/* =========================================================
   ZINC MESH VAULT — Industrial Materials Engineering
   Shared stylesheet for all pages
   ========================================================= */

:root{
  --c-bg:#ffffff;
  --c-bg-alt:#f1f3f4;
  --c-bg-alt2:#e7eaec;
  --c-graphite:#20262b;
  --c-slate:#5b6570;
  --c-slate-light:#8a9399;
  --c-border:#dde1e4;
  --c-border-strong:#c3c9cd;
  --c-accent:#48697a;      /* zinc metallic blue-gray */
  --c-accent-dark:#30495a;
  --c-accent-soft:#e8edf0;
  --c-steel:#5c7f99;       /* steel blue secondary accent */
  --c-copper:#a86a3d;      /* warm copper accent */
  --c-copper-soft:#f3e7da;
  --c-success:#2f6b4f;
  --c-error:#a5342a;
  --radius:3px;
  --maxw:1180px;
  --font:"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",-apple-system,BlinkMacSystemFont,sans-serif;
  --shadow-sm:0 1px 3px rgba(32,38,43,0.08);
  --shadow-md:0 4px 16px rgba(32,38,43,0.10);
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--font);
  color:var(--c-graphite);
  background:var(--c-bg);
  line-height:1.8;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block;height:auto;}
a{color:var(--c-accent-dark);text-decoration:none;}
a:hover{text-decoration:underline;}
ul,ol{padding-left:1.3em;}
h1,h2,h3,h4{
  font-weight:700;
  line-height:1.4;
  color:var(--c-graphite);
  letter-spacing:0.01em;
}
.hs-3.hs-3,.hs-4.hs-4{
  font-weight:700;
  line-height:1.4;
  color:var(--c-graphite);
  letter-spacing:0.01em;
}
h1{font-size:2.1rem;}
h2{font-size:1.65rem;}
h3{font-size:1.25rem;}
.hs-3.hs-3{font-size:1.25rem;}
p{margin:0 0 1em;}
table{width:100%;border-collapse:collapse;font-size:0.95rem;}
th,td{border:1px solid var(--c-border);padding:0.7em 0.9em;text-align:left;vertical-align:top;}
th{background:var(--c-bg-alt);font-weight:700;white-space:nowrap;}
caption{text-align:left;font-size:0.85rem;color:var(--c-slate);margin-bottom:0.4em;}
figure{margin:0;}
figcaption{font-size:0.85rem;color:var(--c-slate);margin-top:0.5em;}
hr{border:none;border-top:1px solid var(--c-border);margin:2.5em 0;}

.container{max-width:var(--maxw);margin:0 auto;padding:0 24px;}
.section{padding:72px 0;}
.section--alt{background:var(--c-bg-alt);}
.section--tight{padding:48px 0;}
.section-head{max-width:760px;margin:0 auto 44px;text-align:center;}
.section-head.align-left{margin:0 0 36px;text-align:left;}
.eyebrow{
  display:inline-block;
  font-size:0.78rem;
  letter-spacing:0.12em;
  color:var(--c-accent-dark);
  font-weight:700;
  background:var(--c-accent-soft);
  padding:5px 12px;
  border-radius:20px;
  margin-bottom:14px;
}
.section-head p{color:var(--c-slate);font-size:1.02rem;}

/* ---------- skip link / accessibility ---------- */
.skip-link{
  position:absolute;left:-999px;top:0;background:var(--c-accent-dark);color:#fff;
  padding:10px 16px;z-index:200;
}
.skip-link:focus{left:8px;top:8px;}

