/* ==========================================================================
   invest.css — BlackRock ও Vanguard আর্টিকেল পেজ
   স্ট্যান্ডঅ্যালোন ফাইল — মূল site style.css এর সাথে কোনো সংঘর্ষ নেই।
   ========================================================================== */

:root{
  --accent:#2563EB;
  --accent-dark:#1D4ED8;
  --accent-light:#EFF4FF;
  --ink:#0F172A;
  --ink-soft:#3F4A5E;
  --muted:#6B7789;
  --bg:#FFFFFF;
  --bg-soft:#F7F9FC;
  --border:#E6EAF1;
  --card:#FFFFFF;
  --green:#059669;
  --green-bg:#ECFDF5;
  --green-bd:#A7F3D0;
  --red:#DC2626;
  --red-bg:#FEF2F2;
  --red-bd:#FECACA;
  --amber:#D97706;
  --amber-bg:#FFFBEB;
  --amber-bd:#FDE68A;
  --purple:#7C3AED;
  --purple-bg:#F5F3FF;
  --purple-bd:#DDD6FE;
  --radius:16px;
  --radius-sm:10px;
  --maxw:820px;
  --shadow:0 1px 2px rgba(15,23,42,.04), 0 8px 24px -12px rgba(15,23,42,.10);
  --shadow-lg:0 20px 44px -18px rgba(15,23,42,.22);
  color-scheme:light;
}

[data-theme="dark"]{
  --ink:#EAEFF9;
  --ink-soft:#C3CBDC;
  --muted:#8B96AC;
  --bg:#0B1220;
  --bg-soft:#0F1729;
  --border:#1F2A40;
  --card:#111B2E;
  --accent-light:#132244;
  --green-bg:#062A20;
  --green-bd:#0E4A36;
  --red-bg:#2A1010;
  --red-bd:#4A1616;
  --amber-bg:#2A2008;
  --amber-bd:#4A3A10;
  --purple-bg:#1C1533;
  --purple-bd:#332358;
  --shadow:0 1px 2px rgba(0,0,0,.3), 0 8px 24px -12px rgba(0,0,0,.5);
  --shadow-lg:0 20px 44px -18px rgba(0,0,0,.6);
  color-scheme:dark;
}

*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0;
  font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  transition:background .25s ease,color .25s ease;
}
body.bn-serif, .bn{
  font-family:"Hind Siliguri","Inter",sans-serif;
}
img{max-width:100%;display:block;}
a{color:var(--accent);text-decoration:none;}
a:hover{text-decoration:underline;}
::selection{background:var(--accent);color:#fff;}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:4px;}

@media (prefers-reduced-motion:reduce){
  *{animation-duration:.001ms !important;transition-duration:.001ms !important;}
}

/* ---------------- Reading progress bar ---------------- */
.progress-bar{
  position:fixed;top:0;left:0;height:3px;width:0%;
  background:linear-gradient(90deg,var(--accent),#60A5FA);
  z-index:1000;transition:width .08s linear;
}

/* ---------------- Top bar ---------------- */
.topbar{
  position:sticky;top:0;z-index:900;
  background:color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter:blur(10px) saturate(160%);
  -webkit-backdrop-filter:blur(10px) saturate(160%);
  border-bottom:1px solid var(--border);
}
.topbar-inner{
  max-width:var(--maxw);margin:0 auto;padding:12px 20px;
  display:flex;align-items:center;justify-content:space-between;gap:12px;
}
.tb-brand{display:flex;align-items:center;gap:8px;font-weight:600;font-size:14.5px;color:var(--ink);}
.tb-brand img{width:26px;height:26px;border-radius:50%;object-fit:cover;}
.tb-actions{display:flex;align-items:center;gap:6px;}
.tb-btn{
  border:1px solid var(--border);background:var(--card);color:var(--ink-soft);
  width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;
  cursor:pointer;font-size:15px;transition:all .15s ease;
}
.tb-btn:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px);}
.tb-back{
  display:flex;align-items:center;gap:8px;font-size:13.5px;font-weight:600;color:var(--muted);
}
.tb-back:hover{color:var(--accent);text-decoration:none;}
.tb-back .tb-arrow{font-size:14px;}
.tb-logo{
  width:26px;height:26px;border-radius:50%;object-fit:cover;
  border:1px solid var(--border);flex-shrink:0;
}

