:root{--paper: #f4f6f6;--card: #ffffff;--card-sunk: #fafbfb;--rail-bg: #eef3f3;--ink: #16222b;--ink-soft: #46545f;--ink-faint: #6f7d87;--brand: #0b4f55;--brand-deep: #063137;--brand-mid: #0d6068;--brand-tint: #e4efef;--brand-line: #b5cfcf;--seal: #a8762b;--seal-tint: #faf3e6;--ok: #15704e;--ok-tint: #e3f2ea;--danger: #b3261e;--danger-tint: #fdeceb;--line: #dde3e3;--line-soft: #e9eded;--radius: 10px;--radius-lg: 16px;--shadow-card: 0 1px 2px rgba(22, 34, 43, .05), 0 10px 26px -16px rgba(22, 34, 43, .22);--shadow-raise: 0 2px 6px rgba(22, 34, 43, .07), 0 22px 44px -22px rgba(11, 79, 85, .42);--font: "Anek Bangla", "Hind Siliguri", system-ui, -apple-system, "Segoe UI", sans-serif;--wrap: 1220px;--measure: 72ch}*,*:before,*:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:80px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--font);font-size:1.125rem;line-height:1.85;font-weight:400;-webkit-font-smoothing:antialiased;overflow-wrap:break-word}img,svg,video{max-width:100%;height:auto;display:block}a{color:var(--brand-mid);font-weight:600;text-decoration-thickness:1px;text-underline-offset:3px}a:hover{color:var(--brand-deep)}:focus-visible{outline:3px solid var(--seal);outline-offset:2px;border-radius:4px}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation-duration:.01ms!important;transition-duration:.01ms!important}}.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:18px}.skip{position:absolute;left:-9999px;background:var(--brand);color:#fff;padding:12px 18px;z-index:200;border-radius:0 0 var(--radius) 0}.skip:focus{left:0;top:0}.site-header{position:sticky;top:0;z-index:100;background:#fff;border-bottom:1px solid var(--line)}.header-inner{display:flex;align-items:center;gap:14px;min-height:60px}.logo{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);margin-right:auto;padding:6px 0;font-weight:400}.logo-mark{flex:none;width:36px;height:36px;border-radius:9px;background:linear-gradient(150deg,var(--brand-mid),var(--brand-deep));color:#f0dcb4;font-weight:700;font-size:.92rem;display:grid;place-items:center}.logo-text{display:grid;line-height:1.2}.logo-name{font-weight:700;font-size:1.06rem;color:var(--brand-deep);letter-spacing:.01em}.logo-sub{font-size:.76rem;font-weight:500;color:var(--ink-faint)}.nav{display:flex;align-items:center;gap:2px}.nav a{color:var(--ink-soft);text-decoration:none;font-size:.97rem;font-weight:500;padding:8px 12px;border-radius:8px}.nav a:hover{background:var(--brand-tint);color:var(--brand-deep)}.nav a[aria-current=page]{color:var(--brand-deep);font-weight:600}.nav-toggle{display:none;background:#fff;border:1px solid var(--line);border-radius:9px;width:44px;height:40px;cursor:pointer;padding:0;align-items:center;justify-content:center;color:var(--brand-deep)}.nav-toggle .bars{position:relative;display:block;width:20px;height:2px;border-radius:2px;background:currentColor;transition:background .18s ease}.nav-toggle .bars:before,.nav-toggle .bars:after{content:"";position:absolute;left:0;width:20px;height:2px;border-radius:2px;background:currentColor;transition:transform .22s ease}.nav-toggle .bars:before{top:-6px}.nav-toggle .bars:after{top:6px}.nav-toggle[aria-expanded=true] .bars{background:transparent}.nav-toggle[aria-expanded=true] .bars:before{transform:translateY(6px) rotate(45deg)}.nav-toggle[aria-expanded=true] .bars:after{transform:translateY(-6px) rotate(-45deg)}@media(max-width:900px){.nav-toggle{display:inline-flex}.nav{position:absolute;inset:60px 0 auto;flex-direction:column;align-items:stretch;gap:0;background:#fff;border-bottom:1px solid var(--line);box-shadow:0 14px 30px -18px #16222b73;padding:6px;display:none}.nav.open{display:flex}.nav a{padding:14px;font-size:1.04rem;font-weight:500;border-radius:8px}.nav a+a{border-top:1px solid var(--line-soft)}}.hero{position:relative;overflow:hidden;background:radial-gradient(125% 95% at 88% 