:root{--ink:#14202e;--ink2:#4a5868;--ink3:#7d8a99;--bg:#f7f6f2;--card:#fff;--line:#e3e0d8;--brand:#1d4e89;--brand2:#163d6b;--accent:#c97a12;--soft:#eef3f9;--warn:#fff7e8;--r:14px;
--font:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Source Han Sans SC",sans-serif}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px}
a{color:var(--brand)}a:hover{color:var(--brand2)}
img,svg,canvas{max-width:100%}
.wrap{max-width:1040px;margin:0 auto;padding:0 18px}
.narrow{max-width:760px}
header.site{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:58px;gap:12px}
.logo{display:flex;align-items:center;gap:8px;text-decoration:none;color:var(--ink);font-weight:700;font-size:17px;white-space:nowrap}
.logo svg{width:30px;height:30px;flex:none}
nav.main{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none}
nav.main::-webkit-scrollbar{display:none}
nav.main a{padding:6px 10px;border-radius:8px;text-decoration:none;color:var(--ink2);font-size:15px;white-space:nowrap}
nav.main a.on,nav.main a:hover{background:var(--soft);color:var(--brand)}
@media (max-width:640px){header.site .wrap{flex-direction:column;height:auto;padding-top:8px;padding-bottom:6px;gap:2px;align-items:flex-start}nav.main{width:100%}}
main{padding:28px 0 48px}
h1{font-size:28px;line-height:1.35;margin:.2em 0 .5em}
h2{font-size:21px;line-height:1.4;margin:1.8em 0 .6em}
h3{font-size:17px;margin:1.4em 0 .4em}
@media (min-width:768px){h1{font-size:34px}}
.lead{font-size:17px;color:var(--ink2)}
.hero{padding:30px 0 10px}
.hero h1{font-size:30px}
@media (min-width:768px){.hero h1{font-size:42px}}
.hero .hl{color:var(--brand)}
.grid{display:grid;gap:14px}
@media (min-width:640px){.g2{grid-template-columns:1fr 1fr}.g3{grid-template-columns:repeat(3,1fr)}.g4{grid-template-columns:repeat(2,1fr)}}
@media (min-width:900px){.g4{grid-template-columns:repeat(4,1fr)}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px;display:block;text-decoration:none;color:var(--ink);transition:border-color .15s,transform .15s}
a.card:hover{border-color:var(--brand);transform:translateY(-1px);color:var(--ink)}
.card h3{margin:.2em 0 .3em;font-size:17px;line-height:1.45}
.card p{margin:0;color:var(--ink2);font-size:14.5px}
.card .tag{display:inline-block;font-size:12px;color:var(--brand);background:var(--soft);border-radius:999px;padding:1px 9px;margin-bottom:6px}
.tool-card{border-top:4px solid var(--brand)}
.tool-card.fx{border-top-color:var(--accent)}
.tool-card .go{display:inline-block;margin-top:10px;font-weight:600;color:var(--brand)}
.tool-card.fx .go{color:var(--accent)}
.btn{display:inline-block;background:var(--brand);color:#fff!important;text-decoration:none;padding:10px 20px;border-radius:10px;font-weight:600;border:0;font-size:15px;cursor:pointer;font-family:inherit}
.btn:hover{background:var(--brand2)}
.btn.ghost{background:transparent;color:var(--brand)!important;border:1px solid var(--brand)}
.cta{background:linear-gradient(135deg,#1d4e89,#2b6aa8);color:#fff;border-radius:var(--r);padding:24px;margin:36px 0 0}
.cta h2,.cta h3{margin-top:0;color:#fff}.cta p{color:#e3ecf7}
.cta .btn{background:#fff;color:var(--brand)!important}
.cta .btn.ghost{background:transparent;color:#fff!important;border-color:#fff}
.note{background:var(--warn);border:1px solid #f0dcb4;border-radius:10px;padding:12px 14px;font-size:14px;color:#6b4a12}
.todo{background:#fdecec;border:1px dashed #d9534f;color:#9b2c2c;border-radius:8px;padding:2px 8px;font-size:13px}
.section-title{display:flex;justify-content:space-between;align-items:baseline;margin-top:40px}
.section-title h2{margin:0}
