/* GT2 belt tools: diagram theme + tool layout (dark). Diagram classes are emitted by belt-core.js. */

/* ---------- diagram ---------- */
.bc-diagram { position: relative; background: radial-gradient(70% 90% at 50% 40%, #1b2650, var(--ink-2)); border: 1px solid var(--line); clip-path: var(--chamfer); --cut: 18px; }
.bc-diagram::before { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: .5;
  background-image: linear-gradient(rgba(244, 244, 238, .04) 1px, transparent 1px), linear-gradient(90deg, rgba(244, 244, 238, .04) 1px, transparent 1px); background-size: 32px 32px; }
.bc-diagram svg { position: relative; display: block; width: 100%; height: auto; }
.bc-belt { fill: none; stroke: var(--gold); stroke-width: 5; stroke-linejoin: round; }
.bc-belt-teeth { fill: none; stroke: #8a5f0c; stroke-width: 2.4; stroke-linejoin: round; }
.bc-body { fill: #22305e; stroke: rgba(244, 244, 238, .75); stroke-width: 2; }
.p2 .bc-body { fill: #1d2b63; }
.bc-teeth line, .bc-teeth circle { stroke: rgba(244, 244, 238, .5); stroke-width: 1.2; }
.bc-spokes line { stroke: rgba(244, 244, 238, .18); stroke-width: 3; stroke-linecap: round; }
.bc-hub { fill: var(--ink-2); stroke: rgba(244, 244, 238, .7); stroke-width: 1.5; }
.bc-axle { fill: var(--paper); }
.bc-dim line { stroke: rgba(244, 244, 238, .22); stroke-width: 1; stroke-dasharray: 3 4; }
.bc-dim .bc-dim-main { stroke: rgba(244, 244, 238, .7); stroke-width: 1.2; stroke-dasharray: none; }
.bc-dim rect { fill: var(--ink-2); }
.bc-dim text { fill: var(--paper); font: 600 12.5px var(--mono); }
.bc-arrow { fill: none; stroke: rgba(244, 244, 238, .7); stroke-width: 1.2; }
.bc-l1, .bc-l2 { font: 400 17px var(--display); letter-spacing: .08em; }
.bc-l1 { fill: var(--gold); }
.bc-l2 { fill: #8ea8ff; }
.bc-ls { fill: rgba(244, 244, 238, .55); font: 11px var(--mono); }
.bc-note { fill: rgba(244, 244, 238, .75); font: 12.5px var(--body); }
.bc-t-err { fill: #ff8f8f; font: 15px var(--body); }

/* ---------- mode chooser ---------- */
.bt-modes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-bottom: 28px; background: var(--line); border: 1px solid var(--line); }
.bt-mode { position: relative; display: grid; grid-template-columns: auto 1fr; column-gap: 14px; align-items: center; padding: 18px 20px; text-align: left; color: var(--paper); background: var(--ink); border: 0; cursor: pointer; font: inherit; transition: background .25s; }
.bt-mode b { grid-row: span 2; font: 400 44px/.8 var(--display); color: rgba(244, 244, 238, .25); transition: color .25s; }
.bt-mode strong { font: 400 26px/1 var(--display); letter-spacing: .03em; text-transform: uppercase; }
.bt-mode span { color: var(--muted); font-size: 14px; line-height: 1.35; margin-top: 4px; }
.bt-mode::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 3px; background: linear-gradient(90deg, var(--gold) 0 50%, var(--blue) 50% 100%); transform: scaleX(0); transition: transform .3s; }
.bt-mode:hover { background: #1a2347; }
.bt-mode[aria-selected="true"] { background: var(--navy); }
.bt-mode[aria-selected="true"] b { color: var(--gold); }
.bt-mode[aria-selected="true"]::after { transform: scaleX(1); }