0%,#0f6a70 0%,var(--brand-deep) 62%,#042227 100%);color:#e6f1f1;border-bottom:3px solid var(--seal)}.hero-guilloche{position:absolute;inset:0;opacity:.2;pointer-events:none}.hero-inner{position:relative;display:grid;gap:30px;padding-block:38px 44px}@media(min-width:1000px){.hero-inner{grid-template-columns:minmax(0,1.02fr) minmax(400px,.98fr);align-items:start;gap:46px;padding-block:52px 58px}}.hero-stamp{display:inline-flex;align-items:center;gap:8px;font-size:.81rem;font-weight:600;color:#f2dfb9;border:1px solid rgba(242,223,185,.4);border-radius:999px;padding:4px 13px;margin-bottom:16px;background:#0000002e}.hero-stamp:before{content:"";width:7px;height:7px;border-radius:50%;background:#f0c477}.hero h1{font-weight:700;font-size:clamp(1.9rem,5.4vw,2.85rem);line-height:1.3;margin:0 0 14px;color:#fff}.hero-dek{font-size:1.1rem;line-height:1.8;color:#c6dcdb;margin:0 0 20px;max-width:52ch}.hero-facts{display:flex;flex-wrap:wrap;gap:8px 22px;font-size:.92rem;color:#a6c6c6;padding-top:16px;border-top:1px solid rgba(255,255,255,.14)}.hero-facts b{color:#f2dfb9;font-weight:600}.verify{background:var(--card);color:var(--ink);border-radius:var(--radius-lg);box-shadow:var(--shadow-raise);overflow:hidden}.verify-head{padding:15px 20px 13px;border-bottom:1px dashed var(--line);background:var(--card-sunk)}.verify-head h2{font-size:1.2rem;font-weight:700;margin:0 0 3px;color:var(--brand-deep)}.verify-head p{margin:0;font-size:.88rem;color:var(--ink-faint);line-height:1.6}.verify-body{padding:18px 20px 20px}.field{margin-bottom:15px}.field label{display:block;font-size:.94rem;font-weight:600;margin-bottom:6px}.field .count{float:right;font-size:.82rem;font-weight:500;color:var(--ink-faint)}.field input{width:100%;font-family:var(--font);font-size:1.08rem;font-weight:500;letter-spacing:.04em;padding:13px 14px;color:var(--ink);background:var(--card-sunk);border:1.5px solid var(--line);border-radius:var(--radius);transition:border-color .15s ease,box-shadow .15s ease}.field input::placeholder{color:#aab3b8;font-weight:400;letter-spacing:.02em}.field input:focus{border-color:var(--brand);background:#fff;outline:none;box-shadow:0 0 0 3px var(--brand-tint)}.field.invalid input{border-color:var(--danger);background:var(--danger-tint)}.field.invalid input:focus{box-shadow:0 0 0 3px #b3261e26}.field.invalid .count{color:var(--danger);font-weight:600}.field .hint{display:block;font-size:.84rem;color:var(--ink-faint);margin-top:5px;line-height:1.6}.field-error{display:none;font-size:.87rem;font-weight:500;color:var(--danger);margin-top:6px;line-height:1.6}.field.invalid .field-error{display:block}.field.invalid .hint{display:none}.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;width:100%;font-family:var(--font);font-size:1.08rem;font-weight:600;padding:14px 18px;border:none;border-radius:var(--radius);background:linear-gradient(180deg,#0f6a70,var(--brand));color:#fff;cursor:pointer;box-shadow:0 1px #ffffff2e inset,0 10px 20px -12px #0b4f55e6;transition:filter .15s ease}.btn:hover{filter:brightness(1.09)}.btn:active{filter:brightness(.95)}.verify-note{font-size:.88rem;color:var(--ink-soft);line-height:1.72;margin:14px 0 0;padding-top:13px;border-top:1px solid var(--line-soft)}.verify-msg{font-size:.9rem;font-weight:500;line-height:1.6;padding:11px 13px;border-radius:var(--radius);margin-bottom:14px}.verify-msg[data-tone=error]{background:var(--danger-tint);color:var(--danger);border:1px solid #f0c8c5}.verify-msg[data-tone=ok]{background:var(--ok-tint);color:var(--ok);border:1px solid #bcdccc}.verify-msg[hidden]{display:none}.shell{display:grid;grid-template-columns:minmax(0,1fr);gap:30px;padding-block:28px 50px;align-items:start}@media(min-width:1060px){.shell{grid-template-columns:minmax(0,1fr) 300px;gap:44px;padding-block:38px 66px}}.rail{display:none}@media(min-width:1060px){.rail{display:block;position:sticky;top:78px;background:var(--rail-bg);border:1px