:root {
  --primary: #0F766E;
  --primary-light: #14B8A6;
  --primary-dark: #115E59;
  --accent: #0891B2;
  --bg: #FAFBFD;
  --bg-card: #FFFFFF;
  --text: #1E293B;
  --text-muted: #64748B;
  --border: #E2E8F0;
  --shadow: 0 4px 14px rgba(15,118,110,0.10), 0 2px 4px rgba(15,23,42,0.04);
  --shadow-lg: 0 18px 40px rgba(15,118,110,0.16), 0 8px 16px rgba(15,23,42,0.06);
  --radius: 12px;
  --radius-sm: 8px;
}

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

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
  background:
    radial-gradient(circle at 1px 1px, rgba(15,118,110,0.05) 1px, transparent 0) 0 0 / 24px 24px,
    var(--bg);
  color: var(--text);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

/* ===== HEADER ===== */
.header {
  position: sticky; top:0; z-index:100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}
.header-inner {
  max-width: 1100px; margin:0 auto;
  display:flex; align-items:center; justify-content:space-between;
  height: 64px;
}
.logo {
  display:flex; align-items:center; gap:10px;
  font-weight:800; font-size:1.2rem; color: var(--primary-dark);
  text-decoration:none;
}
.logo-icon {
  width:32px; height:32px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 9px;
  display:flex; align-items:center; justify-content:center;
  color:#fff; font-weight:800; font-size: .95rem;
}
.lang-toggle {
  background: var(--primary);
  color:#fff; border:none; cursor:pointer;
  padding: 8px 14px; border-radius: 8px; font-weight:600; font-size:.85rem;
  transition: background .2s;
}
.lang-toggle:hover { background: var(--primary-dark); }
.back-link {
  color: var(--text-muted); text-decoration:none; font-size:.9rem; font-weight:500;
}
.back-link:hover { color: var(--primary); }

/* ===== ARTICLE ===== */
.article-wrap { max-width: 820px; margin: 0 auto; padding: 40px 24px 80px; }
.article-meta {
  display:flex; gap:14px; align-items:center; flex-wrap:wrap;
  color: var(--text-muted); font-size:.85rem; margin-bottom: 18px;
}
.tag {
  background: #E0F2F1; color: var(--primary-dark);
  padding: 3px 10px; border-radius: 999px; font-weight:600; font-size:.78rem;
}
.article-wrap h1 {
  font-size: 2rem; line-height: 1.35; margin-bottom: 16px; font-weight:800;
  background: linear-gradient(120deg, var(--primary-dark), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  animation: heroUp .7s ease both;
}
.lead {
  font-size: 1.08rem; color: var(--text-muted);
  border-left: 3px solid var(--primary-light);
  padding-left: 16px; margin: 22px 0 30px;
}
.article-wrap h2 {
  font-size: 1.4rem; color: var(--primary-dark);
  margin: 40px 0 14px; font-weight:700;
  padding-top: 10px; border-top: 1px solid var(--border);
}
.article-wrap h3 { font-size: 1.12rem; color: var(--text); margin: 26px 0 10px; font-weight:700; }
.article-wrap p { margin: 14px 0; }
.article-wrap ul, .article-wrap ol { margin: 14px 0 14px 22px; }
.article-wrap li { margin: 7px 0; }
.article-wrap strong { color: var(--primary-dark); }
.article-wrap code {
  background: #F1F5F9; padding: 2px 6px; border-radius: 5px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size:.9em; color:#0F172A;
}
.callout {
  background: #F0FDFA; border: 1px solid #99F6E4;
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm); padding: 16px 18px;
  margin: 22px 0; color: var(--primary-dark);
  box-shadow: var(--shadow);
}
.callout b { color: var(--primary-dark); }
.table-wrap { overflow-x:auto; margin: 22px 0; }
.article-fig {
  margin: 28px 0; text-align: center;
}
.article-fig svg {
  max-width: 100%; height: auto;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius);
}
.article-fig figcaption {
  margin-top: 10px; font-size: 0.9rem; color: var(--text-muted);
}
table.cmp {
  width:100%; border-collapse: collapse; font-size:.92rem;
  background: var(--bg-card); box-shadow: var(--shadow); border-radius: var(--radius);
  overflow:hidden;
}
table.cmp th, table.cmp td { padding: 12px 14px; text-align:left; border-bottom: 1px solid var(--border); }
table.cmp th { background: var(--primary); color:#fff; font-weight:600; }
table.cmp tr:last-child td { border-bottom:none; }
table.cmp td:first-child { font-weight:600; color: var(--primary-dark); }
.article-nav {
  display:flex; justify-content:space-between; gap:16px; flex-wrap:wrap;
  margin-top: 50px; padding-top: 24px; border-top: 1px solid var(--border);
}
.article-nav a {
  color: var(--primary); text-decoration:none; font-weight:600; font-size:.92rem;
}
.article-nav a:hover { text-decoration: underline; }

/* ===== FOOTER ===== */
.footer {
  background: #0F172A; color:#CBD5E1; padding: 36px 24px;
  text-align:center; font-size:.86rem;
}
.footer a { color:#5EEAD4; text-decoration:none; }
.footer a:hover { text-decoration: underline; }

