/* ============================================================
   App components — THEME-NEUTRAL.
   Every color / shadow / radius / glow value comes from
   style/tokens.css. This file must stay byte-identical across
   themed builds (engineering-desktop, bds-desktop); to restyle,
   swap tokens.css only.
   ============================================================ */

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, "Segoe UI", system-ui, -apple-system, sans-serif;
  line-height: 1.45;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

/* --- The signature glow: full-bleed, behind everything, static.
       Themes without a glow set --glow-layer: none. --- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background: var(--glow-layer);
}

/* ============================================================
   App shell — sidebar + panel host
   ============================================================ */
.app {
  display: grid;
  grid-template-columns: 264px 1fr;
  min-height: 100vh;
}

/* --- Sidebar --- */
.sidebar {
  background: var(--sidebar-bg);
  border-right: 1px solid var(--sidebar-line);
  padding: 22px 14px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

/* Brand block. Themes can turn it into a full-bleed band (e.g. a white
   plate for a light-background logo) via the --brand-* tokens. */
.sidebar__brand {
  padding: var(--brand-pad);
  margin: var(--brand-margin);
  background: var(--brand-bg);
}
.sidebar__brand h1 {
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.2px;
  margin: 0;
  color: var(--brand-ink);
}
.sidebar__brand p {
  margin: 4px 0 0;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.4px;
  color: var(--brand-dim);
}
.sidebar__logo {
  display: block;
  max-width: 100%;
  height: auto;
  margin-bottom: 6px;
}

.nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.nav__label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.6px;
  color: var(--sidebar-dim);
  padding: 0 10px 6px;
}
.nav__item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border: 0;
  border-left: 3px solid transparent;
  background: transparent;
  color: var(--sidebar-muted);
  font: inherit;
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  border-radius: var(--radius-small);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.nav__item:hover { background: var(--sidebar-hover); color: var(--sidebar-ink); }
.nav__item--active {
  background: var(--sidebar-active-bg);
  color: var(--sidebar-active-ink);
  border-left-color: var(--sidebar-accent);
  border-radius: 0 var(--radius-small) var(--radius-small) 0;
}
.nav__item .icon { width: 18px; text-align: center; opacity: 0.9; }

.sidebar__foot {
  margin-top: auto;
  padding: 10px;
  font-size: 11px;
  color: var(--sidebar-dim);
}

/* --- Panel host / main --- */
.host {
  padding: 34px 40px 60px;
  max-width: 1040px;
}

.panel__head { margin-bottom: 26px; }
.panel__head h2 {
  margin: 0;
  font-size: 26px;
  font-weight: 500;
  letter-spacing: -0.2px;
  color: var(--gold);
}
.panel__head p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 14px;
  max-width: 62ch;
}

/* ============================================================
   Components
   ============================================================ */
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 22px;
}
.card + .card { margin-top: 20px; }

.card__title {
  margin: 0 0 16px;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.4px;
  color: var(--dim);
  font-weight: 500;
}

.grid { display: grid; gap: 16px; }
.grid--2 { grid-template-columns: 1fr 1fr; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 720px) {
  .grid--2, .grid--3 { grid-template-columns: 1fr; }
}

/* --- Form controls --- */
.field { display: flex; flex-direction: column; gap: 6px; }
.field label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
}
.input, .select {
  background: var(--inset);
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  color: var(--ink);
  font: inherit;
  font-size: 15px;
  padding: 10px 12px;
  width: 100%;
}
.input:focus, .select:focus {
  outline: none;
  border-color: var(--gold);
}
.select { cursor: pointer; }
.input--error { border-color: var(--danger); }

/* --- Segmented system toggle --- */
.seg {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: var(--radius-btn);
  overflow: hidden;
  background: var(--inset);
}
.seg button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  padding: 8px 18px;
  cursor: pointer;
}
.seg button.is-on { background: var(--panel2); color: var(--ink); }

