/* Tesla VoltBench — original workbench/toolkit stylesheet.
   All classes use the tk- prefix. UI: Tahoma/Segoe UI. Numbers: Menlo/Consolas mono. */

:root {
  --tk-ui: "Tahoma", "Segoe UI", system-ui, sans-serif;
  --tk-mono: "Menlo", "Consolas", ui-monospace, monospace;

  --tk-bg: #f4f6f5;
  --tk-panel: #ffffff;
  --tk-panel-2: #eef1ef;
  --tk-ink: #14231d;
  --tk-ink-soft: #4a5b53;
  --tk-line: #d6ddd8;
  --tk-brand: #0b5138;         /* deep UK green */
  --tk-brand-ink: #06301f;
  --tk-accent: #d9772b;        /* functional amber — actions */
  --tk-accent-ink: #8a4611;
  --tk-ok: #0b6b45;
  --tk-ok-bg: #dff0e6;
  --tk-shadow: 0 1px 2px rgba(12,30,22,.08), 0 6px 18px rgba(12,30,22,.06);
  --tk-radius: 10px;
  --tk-maxw: 1120px;
}

:root[data-theme="dark"] {
  --tk-bg: #0e1512;
  --tk-panel: #16201b;
  --tk-panel-2: #1d2a23;
  --tk-ink: #e6ede9;
  --tk-ink-soft: #a4b4ab;
  --tk-line: #29372f;
  --tk-brand: #35c088;
  --tk-brand-ink: #bff3da;
  --tk-accent: #f0954a;
  --tk-accent-ink: #ffd9b8;
  --tk-ok: #4cd39a;
  --tk-ok-bg: #123326;
  --tk-shadow: 0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --tk-bg: #0e1512; --tk-panel: #16201b; --tk-panel-2: #1d2a23;
    --tk-ink: #e6ede9; --tk-ink-soft: #a4b4ab; --tk-line: #29372f;
    --tk-brand: #35c088; --tk-brand-ink: #bff3da; --tk-accent: #f0954a;
    --tk-accent-ink: #ffd9b8; --tk-ok: #4cd39a; --tk-ok-bg: #123326;
    --tk-shadow: 0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--tk-ui);
  background: var(--tk-bg);
  color: var(--tk-ink);
  line-height: 1.6;
  font-size: 17px;
}
h1, h2, h3 { line-height: 1.2; font-weight: 700; color: var(--tk-ink); }
h1 { font-size: clamp(1.7rem, 4vw, 2.5rem); letter-spacing: -.01em; margin: .2em 0 .4em; }
h2 { font-size: clamp(1.3rem, 2.6vw, 1.7rem); margin: 1.4em 0 .5em; }
h3 { font-size: 1.12rem; margin: 1.2em 0 .3em; }
a { color: var(--tk-brand); }
:root[data-theme="dark"] a { color: var(--tk-brand); }
a:hover { text-decoration: underline; }
code { font-family: var(--tk-mono); font-size: .92em; background: var(--tk-panel-2); padding: .08em .35em; border-radius: 4px; }
img, svg { max-width: 100%; }
.tk-figure { margin: 20px 0; }
.tk-newsimg { display: block; width: 100%; height: auto; border-radius: var(--tk-radius); border: 1px solid var(--tk-line); background: var(--tk-panel-2); }
.tk-newsimg__credit { margin-top: 6px; font-size: .78rem; color: var(--tk-ink-soft); }
.tk-newsimg__credit a { color: inherit; }

.tk-shell { max-width: var(--tk-maxw); margin: 0 auto; padding: 0 20px; }
.tk-skip { position: absolute; left: -999px; top: 0; background: var(--tk-brand); color: #fff; padding: 10px 16px; z-index: 100; }
.tk-skip:focus { left: 8px; top: 8px; }
:focus-visible { outline: 3px solid var(--tk-accent); outline-offset: 2px; border-radius: 4px; }

/* ---- top nav ---- */
.tk-top { border-bottom: 1px solid var(--tk-line); background: var(--tk-panel); position: sticky; top: 0; z-index: 40; }
.tk-top__row { display: flex; align-items: center; gap: 18px; min-height: 60px; }
.tk-brand { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; text-decoration: none; color: var(--tk-ink); }
.tk-brand__name b { color: var(--tk-brand); }
.tk-brand__mark { color: var(--tk-accent); display: inline-flex; }
.tk-nav { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.tk-nav a { text-decoration: none; color: var(--tk-ink-soft); padding: 8px 12px; border-radius: 8px; font-size: .95rem; }
.tk-nav a:hover { background: var(--tk-panel-2); color: var(--tk-ink); text-decoration: none; }
.tk-theme { border: 1px solid var(--tk-line); background: var(--tk-panel-2); color: var(--tk-ink); width: 40px; height: 40px; border-radius: 8px; cursor: pointer; font-size: 1.1rem; }

