/* ==========================================================================
   Black Jade Co., Ltd. — Natural Rubber Trading
   Design tokens
   ========================================================================== */
:root{
  --bg:            #EBE7D8;
  --bg-deep:       #DED7BC;
  --card:          #F7F5EA;
  --ink:           #1C231D;
  --ink-soft:      #4A5147;
  --line:          #C6BE9E;
  --forest:        #26382C;
  --forest-deep:   #182219;
  --forest-tint:   #E4EADF;
  --amber:         #B4802E;
  --amber-deep:    #8C6421;
  --amber-tint:    #F1DFB9;
  --max:           1180px;
  --gap:           clamp(1.25rem, 3vw, 2.5rem);
  --radius:        2px;
}

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }

body{
  margin:0;
  background: var(--bg);
  color: var(--ink);
  font-family:'IBM Plex Sans Thai','Noto Sans Thai',system-ui,sans-serif;
  font-size: 16.5px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1,h2,h3,h4,
.font-display{
  font-family:'Chakra Petch','IBM Plex Sans Thai',sans-serif;
  color: var(--forest-deep);
  line-height: 1.25;
  margin: 0 0 0.5em;
  letter-spacing: 0.01em;
}

h1{ font-size: clamp(2.1rem, 4.4vw, 3.4rem); font-weight:700; }
h2{ font-size: clamp(1.55rem, 2.6vw, 2.15rem); font-weight:700; }
h3{ font-size: 1.2rem; font-weight:600; }

p{ margin:0 0 1.1em; color: var(--ink-soft); max-width: 62ch; }
a{ color: inherit; }
img{ max-width:100%; display:block; }

.max{ max-width: var(--max); margin:0 auto; padding:0 var(--gap); }

.eyebrow{
  display:inline-flex; align-items:center; gap:.6em;
  font-family:'Chakra Petch',sans-serif;
  font-size:.82rem; font-weight:600;
  color: var(--amber-deep);
  margin-bottom: .9em;
}
.eyebrow::before{
  content:""; width:26px; height:2px; background: var(--amber-deep); display:inline-block;
}

/* ---------- Header / Nav ---------- */
.site-header{
  position: sticky; top:0; z-index: 50;
  background: rgba(235,231,216,.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}
.nav-row{
  display:flex; align-items:center; justify-content:space-between;
  height: 76px;
}
.brand{
  display:flex; align-items:center; gap:.7rem;
  text-decoration:none; color: var(--forest-deep);
}
.brand-mark{
  width:38px; height:38px; flex:none;
  background: var(--forest-deep);
  color: var(--amber-tint);
  display:flex; align-items:center; justify-content:center;
  font-family:'Chakra Petch',sans-serif; font-weight:700; font-size:1rem;
  border-radius: var(--radius);
}
.brand-text{ line-height:1.15; }
.brand-text strong{ display:block; font-family:'Chakra Petch',sans-serif; font-size:1.02rem; font-weight:700;}
.brand-text span{ display:block; font-size:.72rem; letter-spacing:.06em; color: var(--ink-soft); }

.nav-links{ display:flex; align-items:center; gap: 2rem; list-style:none; margin:0; padding:0; }
.nav-links a{
  text-decoration:none; font-size:.94rem; font-weight:500; color: var(--ink);
  padding: .3em 0; border-bottom: 2px solid transparent;
}
.nav-links a:hover, .nav-links a.active{ border-color: var(--amber-deep); color: var(--forest-deep); }

.nav-cta{
  background: var(--forest-deep); color: var(--amber-tint) !important;
  padding: .6em 1.3em !important; border-radius: var(--radius);
  border: 1px solid var(--forest-deep) !important;
}
.nav-cta:hover{ background: var(--forest); border-color: var(--forest) !important; }

.nav-toggle{
  display:none; background:none; border:1px solid var(--line); border-radius: var(--radius);
  width:42px; height:42px; align-items:center; justify-content:center; cursor:pointer;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after{
  content:""; display:block; width:20px; height:2px; background: var(--forest-deep); position:relative;
  transition:.2s;
}
.nav-toggle span::before{ position:absolute; top:-6px; }
.nav-toggle span::after{ position:absolute; top:6px; }

@media (max-width: 860px){
  .nav-links{
    position:absolute; top:76px; left:0; right:0;
    flex-direction:column; align-items:flex-start; gap:0;
    background: var(--bg); border-bottom:1px solid var(--line);
    max-height:0; overflow:hidden; padding:0 var(--gap);
  }
  .nav-links.open{ max-height: 420px; padding:1rem var(--gap) 1.6rem; }
  .nav-links li{ width:100%; }
  .nav-links a{ display:block; width:100%; padding:.7em 0; }
  .nav-toggle{ display:flex; }
}