/* --- Buttons --- */
.btn {
  border: 0;
  border-radius: var(--radius-btn);
  font: inherit;
  font-size: 14px;
  font-weight: 500;
  padding: 11px 22px;
  cursor: pointer;
}
.btn--primary { background: var(--orange); color: var(--btn-primary-ink); }
.btn--primary:hover { filter: brightness(1.06); }
.btn--secondary {
  background: var(--panel2);
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn--secondary:hover { filter: brightness(1.1); }

/* --- Result / stat cards --- */
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
@media (max-width: 720px) { .stats { grid-template-columns: 1fr; } }

.stat {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 16px 18px;
}
.stat__label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.4px;
  color: var(--dim);
}
.stat__value {
  margin-top: 6px;
  font-size: 22px;
  font-weight: 500;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

/* The headline computed number — accent, no per-element glow */
.result {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 22px 24px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
.result__num {
  font-size: 40px;
  font-weight: 600;
  color: var(--result-ink);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.5px;
}
.result__num--success { color: var(--cyan); }   /* rare zero/exact-fit state */
.result__meta { color: var(--muted); font-size: 14px; text-align: right; }

/* --- Category pill --- */
.pill {
  display: inline-block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  color: var(--muted);
}
.pill--clearance    { color: var(--gold); border-color: var(--gold-border); }
.pill--transition   { color: var(--muted); }
.pill--interference { color: var(--accent2-text); border-color: var(--orange-border); }
.pill--success      { color: var(--cyan); border-color: var(--cyan-border); }

/* --- Definitions: two-layer --- */
.def__plain { color: var(--ink); font-size: 15px; }
.def__toggle {
  margin-top: 10px;
  background: none;
  border: 0;
  color: var(--gold);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
  padding: 0;
}
.def__mechanics {
  margin-top: 10px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}
.def__mechanics[hidden] { display: none; }
.def__mechanics dl { margin: 0; display: grid; grid-template-columns: auto 1fr; gap: 4px 14px; }
.def__mechanics dt { color: var(--gold); font-weight: 500; }
.def__mechanics dd { margin: 0; }

/* --- Notices --- */
.notice {
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  padding: 12px 14px;
  font-size: 13px;
  color: var(--muted);
  background: var(--inset-soft);
}
.notice--warn { border-color: var(--danger-border); color: var(--danger); }
.notice strong { color: var(--ink); font-weight: 500; }

.help { color: var(--dim); font-size: 12px; margin-top: 4px; }

.hidden { display: none !important; }

/* ============================================================
   Nomenclature decoder — token chips, spectrum, comparison
   ============================================================ */
.decoder__tokens {
  display: flex;
  align-items: stretch;
  gap: 8px;
  flex-wrap: wrap;
  margin: 4px 0 18px;
}
.tok {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 46px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  background: var(--inset);
}
.tok__char { font-size: 24px; font-weight: 600; line-height: 1; font-variant-numeric: tabular-nums; }
.tok__tag {
  margin-top: 6px;
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--dim);
}
.tok--letter .tok__char { color: var(--gold); }
.tok--grade  .tok__char { color: var(--muted); }
.tok--sep {
  border: none;
  background: none;
  min-width: 0;
  padding: 8px 2px;
  color: var(--dim);
}
.tok--sep .tok__char { color: var(--dim); font-weight: 400; }

/* per-token explanation list */
.decoder__rows { display: grid; grid-template-columns: auto 1fr; gap: 8px 16px; margin: 0; }
.decoder__rows dt {
  color: var(--gold);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.decoder__rows dd { margin: 0; color: var(--muted); font-size: 14px; }

/* IT grade comparison chips */
.grades {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}
.grade-chip {
  border: 1px solid var(--line);
  border-radius: var(--radius-small);
  padding: 8px 12px;
  min-width: 78px;
  background: var(--inset-soft);
}
.grade-chip__k { font-size: 11px; color: var(--dim); text-transform: uppercase; letter-spacing: 1px; }
.grade-chip__v { margin-top: 3px; font-size: 16px; color: var(--ink); font-variant-numeric: tabular-nums; }
.grade-chip--on { border-color: var(--gold-border-strong); }
.grade-chip--on .grade-chip__v { color: var(--gold); }