/* ---------------- Layout shell ---------------- */
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px;}
.article-shell{display:flex;gap:36px;max-width:1180px;margin:0 auto;padding:0 20px;align-items:flex-start;}
.article-col{flex:1;min-width:0;max-width:820px;margin:0 auto;}

/* ---------------- Hero ---------------- */
.hero{padding:52px 0 30px;max-width:820px;margin:0 auto;}
.hero-meta-row{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-bottom:18px;}
.pill{
  display:inline-flex;align-items:center;gap:6px;
  background:var(--accent-light);color:var(--accent-dark);
  font-size:12.5px;font-weight:700;letter-spacing:.02em;
  padding:6px 12px;border-radius:999px;
}
[data-theme="dark"] .pill{color:#8FB4FF;}
.hero h1{
  font-size:clamp(30px,5.4vw,46px);
  line-height:1.25;font-weight:700;letter-spacing:-.01em;
  margin:0 0 16px;color:var(--ink);
}
.hero .subtitle{font-size:19px;color:var(--ink-soft);line-height:1.65;margin:0 0 12px;font-weight:500;}
.hero .desc{font-size:15.5px;color:var(--muted);line-height:1.8;margin:0 0 26px;}
.hero-stats{display:flex;flex-wrap:wrap;gap:22px;padding:18px 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border);}
.hs-item{display:flex;flex-direction:column;gap:2px;}
.hs-label{font-size:11.5px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;}
.hs-value{font-size:14.5px;font-weight:600;color:var(--ink);}

/* ---------------- Author card ---------------- */
.author-card{
  display:flex;align-items:center;gap:14px;
  margin:26px 0 6px;padding:16px 18px;
  border:1px solid var(--border);border-radius:var(--radius);background:var(--bg-soft);
}
.author-card img{width:48px;height:48px;border-radius:50%;object-fit:cover;border:2px solid var(--card);box-shadow:0 0 0 1px var(--border);}
.author-name{font-weight:700;font-size:14.5px;color:var(--ink);}
.author-role{font-size:12.5px;color:var(--muted);margin-top:1px;}
.author-links{margin-left:auto;display:flex;gap:8px;}
.author-links a{font-size:12px;font-weight:600;color:var(--accent);border:1px solid var(--border);padding:6px 11px;border-radius:999px;}
.author-links a:hover{background:var(--accent-light);text-decoration:none;}

/* ---------------- TOC ---------------- */
.toc-desktop{
  width:230px;flex-shrink:0;position:sticky;top:78px;
  max-height:calc(100vh - 100px);overflow-y:auto;padding-bottom:40px;
}
.toc-label{font-size:11px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:12px;}
.toc-desktop ol{list-style:none;margin:0;padding:0;border-left:2px solid var(--border);}
.toc-desktop li{margin:0;}
.toc-desktop a{
  display:block;padding:7px 0 7px 16px;margin-left:-2px;border-left:2px solid transparent;
  font-size:13px;color:var(--muted);line-height:1.4;transition:all .15s ease;
}
.toc-desktop a:hover{color:var(--ink);text-decoration:none;}
.toc-desktop a.active{color:var(--accent);border-left-color:var(--accent);font-weight:600;}