/* ---------- Mesh pattern decorations ---------- */
.mesh-bg{
  background-image:
    linear-gradient(0deg, rgba(72,105,122,0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(72,105,122,0.07) 1px, transparent 1px);
  background-size:26px 26px;
}
.mesh-divider{
  height:46px;
  background-image:
    linear-gradient(135deg, rgba(72,105,122,0.14) 25%, transparent 25%),
    linear-gradient(225deg, rgba(72,105,122,0.14) 25%, transparent 25%),
    linear-gradient(45deg, rgba(72,105,122,0.14) 25%, transparent 25%),
    linear-gradient(315deg, rgba(72,105,122,0.14) 25%, transparent 25%);
  background-position:16px 0,16px 0,0 0,0 0;
  background-size:32px 32px;
  background-color:var(--c-bg);
}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(255,255,255,0.97);
  border-bottom:1px solid var(--c-border);
  backdrop-filter:saturate(140%) blur(4px);
}
.header-inner{
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 24px;max-width:var(--maxw);margin:0 auto;gap:16px;
}
.brand{display:flex;align-items:center;gap:10px;color:var(--c-graphite);}
.brand:hover{text-decoration:none;}
.brand-mark{width:40px;height:40px;flex:none;}
.brand-text{
  font-weight:700;font-size:1.05rem;letter-spacing:0.05em;
  font-family:var(--font);
  white-space:nowrap;
}
.brand-text small{display:block;font-size:0.62rem;font-weight:500;letter-spacing:0.18em;color:var(--c-slate);}

.main-nav{display:flex;align-items:center;gap:2px;flex-wrap:wrap;}
.main-nav a{
  display:inline-block;padding:10px 12px;font-size:0.88rem;color:var(--c-graphite);
  font-weight:500;border-radius:var(--radius);
}
.main-nav a:hover{background:var(--c-accent-soft);text-decoration:none;color:var(--c-accent-dark);}
.main-nav a.current{color:var(--c-accent-dark);font-weight:700;}
.nav-cta{
  background:var(--c-accent-dark)!important;color:#fff!important;padding:10px 18px!important;
  border-radius:var(--radius);margin-left:6px;
}
.nav-cta:hover{background:var(--c-accent)!important;color:#fff!important;}

.nav-toggle{
  display:none;background:none;border:1px solid var(--c-border-strong);border-radius:var(--radius);
  padding:8px 10px;cursor:pointer;
}
.nav-toggle span{display:block;width:22px;height:2px;background:var(--c-graphite);margin:4px 0;}

@media (max-width:980px){
  .main-nav{
    display:none;position:absolute;top:100%;left:0;right:0;background:#fff;
    flex-direction:column;align-items:stretch;border-bottom:1px solid var(--c-border);
    box-shadow:var(--shadow-md);padding:8px 16px 16px;
  }
  .main-nav.open{display:flex;}
  .main-nav a{padding:12px 8px;border-bottom:1px solid var(--c-bg-alt);}
  .nav-cta{margin-left:0;margin-top:8px;text-align:center;}
  .nav-toggle{display:block;}
  .site-header{position:relative;}
}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 26px;border-radius:var(--radius);font-weight:700;font-size:0.92rem;
  border:1px solid transparent;cursor:pointer;line-height:1.2;
}
.btn:hover{text-decoration:none;}
.btn-primary{background:var(--c-accent-dark);color:#fff;}
.btn-primary:hover{background:var(--c-accent);}
.btn-outline{background:transparent;border-color:var(--c-border-strong);color:var(--c-graphite);}
.btn-outline:hover{border-color:var(--c-accent-dark);color:var(--c-accent-dark);background:var(--c-accent-soft);}
.btn-copper{background:var(--c-copper);color:#fff;}
.btn-copper:hover{background:#8f5830;}
.btn-block{width:100%;justify-content:center;}
.btn-row{display:flex;gap:14px;flex-wrap:wrap;}

/* ---------- Hero ---------- */
.hero{
  padding:76px 0 64px;
  background:linear-gradient(180deg,#fbfcfc 0%,var(--c-bg-alt) 100%);
  border-bottom:1px solid var(--c-border);
}
.hero-grid{display:grid;grid-template-columns:1.1fr 0.9fr;gap:48px;align-items:center;}
.hero h1{font-size:2.5rem;margin-bottom:20px;}
.hero p.lead{font-size:1.1rem;color:var(--c-slate);margin-bottom:28px;}
.hero-media{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-md);border:1px solid var(--c-border);}
.hero-media img{width:100%;}
.page-hero{
  padding:56px 0 48px;background:var(--c-bg-alt);border-bottom:1px solid var(--c-border);
}
.page-hero .eyebrow{background:#fff;}
.page-hero h1{font-size:2.1rem;margin-bottom:12px;}
.page-hero p{color:var(--c-slate);max-width:720px;font-size:1.02rem;margin-bottom:0;}
.breadcrumb{font-size:0.82rem;color:var(--c-slate);margin-bottom:14px;}
.breadcrumb a{color:var(--c-slate);}
.breadcrumb span{margin:0 6px;}