solid var(--line);border-radius:var(--radius-lg);padding:18px;max-height:calc(100vh - 100px);overflow-y:auto}}.toc-title{font-size:.9rem;font-weight:700;color:var(--brand-deep);margin:0 0 10px;padding-bottom:9px;border-bottom:1px solid var(--brand-line)}.toc-list{list-style:none;margin:0;padding:0;font-size:.95rem;line-height:1.5}.toc-list li+li{margin-top:2px}.toc-list a{display:block;padding:7px 10px;border-radius:7px;color:var(--ink-soft);text-decoration:none;font-weight:500;border-left:3px solid transparent}.toc-list a:hover{background:#fff;color:var(--brand-deep)}.toc-list a.active{background:#fff;color:var(--brand-deep);font-weight:600;border-left-color:var(--seal)}.toc-mobile{background:var(--rail-bg);border:1px solid var(--line);border-radius:var(--radius-lg);margin-bottom:26px;overflow:hidden}@media(min-width:1060px){.toc-mobile{display:none}}.toc-mobile summary{list-style:none;cursor:pointer;padding:14px 18px;font-weight:600;font-size:1rem;color:var(--brand-deep);display:flex;justify-content:space-between;align-items:center}.toc-mobile summary::-webkit-details-marker{display:none}.toc-mobile summary:after{content:"";width:8px;height:8px;border-right:2px solid var(--brand);border-bottom:2px solid var(--brand);transform:rotate(45deg) translateY(-2px);transition:transform .2s ease}.toc-mobile[open] summary:after{transform:rotate(-135deg) translateY(-2px)}.toc-mobile .toc-list{padding:0 12px 14px}.prose{max-width:var(--measure)}.prose>*+*{margin-top:1.1em}.prose h2{font-size:clamp(1.45rem,3.8vw,1.78rem);font-weight:700;line-height:1.4;color:var(--brand-deep);margin-top:2.1em;margin-bottom:.5em;padding-left:14px;border-left:4px solid var(--seal)}.prose h3{font-size:clamp(1.2rem,3.1vw,1.35rem);font-weight:600;line-height:1.45;color:var(--ink);margin-top:1.8em;margin-bottom:.4em}.prose h4{font-size:1.08rem;font-weight:600;margin-top:1.5em;margin-bottom:.35em}.prose p{margin:0}.prose strong{font-weight:600;color:var(--ink)}.prose ul,.prose ol{margin:0;padding-left:1.3em}.prose li{margin-bottom:.45em}.prose li::marker{color:var(--seal);font-weight:700}.prose blockquote{margin:1.5em 0;padding:15px 20px;background:var(--seal-tint);border-left:4px solid var(--seal);border-radius:0 var(--radius) var(--radius) 0;font-size:1.04rem;line-height:1.78}.prose blockquote p{margin:0}.prose blockquote p+p{margin-top:.7em}.prose img{border-radius:var(--radius);border:1px solid var(--line);margin:1.4em 0 .3em;background:#fff}.prose hr{border:none;height:1px;background:var(--line);margin:2.2em 0}.table-scroll{overflow-x:auto;margin:1.5em 0;border:1px solid var(--line);border-radius:var(--radius);background:var(--card);-webkit-overflow-scrolling:touch}.prose table{width:100%;min-width:480px;border-collapse:collapse;font-size:1rem;line-height:1.7}.prose thead th{background:var(--brand);color:#fff;font-weight:600;text-align:left;padding:12px 15px;white-space:nowrap}.prose tbody td{padding:12px 15px;border-bottom:1px solid var(--line-soft);vertical-align:top}.prose tbody tr:last-child td{border-bottom:none}.prose tbody tr:nth-child(2n){background:var(--card-sunk)}.prose tbody td:first-child{font-weight:600;color:var(--brand-deep)}.steps{max-width:var(--measure);margin-top:2.2em}.section-h2{font-size:clamp(1.45rem,3.8vw,1.78rem);font-weight:700;color:var(--brand-deep);margin:0 0 .7em;padding-left:14px;border-left:4px solid var(--seal);line-height:1.4}.step-list{list-style:none;margin:0;padding:0;counter-reset:step}.step{counter-increment:step;position:relative;padding-left:50px;padding-bottom:28px}.step:before{content:counter(step);position:absolute;left:0;top:0;width:34px;height:34px;display:grid;place-items:center;border-radius:50%;background:var(--brand);color:#fff;font-weight:700;font-size:1rem}.step:after{content:"";position:absolute;left:16.5px;top:42px;bottom:4px;width:1.5px;background:var(--line)}.step:last-child{padding-bottom:0}.step:last-child:after{display:none}.step