/* Big Dog Mining - shared calculator theme.
   Every calculator links this file. Do not restyle in a calculator; change it
   here so the whole set moves together. Tokens are taken from the Big Dog
   Mining landing page: near-black ground, amber accent, heavy uppercase
   headings, generous letter-spacing on labels. */

:root{
  /* Dark is the default. Ground is pure black; cards lift off it. */
  --bdm-bg:        #000000;
  --bdm-surface:   #121212;
  --bdm-surface-2: #1c1c1c;
  --bdm-line:      #2b2b2b;
  --bdm-ink:       #ffffff;
  --bdm-mute:      #9a9a9a;
  --bdm-accent:    #efa94a;   /* amber */
  --bdm-accent-dk: #d9933a;
  --bdm-warn:      #efa94a;
  --bdm-on-accent: #000000;   /* text sitting on an amber fill */
  --bdm-radius:    10px;
  --bdm-sans: "Inter","Helvetica Neue",-apple-system,BlinkMacSystemFont,"Segoe UI",system-ui,sans-serif;
  /* Heavy condensed-ish display stack. No webfont dependency: these
     calculators are handed out as single files and must render offline. */
  --bdm-display: "Archivo Black","Arial Black","Helvetica Neue",Impact,var(--bdm-sans);
}

/* Light theme. Same amber, darkened just enough to hold contrast on white. */
:root[data-theme="light"]{
  --bdm-bg:        #ffffff;
  --bdm-surface:   #f7f8f9;
  --bdm-surface-2: #ffffff;
  --bdm-line:      #e1e5ea;
  --bdm-ink:       #14181d;
  --bdm-mute:      #5f6b78;
  --bdm-accent:    #c07d18;
  --bdm-accent-dk: #a4690f;
  --bdm-warn:      #c07d18;
  --bdm-on-accent: #ffffff;
}

*{box-sizing:border-box}

body{
  margin:0; background:var(--bdm-bg); color:var(--bdm-ink);
  font:15px/1.55 var(--bdm-sans);
  -webkit-font-smoothing:antialiased;
}

.bdm-wrap{max-width:1040px;margin:0 auto;padding:26px 20px 72px}

/* --- masthead ------------------------------------------------------------ */
.bdm-mast{position:relative;text-align:center;padding:4px 0 26px;
  border-bottom:1px solid var(--bdm-line);margin-bottom:28px}
.bdm-logo{
  display:inline-block;
  font-family:var(--bdm-display);font-size:15px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--bdm-ink);text-decoration:none;
}

/* Theme toggle. Sits out of the way; the wordmark stays the only mark. */
.bdm-theme{
  position:absolute;top:0;right:0;
  background:var(--bdm-surface-2);border:1px solid var(--bdm-line);
  color:var(--bdm-mute);border-radius:999px;padding:6px 13px;
  font:inherit;font-size:12px;letter-spacing:.08em;text-transform:uppercase;
  cursor:pointer;
}
.bdm-theme:hover{color:var(--bdm-accent);border-color:var(--bdm-accent)}
@media(max-width:640px){.bdm-theme{position:static;margin:0 0 14px}}

h1{
  font-family:var(--bdm-display);font-weight:900;
  font-size:clamp(26px,4vw,40px);line-height:1.05;letter-spacing:-.01em;
  text-transform:uppercase;margin:10px 0 6px;
}
.bdm-rule{width:56px;height:3px;background:var(--bdm-accent);margin:16px auto 0;border-radius:2px}
.bdm-sub{color:var(--bdm-mute);margin:14px auto 0;max-width:66ch;text-align:center}

/* --- cards --------------------------------------------------------------- */
.bdm-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}
@media(max-width:860px){.bdm-grid{grid-template-columns:1fr}}