/* ---- glyphs ---- */
.tk-glyph { vertical-align: middle; }
.tk-eyebrow { display: inline-flex; align-items: center; gap: 8px; color: var(--tk-ink-soft); font-size: .85rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; margin: 0 0 .3em; }
.tk-eyebrow .tk-glyph { color: var(--tk-accent); }

/* ---- masthead ---- */
.tk-masthead { background: linear-gradient(160deg, var(--tk-panel) 0%, var(--tk-panel-2) 100%); border-bottom: 1px solid var(--tk-line); padding: clamp(28px, 5vw, 56px) 0; }
.tk-lede { font-size: 1.12rem; color: var(--tk-ink-soft); max-width: 60ch; }

/* ---- referral code box ---- */
.tk-codebox {
  background: var(--tk-panel); border: 1px solid var(--tk-line); border-radius: var(--tk-radius);
  padding: 18px; box-shadow: var(--tk-shadow); min-height: 232px; display: flex; flex-direction: column; gap: 12px;
}
.tk-codebox__top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.tk-codebox__label { font-weight: 700; font-size: .95rem; }
.tk-tag { font-size: .72rem; font-weight: 700; padding: 4px 8px; border-radius: 999px; white-space: nowrap; }
.tk-tag--ok { background: var(--tk-ok-bg); color: var(--tk-ok); }
.tk-codeline { display: flex; gap: 10px; align-items: stretch; }
.tk-codetext {
  flex: 1; font-family: var(--tk-mono); font-size: 1.25rem; font-weight: 700; letter-spacing: .02em;
  background: var(--tk-panel-2); border: 1px dashed var(--tk-line); border-radius: 8px; padding: 12px 14px;
  display: flex; align-items: center; overflow: hidden; text-overflow: ellipsis; min-height: 52px; color: var(--tk-ink);
}
.tk-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; cursor: pointer;
  font-family: var(--tk-ui); font-weight: 700; font-size: 1rem; border-radius: 8px; padding: 12px 16px;
  border: 1px solid transparent; text-decoration: none; text-align: center; transition: transform .05s ease;
}
.tk-btn:active { transform: translateY(1px); }
.tk-btn--go { background: var(--tk-accent); color: #241203; border-color: var(--tk-accent-ink); }
.tk-btn--go:hover { filter: brightness(1.05); text-decoration: none; }
.tk-btn--soft { background: var(--tk-panel-2); color: var(--tk-ink); border-color: var(--tk-line); }
.tk-btn--soft:hover { background: var(--tk-bg); text-decoration: none; }
.tk-copy { white-space: nowrap; min-width: 120px; }
.tk-copy.is-copied { background: var(--tk-ok); color: #fff; border-color: var(--tk-ok); }
.tk-codebox__order { width: 100%; }
.tk-codebox__fine { font-size: .82rem; color: var(--tk-ink-soft); margin: 0; }
.tk-cta { font-weight: 700; }

/* ---- blocks / prose ---- */
.tk-block { padding: 28px 0; }
.tk-blurb { color: var(--tk-ink-soft); max-width: 70ch; }
.tk-prose { max-width: 760px; padding-top: 8px; padding-bottom: 40px; }
.tk-prose p, .tk-prose li { color: var(--tk-ink); }
.tk-prose h2 { border-top: 1px solid var(--tk-line); padding-top: 1em; }
.tk-callout { background: var(--tk-ok-bg); border-left: 4px solid var(--tk-ok); padding: 12px 16px; border-radius: 6px; }

/* ---- tables ---- */
.tk-tablewrap { overflow-x: auto; }
.tk-btable, .tk-ctable { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: .96rem; }
.tk-btable th, .tk-btable td, .tk-ctable th, .tk-ctable td { text-align: left; padding: 11px 12px; border-bottom: 1px solid var(--tk-line); vertical-align: top; }
.tk-btable thead th, .tk-ctable thead th { background: var(--tk-panel-2); font-size: .85rem; text-transform: uppercase; letter-spacing: .04em; }
.tk-btable tbody th[scope="row"], .tk-ctable tbody th[scope="row"] { font-weight: 600; color: var(--tk-ink); }
.tk-ctable td { font-family: var(--tk-mono); }

