/* 折旧计算器 · zhejiujisuanqi.com
   极简静态样式：无外部字体、无图标库、无框架依赖
   -------------------------------------------------- */
:root{
  --ink:#101a15;
  --ink-2:#2b3a33;
  --muted:#5f6f67;
  --line:#e2e8e4;
  --line-2:#cfdad3;
  --bg:#f5f7f5;
  --card:#fff;
  --brand:#146b4f;
  --brand-2:#1d8a66;
  --brand-soft:#eef6f1;
  --warn-bg:#fdf6e9;
  --warn-line:#efdcb8;
  --warn-ink:#7a5312;
  --radius:12px;
  --shadow:0 1px 2px rgba(16,26,21,.04),0 8px 24px -18px rgba(16,26,21,.35);
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;
  --sans:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Segoe UI",sans-serif;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:var(--sans);font-size:16px;line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
img,svg{max-width:100%;height:auto;vertical-align:middle}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{line-height:1.35;margin:0;letter-spacing:-.01em}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.35em}
li{margin:.25em 0}
small{font-size:.82em}
hr{border:0;border-top:1px solid var(--line);margin:28px 0}

.wrap{max-width:1080px;margin:0 auto;padding:0 18px}
.wrap-narrow{max-width:820px;margin:0 auto;padding:0 18px}

/* ---------- 头部 ---------- */
.site-head{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:30}
.site-head .wrap{display:flex;align-items:center;gap:20px;height:58px}
.brand{display:flex;align-items:center;gap:9px;font-weight:700;font-size:16px;color:var(--ink);text-decoration:none;white-space:nowrap;flex:none;min-width:0}
.brand:hover{text-decoration:none}
.brand-mark{width:22px;height:22px;border-radius:6px;background:var(--brand);position:relative;flex:none}
.brand-mark::after{content:"";position:absolute;inset:6px 5px;border-left:2px solid #fff;border-bottom:2px solid #fff;opacity:.9}
.brand small{font-weight:400;color:var(--muted);font-size:12px;margin-left:2px}
.nav{display:flex;gap:2px;margin-left:auto;flex:1 1 auto;min-width:0;overflow-x:auto;-webkit-overflow-scrolling:touch;scrollbar-width:none}
.nav::-webkit-scrollbar{display:none}
.nav a{padding:7px 11px;border-radius:8px;color:var(--ink-2);font-size:14px;white-space:nowrap}
.nav a:hover{background:var(--brand-soft);text-decoration:none;color:var(--brand)}
.nav a[aria-current="page"]{background:var(--brand-soft);color:var(--brand);font-weight:600}

/* ---------- 面包屑 ---------- */
.crumb{font-size:13px;color:var(--muted);padding:14px 0 0}
.crumb a{color:var(--muted)}
.crumb span{margin:0 6px;color:var(--line-2)}

/* ---------- 页头 ---------- */
.page-head{padding:16px 0 4px}
.page-head h1{font-size:clamp(22px,4.2vw,30px);margin:6px 0 8px}
.page-head .lead{color:var(--muted);font-size:15.5px;max-width:76ch;margin:0 0 10px}
.meta{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:12.5px;color:var(--muted);margin:10px 0 0}
.meta b{font-weight:600;color:var(--ink-2)}

/* ---------- 卡片 ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.card+.card{margin-top:16px}
.card h2{font-size:18px;margin:0 0 14px;display:flex;align-items:center;gap:9px}
.card h2::before{content:"";width:3px;height:17px;border-radius:2px;background:var(--brand);flex:none}
.card h3{font-size:15.5px;margin:20px 0 8px}
.card h3:first-of-type{margin-top:6px}
.section{margin-top:22px}