/* ---------- Hero / Banner ---------- */
.hero{
  position:relative; color:#fff;
  min-height: 78vh;
  display:flex; align-items:flex-end;
  background-size: cover; background-position: center;
  isolation:isolate;
}
.hero::after{
  content:""; position:absolute; inset:0; z-index:-1;
  background: linear-gradient(180deg, rgba(22,32,25,.35) 0%, rgba(17,24,18,.55) 45%, rgba(14,19,15,.92) 100%);
}
.hero-inner{ padding-block: 4rem 3.4rem; max-width: 840px; }
.hero .eyebrow{ color: var(--amber-tint); }
.hero .eyebrow::before{ background: var(--amber-tint); }
.hero h1{ color:#fff; }
.hero p.lead{ color: #E9E6D8; font-size:1.12rem; max-width: 56ch; }

.hero-spec{
  display:flex; flex-wrap:wrap; gap: .6rem 1.6rem; margin-top: 2rem;
  border-top:1px solid rgba(255,255,255,.25); padding-top:1.3rem;
}
.hero-spec div{ font-family:'Chakra Petch',sans-serif; font-size:.82rem; color:#D9D2B4; letter-spacing:.03em; }
.hero-spec strong{ display:block; color:#fff; font-size:.98rem; }

.hero-actions{ display:flex; flex-wrap:wrap; gap: .9rem; margin-top: 1.8rem; }

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex; align-items:center; gap:.5em;
  font-weight:600; font-size:.95rem; text-decoration:none;
  padding: .78em 1.5em; border-radius: var(--radius);
  border:1px solid transparent; cursor:pointer;
}
.btn-amber{ background: var(--amber); color:#1C1608; border-color: var(--amber); }
.btn-amber:hover{ background: var(--amber-deep); border-color: var(--amber-deep); }
.btn-outline{ background: transparent; color:#fff; border-color: rgba(255,255,255,.55); }
.btn-outline:hover{ border-color:#fff; background: rgba(255,255,255,.08); }
.btn-forest{ background: var(--forest-deep); color:var(--amber-tint); border-color: var(--forest-deep); }
.btn-forest:hover{ background: var(--forest); }
.btn-line-dark{ background:transparent; color:var(--forest-deep); border-color: var(--forest-deep); }
.btn-line-dark:hover{ background: var(--forest-deep); color:#fff; }

/* ---------- Sections ---------- */
section{ padding-block: clamp(3rem, 7vw, 5.5rem); }
.section-alt{ background: var(--forest-tint); }
.section-dark{ background: var(--forest-deep); color: #EFE9D3; }
.section-dark h2, .section-dark h3{ color:#fff; }
.section-dark p{ color:#C9CFC4; }

.section-head{ display:flex; justify-content:space-between; align-items:flex-end; gap:2rem; flex-wrap:wrap; margin-bottom: 2.4rem; }
.section-head p{ margin:0; }

/* ---------- Grid / Cards ---------- */
.grid{ display:grid; gap: var(--gap); }
.grid-3{ grid-template-columns: repeat(3, 1fr); }
.grid-2{ grid-template-columns: repeat(2, 1fr); }
.grid-4{ grid-template-columns: repeat(4, 1fr); }
@media (max-width: 980px){ .grid-3, .grid-4{ grid-template-columns: repeat(2,1fr);} }
@media (max-width: 640px){ .grid-3, .grid-4, .grid-2{ grid-template-columns: 1fr; } }

.card{
  background: var(--card);
  border:1px solid var(--line);
  border-radius: var(--radius);
  overflow:hidden;
  display:flex; flex-direction:column;
}
.card-media{ aspect-ratio: 4/3; overflow:hidden; background: var(--bg-deep); }
.card-media img{ width:100%; height:100%; object-fit:cover; }
.card-body{ padding: 1.4rem 1.5rem 1.7rem; display:flex; flex-direction:column; gap:.5rem; flex:1; }
.card-code{
  font-family:'Chakra Petch',sans-serif; font-size:.72rem; letter-spacing:.08em;
  color: var(--amber-deep); font-weight:700;
}
.card-body h3{ margin:0; }
.card-body p{ margin:0; font-size:.94rem; }
.card-foot{ margin-top:auto; padding-top:.6rem; font-size:.86rem; font-weight:600; color: var(--forest-deep); }

/* ---------- Spec strip (recurring motif) ---------- */
.spec-strip{
  display:flex; flex-wrap:wrap; border-top:1px solid var(--line); border-bottom:1px solid var(--line);
}
.spec-strip div{
  flex:1 1 160px; padding: 1.1rem var(--gap);
  border-right:1px solid var(--line);
  font-family:'Chakra Petch',sans-serif; font-size:.8rem; color: var(--ink-soft); letter-spacing:.03em;
}
.spec-strip div:last-child{ border-right:none; }
.spec-strip strong{ display:block; font-size:1.35rem; color: var(--forest-deep); margin-bottom:.15rem; }

