/* ===========================================================================
   Arrya — Biomass Gasification Resource
   Custom design system: deep forest green + warm harvest amber, editorial.
   Fonts: Fraunces (display serif) + Inter (body). No UI framework.
   Content is ALWAYS visible with CSS alone — JS is enhancement only.
   =========================================================================== */

:root{
  --forest:#1b4332;
  --forest-2:#22543d;
  --green:#2d6a4f;
  --green-6:#40916c;
  --leaf:#74c69d;
  --leaf-soft:#d8f0e2;
  --amber:#e09f3e;
  --amber-dk:#c07d18;
  --cream:#faf7f0;
  --paper:#ffffff;
  --panel:#f3efe4;
  --ink:#1f2a24;
  --ink-soft:#40514a;
  --muted:#657a70;
  --line:#e2e0d4;
  --shadow:0 6px 24px rgba(27,67,50,.10);
  --shadow-lg:0 18px 48px rgba(27,67,50,.16);
  --radius:14px;
  --radius-sm:10px;
  --maxw:1120px;
  --prose:720px;
}

/* ---------- reset / base ---------- */
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:"Inter",system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);
  background:var(--cream);
  line-height:1.7;
  font-size:18px;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;height:auto;display:block}
a{color:var(--green);text-decoration:underline;text-underline-offset:2px;text-decoration-thickness:1px;transition:color .15s}
a:hover{color:var(--amber-dk)}
h1,h2,h3,h4{font-family:"Fraunces","Fraunces",Georgia,serif;line-height:1.18;color:var(--forest);font-weight:600;margin:0 0 .5em}
h1{font-size:clamp(2.1rem,4.6vw,3.2rem);letter-spacing:-.01em}
h2{font-size:clamp(1.5rem,3vw,2.05rem);margin-top:1.9em}
h3{font-size:1.25rem;margin-top:1.5em}
p{margin:0 0 1.15em}
strong{color:var(--forest-2)}
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:clamp(1.1rem,4vw,2rem)}

/* ---------- header / nav ---------- */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(27,67,50,.97);
  backdrop-filter:saturate(1.4) blur(6px);
  border-bottom:3px solid var(--amber);
}
.nav{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:70px}
.brand{display:inline-flex;align-items:center;gap:.6rem;text-decoration:none;color:#fff}
.brand-mark{
  display:grid;place-items:center;width:38px;height:38px;border-radius:10px;
  background:linear-gradient(135deg,var(--amber),var(--amber-dk));
  color:var(--forest);font-family:"Fraunces",serif;font-weight:700;font-size:1.35rem;
  box-shadow:0 2px 8px rgba(0,0,0,.25);
}
.brand-text{display:flex;flex-direction:column;line-height:1.05}
.brand-text strong{color:#fff;font-family:"Fraunces",serif;font-size:1.22rem;font-weight:600}
.brand-text small{color:var(--leaf);font-size:.68rem;letter-spacing:.08em;text-transform:uppercase}
.nav-links{list-style:none;display:flex;align-items:center;gap:.25rem;margin:0;padding:0;flex-wrap:wrap}
.nav-links a{
  color:#eaf3ee;text-decoration:none;font-size:.94rem;font-weight:500;
  padding:.5rem .7rem;border-radius:8px;white-space:nowrap;
}
.nav-links a:hover{background:rgba(255,255,255,.10);color:#fff}
.nav-links a.active{color:var(--amber)}
.nav-cta{background:var(--amber)!important;color:var(--forest)!important;font-weight:600}
.nav-cta:hover{background:#fff!important}
.nav-toggle{display:none;background:transparent;border:0;cursor:pointer;padding:.4rem;flex-direction:column;gap:5px}
.nav-toggle span{display:block;width:26px;height:2.5px;background:#fff;border-radius:2px;transition:.25s}
.nav-toggle[aria-expanded="true"] span:nth-child(1){transform:translateY(7.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] span:nth-child(3){transform:translateY(-7.5px) rotate(-45deg)}

/* ---------- hero ---------- */
.hero{position:relative;margin:0 auto;max-width:1240px;padding:1.4rem clamp(1.1rem,4vw,2rem) 0}
.hero-img{
  width:100%;height:clamp(240px,42vw,460px);object-fit:cover;
  border-radius:var(--radius);box-shadow:var(--shadow-lg);
  border:1px solid var(--line);
}

/* ---------- prose / article ---------- */
.prose{max-width:calc(var(--prose) + 4rem);padding-top:2.6rem;padding-bottom:3.5rem}
.prose > h1{margin-top:.2em}
.prose p,.prose ul,.prose ol,.prose dl,.prose .table-wrap,.prose figure{max-width:var(--prose)}
.prose .hero-img,.prose figure{max-width:100%}
.lede{font-size:1.22rem;line-height:1.6;color:var(--ink-soft);margin-bottom:1.5em}
.prose ul,.prose ol{margin:0 0 1.3em;padding-left:1.3em}
.prose li{margin-bottom:.5em}
.prose ul li::marker{color:var(--amber-dk)}
.prose h2{position:relative;padding-top:.2em}
.prose h2::before{
  content:"";display:block;width:46px;height:4px;border-radius:4px;
  background:linear-gradient(90deg,var(--amber),var(--leaf));margin-bottom:.7rem;
}