.toc-mobile{
  max-width:820px;margin:26px auto 0;border:1px solid var(--border);border-radius:var(--radius);
  background:var(--bg-soft);overflow:hidden;
}
.toc-mobile summary{
  cursor:pointer;list-style:none;padding:14px 18px;font-weight:700;font-size:14px;
  display:flex;align-items:center;justify-content:space-between;color:var(--ink);
}
.toc-mobile summary::-webkit-details-marker{display:none;}
.toc-mobile summary:after{content:"›";font-size:20px;transform:rotate(90deg);transition:transform .2s ease;color:var(--muted);}
.toc-mobile[open] summary:after{transform:rotate(-90deg);}
.toc-mobile ol{list-style:none;margin:0;padding:0 18px 16px;}
.toc-mobile a{display:block;padding:6px 0;font-size:13.5px;color:var(--ink-soft);}

@media (max-width:980px){ .toc-desktop{display:none;} }
@media (min-width:981px){ .toc-mobile{display:none;} }

/* ---------------- Article body ---------------- */
.article-body{padding:8px 0 10px;max-width:820px;margin:0 auto;}
.section{margin:46px 0;scroll-margin-top:86px;}
.section-head{display:flex;align-items:center;gap:12px;margin-bottom:6px;}
.section-icon{
  width:38px;height:38px;border-radius:11px;background:var(--accent-light);
  display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0;
}
.section-head h2{font-size:23px;font-weight:700;margin:0;letter-spacing:-.005em;color:var(--ink);}
.divider{height:1px;background:linear-gradient(90deg,var(--border),transparent);margin:14px 0 20px;}
.section p{font-size:16.5px;color:var(--ink-soft);margin:0 0 16px;line-height:1.85;}
.section p b, .section p strong{color:var(--ink);font-weight:700;}
.section blockquote{
  margin:22px 0;padding:18px 22px;border-left:3px solid var(--accent);
  background:var(--bg-soft);border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  font-size:16.5px;font-style:italic;color:var(--ink);
}
.cite{
  font-size:11px;font-weight:700;color:var(--accent);vertical-align:super;
  text-decoration:none;margin-left:1px;
}
.cite:hover{text-decoration:underline;}
.section ul, .section ol{padding-right:0;padding-left:20px;color:var(--ink-soft);font-size:16px;}
.section li{margin-bottom:8px;line-height:1.7;}

/* ---------------- Money / Growth / Risk boxes ---------------- */
.stat-box{
  border-radius:var(--radius);padding:26px 26px;margin:24px 0;
  position:relative;overflow:hidden;box-shadow:var(--shadow);
}
.stat-box .sb-label{font-size:12.5px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;opacity:.85;margin-bottom:8px;}
.stat-box .sb-value{font-size:clamp(30px,6vw,44px);font-weight:800;line-height:1.1;margin-bottom:8px;letter-spacing:-.01em;}
.stat-box .sb-explain{font-size:14.5px;line-height:1.6;opacity:.92;max-width:520px;}
.stat-box .sb-icon{position:absolute;right:20px;top:20px;font-size:34px;opacity:.35;}

.money-box{background:linear-gradient(135deg,#2563EB,#1E40AF);color:#fff;}
.growth-box{background:linear-gradient(135deg,#059669,#047857);color:#fff;}
.growth-box .flow{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:14px;font-size:13.5px;font-weight:600;}
.growth-box .flow span{background:rgba(255,255,255,.16);padding:6px 12px;border-radius:999px;}
.risk-box{background:linear-gradient(135deg,#DC2626,#991B1B);color:#fff;}
.risk-box ul{margin:14px 0 0;padding-left:18px;font-size:14.5px;opacity:.95;}
.risk-box li{margin-bottom:6px;}

/* ---------------- Comparison cards ---------------- */
.compare-wrap{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:26px 0;}
@media (max-width:640px){.compare-wrap{grid-template-columns:1fr;}}
.compare-card{
  border:1px solid var(--border);border-radius:var(--radius);padding:22px 20px;background:var(--card);
}
.compare-card .cc-head{display:flex;align-items:center;gap:10px;margin-bottom:14px;}
.compare-card .cc-icon{font-size:24px;}
.compare-card h3{margin:0;font-size:16.5px;font-weight:700;color:var(--ink);}
.compare-card ul{list-style:none;padding:0;margin:0;font-size:14px;color:var(--ink-soft);}
.compare-card li{display:flex;gap:8px;padding:6px 0;border-top:1px solid var(--border);}
.compare-card li:first-child{border-top:none;}
.compare-card li:before{content:"—";color:var(--accent);flex-shrink:0;}
.compare-vs{
  display:flex;align-items:center;justify-content:center;font-weight:800;color:var(--muted);
  font-size:13px;grid-column:1/-1;margin:-8px 0;
}
@media (min-width:641px){.compare-vs{display:none;}}