@media (max-width:860px){
  .hero-grid{grid-template-columns:1fr;}
  .hero h1{font-size:1.9rem;}
}

/* ---------- Grids & Cards ---------- */
.grid{display:grid;gap:24px;}
.grid-2{grid-template-columns:repeat(2,1fr);}
.grid-3{grid-template-columns:repeat(3,1fr);}
.grid-4{grid-template-columns:repeat(4,1fr);}
@media (max-width:980px){.grid-3{grid-template-columns:repeat(2,1fr);}.grid-4{grid-template-columns:repeat(2,1fr);}}
@media (max-width:620px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}}

.card{
  background:#fff;border:1px solid var(--c-border);border-radius:var(--radius);
  padding:26px;box-shadow:var(--shadow-sm);
}
.card h3{margin-top:0;margin-bottom:10px;font-size:1.08rem;}
.card .hs-3{margin-top:0;margin-bottom:10px;font-size:1.08rem;}
.card p{color:var(--c-slate);font-size:0.94rem;margin-bottom:0;}
.card .icon{width:40px;height:40px;margin-bottom:14px;color:var(--c-accent-dark);}

.card-media{
  background:#fff;border:1px solid var(--c-border);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow-sm);display:flex;flex-direction:column;
}
.card-media img{width:100%;aspect-ratio:4/3;object-fit:cover;}
.card-media .body{padding:22px;}
.card-media h3{margin-top:0;font-size:1.05rem;}
.card-media .hs-3{margin-top:0;font-size:1.05rem;}
.card-media p{color:var(--c-slate);font-size:0.92rem;}
.tag{
  display:inline-block;font-size:0.72rem;font-weight:700;letter-spacing:0.05em;
  color:var(--c-accent-dark);background:var(--c-accent-soft);padding:3px 10px;border-radius:20px;
  margin-bottom:10px;
}
.tag-copper{color:var(--c-copper);background:var(--c-copper-soft);}

/* numbered list / challenge cards */
.num-card{
  background:#fff;border:1px solid var(--c-border);border-radius:var(--radius);padding:24px;
  position:relative;padding-top:40px;
}
.num-card .num{
  position:absolute;top:-14px;left:22px;background:var(--c-accent-dark);color:#fff;
  font-weight:700;font-size:0.85rem;width:30px;height:30px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
}

/* ---------- Icons (inline svg) ---------- */
.i{width:28px;height:28px;stroke:var(--c-accent-dark);stroke-width:1.6;fill:none;stroke-linecap:round;stroke-linejoin:round;}

/* ---------- Process steps ---------- */
.process-list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:0;}
.process-step{
  display:grid;grid-template-columns:90px 1fr;gap:24px;padding:28px 0;border-bottom:1px solid var(--c-border);
}
.process-step:last-child{border-bottom:none;}
.process-step .step-no{
  font-size:2rem;font-weight:700;color:var(--c-accent-soft);
  -webkit-text-stroke:1.5px var(--c-accent-dark);color:transparent;
}
.process-step h3{margin-top:0;margin-bottom:8px;}
.process-step .hs-3{margin-top:0;margin-bottom:8px;}
.process-step p{color:var(--c-slate);margin-bottom:0;}
@media (max-width:620px){.process-step{grid-template-columns:1fr;}.process-step .step-no{font-size:1.4rem;}}

/* ---------- Table of contents / anchors ---------- */
.toc{background:var(--c-bg-alt);border:1px solid var(--c-border);border-radius:var(--radius);padding:20px 24px;margin:0 0 36px;}
.toc h2{font-size:1rem;margin:0 0 10px;}
.toc ol{margin:0;padding-left:1.2em;font-size:0.92rem;}
.toc a{color:var(--c-graphite);}