/* figures */
.page-figure{margin:1.8em 0 2em;}
.page-figure img{
  width:100%;border-radius:var(--radius);box-shadow:var(--shadow);
  border:1px solid var(--line);
}

/* tables */
.table-wrap{overflow-x:auto;margin:1.6em 0;border-radius:var(--radius-sm);box-shadow:var(--shadow);border:1px solid var(--line)}
table{border-collapse:collapse;width:100%;min-width:560px;background:var(--paper);font-size:.96rem}
thead th{background:var(--forest);color:#fff;font-family:"Fraunces",serif;font-weight:600;text-align:left}
th,td{padding:.7rem .9rem;border-bottom:1px solid var(--line);vertical-align:top}
tbody tr:nth-child(even){background:var(--panel)}
tbody td:first-child{font-weight:600;color:var(--forest-2)}

/* definition lists (glossary) */
dl.glossary{margin:1.2em 0 1.6em;border-left:3px solid var(--leaf);padding-left:1.2rem}
dl.glossary dt{font-family:"Fraunces",serif;font-weight:600;color:var(--forest);font-size:1.08rem;margin-top:1.1em}
dl.glossary dd{margin:.2em 0 0;color:var(--ink-soft)}

/* ---------- contact form ---------- */
.contact-form{
  display:flex;flex-direction:column;gap:.35rem;max-width:var(--prose);
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:1.6rem;box-shadow:var(--shadow);margin:1.4em 0 2em;
}
.contact-form label{font-weight:600;font-size:.9rem;color:var(--forest-2);margin-top:.6rem}
.contact-form input,.contact-form textarea{
  font:inherit;font-size:1rem;padding:.7rem .8rem;border:1px solid var(--line);
  border-radius:10px;background:var(--cream);color:var(--ink);width:100%;
}
.contact-form input:focus,.contact-form textarea:focus{
  outline:none;border-color:var(--green-6);box-shadow:0 0 0 3px rgba(64,145,108,.18);background:#fff
}
.contact-form button,.error-page a.btn{
  align-self:flex-start;margin-top:1.1rem;cursor:pointer;
  background:linear-gradient(135deg,var(--green),var(--forest-2));color:#fff;
  border:0;border-radius:999px;padding:.8rem 1.6rem;font:inherit;font-weight:600;
  box-shadow:var(--shadow);transition:transform .15s,box-shadow .15s;
}
.contact-form button:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}

/* ---------- 404 ---------- */
.error-page{text-align:center;padding-top:4rem;padding-bottom:5rem}
.error-page .err-code{font-family:"Fraunces",serif;font-size:5rem;color:var(--amber);margin:0;line-height:1}
.error-page .lede{margin-inline:auto}
.error-page p{max-width:var(--prose);margin-inline:auto}

/* ---------- footer ---------- */
.site-footer{background:var(--forest);color:#cfe0d6;margin-top:2rem}
.foot-inner{
  max-width:var(--maxw);margin-inline:auto;padding:3rem clamp(1.1rem,4vw,2rem) 1.6rem;
  display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:2rem;
}
.foot-brand p{font-size:.92rem;color:#a9c4b6;margin-top:.9rem;max-width:32ch}
.foot-brand .brand-text strong{color:#fff}
.foot-col h3{color:#fff;font-size:1rem;margin-bottom:.7rem}
.foot-col ul{list-style:none;margin:0;padding:0}
.foot-col li{margin-bottom:.45rem}
.foot-col a{color:#bcd4c8;text-decoration:none;font-size:.92rem}
.foot-col a:hover{color:var(--amber);text-decoration:underline}
.foot-bottom{border-top:1px solid rgba(255,255,255,.12)}
.foot-bottom p{max-width:var(--maxw);margin:0 auto;padding:1.1rem clamp(1.1rem,4vw,2rem);font-size:.82rem;color:#95b3a4}

/* ---------- entrance animation: CSS-only, ends visible (fill-mode both) ---------- */
@keyframes rise{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:none}}
@media (prefers-reduced-motion:no-preference){
  .reveal{animation:rise .6s ease both}
  .prose.reveal{animation-delay:.05s}
}
/* Safeguard: never leave content hidden waiting on JS (AOS-class incident guard) */
[data-aos]{opacity:1!important;transform:none!important}
.reveal{opacity:1} /* if animation never runs, content still shows */

/* ---------- responsive ---------- */
@media (max-width:900px){
  .foot-inner{grid-template-columns:1fr 1fr}
  .foot-brand{grid-column:1 / -1}
}
@media (max-width:760px){
  body{font-size:17px}
  .nav-toggle{display:flex}
  .nav-links{
    position:absolute;top:100%;left:0;right:0;
    flex-direction:column;align-items:stretch;gap:0;
    background:var(--forest-2);padding:.5rem;
    max-height:0;overflow:hidden;transition:max-height .3s ease;
    border-bottom:3px solid var(--amber);
  }
  .nav-links.open{max-height:80vh;overflow:auto}
  .nav-links a{padding:.8rem 1rem;border-radius:8px}
  .nav-cta{text-align:center;margin-top:.3rem}
}
@media (max-width:520px){
  .foot-inner{grid-template-columns:1fr}
  .brand-text small{display:none}
}