.muted{color:var(--ink3);font-size:14px}
footer.site{border-top:1px solid var(--line);background:#fff;padding:26px 0 34px;font-size:14px;color:var(--ink2)}
footer.site nav{display:flex;flex-wrap:wrap;gap:6px 16px;margin-bottom:10px}
footer.site a{color:var(--ink2)}
article.post{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:22px 18px}
@media (min-width:768px){article.post{padding:36px 44px}}
article.post p,article.post li{font-size:16.5px}
article.post blockquote{margin:1em 0;padding:10px 16px;background:var(--soft);border-left:4px solid var(--brand);border-radius:6px}
article.post blockquote p{margin:0}
.tbl{overflow-x:auto;margin:1em 0}
table{border-collapse:collapse;width:100%;font-size:14.5px;background:#fff}
th,td{border:1px solid var(--line);padding:7px 9px;text-align:left;vertical-align:top}
th{background:var(--soft);font-weight:600;white-space:nowrap}
td.num,th.num{text-align:right;font-variant-numeric:tabular-nums;white-space:nowrap}
.crumbs{font-size:13.5px;color:var(--ink3);margin-bottom:6px}.crumbs a{color:var(--ink3)}
.meta{color:var(--ink3);font-size:14px;margin-bottom:12px}
.disclaimer{font-size:13.5px;color:var(--ink3);border-top:1px solid var(--line);margin-top:28px;padding-top:12px}
/* calculators */
.calc{display:grid;gap:18px}
@media (min-width:900px){.calc{grid-template-columns:340px 1fr;align-items:start}}
.panel{background:#fff;border:1px solid var(--line);border-radius:var(--r);padding:18px}
.field{margin-bottom:12px}
.field label{display:block;font-size:14px;color:var(--ink2);margin-bottom:4px}
.field input{width:100%;font-size:16px;padding:9px 11px;border:1px solid #cfcabd;border-radius:9px;font-family:inherit;background:#fff}
.field input:focus{outline:2px solid #9cc0ea;border-color:var(--brand)}
.field .hint{font-size:12.5px;color:var(--ink3);margin-top:3px}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chips label{display:inline-flex;align-items:center;gap:4px;border:1px solid #cfcabd;border-radius:999px;padding:4px 10px;font-size:14px;cursor:pointer;background:#fff;color:var(--ink)}
.chips input{width:auto;margin:0}
.kpis{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:14px}
@media (min-width:640px){.kpis{grid-template-columns:repeat(4,1fr)}}
.kpi{background:var(--soft);border-radius:10px;padding:10px 12px}
.kpi .k{font-size:12.5px;color:var(--ink2)}.kpi .v{font-size:19px;font-weight:700;font-variant-numeric:tabular-nums}
.kpi .s{font-size:12px;color:var(--ink3)}
.chartbox{position:relative;width:100%;height:300px;margin:6px 0 4px}
@media (min-width:768px){.chartbox{height:360px}}
.chartbox canvas{width:100%;height:100%;display:block}
.legend{display:flex;flex-wrap:wrap;gap:6px 14px;font-size:13px;color:var(--ink2)}
.legend i{display:inline-block;width:12px;height:3px;border-radius:2px;margin-right:5px;vertical-align:middle}
.seg{display:inline-flex;border:1px solid #cfcabd;border-radius:9px;overflow:hidden;margin:4px 0 8px}
.seg button{border:0;background:#fff;padding:6px 12px;font-size:14px;cursor:pointer;font-family:inherit;color:var(--ink2)}
.seg button.on{background:var(--brand);color:#fff}
.bar{display:flex;height:26px;border-radius:7px;overflow:hidden;background:#eee;margin:6px 0}
.bar span{display:block;height:100%}
.pos{color:#1d4e89}.neg{color:#b5531b}
.tooltip{position:absolute;pointer-events:none;background:rgba(20,32,46,.92);color:#fff;font-size:12.5px;padding:7px 9px;border-radius:7px;white-space:nowrap;display:none;line-height:1.5}
.toc-cat{margin:28px 0 8px;font-size:18px}
.calc>*{min-width:0}
#scen td:first-child{white-space:nowrap}