/* ---------- Accordion (FAQ / resources) ---------- */
.accordion-item{border:1px solid var(--c-border);border-radius:var(--radius);margin-bottom:10px;overflow:hidden;}
.accordion-trigger{
  width:100%;text-align:left;background:#fff;border:none;padding:18px 20px;font-weight:700;
  font-size:0.98rem;cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:12px;
  color:var(--c-graphite);
}
.accordion-trigger:hover{background:var(--c-bg-alt);}
.accordion-trigger .plus{flex:none;font-size:1.2rem;color:var(--c-accent-dark);transition:transform 0.2s;}
.accordion-trigger[aria-expanded="true"] .plus{transform:rotate(45deg);}
.accordion-panel{padding:0 20px;max-height:0;overflow:hidden;transition:max-height 0.25s ease;background:#fcfdfd;}
.accordion-panel.open{padding:4px 20px 20px;max-height:none;}
.accordion-panel p,.accordion-panel ul{color:var(--c-slate);font-size:0.94rem;}

/* ---------- Forms ---------- */
.form-card{background:#fff;border:1px solid var(--c-border);border-radius:var(--radius);padding:36px;box-shadow:var(--shadow-sm);}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:20px;}
@media (max-width:620px){.form-row{grid-template-columns:1fr;}}
.field{margin-bottom:20px;}
.field label{display:block;font-weight:700;font-size:0.9rem;margin-bottom:6px;}
.field .optional{font-weight:400;color:var(--c-slate);font-size:0.78rem;margin-left:6px;}
.field .required{color:var(--c-error);font-size:0.78rem;margin-left:6px;}
.field input[type="text"],
.field input[type="email"],
.field input[type="tel"],
.field input[type="url"],
.field input[type="number"],
.field select,
.field textarea{
  width:100%;padding:11px 13px;border:1px solid var(--c-border-strong);border-radius:var(--radius);
  font-family:var(--font);font-size:0.95rem;background:#fff;color:var(--c-graphite);
}
.field textarea{resize:vertical;min-height:120px;}
.field input:focus,.field select:focus,.field textarea:focus{outline:2px solid var(--c-accent);outline-offset:1px;}
.field-hint{font-size:0.8rem;color:var(--c-slate);margin-top:4px;}
.field-error{font-size:0.8rem;color:var(--c-error);margin-top:4px;display:none;}
.field.has-error input,.field.has-error select,.field.has-error textarea{border-color:var(--c-error);}
.field.has-error .field-error{display:block;}
.checkbox-field{display:flex;align-items:flex-start;gap:10px;}
.checkbox-field input{margin-top:4px;}
.checkbox-field label{font-weight:400;font-size:0.9rem;}
.hp-field{position:absolute;left:-9999px;top:-9999px;opacity:0;height:0;overflow:hidden;}
.form-status{
  margin-top:18px;padding:14px 16px;border-radius:var(--radius);font-size:0.92rem;display:none;
}
.form-status.show{display:block;}
.form-status.success{background:#e9f3ee;color:var(--c-success);border:1px solid #bfe0cf;}
.form-status.error{background:#f8eceb;color:var(--c-error);border:1px solid #edc2bd;}
.form-status.sending{background:var(--c-bg-alt);color:var(--c-slate);}
fieldset{border:1px solid var(--c-border);border-radius:var(--radius);padding:20px;margin:0 0 20px;}
fieldset legend{font-weight:700;padding:0 8px;font-size:0.95rem;}

/* ---------- CTA band ---------- */
.cta-band{
  background:var(--c-accent-dark);color:#fff;border-radius:var(--radius);padding:48px;
  display:flex;justify-content:space-between;align-items:center;gap:24px;flex-wrap:wrap;
}
.cta-band h2{color:#fff;margin:0 0 6px;}
.cta-band p{color:#d9e1e6;margin:0;max-width:480px;}
.cta-band .btn-outline{color:#fff;border-color:rgba(255,255,255,0.5);}
.cta-band .btn-outline:hover{background:rgba(255,255,255,0.1);color:#fff;}

