:root{--navy:#0d2740;--teal:#0f7c86;--sand:#f7f2e8;--coral:#e0664a;--ink:#1c2630}
*{box-sizing:border-box}body{margin:0;background:var(--sand);color:var(--ink);font:17px/1.7 Georgia,"Iowan Old Style","Palatino Linotype",serif}
.wrap{max-width:960px;margin:0 auto;padding:0 20px}
.masthead{background:var(--navy);border-bottom:4px solid var(--teal)}.masthead .wrap{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;padding:12px 20px}
.logo{color:#fff;text-decoration:none;font:700 1.3rem/1 system-ui,sans-serif;letter-spacing:.02em}.anchor{color:#6fd3db}
nav.main{display:flex;gap:18px}nav.main a{color:#cfe7ea;text-decoration:none;font:500 .95rem system-ui,sans-serif}nav.main a:hover{color:#fff}
.menu{display:none;background:transparent;border:1px solid #6fd3db;color:#fff;border-radius:4px;padding:4px 10px;font:500 .9rem system-ui,sans-serif}
@media(max-width:680px){.menu{display:block}nav.main{display:none;width:100%;flex-direction:column;gap:6px;padding-top:10px}.open nav.main{display:flex}}
.content{padding-top:14px;padding-bottom:30px}article{background:#fff;border-radius:4px;padding:24px 28px 32px;border-top:3px solid var(--coral)}
@media(max-width:600px){article{padding:18px 16px}}
h1,h2,h3{font-family:system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--navy);line-height:1.25}h1{font-size:2rem;margin-top:.2em}h2{font-size:1.4rem;margin-top:1.9em;border-bottom:1px solid #e3ddd0;padding-bottom:4px}h3{font-size:1.12rem}
a{color:var(--teal)}.crumbs{font:500 .85rem system-ui,sans-serif;margin:6px 0 12px;color:#6b737a}.crumbs a{color:#46606f}
.calc{background:#eef6f6;border:1px solid #bfdfe1;border-left:6px solid var(--teal);border-radius:4px;padding:18px 20px;margin:20px 0;font-family:system-ui,sans-serif}
.calc .grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:4px 18px}
.calc label{display:block;font-weight:600;font-size:.92rem;margin:10px 0 4px}.calc input,.calc select{width:100%;padding:9px;font-size:1rem;border:1px solid #9cc5c9;border-radius:4px;background:#fff}
.calc button{margin-top:16px;background:var(--coral);color:#fff;border:0;padding:11px 22px;font-size:1rem;font-weight:600;border-radius:4px;cursor:pointer}
.result{margin-top:16px;background:#fff;border:1px solid #bfdfe1;border-radius:4px;padding:12px 14px;font-size:1rem}.result:empty{display:none}.result b{color:var(--navy)}
.result table{margin:6px 0 0}.note{font-size:.88rem;color:#55606a;font-family:system-ui,sans-serif}
.tbl{overflow-x:auto}table{border-collapse:collapse;width:100%;margin:14px 0;font:.94rem/1.45 system-ui,sans-serif}th,td{border:1px solid #ddd6c8;padding:8px;text-align:left;vertical-align:top}th{background:#f1ebdf;color:var(--navy)}
.author{margin-top:34px;background:var(--sand);border-left:4px solid var(--navy);padding:12px 16px;font-size:.93rem}.author p{margin:.3em 0 0}
.related ul{columns:2;column-gap:28px}@media(max-width:600px){.related ul{columns:1}}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:14px;margin:16px 0}.cards a{display:block;padding:14px 16px;background:#fbf8f2;border:1px solid #e3ddd0;border-top:3px solid var(--teal);border-radius:4px;text-decoration:none}
.cards strong{display:block;color:var(--navy);font-family:system-ui,sans-serif}.cards span{display:block;color:#55606a;font-size:.9rem;margin-top:4px}
.foot{background:var(--navy);color:#b9ccd6;font:.88rem/1.6 system-ui,sans-serif;padding:20px 0 34px}.foot a{color:#e7f4f6}