:root{
  --bg:#f6f7fb; --panel:#ffffff; --ink:#111827; --muted:#5b6474; --line:#e3e6ee;
  --accent:#e8590c; --accent-ink:#ffffff; --money:#c2410c; --good:#15803d; --chip:#eef1f7;
  --radius:14px; --shadow:0 1px 2px rgba(17,24,39,.06),0 6px 24px rgba(17,24,39,.06);
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0d1117; --panel:#151b24; --ink:#e8edf5; --muted:#9aa5b8; --line:#273142;
    --accent:#ff7a2e; --accent-ink:#1a0d03; --money:#ff9a5c; --good:#4ade80; --chip:#1d2633;
    --shadow:none;
  }
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif}
a{color:inherit}
.wrap{max-width:1040px;margin:0 auto;padding:0 16px}
.skip{position:absolute;left:-9999px}.skip:focus{left:16px;top:8px;background:var(--panel);padding:8px;z-index:9}

/* header / footer */
.site-head{border-bottom:1px solid var(--line);background:var(--panel)}
.site-head .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:56px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;text-decoration:none;letter-spacing:-.01em}
.brand svg{width:26px;height:26px}
.nav{display:flex;gap:14px;flex-wrap:wrap;font-size:14px}
.nav a{text-decoration:none;color:var(--muted)}
.nav a[aria-current="page"],.nav a:hover{color:var(--ink)}
.site-foot{margin-top:48px;border-top:1px solid var(--line);color:var(--muted);font-size:13px;padding:22px 0 40px}
.site-foot a{color:var(--muted)}
.site-foot .links{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:8px}

/* hero */
.hero{padding:28px 0 8px}
.hero h1{font-size:clamp(30px,6.4vw,50px);line-height:1.05;margin:0 0 10px;letter-spacing:-.02em}
.hero h1 .strike{text-decoration:line-through;text-decoration-color:var(--accent);text-decoration-thickness:4px}
.hero p.lead{color:var(--muted);font-size:clamp(16px,2.4vw,19px);margin:0;max-width:640px}

/* tool */
.tool{display:grid;gap:16px;margin:18px 0}
@media(min-width:900px){.tool{grid-template-columns:1fr 1fr;align-items:start}.result{position:sticky;top:12px}}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:16px;box-shadow:var(--shadow)}
.step{margin-bottom:16px}
.step:last-child{margin-bottom:0}
.step-label{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 8px;font-weight:700;margin-bottom:8px}
.step-label .hint{flex-basis:100%;padding-left:30px}
.step-label .n{display:inline-grid;place-items:center;width:22px;height:22px;border-radius:50%;background:var(--ink);color:var(--panel);font-size:12px}
.hint{color:var(--muted);font-size:13px;font-weight:400}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{border:1px solid var(--line);background:var(--chip);color:var(--ink);border-radius:999px;padding:9px 13px;font-size:15px;cursor:pointer}
.chip[aria-pressed="true"]{background:var(--ink);color:var(--panel);border-color:var(--ink)}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.field{display:flex;flex-direction:column;gap:4px;flex:1 1 140px}
.field label{font-size:13px;color:var(--muted)}
.money-in{display:flex;align-items:center;border:1px solid var(--line);border-radius:10px;background:var(--panel);overflow:hidden}
.money-in span{padding:0 8px;color:var(--muted)}
.money-in input{border:0;background:transparent;color:var(--ink);font-size:17px;padding:10px 10px 10px 0;width:100%;min-width:0}
select{border:1px solid var(--line);border-radius:10px;background:var(--panel);color:var(--ink);font-size:15px;padding:10px;width:100%}
.stepper{display:inline-flex;align-items:center;border:1px solid var(--line);border-radius:10px;overflow:hidden}
.stepper button{width:40px;height:40px;border:0;background:var(--chip);color:var(--ink);font-size:20px;cursor:pointer}
.stepper output{min-width:40px;text-align:center;font-weight:700}
.extras{display:grid;gap:8px}
.extra{display:grid;grid-template-columns:auto 1fr 110px;gap:8px;align-items:center}
.extra input[type=checkbox]{width:20px;height:20px;accent-color:var(--accent)}
.extra .money-in input{font-size:15px;padding:7px 8px 7px 0}