h3{font-size:1.2rem;font-weight:600;color:var(--ink);margin:2px 0 7px;line-height:1.45}.step p{margin:0 0 .65em}.step figure{margin:12px 0 0}.step figure img{border-radius:var(--radius);border:1px solid var(--line);box-shadow:var(--shadow-card)}.step figcaption{font-size:.85rem;color:var(--ink-faint);margin-top:7px;line-height:1.6}.faq{max-width:var(--measure);margin-top:2.4em}.faq-item{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);margin-bottom:10px;overflow:hidden}.faq-item[open]{border-color:var(--brand-line)}.faq-item summary{list-style:none;cursor:pointer;padding:15px 46px 15px 17px;position:relative;font-weight:600;font-size:1.06rem;line-height:1.6;color:var(--ink)}.faq-item summary::-webkit-details-marker{display:none}.faq-item[open] summary{color:var(--brand-deep);background:var(--brand-tint)}.faq-item summary:hover{color:var(--brand-deep)}.faq-item summary:after{content:"";position:absolute;right:18px;top:22px;width:12px;height:2px;border-radius:2px;background:var(--seal)}.faq-item summary:before{content:"";position:absolute;right:23px;top:17px;width:2px;height:12px;border-radius:2px;background:var(--seal);transition:transform .2s ease,opacity .2s ease}.faq-item[open] summary:before{transform:scaleY(0);opacity:0}.faq-answer{padding:14px 17px 16px;font-size:1.04rem;line-height:1.8;color:var(--ink-soft);border-top:1px solid var(--line-soft)}.faq-answer p{margin:0}.faq-answer p+p{margin-top:.7em}.author-box{max-width:var(--measure);margin-top:2.6em;background:linear-gradient(180deg,#fff,var(--card-sunk));border:1px solid var(--line);border-top:3px solid var(--brand);border-radius:var(--radius-lg);padding:22px;display:grid;grid-template-columns:auto minmax(0,1fr);gap:18px;align-items:start}.author-avatar{width:72px;height:72px;border-radius:50%;background:linear-gradient(150deg,var(--brand-mid),var(--brand-deep));color:#f0dcb4;display:grid;place-items:center;font-size:1.7rem;font-weight:700;flex:none;object-fit:cover}.author-label{font-size:.78rem;font-weight:600;color:var(--ink-faint);margin:0 0 2px}.author-name{display:flex;align-items:center;gap:6px;flex-wrap:wrap;font-size:1.22rem;font-weight:700;color:var(--ink);margin:0 0 2px;line-height:1.4}.verified-tick{flex:none}.author-role{font-size:.92rem;color:var(--seal);font-weight:600;margin:0 0 9px}.author-bio{font-size:1rem;line-height:1.78;color:var(--ink-soft);margin:0}.social-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px;padding:0;list-style:none}.social-list a{display:grid;place-items:center;width:38px;height:38px;border-radius:50%;background:#fff;border:1px solid var(--line);color:var(--brand-deep);transition:background .15s ease,border-color .15s ease}.social-list a:hover{background:var(--brand-tint);border-color:var(--brand-line)}@media(max-width:520px){.author-box{grid-template-columns:minmax(0,1fr)}}.page-head{max-width:var(--measure)}.breadcrumb{font-size:.88rem;color:var(--ink-faint);margin-bottom:12px}.breadcrumb ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:0}.breadcrumb li:after{content:"›";margin-left:6px;color:var(--ink-faint)}.breadcrumb li:last-child:after{content:""}.breadcrumb a{color:var(--ink-soft);text-decoration:none;font-weight:500}.breadcrumb a:hover{color:var(--brand);text-decoration:underline}.page-title{font-weight:700;font-size:clamp(1.75rem,5vw,2.3rem);line-height:1.32;color:var(--ink);margin:0 0 12px}.byline{display:flex;flex-wrap:wrap;align-items:center;gap:6px 14px;font-size:.9rem;color:var(--ink-faint);padding-bottom:18px;margin-bottom:24px;border-bottom:1px solid var(--line)}.byline-author{display:inline-flex;align-items:center;gap:5px;color:var(--ink-soft);font-weight:600}.lede{font-size:1.15rem;line-height:1.8;color:var(--ink-soft)}.related{max-width:var(--measure);margin-top:2.6em}.related-grid{display:grid;gap:10px}@media(min-width:640px){.related-grid{grid-template-columns:1fr 