.bdm-card{
  background:var(--bdm-surface);border:1px solid var(--bdm-line);
  border-radius:var(--bdm-radius);padding:20px;
}
.bdm-card h2{
  font-size:11.5px;text-transform:uppercase;letter-spacing:.16em;
  color:var(--bdm-accent);margin:0 0 4px;font-weight:700;
}
.bdm-card .hint{font-size:13px;color:var(--bdm-mute);margin:0 0 16px}

label{display:block;margin:0 0 15px}
.lbl{display:flex;align-items:center;gap:6px;font-size:13px;font-weight:600;
     margin-bottom:2px;letter-spacing:.02em}
.help{font-size:12.5px;color:var(--bdm-mute);margin:0 0 6px;line-height:1.45}

input,select{
  width:100%;padding:9px 10px;border:1px solid var(--bdm-line);
  border-radius:7px;font:inherit;background:var(--bdm-surface-2);color:var(--bdm-ink);
}
input:focus,select:focus{outline:none;border-color:var(--bdm-accent);
  box-shadow:0 0 0 2px rgba(239,169,74,.18)}
select option{background:var(--bdm-surface-2);color:var(--bdm-ink)}
::placeholder{color:var(--bdm-mute);opacity:.7}

.row{display:grid;grid-template-columns:1fr 1fr;gap:12px}

/* Unit chip, pinned to the right of a field label. A number box with no unit
   on it is an invitation to type feet into a metres field. */
.unit{margin-left:auto;padding-left:10px;font-size:11.5px;font-weight:700;
  letter-spacing:.06em;color:var(--bdm-accent);text-transform:none;white-space:nowrap}

.q{display:inline-flex;align-items:center;justify-content:center;width:15px;height:15px;
   border-radius:50%;background:var(--bdm-line);color:var(--bdm-accent);font-size:10px;
   font-weight:800;cursor:help;flex:none}
.auto{font-size:10.5px;background:rgba(239,169,74,.15);color:var(--bdm-accent);
  padding:1px 7px;border-radius:10px;font-weight:700;letter-spacing:.04em}

/* --- banner -------------------------------------------------------------- */
.bdm-banner{display:block;width:100%;height:auto;border-radius:var(--bdm-radius);
  border:1px solid var(--bdm-line);margin:0 0 24px;object-fit:cover;aspect-ratio:4/1}

/* --- live diagram -------------------------------------------------------- */
/* Redrawn from the same numbers the working table prints, so a wrong figure
   shows up as a wrong picture rather than hiding in a column. */
.bdm-figure{background:var(--bdm-surface);border:1px solid var(--bdm-line);
  border-radius:var(--bdm-radius);padding:18px 20px 14px;margin-top:20px}
.bdm-figure h3{font-size:11.5px;text-transform:uppercase;letter-spacing:.16em;
  color:var(--bdm-accent);margin:0 0 14px;font-weight:700}
.bdm-figure svg{display:block;width:100%;height:auto;overflow:visible}
.bdm-figs{display:grid;grid-template-columns:1fr 1fr;gap:20px}
@media(max-width:860px){.bdm-figs{grid-template-columns:1fr}}

/* SVG parts. Kept as classes so both themes move together. */
.f-ground{fill:var(--bdm-surface-2);stroke:var(--bdm-line);stroke-width:1}
.f-rock{fill:var(--bdm-surface-2)}
.f-line{stroke:var(--bdm-line);stroke-width:1;fill:none}
.f-edge{stroke:var(--bdm-mute);stroke-width:1.5;fill:none}
.f-accent{stroke:var(--bdm-accent);stroke-width:2;fill:none}
.f-fill{fill:var(--bdm-accent)}
.f-fill-soft{fill:var(--bdm-accent);opacity:.28}
.f-stem{fill:var(--bdm-mute);opacity:.35}
.f-dash{stroke:var(--bdm-mute);stroke-width:1;stroke-dasharray:4 4;fill:none}
.f-warn{stroke:var(--bdm-warn);stroke-width:2;fill:none}
.f-t{fill:var(--bdm-mute);font:600 10px var(--bdm-sans);letter-spacing:.04em}
.f-t-ink{fill:var(--bdm-ink);font:700 11px var(--bdm-sans)}
.f-t-accent{fill:var(--bdm-accent);font:700 11px var(--bdm-sans)}
.f-dim{stroke:var(--bdm-mute);stroke-width:1;fill:none;marker-start:url(#ar);marker-end:url(#ar)}
.f-move{animation:bdmflow 2.4s linear infinite}
@keyframes bdmflow{to{stroke-dashoffset:-28}}
@media(prefers-reduced-motion:reduce){.f-move{animation:none}}