/* result */
.result h2{font-size:14px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin:0 0 6px}
.big{font-size:clamp(44px,11vw,68px);font-weight:900;line-height:1;color:var(--money);letter-spacing:-.03em}
.big-sub{font-size:17px;margin:6px 0 14px}
.big-sub b{color:var(--money)}
.years{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:10px 0}
.years div{background:var(--chip);border-radius:10px;padding:10px;text-align:center}
.years div span{display:block;font-size:12px;color:var(--muted)}
.years div strong{font-size:19px}
.years div.on{outline:2px solid var(--accent)}
.bar{display:flex;height:16px;border-radius:999px;overflow:hidden;background:var(--chip);margin:12px 0 6px}
.bar i{display:block;height:100%}
.legend{display:flex;flex-wrap:wrap;gap:12px;font-size:13px;color:var(--muted)}
.legend b{display:inline-block;width:10px;height:10px;border-radius:2px;margin-right:5px;vertical-align:middle}
.c-hw{background:#64748b}.c-ex{background:#0ea5e9}.c-plan{background:var(--accent)}
.actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.btn{border:0;border-radius:10px;padding:11px 15px;font-size:15px;font-weight:700;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;gap:6px}
.btn-primary{background:var(--accent);color:var(--accent-ink)}
.btn-ghost{background:var(--chip);color:var(--ink)}
.note{color:var(--muted);font-size:13px}
.toast{position:fixed;left:50%;bottom:18px;transform:translateX(-50%);background:#111827;color:#fff;padding:10px 14px;border-radius:10px;font-size:14px;opacity:0;pointer-events:none;transition:opacity .2s}
.toast.show{opacity:1}

/* compare */
.compare{margin:26px 0}
.compare h2{font-size:22px;margin:0 0 4px}
.cards{display:grid;gap:12px;margin-top:12px}
@media(min-width:760px){.cards{grid-template-columns:repeat(2,1fr)}}
.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:14px;box-shadow:var(--shadow)}
.card h3{margin:0 0 4px;font-size:17px}
.card .cost{font-weight:800;font-size:22px}
.card ul{margin:8px 0;padding-left:18px;font-size:14px}
.card .lose{color:var(--money)}
.card .keep{color:var(--good)}
.tag{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;border-radius:6px;padding:2px 6px;background:var(--chip);color:var(--muted)}
.disclosure{font-size:13px;color:var(--muted);border-left:3px solid var(--line);padding-left:10px;margin:10px 0}

/* content pages */
.doc{max-width:760px}
.doc h1{font-size:clamp(28px,5vw,40px);line-height:1.1;margin:24px 0 8px}
.doc h2{margin-top:28px}
.doc p,.doc li{font-size:17px}
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:10px;background:var(--panel)}
table{border-collapse:collapse;width:100%;font-size:14px}
th,td{padding:9px 10px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
th{background:var(--chip);font-weight:700}
.updated{color:var(--muted);font-size:13px}
.callout{background:var(--panel);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:10px;padding:12px 14px;margin:16px 0}
.cta-tool{display:inline-block;margin:10px 0}
.mbar{display:none}
@media(max-width:899px){
  .mbar{display:flex;position:fixed;left:0;right:0;bottom:0;z-index:5;background:var(--panel);border-top:1px solid var(--line);padding:10px 16px;justify-content:space-between;align-items:center;font-weight:800;text-decoration:none}
  .mbar span{color:var(--money)}
  .mbar small{color:var(--muted);font-weight:500}
  body.has-mbar{padding-bottom:62px}
}