:root{--night:#0d1526;--night-2:#16223c;--card:#1a2842;--line:#2b3c60;--sun:#ffb020;--sun-soft:#ffd06e;--volt:#57d9a3;--ink:#eef3fb;--ink-dim:#9fb0cc;--danger:#ff7a6b}*{box-sizing:border-box;margin:0;padding:0}body{background:radial-gradient(900px 500px at 85% -10%, #ffb02029, transparent 60%), linear-gradient(180deg, var(--night) 0%, var(--night-2) 100%);color:var(--ink);min-height:100vh;font-family:Noto Sans Bengali,Space Grotesk,sans-serif}.wrap{max-width:980px;margin:0 auto;padding:40px 18px 80px}.eyebrow{letter-spacing:.22em;text-transform:uppercase;color:var(--sun);font-family:IBM Plex Mono,monospace;font-size:12px}h1{margin:10px 0 6px;font-family:Space Grotesk,Noto Sans Bengali,sans-serif;font-size:clamp(30px,5vw,46px);line-height:1.12}h1 .bn{color:var(--sun-soft)}.sub{color:var(--ink-dim);max-width:60ch;font-size:15px}.mode{border:1px solid var(--line);border-radius:999px;margin:26px 0 18px;display:inline-flex;overflow:hidden}.mode button{color:var(--ink-dim);cursor:pointer;background:0 0;border:0;padding:10px 22px;font:600 14px Space Grotesk,sans-serif}.mode button.on{background:var(--sun);color:#1a1206}.grid{grid-template-columns:380px 1fr;align-items:start;gap:22px;display:grid}@media (max-width:860px){.grid{grid-template-columns:1fr}}.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:22px}label.f{margin-bottom:16px;display:block}label.f .t{margin-bottom:6px;font-size:14px;font-weight:600;display:block}label.f .en{color:var(--ink-dim);font-size:12px;font-weight:400}input[type=number]{background:var(--night);border:1px solid var(--line);width:100%;color:var(--ink);border-radius:8px;padding:10px 12px;font:600 16px IBM Plex Mono,monospace}input[type=number]:focus{outline:2px solid var(--sun);border-color:#0000}.radios{flex-wrap:wrap;gap:10px;display:flex}.radios label{border:1px solid var(--line);cursor:pointer;color:var(--ink-dim);border-radius:8px;padding:9px 12px;font-size:13px}.radios input{display:none}.radios label.sel{border-color:var(--sun);color:var(--ink);background:#ffb02014}.flow{background:var(--night);border:1px solid var(--line);border-radius:12px;grid-template-columns:1fr auto 1fr auto 1fr auto 1fr;align-items:center;gap:6px;margin-bottom:18px;padding:16px 14px;display:grid}.node{text-align:center}.node .ic{font-size:22px}.node .nm{color:var(--ink-dim);margin-top:2px;font-size:11px}.node .vl{color:var(--volt);font:600 13px IBM Plex Mono,monospace}.arrow{color:var(--sun);font-size:16px;animation:1.6s infinite pulse}@keyframes pulse{0%,to{opacity:.35}50%{opacity:1}}@media (prefers-reduced-motion:reduce){.arrow{animation:none}}.results{grid-template-columns:1fr 1fr;gap:12px;display:grid}@media (max-width:500px){.results{grid-template-columns:1fr}}.res{background:var(--night);border:1px solid var(--line);border-left:3px solid var(--sun);border-radius:10px;padding:14px 16px}.res .k{color:var(--ink-dim);font-size:12px}.res .v{margin:2px 0;font:700 22px Space Grotesk,sans-serif}.res .v span{color:var(--sun-soft);font-size:13px;font-weight:500}.res .note{color:var(--ink-dim);font-size:12px}.formula{color:var(--ink-dim);background:var(--night);border:1px dashed var(--line);white-space:pre-wrap;border-radius:10px;margin-top:16px;padding:14px 16px;font:13px/1.7 IBM Plex Mono,monospace}.formula b{color:var(--sun-soft)}.warn{color:var(--danger);margin-top:10px;font-size:13px}.vh{margin:24px 0 4px;font-family:Space Grotesk,sans-serif;font-size:16px}.vh-sub{color:var(--ink-dim);margin-bottom:12px;font-size:12px}.voltrow{grid-template-columns:repeat(3,1fr);gap:12px;display:grid}@media (max-width:640px){.voltrow{grid-template-columns:1fr}}.volt{background:var(--night);border:1px solid var(--line);border-radius:10px;padding:16px 14px;position:relative}.volt-rec{border-color:var(--sun);background:#ffb0200f}.volt-badge{background:var(--sun);color:#1a1206;border-radius:999px;padding:2px 8px;font-size:10px;font-weight:700;position:absolute;top:-10px;left:12px}.volt-v{color:var(--ink-dim);font:700 15px IBM Plex Mono,monospace}.volt-ah{margin:4px 0 8px;font:700 26px Space Grotesk,sans-serif}.volt-ah span{color:var(--sun-soft);font-size:14px;font-weight:500}.volt-line{color:var(--ink-dim);font-size:12px;line-height:1.5}.volt-current{color:var(--volt);font-weight:600}.const-card{margin-top:22px}.const-grid{grid-template-columns:1fr 1fr;gap:24px;display:grid}@media (max-width:640px){.const-grid{grid-template-columns:1fr}}.const-sub{color:var(--sun-soft);text-transform:uppercase;letter-spacing:.05em;margin-bottom:6px;font-size:12px;font-weight:700}.const-row{border-bottom:1px dashed var(--line);justify-content:space-between;align-items:baseline;padding:8px 0;font-size:14px;display:flex}.const-row:last-child{border-bottom:none}.const-row span{color:var(--ink-dim)}.const-row b{font-family:IBM Plex Mono,monospace;font-weight:600}.const-row i{color:var(--sun);font-size:11px;font-style:normal}.const-rec b{color:var(--sun-soft)}footer{color:var(--ink-dim);margin-top:34px;font-size:12px}