/* SellerTools — mobile-first UI for the profit calculator */
:root{
  --ink:#152029;
  --ink-soft:#3c4c59;
  --muted:#657785;
  --line:#e2e8ed;
  --line-strong:#c3d0d9;
  --surface:#fff;
  --surface-2:#f5f8f9;
  --canvas:#eef2f4;
  --accent:#0f6f62;
  --accent-dark:#0b5449;
  --accent-soft:#e2f1ee;
  --danger:#b32340;
  --danger-soft:#fdeef1;
  --focus:#c9701a;
  --radius:16px;
  --radius-sm:10px;
  --shadow:0 1px 2px rgba(21,32,41,.05),0 10px 28px -18px rgba(21,32,41,.35);
  --header-h:56px;
}
@media (prefers-color-scheme:dark){
  :root{
    --ink:#e8eef2;--ink-soft:#c3cfd8;--muted:#93a3b0;--line:#26333d;--line-strong:#3c4b57;
    --surface:#151e25;--surface-2:#111920;--canvas:#0d141a;--accent:#3ec6ad;--accent-dark:#59d9c1;
    --accent-soft:#12302c;--danger:#ff8095;--danger-soft:#2a151b;--focus:#f0a44b;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 12px 30px -20px rgba(0,0,0,.9);
  }
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;background:var(--canvas);color:var(--ink);
  font-family:system-ui,-apple-system,BlinkMacSystemFont,"Noto Sans Thai","Segoe UI",sans-serif;
  font-size:16px;line-height:1.6;overflow-wrap:break-word;
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip-link{position:absolute;left:-9999px;top:0;z-index:60;background:var(--accent);color:#fff;padding:10px 16px;border-radius:0 0 var(--radius-sm) 0;text-decoration:none;font-weight:600}
.skip-link:focus{left:0}

/* ---------- shell ---------- */
main,.site-footer{width:min(100% - 32px,1080px);margin-inline:auto}
.site-header{
  position:sticky;top:0;z-index:30;min-height:var(--header-h);
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:8px max(16px,calc(50% - 540px));
  background:var(--canvas);border-bottom:1px solid var(--line);
}
.site-header a{color:var(--ink);text-decoration:none}
.brand{font-weight:750;letter-spacing:-.025em;font-size:1.02rem;display:inline-flex;align-items:center;gap:8px;white-space:nowrap}
.brand-mark{
  width:26px;height:26px;flex:0 0 26px;border-radius:8px;display:grid;place-items:center;
  background:var(--accent);color:#fff;font-size:.78rem;font-weight:800;letter-spacing:-.04em;
}
@media (prefers-color-scheme:dark){.brand-mark{color:#0d141a}}
.header-nav{display:flex;gap:14px;align-items:center;font-size:.92rem}
.header-nav a{color:var(--accent);text-decoration:none;font-weight:600;white-space:nowrap}
.header-nav a:hover{text-decoration:underline;text-underline-offset:3px}

/* ---------- hero ---------- */
.intro{padding:18px 0 14px}
.intro h1,.page-content h1{
  font-size:clamp(1.35rem,4.4vw,2.1rem);line-height:1.3;letter-spacing:-.025em;margin:0 0 6px;
}
.intro p{color:var(--muted);margin:0;font-size:.95rem}
.trust-row{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0 0;padding:0;list-style:none}
.trust-row li{
  font-size:.76rem;color:var(--ink-soft);background:var(--surface);
  border:1px solid var(--line);border-radius:999px;padding:3px 10px;white-space:nowrap;
}

/* ---------- calculator shell ---------- */
.calculator{
  background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  box-shadow:var(--shadow);display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);
}
.form-column{border-radius:var(--radius) 0 0 var(--radius)}
.results{border-radius:0 var(--radius) var(--radius) 0}
.form-column{padding:18px;min-width:0}
.results{padding:18px;border-left:1px solid var(--line);background:var(--surface-2);min-width:0}
.calculator h2{font-size:1.02rem;line-height:1.4;margin:0 0 4px;letter-spacing:-.01em}
.form-note,.field-help,.small-note{margin:0;color:var(--muted);font-size:.8rem;line-height:1.5}
.form-note{margin-bottom:14px}

