/* PayCalc Hub - 公共样式（纯静态、0 外部依赖、浅色响应式）
   参考 calculator-studio 的卡片化 / 清晰分区思路，并补齐参考表格与页头样式 */
:root{
  --bg:#f5f7fb;
  --surface:#ffffff;
  --ink:#16202c;
  --muted:#5b6b7b;
  --line:#e3e9f0;
  --brand:#1f6feb;
  --brand-ink:#0b4fc4;
  --brand-soft:#eaf2ff;
  --accent:#e8590c;
  --warn:#b54708;
  --radius:14px;
  --shadow:0 1px 2px rgba(16,24,40,.06),0 8px 24px rgba(16,24,40,.06);
  --maxw:1080px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,"PingFang SC","Microsoft YaHei",sans-serif;
  color:var(--ink);
  background:var(--bg);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--brand-ink);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}

/* 顶栏 */
header.site{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;height:62px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;color:var(--ink);letter-spacing:.2px}
.brand .logo{width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,var(--brand),var(--accent));display:inline-flex;align-items:center;justify-content:center;color:#fff;font-weight:900}
.nav nav{display:flex;gap:22px;font-size:14.5px}
.nav nav a{color:var(--muted);font-weight:600}
.nav nav a:hover{color:var(--brand-ink);text-decoration:none}
.menu-btn{display:none;background:none;border:1px solid var(--line);border-radius:8px;padding:8px 10px;font-size:18px;cursor:pointer}

/* 首页英雄区 */
.hero{padding:54px 0 30px}
.hero h1{font-size:38px;line-height:1.2;margin:0 0 14px;letter-spacing:-.5px}
.hero p.lead{font-size:17px;color:var(--muted);max-width:680px;margin:0 0 22px}
.pills{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px}
.pill{background:var(--brand-soft);color:var(--brand-ink);font-weight:600;font-size:13.5px;padding:7px 13px;border-radius:999px}

/* 卡片网格 */
.grid{display:grid;gap:18px}
.grid.cols-2{grid-template-columns:repeat(2,1fr)}
.grid.cols-3{grid-template-columns:repeat(3,1fr)}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);transition:transform .15s ease,box-shadow .15s ease}
.card:hover{transform:translateY(-3px);box-shadow:0 2px 4px rgba(16,24,40,.08),0 14px 34px rgba(16,24,40,.10)}
.card h3{margin:0 0 8px;font-size:18px}
.card p{margin:0 0 14px;color:var(--muted);font-size:14.5px}
.card .go{display:inline-block;font-weight:700;font-size:14px}
.card .ico{font-size:26px;margin-bottom:8px;display:block}

/* 区块标题 */
section.block{padding:30px 0}
section.block h2{font-size:26px;margin:0 0 6px;letter-spacing:-.3px}
section.block .sub{color:var(--muted);margin:0 0 20px}

/* 页面头（计算器页）：面包屑 + H1 + 副标题 + 信任条 */
.page-head{background:linear-gradient(135deg,#eaf2ff,#e9faf4);border:1px solid var(--line);border-radius:var(--radius);padding:26px 28px;margin-bottom:24px}
.crumbs{font-size:13px;color:var(--muted);margin-bottom:12px}
.crumbs a{color:var(--brand-ink);font-weight:600}
.crumbs span{margin:0 8px;color:#c3cfdd}
.page-head h1{font-size:34px;line-height:1.15;margin:0 0 8px;letter-spacing:-.5px}
.page-head .sub{font-size:16px;color:var(--muted);margin:0 0 16px;max-width:740px}
.trust{display:flex;flex-wrap:wrap;gap:10px}
.trust span{background:#fff;border:1px solid var(--line);color:var(--muted);font-size:13px;font-weight:600;padding:6px 13px;border-radius:999px;display:inline-flex;align-items:center;gap:6px}
.trust span::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--accent)}