/* ---------- Two column media ---------- */
.split{ display:grid; grid-template-columns: 1.05fr 0.95fr; gap: clamp(2rem,5vw,4rem); align-items:center; }
.split.reverse .split-media{ order:2; }
@media (max-width: 860px){ .split{ grid-template-columns:1fr; } .split.reverse .split-media{ order:0; } }
.split-media img{ width:100%; border-radius: var(--radius); }
.split-media figcaption{ font-size:.8rem; color: var(--ink-soft); margin-top:.6rem; }

/* ---------- Process steps ---------- */
.steps{ display:grid; grid-template-columns: repeat(4,1fr); gap: var(--gap); counter-reset: step; }
@media (max-width: 860px){ .steps{ grid-template-columns: repeat(2,1fr); } }
@media (max-width: 520px){ .steps{ grid-template-columns: 1fr; } }
.step{ border-top: 3px solid var(--amber-deep); padding-top: 1rem; }
.step-num{ font-family:'Chakra Petch',sans-serif; font-weight:700; font-size:1.6rem; color: var(--amber-deep); }

/* ---------- Article / prose pages ---------- */
.prose{ max-width: 74ch; }
.prose h2{ margin-top:2rem; }
.prose ul{ color: var(--ink-soft); padding-left:1.3rem; }
.prose li{ margin-bottom:.5rem; }
.page-hero{
  background: var(--forest-tint); border-bottom:1px solid var(--line);
  padding-block: 3.4rem 2.6rem;
}
.page-hero .eyebrow{ color: var(--amber-deep); }
.breadcrumb{ font-size:.82rem; color: var(--ink-soft); margin-bottom:1rem; }
.breadcrumb a{ text-decoration:none; color: var(--forest-deep); font-weight:600; }

/* ---------- Contact ---------- */
.contact-grid{ display:grid; grid-template-columns: 1fr 1fr; gap: var(--gap); }
@media (max-width: 860px){ .contact-grid{ grid-template-columns:1fr; } }
.info-list{ list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:1.3rem; }
.info-list li{ display:flex; gap:1rem; align-items:flex-start; border-bottom:1px solid var(--line); padding-bottom:1.2rem; }
.info-icon{
  flex:none; width:42px; height:42px; border-radius: var(--radius);
  background: var(--forest-deep); color: var(--amber-tint);
  display:flex; align-items:center; justify-content:center; font-family:'Chakra Petch',sans-serif; font-weight:700;
}
.info-list h3{ margin:0 0 .2rem; font-size:1rem; }
.info-list p{ margin:0; font-size:.94rem; }
.map-frame{ border:1px solid var(--line); border-radius: var(--radius); overflow:hidden; height: 100%; min-height:340px; }
.map-frame iframe{ width:100%; height:100%; min-height:340px; border:0; display:block; }

.form-box{ background: var(--card); border:1px solid var(--line); border-radius: var(--radius); padding: 1.8rem; }
.form-row{ margin-bottom:1.1rem; display:flex; flex-direction:column; gap:.4rem; }
.form-row label{ font-size:.86rem; font-weight:600; color: var(--forest-deep); }
.form-row input, .form-row textarea, .form-row select{
  font: inherit; padding:.75em .9em; border:1px solid var(--line); border-radius: var(--radius);
  background:#fff; color: var(--ink);
}
.form-row input:focus, .form-row textarea:focus{ outline:2px solid var(--amber); outline-offset:1px; }

/* ---------- Footer ---------- */
.site-footer{ background: var(--forest-deep); color:#C9CFC4; padding-block: 3.2rem 1.6rem; }
.footer-grid{ display:grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: var(--gap); margin-bottom: 2.2rem; }
@media (max-width: 860px){ .footer-grid{ grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px){ .footer-grid{ grid-template-columns: 1fr; } }
.site-footer h4{ color:#fff; font-size:.86rem; letter-spacing:.04em; margin-bottom:1rem; }
.site-footer .brand-text strong{ color:#fff; }
.site-footer .brand-text span{ color:#9AA394; }
.site-footer ul{ list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:.6rem; }
.site-footer a{ text-decoration:none; color:#C9CFC4; font-size:.92rem; }
.site-footer a:hover{ color:#fff; }
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.12); padding-top:1.3rem;
  display:flex; justify-content:space-between; flex-wrap:wrap; gap:.8rem; font-size:.8rem; color:#8B9385;
}

/* ---------- Utility ---------- */
.mt-0{ margin-top:0; } .mb-0{ margin-bottom:0; }
.visually-hidden{ position:absolute !important; width:1px;height:1px; overflow:hidden; clip:rect(0 0 0 0); }
.center-text{ text-align:center; margin-left:auto; margin-right:auto; }