/* ---- tool tabs / workbench ---- */
.tk-tabs { display: flex; gap: 6px; overflow-x: auto; padding: 6px; background: var(--tk-panel-2); border: 1px solid var(--tk-line); border-radius: 12px; margin: 8px 0 4px; }
.tk-tab { flex: 0 0 auto; text-decoration: none; color: var(--tk-ink-soft); padding: 9px 14px; border-radius: 8px; font-weight: 700; font-size: .92rem; white-space: nowrap; }
.tk-tab:hover { background: var(--tk-panel); color: var(--tk-ink); text-decoration: none; }
.tk-tab--on { background: var(--tk-brand); color: #fff; }
:root[data-theme="dark"] .tk-tab--on { color: #06201a; }

.tk-toolhead { padding-top: 22px; }
.tk-workbench { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 10px 0 4px; }
.tk-panel {
  background: var(--tk-panel); border: 1px solid var(--tk-line); border-radius: var(--tk-radius);
  padding: 20px; box-shadow: var(--tk-shadow);
}
.tk-panel__h { margin: 0 0 12px; font-size: 1.05rem; text-transform: uppercase; letter-spacing: .05em; color: var(--tk-ink-soft); }
.tk-panel--out { background: linear-gradient(180deg, var(--tk-panel) 0%, var(--tk-panel-2) 100%); }

/* ---- form fields ---- */
.tk-form { display: grid; gap: 14px; }
.tk-field { display: grid; gap: 6px; }
.tk-field__lab { font-weight: 600; font-size: .95rem; }
.tk-field__unit { color: var(--tk-ink-soft); font-weight: 400; font-size: .85rem; }
.tk-field__in {
  font-family: var(--tk-mono); font-size: 1rem; padding: 10px 12px; border-radius: 8px;
  border: 1px solid var(--tk-line); background: var(--tk-bg); color: var(--tk-ink); width: 100%;
}
select.tk-field__in { font-family: var(--tk-ui); }
.tk-field__note { font-size: .8rem; color: var(--tk-ink-soft); }
.tk-field__slider { width: 100%; accent-color: var(--tk-accent); }
.tk-field--range .tk-field__lab output { font-family: var(--tk-mono); color: var(--tk-accent-ink); font-weight: 700; }
:root[data-theme="dark"] .tk-field--range .tk-field__lab output { color: var(--tk-accent); }
.tk-assume { font-size: .8rem; color: var(--tk-ink-soft); margin: 12px 0 0; }
.tk-assume--est { font-style: italic; }

/* ---- readouts ---- */
.tk-readouts { display: grid; gap: 12px; }
.tk-readout { display: flex; flex-direction: column; gap: 2px; padding: 12px 14px; background: var(--tk-panel); border: 1px solid var(--tk-line); border-radius: 8px; }
.tk-readout__lab { font-size: .85rem; color: var(--tk-ink-soft); }
.tk-readout__val { font-family: var(--tk-mono); font-size: 1.3rem; font-weight: 700; color: var(--tk-ink); }
.tk-readout__hint { font-size: .78rem; color: var(--tk-ink-soft); }
.tk-readout--big { border: 2px solid var(--tk-accent); background: var(--tk-panel); }
.tk-readout--big .tk-readout__val { font-size: 2rem; color: var(--tk-accent-ink); }
:root[data-theme="dark"] .tk-readout--big .tk-readout__val { color: var(--tk-accent); }

/* ---- two column ---- */
.tk-twocol { display: grid; grid-template-columns: 1.5fr 1fr; gap: 20px; margin: 20px auto; max-width: var(--tk-maxw); padding: 0 20px; }
.tk-twocol--flat { max-width: none; padding: 0; }
.tk-note { color: var(--tk-ink-soft); }
.tk-side { background: var(--tk-panel-2); border: 1px solid var(--tk-line); border-radius: var(--tk-radius); padding: 20px; }
.tk-ctaline { font-weight: 600; background: var(--tk-panel-2); border: 1px solid var(--tk-line); padding: 14px 16px; border-radius: 8px; }

/* ---- steps / howto ---- */
.tk-steps { padding-left: 1.2em; display: grid; gap: 10px; }
.tk-howto .tk-steps li { padding-left: 4px; }