/* 工具页布局 */
.tool-layout{display:grid;grid-template-columns:minmax(0,420px) minmax(0,1fr);gap:30px;align-items:start}
.calc{background:var(--surface);border:1px solid var(--line);border-top:3px solid var(--brand);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);position:sticky;top:84px}
.calc h2{font-size:20px;margin:0 0 16px;padding-bottom:12px;border-bottom:1px solid var(--line)}
.field{margin-bottom:16px}
.field label{display:block;font-weight:600;font-size:14px;margin-bottom:6px}
.field .hint{color:var(--muted);font-weight:400;font-size:12.5px}
.field input,.field select{
  width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:10px;font-size:15px;background:#fff;color:var(--ink);transition:border-color .12s,box-shadow .12s;
}
.field input:focus,.field select:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.btn{display:inline-block;width:100%;border:0;border-radius:10px;background:linear-gradient(135deg,var(--brand),#2f80ed);color:#fff;font-weight:700;font-size:15.5px;padding:13px;cursor:pointer;transition:filter .12s,transform .05s}
.btn:hover{filter:brightness(1.05)}
.btn:active{transform:translateY(1px)}
.btn.ghost{background:var(--brand-soft);color:var(--brand-ink)}
.result{margin-top:18px;border-top:1px dashed var(--line);padding-top:16px;min-height:8px}
.result .line{display:flex;justify-content:space-between;padding:7px 0;border-bottom:1px solid #f1f5f9;font-size:15px}
.result .line:last-child{border-bottom:0}
.result .line b{color:var(--brand-ink)}
.result .big{font-size:26px;font-weight:800;color:var(--brand-ink);text-align:center;margin:6px 0 12px;letter-spacing:-.3px}
.note{font-size:13px;color:var(--muted);margin-top:10px}

/* 文章区 */
.article{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow)}
.article h2{font-size:23px;margin:26px 0 10px}
.article h3{font-size:18px;margin:20px 0 8px}
.article p,.article li{color:#334155;font-size:15.5px}
.article ul,.article ol{padding-left:22px}
.article li{margin:6px 0}
.article code{background:#f1f5f9;padding:2px 6px;border-radius:6px;font-size:13.5px}
.formula{background:var(--brand-soft);border-left:4px solid var(--brand);padding:12px 16px;border-radius:8px;font-size:14.5px;color:var(--brand-ink);overflow-x:auto}
pre.code{background:#0f172a;color:#e2e8f0;padding:14px 16px;border-radius:10px;overflow-x:auto;font-size:13.5px}

/* 参考表（关键修复：此前缺失 .ref 样式导致裸表格） */
.ref{width:100%;border-collapse:collapse;margin:16px 0 24px;font-size:14.5px;overflow:hidden;border-radius:10px;border:1px solid var(--line);box-shadow:var(--shadow)}
.ref thead th{background:var(--brand);color:#fff;text-align:left;padding:11px 14px;font-weight:700;letter-spacing:.2px}
.ref thead th:first-child{border-top-left-radius:10px}
.ref thead th:last-child{border-top-right-radius:10px}
.ref tbody td{padding:10px 14px;border-top:1px solid var(--line)}
.ref tbody tr:nth-child(even){background:#f8fafc}
.ref tbody tr:hover{background:var(--brand-soft)}
.ref tbody td:first-child{font-weight:600;color:var(--ink)}
.ref caption{caption-side:bottom;font-size:12.5px;color:var(--muted);padding-top:8px}

/* FAQ */
.faq details{border:1px solid var(--line);border-radius:10px;padding:0 16px;margin-bottom:10px;background:#fff}
.faq summary{cursor:pointer;font-weight:700;padding:14px 0;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"+";color:var(--brand);font-weight:900;margin-right:10px}
.faq details[open] summary::before{content:"\2212"}
.faq .ans{padding:0 0 14px;color:#475569;font-size:14.5px}

/* 广告占位 */
.adslot{margin:22px 0;background:repeating-linear-gradient(45deg,#f8fafc,#f8fafc 12px,#f1f5f9 12px,#f1f5f9 24px);border:1px dashed #cbd5e1;border-radius:10px;min-height:100px;display:flex;align-items:center;justify-content:center;color:#94a3b8;font-size:13px;text-align:center;padding:14px}
.adslot.big{min-height:280px}
.disclaimer{font-size:12.5px;color:var(--muted);background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px 16px;margin:22px 0}