1fr}}.related-card{display:block;padding:15px 17px;background:var(--card);border:1px solid var(--line);border-left:3px solid var(--brand-line);border-radius:var(--radius);text-decoration:none;color:var(--ink);font-weight:400}.related-card:hover{border-left-color:var(--seal);background:var(--card-sunk)}.related-card b{display:block;font-weight:600;font-size:1.02rem;line-height:1.5;color:var(--brand-deep)}.related-card span{display:block;font-size:.89rem;color:var(--ink-faint);margin-top:3px;line-height:1.6}.gsource{max-width:var(--measure);margin-top:2.4em;display:grid;gap:14px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);padding:20px 22px}@media(min-width:620px){.gsource{grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:22px}}.gsource h3{font-size:1.12rem;font-weight:700;color:var(--ink);margin:0 0 3px}.gsource p{font-size:.94rem;color:var(--ink-soft);margin:0;line-height:1.7}.gbtn{display:inline-flex;align-items:center;gap:10px;font-size:.98rem;font-weight:600;color:var(--ink);text-decoration:none;background:#fff;border:1.5px solid var(--line);border-radius:999px;padding:9px 18px 9px 14px;white-space:nowrap;box-shadow:0 1px 2px #16222b0f}.gbtn:hover{border-color:var(--brand-line);background:var(--card-sunk);color:var(--ink)}.contact-form{max-width:var(--measure);margin-top:1.8em;background:var(--card);border:1px solid var(--line);border-radius:var(--radius-lg);padding:22px}.contact-form .field textarea{width:100%;font-family:var(--font);font-size:1.04rem;padding:12px 14px;color:var(--ink);background:var(--card-sunk);border:1.5px solid var(--line);border-radius:var(--radius);resize:vertical;min-height:140px}.contact-form .field textarea:focus{border-color:var(--brand);background:#fff;outline:none;box-shadow:0 0 0 3px var(--brand-tint)}.contact-form .field input{font-size:1.04rem;letter-spacing:normal;font-weight:400}.form-note{font-size:.88rem;color:var(--ink-faint);line-height:1.7;margin:14px 0 0}.site-footer{background:var(--brand-deep);color:#b3cbcc;font-size:.96rem;line-height:1.8;margin-top:36px;border-top:3px solid var(--seal)}.footer-grid{display:grid;gap:28px;padding-block:38px 26px}@media(min-width:760px){.footer-grid{grid-template-columns:1.5fr 1fr 1fr;gap:42px}}.footer-grid h3{font-size:.92rem;font-weight:700;color:#f2dfb9;margin:0 0 11px}.footer-grid ul{list-style:none;margin:0;padding:0}.footer-grid li{margin-bottom:6px}.footer-grid a{color:#cde0e0;text-decoration:none;font-weight:400}.footer-grid a:hover{color:#fff;text-decoration:underline}.footer-about{font-size:.94rem;color:#a1bdbe;max-width:44ch;margin:0 0 14px}.footer-disclaimer{font-size:.88rem;color:#8dabad;border:1px solid rgba(255,255,255,.14);border-radius:var(--radius);padding:12px 14px;background:#0000002e;max-width:44ch}.footer-disclaimer a{color:#cde0e0;font-weight:500}.footer-social{display:flex;gap:9px;margin-top:14px;padding:0;list-style:none}.footer-social a{display:grid;place-items:center;width:36px;height:36px;border-radius:50%;border:1px solid rgba(255,255,255,.2);color:#cde0e0}.footer-social a:hover{background:#ffffff1a}.footer-bottom{border-top:1px solid rgba(255,255,255,.12);padding-block:15px 20px;display:flex;flex-wrap:wrap;gap:6px 18px;justify-content:space-between;font-size:.88rem;color:#8dabad}.ad-slot{max-width:var(--measure);margin:2.2em 0;min-height:90px;display:grid;place-items:center;border:1px dashed var(--line);border-radius:var(--radius);color:var(--ink-faint);font-size:.8rem;background:var(--card-sunk)}.notfound{text-align:center;padding-block:80px 100px;max-width:52ch;margin-inline:auto}.notfound h1{font-size:2.1rem;margin:0 0 12px;color:var(--brand-deep)}.notfound .gbtn{margin-top:10px}.faq,.related,.gsource,.author-box{content-visibility:auto;contain-intrinsic-size:auto 400px}