/* ---- faq ---- */
.tk-faq { display: grid; gap: 8px; max-width: 820px; }
.tk-qa { border: 1px solid var(--tk-line); border-radius: 8px; background: var(--tk-panel); padding: 4px 14px; }
.tk-qa summary { cursor: pointer; font-weight: 700; padding: 10px 0; }
.tk-qa p { margin: 0 0 12px; color: var(--tk-ink-soft); }

/* ---- home: calculator picker (first-screen mechanic) ---- */
.tk-picker { display: grid; grid-template-columns: repeat(auto-fit, minmax(148px, 1fr)); gap: 10px; margin-top: 24px; }
.tk-picktile { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 9px; padding: 16px 12px; background: var(--tk-panel); border: 1px solid var(--tk-line); border-radius: var(--tk-radius); text-decoration: none; color: var(--tk-ink); box-shadow: var(--tk-shadow); font-weight: 700; }
.tk-picktile:hover { border-color: var(--tk-brand); transform: translateY(-2px); transition: transform .1s ease; text-decoration: none; }
.tk-picktile__ico { color: var(--tk-brand); display: inline-flex; }
.tk-picktile__name { font-size: .9rem; line-height: 1.25; }

/* ---- home: featured (spotlight) calculator ---- */
.tk-spotlight { border-top: 3px solid var(--tk-accent); background: linear-gradient(180deg, var(--tk-panel) 0%, var(--tk-bg) 60%); border-radius: 0 0 var(--tk-radius) var(--tk-radius); }
.tk-spotlight .tk-workbench { margin-top: 4px; }
.tk-spotlight__code { max-width: 520px; margin-top: 6px; }

/* ---- tool cards grid (home) ---- */
.tk-toolgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; }
.tk-toolcard { display: flex; flex-direction: column; gap: 6px; padding: 16px; background: var(--tk-panel); border: 1px solid var(--tk-line); border-radius: var(--tk-radius); text-decoration: none; color: var(--tk-ink); box-shadow: var(--tk-shadow); }
.tk-toolcard:hover { border-color: var(--tk-brand); text-decoration: none; transform: translateY(-2px); transition: transform .1s ease; }
.tk-toolcard__ico { color: var(--tk-brand); }
.tk-toolcard__name { font-weight: 700; }
.tk-toolcard__desc { font-size: .88rem; color: var(--tk-ink-soft); }
.tk-toolcard__meta { font-size: .78rem; color: var(--tk-ink-soft); margin-top: auto; }

/* ---- crumb, disclose, related ---- */
.tk-crumb { font-size: .85rem; color: var(--tk-ink-soft); padding: 14px 0 0; }
.tk-crumb a { color: var(--tk-ink-soft); }
.tk-crumb__sep { margin: 0 8px; opacity: .5; }
.tk-disclose { font-size: .9rem; }
.tk-disclose p { background: var(--tk-panel-2); border: 1px solid var(--tk-line); border-radius: 8px; padding: 16px; color: var(--tk-ink-soft); }
.tk-related { padding: 24px 0 48px; }

/* ---- footer ---- */
.tk-foot { background: var(--tk-panel); border-top: 1px solid var(--tk-line); margin-top: 30px; padding: 34px 0 20px; }
.tk-foot__grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 26px; }
.tk-foot__brand { font-weight: 700; display: flex; align-items: center; gap: 6px; margin: 0 0 6px; }
.tk-foot__brand .tk-glyph { color: var(--tk-accent); }
.tk-foot__muted { color: var(--tk-ink-soft); font-size: .88rem; }
.tk-foot__h { font-size: .8rem; text-transform: uppercase; letter-spacing: .05em; color: var(--tk-ink-soft); margin: 0 0 8px; }
.tk-foot__list { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.tk-foot__list a { text-decoration: none; color: var(--tk-ink); font-size: .9rem; }
.tk-foot__list a:hover { text-decoration: underline; }
.tk-foot__legal { border-top: 1px solid var(--tk-line); margin-top: 22px; padding-top: 16px; color: var(--tk-ink-soft); font-size: .82rem; }
.tk-foot__legal code { font-size: .82em; }

/* ---- responsive ---- */
@media (max-width: 860px) {
  .tk-workbench, .tk-twocol, .tk-foot__grid { grid-template-columns: 1fr; }
  .tk-nav { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}