/* ---------- live summary (phones only) ---------- */
.live-summary{display:none}
@media (max-width:860px){
  .live-summary{
    position:sticky;top:var(--header-h);z-index:20;
    margin:0 0 14px;padding:8px 12px;
    background:var(--accent-soft);border:1px solid var(--line);border-radius:var(--radius-sm);
    box-shadow:0 6px 18px -14px rgba(21,32,41,.6);
    display:none;align-items:center;justify-content:space-between;gap:10px;
  }
  .live-summary.is-live{display:flex}
}
.live-label{display:block;font-size:.72rem;color:var(--muted);line-height:1.3}
.live-value{
  display:block;font-size:1.3rem;font-weight:770;letter-spacing:-.03em;
  font-variant-numeric:tabular-nums;line-height:1.25;
}
.live-meta{display:flex;gap:14px;margin:0;text-align:right}
.live-meta div{min-width:0}
.live-meta dt{font-size:.68rem;color:var(--muted);line-height:1.2}
.live-meta dd{margin:0;font-size:.86rem;font-weight:700;font-variant-numeric:tabular-nums}

/* ---------- form ---------- */
.field{border:0;padding:0;margin:0 0 14px;min-width:0}
.field:last-of-type{margin-bottom:0}
.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 12px}
.field-grid .field.span-2{grid-column:1 / -1}
.field label,.field legend{
  font-weight:640;display:block;margin:0 0 5px;font-size:.87rem;color:var(--ink-soft);padding:0;
}
.field .field-help{margin:5px 0 0}
.req{color:var(--accent)}
.input-unit{position:relative;display:block}
.input-unit .unit{
  position:absolute;right:12px;top:50%;transform:translateY(-50%);
  color:var(--muted);font-size:.82rem;pointer-events:none;
}
.input-unit input{padding-right:46px}
input,select{
  width:100%;background:var(--surface);border:1px solid var(--line-strong);border-radius:var(--radius-sm);
  color:var(--ink);font:inherit;font-size:16px;min-height:46px;padding:9px 12px;
  transition:border-color .15s,box-shadow .15s;
}
input::placeholder{color:var(--muted);opacity:.6}
input:hover,select:hover{border-color:var(--accent)}
input:focus-visible,select:focus-visible,button:focus-visible,a:focus-visible,summary:focus-visible{
  outline:3px solid var(--focus);outline-offset:2px;
}
input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
input[aria-invalid=true]{border-color:var(--danger);background:var(--danger-soft)}
.fee-row{display:flex;gap:8px;align-items:stretch}
.fee-input{flex:1 1 auto;min-width:0}
.fee-row select{flex:0 0 92px;width:92px;padding-inline:10px}
.error{color:var(--danger);font-size:.8rem;margin:0;line-height:1.4}
.error:not(:empty){margin-top:5px}
.hint-box{
  border:1px solid var(--line);border-radius:var(--radius-sm);padding:9px 12px;
  background:var(--surface-2);margin-top:14px;
}
.hint-box summary{font-size:.83rem;font-weight:600;color:var(--muted)}
.hint-box p{margin:7px 0 0}

.actions{display:flex;flex-wrap:wrap;align-items:center;gap:10px 16px;margin-top:16px}
.primary-button{
  border:0;border-radius:var(--radius-sm);background:var(--accent);color:#fff;font:inherit;
  font-weight:700;min-height:48px;padding:10px 24px;cursor:pointer;transition:background .15s,transform .05s;
}
@media (prefers-color-scheme:dark){.primary-button{color:#08110f}}
.primary-button:hover{background:var(--accent-dark)}
.primary-button:active{transform:translateY(1px)}
.secondary-actions{display:flex;gap:16px;margin-left:auto}
.text-button{
  background:none;border:0;padding:6px 0;cursor:pointer;font:inherit;font-size:.9rem;
  color:var(--accent);text-decoration:underline;text-underline-offset:3px;
}