/* ---------- 计算器 ---------- */
.calc{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:16px;align-items:start}
@media(max-width:880px){.calc{grid-template-columns:1fr}}
.field{margin-bottom:12px}
.field:last-child{margin-bottom:0}
label{display:block;font-size:13px;color:var(--muted);margin:0 0 5px}
.input-wrap{position:relative}
input[type=number],input[type=text],select{
  width:100%;padding:10px 46px 10px 12px;border:1px solid var(--line-2);border-radius:9px;
  background:#fff;color:var(--ink);font-size:16px;font-family:inherit;
  transition:border-color .15s,box-shadow .15s;appearance:none
}
input[type=text]{padding-right:12px}
select{padding-right:34px;cursor:pointer}
input:focus,select:focus{outline:none;border-color:var(--brand-2);box-shadow:0 0 0 3px rgba(29,138,102,.13)}
input[type=number]{font-family:var(--mono)}
.unit{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-size:13px;color:var(--muted);pointer-events:none}
.row2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
@media(max-width:420px){.row2{grid-template-columns:1fr}}
.hint{font-size:12.5px;color:var(--muted);margin:8px 0 0}
.err{font-size:13px;color:#b42318;margin:8px 0 0;display:none}
.err.on{display:block}

.result{background:linear-gradient(180deg,#f0f7f3 0%,#fff 62%);border-color:#d5e7dc}
.result .stats{display:flex;flex-wrap:wrap;gap:18px;margin:0 0 12px}
.stat{flex:1 1 108px;min-width:0}
.stat .k{font-size:12px;color:var(--muted);white-space:nowrap}
.stat .v{font-family:var(--mono);font-size:clamp(20px,3.4vw,26px);font-weight:700;color:var(--brand);letter-spacing:-.02em;overflow-wrap:anywhere}
.stat .v small{font-size:12px;font-weight:400;color:var(--muted);margin-left:3px;letter-spacing:0}
.kv{display:flex;justify-content:space-between;gap:8px 12px;padding:8px 0;border-bottom:1px dashed var(--line);font-size:14px;flex-wrap:wrap}
.kv:last-child{border-bottom:0}
.kv b{font-family:var(--mono);font-weight:600;text-align:right;white-space:nowrap}

.je{background:#0e1b15;color:#e9f4ed;border-radius:10px;padding:14px 16px;margin-top:12px;font-family:var(--mono);font-size:13px;line-height:1.95;overflow-x:auto}
.je .t{font-family:var(--sans);color:#8fb8a4;font-size:11px;letter-spacing:.08em;margin-bottom:6px}
.je .dr{color:#a9e7c5}
.je .cr{color:#ffd79a;padding-left:22px}
.je .amt{float:right;color:#fff}

/* ---------- 表格 ---------- */
.tablewrap{overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid var(--line);border-radius:10px;margin:14px 0}
table{width:100%;border-collapse:collapse;font-size:14px}
th,td{padding:9px 12px;text-align:right;border-bottom:1px solid var(--line);white-space:nowrap}
th:first-child,td:first-child{text-align:left}
th{background:#fafcfa;font-size:12.5px;color:var(--muted);font-weight:600}
td{font-family:var(--mono);font-variant-numeric:tabular-nums}
td:first-child,th:first-child{font-family:var(--sans)}
tr:last-child td{border-bottom:0}
tr.total td{background:#fafcfa;font-weight:700;border-top:1px solid var(--ink)}
table.plain th,table.plain td{white-space:normal;text-align:left}
table.plain td:first-child{width:auto}
table.plain th{white-space:nowrap}
.cell-text{white-space:normal!important;text-align:left!important;font-family:var(--sans)!important;line-height:1.7}

/* ---------- 表格滑动提示 ---------- */
.scroll-tip{display:none;font-size:12px;color:var(--muted);margin:6px 0 0;text-align:center}
@media(max-width:700px){.scroll-tip{display:block}.tablewrap{font-size:13px}.tablewrap th,.tablewrap td{padding:8px 9px}}
@media(max-width:700px){.tablewrap table#tbl{min-width:520px}}

/* ---------- 提示块 ---------- */
.note{background:var(--brand-soft);border:1px solid #d9e9e0;border-radius:10px;padding:12px 14px;font-size:14px;color:#26463a;margin:14px 0}
.note p:last-child{margin:0}
.warn{background:var(--warn-bg);border:1px solid var(--warn-line);border-radius:10px;padding:12px 14px;font-size:14px;color:var(--warn-ink);margin:14px 0}
.warn p:last-child{margin:0}