/* clearance -> transition -> interference spectrum */
.spectrum { margin-top: 18px; }
.spectrum__bar { display: flex; border-radius: var(--radius-small); overflow: hidden; border: 1px solid var(--line); }
.spectrum__seg {
  flex: 1;
  padding: 8px 6px;
  text-align: center;
  font-size: 11px;
  color: var(--muted);
  border-right: 1px solid var(--line);
  background: var(--inset-soft2);
}
.spectrum__seg:last-child { border-right: none; }
.spectrum__seg b { display: block; font-size: 13px; color: var(--ink); font-weight: 600; }
.spectrum__seg--on { background: var(--panel2); }
.spectrum__seg--on b { color: var(--gold); }
.spectrum__note { margin-top: 8px; color: var(--dim); font-size: 12px; }

/* general primer + comparison */
.primer p { color: var(--muted); font-size: 14px; margin: 0 0 12px; }
.compare {
  width: 100%;
  border-collapse: collapse;
  margin-top: 8px;
  font-size: 13px;
}
.compare th, .compare td {
  text-align: left;
  padding: 8px 10px;
  border-top: 1px solid var(--line);
  vertical-align: top;
}
.compare th { color: var(--dim); font-weight: 500; text-transform: uppercase; letter-spacing: 0.6px; font-size: 11px; }
.compare td:first-child { color: var(--gold); white-space: nowrap; }
.compare td { color: var(--muted); }

.family-list { display: grid; gap: 8px; margin-top: 4px; }
.family {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 12px;
  align-items: baseline;
  padding: 8px 0;
  border-top: 1px solid var(--line);
}
.family__code { color: var(--gold); font-weight: 600; }
.family--on { background: var(--row-hover); border-radius: var(--radius-small); padding: 8px 10px; }
.family__name { color: var(--ink); font-size: 14px; }
.family__note { color: var(--dim); font-size: 12px; }

/* ============================================================
   RPN calculator — stack display + keypad
   ============================================================ */
.rpn { max-width: 460px; }
.rpn:focus { outline: none; }
.rpn:focus-within { border-color: var(--gold); } /* show the panel owns the keyboard */

.rpn__modes {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  align-items: end;
  margin-bottom: 16px;
}
.rpn__modes .field { gap: 6px; }

/* readout — inset, monospace, calculator-like */
.rpn__display {
  background: var(--inset-strong);
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  padding: 12px 14px;
  font-family: "SF Mono", ui-monospace, "Cascadia Code", Consolas, monospace;
  font-variant-numeric: tabular-nums;
}
.rpn__stack {
  max-height: 168px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.rpn__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 14px;
}
.rpn__lvl { color: var(--dim); font-size: 12px; }
.rpn__val {
  color: var(--ink);
  font-size: 20px;
  overflow-wrap: anywhere;
  text-align: right;
}
.rpn__val--zero { color: var(--cyan); } /* kit rule: success slot == zero/success only */
.rpn__empty { color: var(--dim); font-size: 13px; padding: 6px 0; }

.rpn__cmdline {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
  min-height: 30px;
  font-size: 22px;
  color: var(--gold);
  text-align: right;
  word-break: break-all;
}
.rpn__cmdline--error { color: var(--danger); font-size: 15px; }
.rpn__caret {
  display: inline-block;
  width: 2px;
  height: 20px;
  vertical-align: -3px;
  margin-left: 1px;
  background: var(--gold);
  animation: rpn-blink 1.05s step-end infinite;
}
@keyframes rpn-blink { 50% { opacity: 0; } }

/* keypad */
.rpn__keypad {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin-top: 16px;
}
.rpn-key {
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  padding: 12px 0;
  font: inherit;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink);
  background: var(--inset);
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, filter 0.12s;
}
.rpn-key:hover { background: var(--panel2); }
.rpn-key:active { filter: brightness(1.15); }
.rpn-key--wide { grid-column: span 2; }

.rpn-key--num { color: var(--ink); }
.rpn-key--fn { color: var(--muted); font-size: 14px; }
.rpn-key--op { color: var(--gold); border-color: var(--gold-border-soft); }
.rpn-key--act { color: var(--dim); font-size: 13px; }
.rpn-key--ent { background: var(--orange); color: var(--btn-primary-ink); border-color: transparent; }
.rpn-key--ent:hover { background: var(--orange); filter: brightness(1.06); }

