 0 16px}
.prose ul,.prose ol{margin:0 0 16px;padding-left:22px}
.prose li{margin:5px 0}
.prose strong{color:var(--navy)}
.prose a{color:var(--sky);font-weight:500}
.prose a:hover{text-decoration:underline}
.prose figure{margin:0 0 18px}
.prose table{border-collapse:collapse;width:100%;margin:0 0 18px;font-size:.9rem}
.prose th,.prose td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
.prose thead th{background:var(--wash);color:var(--navy);font-weight:600}
.prose td.sym{font-family:var(--g-mono);color:var(--navy);white-space:nowrap}
.prose .tbl-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px}
.prose .tbl-scroll table{margin:0;min-width:520px}

.g-keyfacts{background:var(--wash);border:1px solid var(--line);border-left:4px solid var(--orange);
  border-radius:12px;padding:18px 20px;margin:0 0 26px}
.g-keyfacts .kf-h{font-size:.68rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--orange);margin-bottom:12px}
.g-keyfacts dl{display:grid;grid-template-columns:repeat(auto-fit,minmax(148px,1fr));gap:12px 24px;margin:0}
.g-keyfacts dt{font-size:.68rem;color:var(--muted);letter-spacing:.03em;text-transform:uppercase}
.g-keyfacts dd{margin:2px 0 0;font-weight:600;color:var(--navy);font-size:.92rem;font-variant-numeric:tabular-nums}
.g-keyfacts .src{margin-top:12px;font-size:.74rem;color:#8a97ab}
.g-keyfacts .src a{color:var(--sky)}

.g-example{background:#fff;border:1px solid var(--line);border-left:4px solid var(--sky);border-radius:12px;padding:16px 18px;margin:0 0 20px}
.g-example .ex-h{font-size:.68rem;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--sky);margin-bottom:8px}
.g-example pre{font-family:var(--g-mono);font-size:.82rem;line-height:1.75;background:var(--wash);border:1px solid var(--line);
  border-radius:8px;padding:12px 14px;margin:10px 0 0;overflow-x:auto;color:var(--ink);white-space:pre}
.g-example .ans{margin:10px 0 0;font-weight:600;color:var(--navy);font-size:.9rem}

.g-pq{border:1px solid var(--line);border-radius:11px;margin:0 0 12px;overflow:hidden;background:#fff}
.g-pq summary{list-style:none;cursor:pointer;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;font-weight:500}
.g-pq summary::-webkit-details-marker{display:none}
.g-pq summary .n{flex:none;width:22px;height:22px;border-radius:6px;background:var(--navy);color:#fff;font-size:.72rem;
  font-weight:700;display:grid;place-items:center;margin-top:2px}
.g-pq summary .qtxt{flex:1}
.g-pq summary .rev{flex:none;font-size:.74rem;font-weight:700;color:var(--sky)}
.g-pq[open] summary .rev{color:var(--muted)}
.g-pq .body{padding:0 16px 15px 50px;border-top:1px solid var(--line)}
.g-pq .body .opt{font-size:.88rem;margin:10px 0}
.g-pq .body .opt.correct{color:var(--navy);font-weight:600}
.g-pq .body .work{font-family:var(--g-mono);font-size:.8rem;background:var(--wash);border:1px solid var(--line);
  border-radius:8px;padding:10px 12px;margin-top:8px;white-space:pre-wrap;color:var(--ink)}

.g-faq{border-bottom:1px solid var(--line)}
.g-faq summary{list-style:none;cursor:pointer;padding:15px 2px;font-weight:600;color:var(--navy);
  display:flex;justify-content:space-between;gap:16px;font-family:'Outfit',-apple-system,'Segoe UI',sans-serif}
.g-faq summary::-webkit-details-marker{display:none}
.g-faq summary::after{content:"+";color:var(--sky);font-weight:700;flex:none}
.g-faq[open] summary::after{content:"\2013"}
.g-faq .fa{padding:0 2px 16px;color:var(--muted);font-size:.93rem}
.g-faq .fa a{color:var(--sky)}

.g-author{display:flex;gap:14px;align-items:flex-start;background:var(--wash);border:1px solid var(--line);
  border-radius:12px;padding:16px 18px;margin:34px 0 0}
.g-author .av{flex:none;width:46px;height:46px;border-radius:50%;background:var(--navy);
  object-fit:contain;padding:8px}
.g-author .nm{font-weight:700;color:var(--navy)}
.g-author .cr{font-size:.82rem;color:var(--muted);margin:2px 0 6px}
.g-author .bio{font-size:.84rem;color:var(--muted);margin:0}