/* --- results ------------------------------------------------------------- */
.bdm-out{background:var(--bdm-surface);border:1px solid var(--bdm-line);
  border-radius:var(--bdm-radius);padding:20px;margin-top:20px}
.bdm-big{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:6px}
@media(max-width:860px){.bdm-big{grid-template-columns:1fr}}
.metric{padding:15px 16px;background:var(--bdm-surface-2);border-radius:8px;
  border-left:3px solid var(--bdm-accent)}
.metric .v{font-family:var(--bdm-display);font-size:28px;color:var(--bdm-accent);
  font-variant-numeric:tabular-nums;line-height:1.1}
.metric .l{font-size:11px;color:var(--bdm-mute);text-transform:uppercase;letter-spacing:.11em;margin-top:3px}

table{width:100%;border-collapse:collapse;font-size:13.5px;margin-top:12px}
th,td{text-align:left;padding:7px 8px;border-bottom:1px solid var(--bdm-line)}
th{font-size:11px;color:var(--bdm-mute);text-transform:uppercase;letter-spacing:.1em}
td.n{text-align:right;font-variant-numeric:tabular-nums}
.cite{font-size:12px;color:var(--bdm-mute)}

.bdm-note{margin-top:20px;padding:14px 16px;border-left:3px solid var(--bdm-warn);
  background:rgba(239,169,74,.07);font-size:13px;border-radius:0 8px 8px 0}

details{margin-top:20px;background:var(--bdm-surface);border:1px solid var(--bdm-line);
  border-radius:var(--bdm-radius);padding:14px 18px}
summary{cursor:pointer;font-weight:700;font-size:13.5px;letter-spacing:.02em}
summary::marker{color:var(--bdm-accent)}

/* --- CTA + footer -------------------------------------------------------- */
.bdm-cta{text-align:center;margin-top:34px;padding:28px 20px;
  background:var(--bdm-surface);border:1px solid var(--bdm-line);border-radius:var(--bdm-radius)}
.bdm-cta h3{font-family:var(--bdm-display);text-transform:uppercase;font-size:20px;
  margin:0 0 8px;letter-spacing:.01em}
.bdm-cta p{color:var(--bdm-mute);margin:0 0 18px;font-size:14px}
.bdm-btn{display:inline-block;background:var(--bdm-accent);color:var(--bdm-on-accent);
  font-weight:700;text-decoration:none;padding:13px 30px;border-radius:999px;
  font-size:15px;letter-spacing:.01em}
.bdm-btn:hover{background:var(--bdm-accent-dk)}

.bdm-foot{margin-top:26px;font-size:12px;color:var(--bdm-mute);
  border-top:1px solid var(--bdm-line);padding-top:16px;line-height:1.65}
.bdm-foot strong{color:var(--bdm-ink);opacity:.85}
.bdm-by{margin-top:14px;font-size:11.5px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--bdm-mute);text-align:center}
.bdm-by b{color:var(--bdm-accent);font-weight:700}

/* Legal notice. Deliberately always visible rather than tucked behind a
   <details>: a disclaimer of warranty and a limitation of liability only do
   their job if they are conspicuous, and a collapsed one is not. Quiet, not
   hidden. Tokens only, so it moves with both themes. */
.bdm-legal{margin-top:22px;padding-top:16px;border-top:1px solid var(--bdm-line);
  font-size:11.5px;line-height:1.7;color:var(--bdm-mute)}
.bdm-legal h4{margin:0 0 8px;font-family:var(--bdm-display);font-size:12px;
  letter-spacing:.14em;text-transform:uppercase;color:var(--bdm-ink);opacity:.9}
.bdm-legal p{margin:0 0 8px}
.bdm-legal strong{color:var(--bdm-ink);opacity:.85}