/* ---------- FAQ ---------- */
.faq details{border-bottom:1px solid var(--line);padding:13px 0}
.faq details:first-of-type{border-top:1px solid var(--line)}
.faq summary{cursor:pointer;font-weight:600;font-size:15px;list-style:none;display:flex;gap:8px;align-items:flex-start}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"＋";color:var(--brand);font-weight:400;flex:none}
.faq details[open] summary::before{content:"－"}
.faq .a{margin:8px 0 0 22px;color:var(--ink-2);font-size:14.5px}
.faq .a p:last-child{margin:0}

/* ---------- 网格 ---------- */
.grid{display:grid;gap:12px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}
@media(max-width:860px){.grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}.grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:520px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}

.tile{display:block;background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px;color:var(--ink);text-decoration:none;transition:border-color .15s,transform .15s}
.tile:hover{border-color:var(--brand-2);text-decoration:none;transform:translateY(-1px)}
.tile b{display:block;font-size:15px;margin-bottom:3px}
.tile span{font-size:12.5px;color:var(--muted);line-height:1.5;display:block}

/* ---------- 首页 ---------- */
.hero{background:#fff;border-bottom:1px solid var(--line);padding:30px 0 34px}
.hero h1{font-size:clamp(26px,5vw,38px);margin:0 0 10px;letter-spacing:-.02em}
.hero .lead{font-size:16px;color:var(--muted);max-width:70ch;margin:0 0 18px}
.hero .quick{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:22px}
.pill{display:inline-block;padding:6px 13px;border:1px solid var(--line-2);border-radius:999px;font-size:13px;color:var(--ink-2);background:#fff}
.pill:hover{border-color:var(--brand-2);color:var(--brand);text-decoration:none}

/* ---------- 页脚 ---------- */
.site-foot{margin-top:40px;background:#fff;border-top:1px solid var(--line);padding:26px 0 30px;font-size:13px;color:var(--muted)}
.site-foot .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:22px}
@media(max-width:760px){.site-foot .cols{grid-template-columns:1fr 1fr}}
.site-foot h4{font-size:13px;color:var(--ink);margin:0 0 8px}
.site-foot a{color:var(--ink-2);display:block;padding:2px 0;font-size:13px}
.site-foot .about p{margin:0 0 8px;line-height:1.7}
.site-foot .bottom{margin-top:20px;padding-top:14px;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;gap:8px 16px;justify-content:space-between;font-size:12px}

/* ---------- 杂项 ---------- */
.tag{display:inline-block;font-size:11.5px;padding:2px 8px;border-radius:999px;background:var(--brand-soft);color:var(--brand);border:1px solid #d9e9e0;margin-right:6px}
.sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line-2);background:#fff;color:var(--ink);border-radius:9px;padding:8px 14px;font-size:13.5px;font-family:inherit;cursor:pointer}
.btn:hover{border-color:var(--brand-2);color:var(--brand)}
.btn-primary{background:var(--brand);border-color:var(--brand);color:#fff}
.btn-primary:hover{background:var(--brand-2);color:#fff}
.center{text-align:center}
.anchor{scroll-margin-top:70px}
@media(max-width:760px){
  .site-head{position:static}
  .site-head .wrap{height:auto;flex-wrap:wrap;padding:9px 0 0}
  .nav{order:3;flex:1 0 100%;width:100%;justify-content:space-between;gap:0;overflow:visible;border-top:1px solid var(--line);margin-top:8px}
  .nav a{padding:9px 0;font-size:13px;flex:1 1 auto;text-align:center}
  .nav a:first-child{display:none}
}
@media(max-width:520px){
  .je{font-size:12.5px;padding:12px 13px}
  .je .amt{float:none;display:inline;margin-left:6px;color:#cfe9d9}
  .je .dr,.je .cr{display:block}
  .brand small{display:none}
  .site-head .wrap{gap:10px}
  .nav a{padding:7px 9px;font-size:13.5px}
  .page-head{padding-top:10px}
}
@media print{.site-head,.site-foot,.nav,.btn,.related,.crumb{display:none}body{background:#fff}.card{box-shadow:none;border-color:#ccc}}