/* ============================================================
   Fraction / Decimal / mm chart
   ============================================================ */
.fchart-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}
@media (max-width: 720px) { .fchart-wrap { grid-template-columns: 1fr; } }

.fchart {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
  font-size: 14px;
}
.fchart th {
  text-align: right;
  padding: 0 8px 8px;
  font-size: 10px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--dim);
  border-bottom: 1px solid var(--line);
}
.fchart th:first-child { text-align: left; }
.fchart td {
  padding: 5px 8px;
  text-align: right;
  color: var(--muted);
  border-top: 1px solid var(--line-faint);
}
.fchart__frac { text-align: left; color: var(--ink); font-weight: 500; }
.fchart__dec { color: var(--muted); }
.fchart__mm { color: var(--dim); }
.fchart tbody tr:hover td,
.fchart tr:hover td { background: var(--row-hover); }

/* the "round" fractions (eighths and simpler) — accent, with a divider above
   to reproduce the source chart's visual grouping */
.fchart tr.is-eighth td { border-top: 1px solid var(--gold-border-div); }
.fchart tr.is-eighth .fchart__frac { color: var(--gold); font-weight: 600; }

.fchart-notes {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}
.fchart-note {
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  padding: 5px 14px;
  font-size: 13px;
  color: var(--muted);
  background: var(--inset-soft);
  font-variant-numeric: tabular-nums;
}

/* ============================================================
   Bend calculator — inputs | results columns, flat pattern rows
   ============================================================ */
.bend-cols {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 860px) { .bend-cols { grid-template-columns: 1fr; } }

.bend-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.bend-stats .stat__value { color: var(--result-ink); }

/* manual K override — accent highlight so it's obvious the number is manual */
.input--override {
  border-color: var(--gold-border-hot);
  color: var(--gold);
  background: var(--override-bg);
}

/* de-emphasize the custom-thickness field while a gauge is selected */
.bend-dim { opacity: 0.45; }

/* flat pattern rows */
.bend-rows { display: flex; flex-direction: column; gap: 8px; margin: 14px 0 4px; }
.bend-row {
  display: grid;
  grid-template-columns: 84px 1fr 1fr 34px;
  gap: 10px;
  align-items: center;
}
.bend-row--bend {
  grid-template-columns: 84px 1fr 1fr minmax(110px, auto);
  padding: 6px 0 6px 14px;
  border-left: 2px solid var(--orange-border);
}
.bend-row__tag {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--dim);
}
.bend-row__tag--bend { color: var(--accent2-text); }
.bend-row__readout {
  font-size: 13px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  text-align: right;
  white-space: nowrap;
}
.bend-row__remove {
  border: 1px solid var(--line);
  border-radius: var(--radius-small);
  background: transparent;
  color: var(--dim);
  font: inherit;
  font-size: 12px;
  padding: 6px 0;
  cursor: pointer;
}
.bend-row__remove:hover { color: var(--danger); border-color: var(--danger-border); }
@media (max-width: 720px) {
  .bend-row, .bend-row--bend { grid-template-columns: 70px 1fr 1fr; }
  .bend-row__readout { grid-column: 2 / -1; }
}

.bend-actions { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; }

/* ============================================================
   Friction lookup — twin μ stat cards, source line, no-data state
   ============================================================ */
.mu-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 720px) { .mu-stats { grid-template-columns: 1fr; } }

.mu-value {
  color: var(--result-ink);
  font-size: 30px;
  letter-spacing: -0.3px;
}
.mu-value--none { color: var(--dim); font-size: 22px; }
.mu-sym { text-transform: none; } /* keep μ lowercase inside uppercase labels */

/* per-entry citation */
.mu-source {
  margin-top: 12px;
  color: var(--dim);
  font-size: 12px;
  font-style: italic;
}

/* absence of data is normal, not an error — muted, no alarm styling */
.mu-nodata {
  color: var(--muted);
  font-size: 14px;
  padding: 18px 4px;
}

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