/* ---------- Lists with icon bullets ---------- */
.check-list{list-style:none;padding:0;margin:0;}
.check-list li{position:relative;padding-left:28px;margin-bottom:12px;color:var(--c-slate);}
.check-list li::before{content:"";position:absolute;left:0;top:0.4em;width:14px;height:14px;
  border:2px solid var(--c-accent-dark);border-radius:2px;}

/* ---------- Article ---------- */
.article-body{max-width:720px;}
.article-body h2{margin-top:2em;}
.article-body h3{margin-top:1.6em;}
.article-body .hs-3{margin-top:1.6em;}
.article-body img{border-radius:var(--radius);border:1px solid var(--c-border);margin:1.6em 0;}
.article-meta{display:flex;gap:14px;align-items:center;color:var(--c-slate);font-size:0.85rem;margin-bottom:24px;flex-wrap:wrap;}
.related-articles{margin-top:3em;padding-top:2em;border-top:1px solid var(--c-border);}

/* ---------- Table styles for specs ---------- */
.spec-table-wrap{overflow-x:auto;margin:1.4em 0;}
.note-box{
  background:var(--c-bg-alt);border-left:3px solid var(--c-accent-dark);padding:16px 20px;
  border-radius:var(--radius);font-size:0.92rem;color:var(--c-slate);margin:1.4em 0;
}
.note-box.copper{border-left-color:var(--c-copper);}
.note-box strong{color:var(--c-graphite);}

/* ---------- Footer ---------- */
.site-footer{background:var(--c-graphite);color:#cfd6da;padding:56px 0 28px;margin-top:0;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:32px;margin-bottom:36px;}
.footer-brand{display:flex;align-items:center;gap:10px;margin-bottom:14px;}
.footer-brand .brand-text{color:#fff;}
.footer-brand .brand-text small{color:#9aa6ac;}
.site-footer p{color:#9aa6ac;font-size:0.88rem;}
.site-footer h4{color:#fff;font-size:0.88rem;letter-spacing:0.06em;margin:0 0 14px;}
.site-footer .hs-4{color:#fff;font-size:0.88rem;letter-spacing:0.06em;margin:0 0 14px;}
.site-footer ul{list-style:none;padding:0;margin:0;}
.site-footer li{margin-bottom:9px;}
.site-footer a{color:#cfd6da;font-size:0.88rem;}
.site-footer a:hover{color:#fff;}
.footer-bottom{
  border-top:1px solid #3a4349;padding-top:22px;display:flex;justify-content:space-between;
  flex-wrap:wrap;gap:12px;font-size:0.8rem;color:#8c979d;
}
@media (max-width:860px){.footer-grid{grid-template-columns:1fr 1fr;}}
@media (max-width:560px){.footer-grid{grid-template-columns:1fr;}}

/* ---------- 404 ---------- */
.error-page{padding:100px 0;text-align:center;}
.error-page .code{font-size:5rem;font-weight:700;color:var(--c-accent-soft);-webkit-text-stroke:2px var(--c-accent-dark);color:transparent;margin:0;}
.error-page h1{margin-top:8px;}
.error-page p{color:var(--c-slate);max-width:480px;margin:0 auto 28px;}

/* ---------- Utility ---------- */
.mt-0{margin-top:0;}
.mb-0{margin-bottom:0;}
.text-center{text-align:center;}
.muted{color:var(--c-slate);}
.small{font-size:0.85rem;}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);}

/* ---------- tabs (legal page) ---------- */
.tab-list{display:flex;gap:4px;border-bottom:1px solid var(--c-border);margin-bottom:32px;flex-wrap:wrap;}
.tab-btn{
  background:none;border:none;padding:14px 18px;font-size:0.95rem;font-weight:700;cursor:pointer;
  color:var(--c-slate);border-bottom:3px solid transparent;margin-bottom:-1px;
}
.tab-btn[aria-selected="true"]{color:var(--c-accent-dark);border-bottom-color:var(--c-accent-dark);}
.tab-panel{display:none;}
.tab-panel.active{display:block;}