:root{--bg: #f7f9fc;--surface: #ffffff;--surface-2: #eef4ff;--text: #132238;--muted: #5f6f85;--line: #dce4ef;--brand: #1769e0;--brand-strong: #0d4fad;--good: #0e7c66;--warning: #9a5b00;--danger: #b42318;--radius: 18px;--shadow: 0 12px 35px rgba(19,34,56,.08);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;color-scheme:light}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);line-height:1.6}a{color:var(--brand-strong);text-decoration-thickness:.08em;text-underline-offset:.16em}a:hover{color:var(--brand)}img,svg{max-width:100%}button,input,select{font:inherit}button{cursor:pointer}.container{width:min(1160px,calc(100% - 32px));margin-inline:auto}.narrow{width:min(820px,calc(100% - 32px));margin-inline:auto}.skip-link{position:absolute;left:-999px;top:8px;background:#fff;padding:8px 12px;z-index:100}.skip-link:focus{left:8px}.site-header{position:sticky;top:0;z-index:20;background:#f7f9fcf0;backdrop-filter:blur(14px);border-bottom:1px solid rgba(220,228,239,.8)}.header-inner{min-height:70px;display:flex;align-items:center;justify-content:space-between;gap:24px}.brand{display:flex;align-items:center;gap:10px;font-weight:800;color:var(--text);text-decoration:none;letter-spacing:-.02em}.brand-mark{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:linear-gradient(145deg,var(--brand),#49a4ff);color:#fff;box-shadow:0 6px 18px #1769e040}.desktop-nav{display:flex;align-items:center;gap:20px}.desktop-nav a{color:var(--muted);text-decoration:none;font-weight:650;font-size:.95rem}.desktop-nav a:hover{color:var(--text)}.mobile-nav{display:none}main{min-height:70vh}.hero{padding:72px 0 36px}.eyebrow{display:inline-flex;align-items:center;gap:8px;color:var(--brand-strong);background:#eaf2ff;border:1px solid #cfe0ff;padding:6px 10px;border-radius:999px;font-size:.86rem;font-weight:750}h1,h2,h3{line-height:1.16;letter-spacing:-.025em}h1{font-size:clamp(2.2rem,5vw,4.4rem);margin:.4em 0 .22em}h2{font-size:clamp(1.5rem,3vw,2.25rem);margin-top:1.8em}h3{font-size:1.18rem}.lead{color:var(--muted);font-size:clamp(1.05rem,2vw,1.25rem);max-width:760px}.hero-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}.button{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 18px;border-radius:12px;border:1px solid transparent;font-weight:750;text-decoration:none}.button.primary{background:var(--brand);color:#fff;box-shadow:0 8px 22px #1769e033}.button.primary:hover{background:var(--brand-strong);color:#fff}.button.secondary{background:#fff;border-color:var(--line);color:var(--text)}.grid{display:grid;gap:18px}.tool-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:0 6px 24px #1322380b}.card h3{margin:0 0 6px}.card p{color:var(--muted);margin:0}.tool-card{transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;text-decoration:none;color:inherit}.tool-card:hover{transform:translateY(-2px);border-color:#b8cff7;box-shadow:var(--shadow);color:inherit}.tool-tag{display:inline-block;margin-top:14px;font-size:.82rem;font-weight:750;color:var(--brand-strong)}.section{padding:34px 0 54px}.section-head{max-width:760px;margin-bottom:22px}.section-head h2{margin-top:0}.breadcrumbs{font-size:.9rem;color:var(--muted);padding-top:24px}.breadcrumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;padding:0;margin:0}.breadcrumbs li:not(:last-child):after{content:"›";margin-left:8px;color:#9aa8ba}.breadcrumbs a{color:inherit}.tool-page-head{padding:34px 0 20px}.tool-page-head h1{font-size:clamp(2rem,4vw,3.35rem)}.tool-layout{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(280px,.65fr);gap:22px;align-items:start}.calculator{background:var(--surface);border:1px solid var(--line);border-radius:22px;padding:24px;box-shadow:var(--shadow)}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.field{display:grid;gap:7px}.field.full{grid-column:1 / -1}.field label{font-weight:700;font-size:.94rem}.field small{color:var(--muted)}.input-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px}input,select{width:100%;min-height:46px;border:1px solid #bdc9d8;background:#fff;color:var(--text);border-radius:11px;padding:0 12px;outline:none}input:focus,select:focus{border-color:var(--brand);box-shadow:0 0 0 3px #1769e01f}select.unit{width:auto;min-width:82px}.calc-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}.result{margin-top:20px;border-radius:16px;background:linear-gradient(160deg,#eef5ff,#f7fbff);border:1px solid #cfe0ff;padding:20px}.result[hidden]{display:none}.result-kicker{color:var(--muted);font-size:.86rem;font-weight:700}.result-main{display:block;margin:2px 0 8px;font-size:clamp(2rem,5vw,3rem);line-height:1.1;font-weight:850;letter-spacing:-.035em}.result-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-top:14px}.metric{background:#fff;border:1px solid #dce8fb;border-radius:12px;padding:12px}.metric span{display:block;color:var(--muted);font-size:.78rem}.metric strong{display:block;margin-top:3px}.error{margin-top:14px;color:var(--danger);font-weight:700}.diagram-card{background:var(--surface);border:1px solid var(--line);border-radius:22px;padding:20px;position:sticky;top:92px}.diagram-card h2{font-size:1.1rem;margin:0 0 8px}.diagram-card p{color:var(--muted);font-size:.92rem}.content{background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line);margin-top:48px}.content .narrow{padding-block:42px 56px}.content p,.content li{color:#33455d}.formula{overflow:auto;background:#0f1d2e;color:#f5f8fc;border-radius:14px;padding:16px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.note{border-left:4px solid var(--brand);background:#f1f6ff;padding:14px 16px;border-radius:0 12px 12px 0}.related{padding:44px 0}.related-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.related a{text-decoration:none;color:inherit}.site-footer{padding:42px 0;color:var(--muted)}.footer-grid{display:grid;grid-template-columns:1.3fr repeat(2,1fr);gap:28px}.footer-links{display:grid;gap:8px;align-content:start}.footer-links strong{color:var(--text)}.footer-links a{color:var(--muted);text-decoration:none}.footer-bottom{border-top:1px solid var(--line);margin-top:28px;padding-top:18px;font-size:.9rem}.kpi-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:26px}.kpi{background:#fff;border:1px solid var(--line);border-radius:14px;padding:15px}.kpi strong{display:block;font-size:1.08rem}.kpi span{color:var(--muted);font-size:.86rem}@media(max-width:900px){.desktop-nav{display:none}.mobile-nav{display:block;position:relative}.mobile-nav summary{list-style:none;cursor:pointer;border:1px solid var(--line);background:#fff;border-radius:10px;padding:8px 11px;font-weight:700}.mobile-nav summary::-webkit-details-marker{display:none}.mobile-nav nav{position:absolute;right:0;top:46px;width:min(280px,calc(100vw - 32px));padding:12px;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);display:grid;gap:4px}.mobile-nav nav a{padding:9px 10px;text-decoration:none;color:var(--text);border-radius:8px}.mobile-nav nav a:hover{background:var(--surface-2)}.tool-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.tool-layout{grid-template-columns:1fr}.diagram-card{position:static}.related-grid{grid-template-columns:1fr 1fr}}@media(max-width:620px){.container,.narrow{width:min(100% - 22px,1160px)}.hero{padding-top:48px}.tool-grid,.related-grid,.footer-grid,.form-grid,.kpi-strip{grid-template-columns:1fr}.field.full{grid-column:auto}.result-grid{grid-template-columns:1fr}.calculator{padding:18px;border-radius:16px}.diagram-card{border-radius:16px}.input-row{grid-template-columns:minmax(0,1fr) 86px}}