/* ---------------- Timeline ---------------- */
.timeline{position:relative;margin:30px 0 10px;padding-left:26px;}
.timeline:before{content:"";position:absolute;left:6px;top:6px;bottom:6px;width:2px;background:var(--border);}
.tl-item{position:relative;padding-bottom:26px;}
.tl-item:last-child{padding-bottom:0;}
.tl-item:before{
  content:"";position:absolute;left:-26px;top:4px;width:14px;height:14px;border-radius:50%;
  background:var(--accent);box-shadow:0 0 0 4px var(--accent-light);
}
.tl-year{font-size:12.5px;font-weight:800;color:var(--accent);letter-spacing:.03em;margin-bottom:3px;}
.tl-title{font-size:15.5px;font-weight:700;color:var(--ink);margin-bottom:3px;}
.tl-desc{font-size:13.5px;color:var(--muted);line-height:1.6;}

/* ---------------- Highlight / research boxes ---------------- */
.info-box{
  border-radius:var(--radius-sm);padding:18px 20px;margin:20px 0;border:1px solid;
  display:flex;gap:12px;
}
.info-box .ib-icon{font-size:20px;flex-shrink:0;}
.info-box .ib-title{font-weight:700;font-size:14.5px;margin-bottom:4px;}
.info-box .ib-text{font-size:14.5px;line-height:1.65;color:var(--ink-soft);}
.info-box.fact{background:var(--accent-light);border-color:#C7D8FC;}
.info-box.fact .ib-title{color:var(--accent-dark);}
[data-theme="dark"] .info-box.fact{border-color:#25407A;}
.info-box.warn{background:var(--amber-bg);border-color:var(--amber-bd);}
.info-box.warn .ib-title{color:var(--amber);}
.info-box.note{background:var(--green-bg);border-color:var(--green-bd);}
.info-box.note .ib-title{color:var(--green);}
.info-box.research{background:var(--purple-bg);border-color:var(--purple-bd);}
.info-box.research .ib-title{color:var(--purple);}

.research-card{
  border:1px solid var(--border);border-radius:var(--radius);padding:18px 20px;margin:20px 0;
  background:var(--card);display:flex;gap:14px;align-items:flex-start;box-shadow:var(--shadow);
}
.research-card .rc-badge{
  width:36px;height:36px;border-radius:10px;background:var(--purple-bg);color:var(--purple);
  display:flex;align-items:center;justify-content:center;font-size:17px;flex-shrink:0;
}
.research-card .rc-title{font-weight:700;font-size:14.5px;color:var(--ink);margin-bottom:3px;}
.research-card .rc-tag{font-size:11px;font-weight:700;color:var(--purple);text-transform:uppercase;letter-spacing:.04em;margin-bottom:6px;}
.research-card .rc-text{font-size:14px;color:var(--ink-soft);line-height:1.65;}

/* ---------------- Conclusion card ---------------- */
.final-card{
  margin:46px 0;padding:34px 30px;border-radius:20px;
  background:linear-gradient(160deg,var(--ink) 0%,#1E293B 100%);
  color:#fff;box-shadow:var(--shadow-lg);
}
[data-theme="dark"] .final-card{background:linear-gradient(160deg,#182238 0%,#0B1220 100%);}
.final-card .fc-eyebrow{font-size:12px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:#93C5FD;margin-bottom:8px;}
.final-card h3{font-size:24px;margin:0 0 14px;font-weight:700;}
.final-card p{color:#CBD5E1;font-size:15.5px;line-height:1.8;margin:0 0 12px;}
.final-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:20px;}
@media (max-width:640px){.final-grid{grid-template-columns:1fr;}}
.final-grid .fg-item{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.1);border-radius:12px;padding:14px 16px;}
.final-grid .fg-item b{display:block;font-size:13.5px;color:#fff;margin-bottom:4px;}
.final-grid .fg-item span{font-size:13px;color:#94A3B8;line-height:1.55;}