/* ---------- workbench: inputs | diagram ---------- */
.bt-bench { display: grid; grid-template-columns: minmax(260px, 340px) 1fr; gap: clamp(20px, 3vw, 40px); align-items: start; }
.bt-panel[hidden] { display: none; }
.bt-panel h2 { margin: 0 0 6px; font: 400 34px/1 var(--display); text-transform: uppercase; }
.bt-panel > p { margin: 0 0 20px; color: var(--muted); font-size: 15px; }
.bt-fields { display: grid; gap: 16px; }
.bt-fields .row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.field small { font: 12.5px/1.3 var(--body); letter-spacing: 0; text-transform: none; color: rgba(244, 244, 238, .5); }
.bt-adv { margin-top: 18px; border-top: 1px solid var(--line); }
.bt-adv summary { padding: 14px 0; cursor: pointer; font: 700 11px/1 var(--body); letter-spacing: .2em; text-transform: uppercase; color: var(--muted); }
.bt-adv summary:hover { color: var(--gold); }
.bt-adv .bt-fields { padding-bottom: 6px; }
.bt-stage { position: sticky; top: calc(var(--nav-h) + 16px); }

/* ---------- results ---------- */
.bc-out { margin-top: 30px; }
.bc-out h3 { margin: 0 0 14px; font: 400 26px/1 var(--display); letter-spacing: .03em; text-transform: uppercase; }
.bc-out h3 small { margin-left: 10px; font: 13px var(--body); letter-spacing: 0; text-transform: none; color: var(--muted); }
.bc-stats { display: flex; flex-wrap: wrap; gap: 1px; margin: 0 0 18px; background: var(--line); border: 1px solid var(--line); }
.bc-stat { flex: 1 1 140px; padding: 14px 16px; background: var(--ink); }
.bc-stat small { display: block; font: 700 10.5px/1 var(--body); letter-spacing: .18em; text-transform: uppercase; color: var(--muted); }
.bc-stat b { display: block; margin-top: 8px; font: 400 34px/1 var(--display); color: var(--paper); letter-spacing: .02em; }
.bc-stat.hi b { color: var(--gold); }
.bc-warn, .bc-err { margin: 12px 0; padding: 12px 16px; font-size: 14.5px; border-left: 4px solid var(--gold); background: rgba(239, 171, 40, .1); }
.bc-err { border-left-color: #e05656; background: rgba(224, 86, 86, .12); }
.bc-tbl tbody tr[data-n1] { cursor: pointer; }
.bc-tbl tbody tr.sel td { background: rgba(68, 108, 227, .2); }
.bc-tbl tbody tr.rec td:first-child { box-shadow: inset 3px 0 0 var(--gold); }
.bc-pill { display: inline-block; margin-left: 8px; padding: 2px 7px; font: 700 10px/1.4 var(--body); letter-spacing: .12em; text-transform: uppercase; color: var(--ink); background: var(--gold); }
.bc-sku { white-space: nowrap; font: 13px var(--mono); }
.bc-sku a { color: var(--paper); }
.copy-btn { margin-left: 8px; padding: 2px 8px; font: 700 10px/1.4 var(--body); letter-spacing: .12em; text-transform: uppercase; color: var(--muted); background: transparent; border: 1px solid var(--line); cursor: pointer; }
.copy-btn:hover { color: var(--ink); background: var(--gold); border-color: var(--gold); }
.bt-how { margin-top: 26px; padding: 18px 20px; color: var(--muted); font-size: 15px; border-left: 3px solid var(--blue); background: rgba(68, 108, 227, .08); }
.bt-how b { color: var(--paper); }

/* ---------- catalog ---------- */
.bt-cat summary { padding: 16px 0; cursor: pointer; font: 400 26px/1 var(--display); letter-spacing: .03em; text-transform: uppercase; border-top: 1px solid var(--line); }
.bt-cat summary:hover { color: var(--gold); }
.bt-cat .dtable-wrap { max-height: 520px; overflow: auto; }

@media (max-width: 900px) {
  .bt-modes { grid-template-columns: 1fr; }
  .bt-bench { grid-template-columns: 1fr; }
  .bt-stage { position: static; order: -1; }
}