*{box-sizing:border-box;margin:0;padding:0}
:root{--primary:#0a66c2;--primary-dark:#004182;--text:#1a1a1a;--muted:#666;--border:#ddd;--bg-soft:#f0f8ff}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;color:var(--text);line-height:1.7;background:#fff;-webkit-font-smoothing:antialiased}
header{background:var(--primary);padding:1rem 1.5rem;position:sticky;top:0;z-index:100;box-shadow:0 2px 4px rgba(0,0,0,.1)}
header nav{max-width:1100px;margin:0 auto;display:flex;flex-wrap:wrap;gap:1.25rem;align-items:center}
header nav .brand{color:#fff;font-weight:700;font-size:1.15rem;text-decoration:none;margin-right:auto}
header nav a{color:#fff;text-decoration:none;font-weight:500;font-size:.95rem}
header nav a:hover{text-decoration:underline}
main{max-width:850px;margin:0 auto;padding:2rem 1rem;min-height:70vh}
h1{font-size:2.1rem;margin-bottom:1rem;color:var(--primary-dark);line-height:1.3}
h2{font-size:1.5rem;margin:2.5rem 0 1rem;color:var(--primary-dark);border-bottom:2px solid var(--bg-soft);padding-bottom:.35rem}
h3{font-size:1.15rem;margin:1.75rem 0 .5rem;color:var(--primary-dark)}
h4{font-size:1rem;margin:1rem 0 .4rem}
p{margin-bottom:1rem}
ul,ol{margin-bottom:1rem;padding-left:1.5rem}
li{margin-bottom:.5rem}
a{color:var(--primary);text-decoration:none}
a:hover{color:var(--primary-dark);text-decoration:underline}
footer{background:#1a1a1a;color:#ccc;text-align:center;padding:2rem 1rem;font-size:.9rem;margin-top:3rem}
footer a{color:#7fb8ff}
table{width:100%;border-collapse:collapse;margin:1.25rem 0;font-size:.95rem}
th,td{padding:.75rem;border:1px solid var(--border);text-align:left}
th{background:var(--bg-soft);font-weight:600}
.calculator{max-width:750px;margin:2rem auto;padding:1.5rem;border:1px solid var(--border);border-radius:8px;background:#fafafa}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}
@media(max-width:600px){.grid{grid-template-columns:1fr}h1{font-size:1.6rem}h2{font-size:1.25rem}main{padding:1.5rem 1rem}header nav{gap:.75rem}header nav a{font-size:.85rem}}
label{display:block;font-weight:600;font-size:.9rem}
input,select{width:100%;padding:.5rem;margin-top:.25rem;border:1px solid var(--border);border-radius:4px;font-size:1rem;background:#fff;font-family:inherit}
button{margin-top:1.5rem;background:var(--primary);color:#fff;padding:.85rem 2rem;border:none;border-radius:6px;cursor:pointer;font-size:1rem;font-weight:600;width:100%}
button:hover{background:var(--primary-dark)}
.result{margin-top:1.5rem;padding:1rem;background:var(--bg-soft);border-radius:6px;border-left:4px solid var(--primary)}
.result h2{margin-top:0;font-size:1.2rem;border:none;padding:0}
.total{font-size:1.15rem;color:var(--primary);margin-top:1rem}
.note{font-size:.85rem;color:var(--muted);margin-top:.5rem}
.toc{background:var(--bg-soft);padding:1rem 1.5rem;border-radius:6px;margin:1.5rem 0}
.toc h4{margin-top:0}
.toc ul{margin-bottom:0}
.faq details{background:#fafafa;padding:1rem;border-radius:6px;margin-bottom:.75rem;border-left:3px solid var(--primary)}
.faq summary{font-weight:600;cursor:pointer;color:var(--primary-dark)}
.faq details[open] summary{margin-bottom:.5rem}
.cta{background:var(--primary);color:#fff;padding:1.5rem;border-radius:8px;text-align:center;margin:2rem 0}
.cta a{color:#fff;text-decoration:underline}