/* 联盟推荐卡片 */
.affcard{margin:22px 0;background:linear-gradient(135deg,#fffdf5,#f5fbff);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:12px;padding:20px 22px}
.affcard h3{margin:0 0 6px;font-size:17px;color:var(--ink)}
.affcard .affnote{font-size:13px;color:var(--muted);margin:0 0 12px}
.affcard .afflist{list-style:none;padding:0;margin:0;display:grid;gap:8px}
.affcard .afflist li{margin:0}
.affcard .afflist a{display:block;background:#fff;border:1px solid var(--line);border-radius:10px;padding:11px 14px;font-weight:600;font-size:14.5px;color:var(--brand-ink);transition:border-color .12s,transform .08s}
.affcard .afflist a:hover{border-color:var(--brand);text-decoration:none;transform:translateX(2px)}
body.dark .affcard{background:linear-gradient(135deg,#162031,#13251f)}
body.dark .affcard .afflist a{background:#162031}

/* 页脚 */
footer.site{background:#0f172a;color:#cbd5e1;margin-top:50px;padding:34px 0}
footer.site a{color:#93c5fd}
footer.site .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:24px}
footer.site h4{color:#fff;font-size:14px;margin:0 0 10px}
footer.site ul{list-style:none;padding:0;margin:0;font-size:13.5px}
footer.site ul li{margin:7px 0}
footer.site .copy{border-top:1px solid #1e293b;margin-top:24px;padding-top:16px;font-size:12.5px;color:#64748b}

/* 深色模式（由 common.js 切换 body.dark） */
body.dark{--bg:#0f172a;--surface:#162031;--ink:#e6edf6;--muted:#9fb0c3;--line:#27344a;--brand-soft:#15263f;--shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35)}
body.dark .formula{background:#15263f;color:#bcd3f5}
body.dark .article code{background:#0b1220}
body.dark .faq details{background:#162031}
body.dark .disclaimer{background:#162031}
body.dark .adslot{background:repeating-linear-gradient(45deg,#162031,#162031 12px,#1b2942 12px,#1b2942 24px)}
body.dark .ref tbody tr:nth-child(even){background:#101a2b}
body.dark .ref tbody tr:hover{background:#15263f}
body.dark .ref tbody td{color:#cdd9e8}
body.dark .page-head{background:linear-gradient(135deg,#15263f,#13251f)}
body.dark .trust span{background:#162031}
body.dark .card:hover{box-shadow:0 14px 34px rgba(0,0,0,.5)}

/* 主题切换按钮 */
.theme-toggle{margin-left:auto;border:1px solid var(--line);background:var(--surface);color:var(--muted);border-radius:999px;width:38px;height:38px;font-size:16px;cursor:pointer;display:flex;align-items:center;justify-content:center}
.theme-toggle:hover{color:var(--brand-ink)}

/* 站内搜索 */
.search{position:relative;max-width:520px;margin:18px 0 26px}
.search input{width:100%;padding:13px 16px 13px 42px;border:1px solid var(--line);border-radius:12px;font-size:15px;background:var(--surface);color:var(--ink)}
.search input:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
.search .ico{position:absolute;left:14px;top:50%;transform:translateY(-50%);color:var(--muted)}
.hidden{display:none !important}

/* 响应式 */
@media (max-width:880px){
  .tool-layout{grid-template-columns:1fr}
  .calc{position:static}
  .grid.cols-3{grid-template-columns:1fr 1fr}
  .nav nav{display:none}
  .menu-btn{display:block}
  .nav nav.open{display:flex;position:absolute;top:62px;left:0;right:0;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;gap:0;padding:8px 20px}
  .nav nav.open a{padding:12px 0;border-bottom:1px solid var(--line)}
  .hero h1{font-size:30px}
  .page-head h1{font-size:27px}
  footer.site .cols{grid-template-columns:1fr}
}
@media (max-width:560px){
  .grid.cols-2,.grid.cols-3{grid-template-columns:1fr}
  .row2{grid-template-columns:1fr}
}