/* ---------- results ---------- */
.results-empty{color:var(--muted)}
.results-empty p{margin:6px 0 0;font-size:.9rem}
.profit-label{font-size:.85rem;color:var(--muted);margin:0}
.profit{
  font-weight:780;font-size:clamp(1.8rem,5.5vw,2.4rem);letter-spacing:-.04em;line-height:1.15;
  margin:2px 0;font-variant-numeric:tabular-nums;
}
.negative,.loss-note{color:var(--danger)}
#profit-status{margin:0;font-size:.8rem;color:var(--muted)}
.loss-note{
  font-weight:600;font-size:.85rem;margin:10px 0 0;background:var(--danger-soft);
  border-radius:var(--radius-sm);padding:8px 10px;
}
.metrics{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:14px 0 0}
.metrics div{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:8px 10px;min-width:0}
.metrics dt,.breakdown dt{color:var(--muted);font-size:.78rem}
.metrics dd{font-size:1.05rem;font-weight:720;margin:1px 0 0;font-variant-numeric:tabular-nums;letter-spacing:-.02em}
.breakdown{display:grid;gap:6px;margin:14px 0 0}
.breakdown div{display:flex;justify-content:space-between;gap:12px;font-size:.87rem}
.breakdown dd{font-variant-numeric:tabular-nums;margin:0;font-weight:650;text-align:right}
.scenario-toggle{margin-top:14px;border-top:1px solid var(--line);padding-top:12px}
.scenario-toggle summary{font-size:.9rem}
.table-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse;margin-top:8px;font-variant-numeric:tabular-nums;font-size:.87rem}
th,td{padding:7px 0;border-bottom:1px solid var(--line);text-align:right;white-space:nowrap}
th:first-child,td:first-child{text-align:left;font-weight:600}
thead{color:var(--muted);font-size:.8rem}
tbody tr:last-child th,tbody tr:last-child td{border-bottom:0}

/* ---------- content / FAQ ---------- */
.content{width:min(100%,760px);margin:22px auto 32px}
.content p{margin:0 0 12px;color:var(--ink-soft);font-size:.93rem}
.content details{
  border:1px solid var(--line);border-radius:var(--radius-sm);background:var(--surface);
  padding:10px 13px;margin-top:6px;
}
.content details[open]{box-shadow:var(--shadow)}
.content details p{margin:8px 0 0;font-size:.9rem}
.plain-list{margin:8px 0 0;padding-left:1.25em;color:var(--ink-soft);font-size:.9rem}
.plain-list li{margin:0 0 5px}
.plain-list li:last-child{margin-bottom:0}
.plain-list strong{color:var(--ink);font-weight:700}
.content details .formula{margin-top:10px}
.content summary h3{display:inline;margin:0;font-size:.93rem;font-weight:640;line-height:1.45}
summary{cursor:pointer;font-weight:640;font-size:.93rem}
.content .section-fold{border:0;background:none;padding:0;margin:0;box-shadow:none}
.content .section-fold>summary{
  display:flex;align-items:baseline;gap:10px;flex-wrap:wrap;padding:4px 0;list-style:none;
}
.content .section-fold>summary::-webkit-details-marker{display:none}
.content .section-fold>summary::before{content:"\25B8";color:var(--muted);font-size:.95rem}
.content .section-fold[open]>summary::before{content:"\25BE"}
.content .section-fold>summary h2{display:inline;margin:0;font-size:1.08rem;letter-spacing:-.015em}
.fold-hint{font-size:.78rem;color:var(--muted);font-weight:400}
.section-fold-body{margin-top:8px}
.formula{
  background:var(--surface-2);border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:12px 14px;font-size:.88rem;line-height:1.95;color:var(--ink-soft);
}
.page-content{min-height:42vh;margin-top:20px}
.page-content h1{margin-bottom:12px}
.page-content h2{font-size:1.05rem;margin:20px 0 6px}
.not-found{text-align:center}
.inline-button{display:inline-block;text-decoration:none;margin-top:12px}

/* ---------- footer ---------- */
.site-footer{
  border-top:1px solid var(--line);margin-top:8px;padding:16px 0 28px;color:var(--muted);
  font-size:.84rem;display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;
}
.site-footer p{margin:0}
.site-footer nav{display:flex;gap:16px;flex-wrap:wrap}
.site-footer a{color:var(--accent);text-decoration:none}
.site-footer a:hover{text-decoration:underline;text-underline-offset:3px}

/* ---------- responsive ---------- */
@media (max-width:860px){
  .calculator{grid-template-columns:1fr}
  .form-column{border-radius:var(--radius) var(--radius) 0 0}
  .results{border-left:0;border-top:1px solid var(--line);border-radius:0 0 var(--radius) var(--radius)}
}
@media (max-width:560px){
  main,.site-footer{width:min(100% - 24px,1080px)}
  .intro{padding:14px 0 12px}
  .form-column,.results{padding:16px 14px}
  .field{margin-bottom:12px}
  .field-grid{gap:0 10px}
  .secondary-actions{margin-left:0;width:100%;justify-content:space-between}
  .primary-button{width:100%}
  .content{margin:18px auto 24px}
}
@media (max-width:339px){
  .field-grid{grid-template-columns:1fr}
  .live-meta{gap:10px}
}