/* ---------------- References ---------------- */
.ref-section{margin:50px 0;}
.ref-cat{margin-bottom:26px;}
.ref-cat h4{font-size:14px;font-weight:700;color:var(--accent);text-transform:uppercase;letter-spacing:.04em;margin:0 0 12px;}
.ref-list{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:8px 20px;}
@media (max-width:640px){.ref-list{grid-template-columns:1fr;}}
.ref-list li{font-size:13.5px;color:var(--ink-soft);padding:8px 0;border-top:1px solid var(--border);display:flex;gap:8px;}
.ref-list li:nth-child(-n+2){border-top:none;}
@media (max-width:640px){.ref-list li:nth-child(2){border-top:1px solid var(--border);}}
.ref-num{color:var(--muted);font-weight:700;flex-shrink:0;}
.ref-list a{color:var(--ink-soft);}
.ref-list a:hover{color:var(--accent);}

/* ---------------- Social / Follow card ---------------- */
.social-card{
  margin:50px 0 30px;padding:32px 28px;border-radius:20px;text-align:center;
  background:var(--bg-soft);border:1px solid var(--border);
}
.social-card h3{font-size:21px;margin:0 0 6px;color:var(--ink);}
.social-card p{font-size:14.5px;color:var(--muted);margin:0 0 22px;}
.social-grid{display:flex;flex-wrap:wrap;justify-content:center;gap:10px;}
.social-btn{
  display:flex;align-items:center;gap:8px;padding:10px 16px;border-radius:999px;
  background:var(--card);border:1px solid var(--border);font-size:13.5px;font-weight:600;color:var(--ink);
  transition:all .15s ease;
}
.social-btn:hover{border-color:var(--accent);color:var(--accent);text-decoration:none;transform:translateY(-2px);box-shadow:var(--shadow);}
.social-btn .sb-emoji{font-size:16px;}

/* ---------------- Copy toast ---------------- */
.toast{
  position:fixed;bottom:26px;left:50%;transform:translateX(-50%) translateY(20px);
  background:var(--ink);color:var(--bg);font-size:13.5px;font-weight:600;
  padding:11px 20px;border-radius:999px;opacity:0;pointer-events:none;
  transition:all .25s ease;z-index:1000;box-shadow:var(--shadow-lg);
}
.toast.show{opacity:1;transform:translateX(-50%) translateY(0);}

/* ---------------- Footer ---------------- */
.article-footer{
  max-width:820px;margin:0 auto;padding:26px 20px 60px;text-align:center;
  color:var(--muted);font-size:12.5px;border-top:1px solid var(--border);
}
.article-footer a{color:var(--muted);}

/* ---------------- Back to top ---------------- */
.back-top{
  position:fixed;bottom:24px;right:24px;width:44px;height:44px;border-radius:50%;
  background:var(--ink);color:var(--bg);border:none;display:flex;align-items:center;justify-content:center;
  font-size:17px;cursor:pointer;box-shadow:var(--shadow-lg);opacity:0;pointer-events:none;
  transform:translateY(10px);transition:all .25s ease;z-index:800;
}
.back-top.show{opacity:1;pointer-events:auto;transform:translateY(0);}

@media (max-width:520px){
  .hero{padding:36px 0 22px;}
  .author-card{flex-wrap:wrap;}
  .author-links{margin-left:0;}
  .final-card{padding:26px 20px;}
  .social-card{padding:26px 18px;}
}