.g-sources{margin:26px 0 0;font-size:.84rem;color:var(--muted)}
.g-sources h2{font-size:.7rem;letter-spacing:.13em;text-transform:uppercase;color:var(--muted);
  font-family:'Inter',sans-serif;font-weight:700;margin:0 0 8px}
.g-sources ul{margin:0;padding-left:20px}
.g-sources li{margin:5px 0}
.g-sources em{color:var(--ink)}
.g-updated{margin:16px 0 0;font-size:.78rem;color:#8a97ab;line-height:1.7}
.g-updated a{color:var(--sky)}

.g-prevnext{display:flex;justify-content:space-between;gap:16px;margin:34px 0 0;padding-top:20px;
  border-top:1px solid var(--line);font-size:.85rem}
.g-prevnext a{text-decoration:none;color:var(--navy);font-weight:600;max-width:47%}
.g-prevnext a.nx{text-align:right;margin-left:auto}
.g-prevnext a span{display:block;font-size:.66rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:#8a97ab;margin-bottom:3px}
.g-prevnext a:hover{color:var(--sky)}

/* aside */
.g-aside{align-self:start;position:sticky;top:96px;display:flex;flex-direction:column;gap:22px}
@media(max-width:1000px){.g-aside{position:static;margin:26px 0 0}}
.g-aside .box{border:1px solid var(--line);border-radius:12px;padding:15px 16px}
.g-aside .bh{font-size:.64rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--muted);margin-bottom:10px}
.g-toc a{display:block;text-decoration:none;color:var(--muted);font-size:.84rem;padding:5px 0;
  border-left:2px solid transparent;padding-left:10px;margin-left:-2px}
.g-toc a:hover{color:var(--navy)}
.g-toc a.active{color:var(--navy);font-weight:600;border-left-color:var(--orange)}
.g-related a{display:block;text-decoration:none;color:var(--navy);font-weight:600;font-size:.85rem;padding:6px 0}
.g-related a:hover{color:var(--sky)}
.g-related a small{display:block;font-weight:500;color:#8a97ab;font-size:.72rem}
.g-pcta{background:var(--navy);color:#fff;border-radius:12px;padding:18px}
.g-pcta .pk{font-size:.62rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:#8fb0ef}
.g-pcta p{margin:8px 0 12px;font-size:.86rem;color:#c6d3ec;line-height:1.55}
.g-pcta a{display:inline-block;text-decoration:none;background:var(--orange);color:#fff;font-weight:600;font-size:.82rem;padding:9px 15px;border-radius:9px}
.g-pcta a:hover{background:#d8410c}
.g-mob-toc{margin:0 0 8px}
.g-mob-toc summary{cursor:pointer;font-weight:600;color:var(--navy);padding:12px 14px;border:1px solid var(--line);border-radius:10px}
.g-mob-toc[open] summary{border-bottom-left-radius:0;border-bottom-right-radius:0}
.g-mob-toc .g-toc{border:1px solid var(--line);border-top:0;border-radius:0 0 10px 10px;padding:8px 14px}
@media(min-width:1001px){.g-mob-toc{display:none}}

/* ============================================================ xlink ===== */
.xlink{background:var(--wash);border-top:1px solid var(--line);padding:44px 0}
.xlink .wrap{max-width:1240px;margin:0 auto;padding:0 40px}
.xl-card{display:flex;align-items:center;gap:28px;justify-content:space-between;flex-wrap:wrap;background:#fff;
  border:1px solid var(--line);border-left:4px solid var(--orange);border-radius:14px;padding:26px 30px}
.xl-txt{flex:1 1 420px}
.xl-k{display:block;font-size:.7rem;font-weight:700;letter-spacing:.13em;text-transform:uppercase;color:var(--sky);margin-bottom:7px}
.xl-card h2{font-family:'Outfit',-apple-system,'Segoe UI',sans-serif;font-weight:600;letter-spacing:-.02em;font-size:1.28rem;color:var(--navy);margin:0 0 8px}
.xl-card p{color:#3b4a63;font-size:.95rem;line-height:1.7;margin:0;max-width:66ch}
.xl-ctas{display:flex;gap:10px;flex-wrap:wrap;flex:none}
.xl-cta{display:inline-flex;align-items:center;justify-content:center;white-space:nowrap;font-size:.9rem;font-weight:600;
  text-decoration:none;padding:12px 22px;border-radius:10px;background:var(--orange);border:1px solid var(--orange);color:#fff}
.xl-cta:hover{background:#d8410c;border-color:#d8410c}
.xl-cta.ghost{background:#fff;border-color:var(--line);color:var(--navy)}
.xl-cta.ghost:hover{border-color:var(--sky);background:var(--wash)}
@media(max-width:767px){
  .g-wrap,.xlink .wrap{padding:0 20px}
  .xlink{padding:28px 0}
  .xl-card{padding:20px;gap:16px}
  .xl-card h2{font-size:1.1rem}
  .xl-ctas{width:100%}
  .xl-cta{flex:1}
}
@media(max-width:430px){.g-wrap,.xlink .wrap{padding:0 16px}}