/* ===== HOMEPAGE INSIGHTS CARDS ===== */
.insights-grid {
  display:grid; grid-template-columns: repeat(auto-fill, minmax(280px,1fr));
  gap: 22px; margin-top: 32px;
}
.insight-card {
  background: var(--bg-card); border:1px solid var(--border);
  border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow);
  display:flex; flex-direction:column; transition: transform .2s, box-shadow .2s;
  text-decoration:none; color: inherit;
}
.insight-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.insight-card .ic-tag {
  align-self:flex-start; background:#E0F2F1; color: var(--primary-dark);
  padding: 3px 10px; border-radius:999px; font-weight:600; font-size:.72rem; margin-bottom:12px;
}
.insight-card h3 { font-size:1.08rem; color: var(--primary-dark); margin-bottom:8px; font-weight:700; }
.insight-card p { color: var(--text-muted); font-size:.9rem; flex:1; }
.insight-card .ic-more {
  margin-top:14px; color: var(--primary); font-weight:600; font-size:.86rem;
}

@media (max-width: 640px) {
  .article-wrap h1 { font-size: 1.55rem; }
  .header-inner { padding: 0; }
}

/* ===== VISUAL UPGRADE: scroll reveal ===== */
@keyframes heroUp { from { opacity:0; transform: translateY(26px); } to { opacity:1; transform: none; } }
.js .reveal { opacity:0; transform: translateY(22px); transition: opacity .6s ease, transform .6s ease; }
.js .reveal.in { opacity:1; transform: none; }
@media (prefers-reduced-motion: reduce){ .js .reveal { opacity:1; transform:none; transition:none; } .article-wrap h1 { animation:none; } }

/* ===== CALC PANEL (shared visual language with #panel-hx) ===== */
.calc-card {
  max-width: 820px; margin: 22px 0; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 26px;
}
.calc-card .calc-h { font-size: 1.05rem; color: var(--primary-dark); font-weight: 700; margin-bottom: 4px; }
.calc-card .calc-sub { font-size: .88rem; color: var(--text-muted); margin: 0 0 16px; }
.calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px 20px; }
.calc-grid .full { grid-column: 1 / -1; }
.calc-card label { display: block; font-weight: 600; font-size: .85rem; color: var(--text); margin-bottom: 6px; }
.calc-card input, .calc-card select {
  width: 100%; padding: 10px 12px; border: 1px solid var(--border);
  border-radius: 8px; font-size: .92rem; font-family: inherit; background: #fff; color: var(--text);
}
.calc-card input:focus, .calc-card select:focus { outline: none; border-color: var(--primary); }
.calc-actions { margin-top: 18px; }
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff; border: none; padding: 12px 28px; border-radius: var(--radius-sm);
  font-size: .95rem; font-weight: 600; cursor: pointer;
  transition: transform .2s, box-shadow .2s;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(15,118,110,.38); }
.calc-result { margin-top: 20px; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.calc-result .cr-item { background: #F0FDFA; border: 1px solid #99F6E4; border-radius: var(--radius-sm); padding: 12px 14px; }
.calc-result .cr-item .cr-l { font-size: .8rem; color: var(--primary-dark); display: block; margin-bottom: 4px; font-weight: 600; }
.calc-result .cr-item b { font-size: 1.12rem; color: var(--text); }
.calc-note { margin-top: 14px; padding: 12px 14px; border-radius: var(--radius-sm); font-size: .9rem; font-weight: 600; line-height: 1.55; }
.calc-note.ok { background: #ECFDF5; border: 1px solid #6EE7B7; color: #065F46; }
.calc-note.warn { background: #FEF2F2; border: 1px solid #FCA5A5; color: #991B1B; }

/* ===== CHECKLIST (WFI zero-throttle selection) ===== */
.check-list { list-style: none; margin: 18px 0; padding: 0; counter-reset: chk; }
.check-list li {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 14px 16px; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-sm); margin-bottom: 10px; box-shadow: var(--shadow);
}
.check-list li .ck { width: 20px; height: 20px; flex: 0 0 auto; margin-top: 3px; accent-color: var(--primary); cursor: pointer; }
.check-list li .ck-body strong { display: block; color: var(--primary-dark); margin-bottom: 2px; }
.check-list li .ck-body span { font-size: .88rem; color: var(--text-muted); }
.check-list li .ck-body code { background: #F1F5F9; padding: 1px 5px; border-radius: 4px; font-size: .85em; }
.check-progress { margin: 16px 0 4px; font-weight: 700; color: var(--primary-dark); font-size: .95rem; }

/* ===== JUMP CARD (one-click link to calculator) ===== */
.jump-card { margin: 18px 0; padding: 18px 20px; border: 1px solid var(--border); border-left: 4px solid var(--primary); border-radius: var(--radius); background: var(--bg-card); box-shadow: var(--shadow); }
.jump-card h3 { margin: 0 0 8px; font-size: 1.05rem; color: var(--primary-dark); font-weight: 700; }
.jump-card p { margin: 0 0 14px; color: var(--text-muted); line-height: 1.7; font-size: .95rem; }
.jump-card .btn-primary { display: inline-block; text-decoration: none; }
@media (max-width: 560px) { .calc-grid, .calc-result { grid-template-columns: 1fr; } }