:root{--ink:#142033;--muted:#627087;--paper:#f7f9fc;--blue:#4169e1;--cyan:#2cc7c9;--navy:#101b31;--line:#e4eaf2}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 system-ui,Arial,sans-serif}a{color:var(--blue);text-decoration:none}.wrap{width:min(1100px,calc(100% - 36px));margin:auto}.topbar{background:white;border-bottom:1px solid var(--line);position:sticky;top:0}.nav{height:72px;display:flex;align-items:center;justify-content:space-between}.brand{font-weight:850;font-size:1.25rem;color:var(--ink)}.mark{display:inline-grid;place-items:center;background:linear-gradient(135deg,var(--blue),var(--cyan));color:white;border-radius:10px;width:34px;height:34px;margin-right:8px}.navlinks{display:flex;gap:22px}.navlinks a{color:#42516a;font-weight:650}.btn{display:inline-block;background:var(--blue);color:white;padding:12px 18px;border-radius:11px;font-weight:750;border:0;cursor:pointer}.secondary{background:white;color:var(--ink);border:1px solid var(--line)}.hero{padding:76px 0;background:radial-gradient(ellipse at 80% 0%,#dff7f5,transparent 40%),radial-gradient(ellipse at 0% 20%,#e8edff,transparent 42%),white}.eyebrow{font-size:.78rem;text-transform:uppercase;letter-spacing:.13em;color:var(--blue);font-weight:800}.hero h1{font-size:clamp(2.6rem,6vw,4.6rem);line-height:1.04;letter-spacing:-.06em;max-width:850px;margin:12px 0}.hero p{font-size:1.15rem;color:var(--muted);max-width:720px}.section{padding:54px 0}.section h2{font-size:2.2rem;letter-spacing:-.04em}.muted{color:var(--muted)}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.card,.toolbox,.resultbox{background:white;border:1px solid var(--line);border-radius:18px;padding:23px;box-shadow:0 12px 34px #192a4610}.card h3{margin:0 0 8px}.card p{margin:0;color:var(--muted)}.iconbox{width:40px;height:40px;border-radius:12px;background:#edf2ff;color:var(--blue);display:grid;place-items:center;font-weight:900;margin-bottom:16px}.tool-layout{display:grid;grid-template-columns:1fr .8fr;gap:20px}.field{display:block;margin:0 0 16px}.field span{display:block;font-weight:700;margin-bottom:6px}.field input,.field select{width:100%;padding:12px;border:1px solid #d5deea;border-radius:9px;font:inherit}.result{font-size:2.4rem;font-weight:850;color:var(--blue)}.formula,.notice{padding:13px;background:#eff5fb;border-radius:10px;color:#52637a}.article{max-width:780px;margin:auto}.article h1{font-size:clamp(2.3rem,5vw,3.7rem);line-height:1.08;letter-spacing:-.05em}.article h2{margin-top:34px}.article p,.article li{color:#4d5b70}.lead{font-size:1.15rem}.breadcrumbs{margin:22px 0;color:var(--muted);font-size:.9rem}.footer{margin-top:40px;background:var(--navy);color:#c4cddd;padding:42px 0}.footer a{color:white}.footergrid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:25px}.small{font-size:.88rem}.pill{display:inline-block;background:#edf7f7;color:#157d80;border-radius:20px;padding:4px 9px;font-size:.75rem;font-weight:800}.resizer-preview{max-width:100%;max-height:280px;display:block;margin:16px auto}@media(max-width:760px){.navlinks{display:none}.grid{grid-template-columns:repeat(2,1fr)}.tool-layout{grid-template-columns:1fr}.hero{padding:50px 0}}@media(max-width:520px){.grid,.footergrid{grid-template-columns:1fr}.section{padding:38px 0}}