/* =========================================================================
   DerivLab — page identity on top of kit.css.

   Orchid, the fourth stop on the Mathematics track. In the shared figure
   palette this colour has always meant "the leftover, the part across" —
   and a derivative is precisely a rate ACROSS something, so the accent and
   the figures agree.
   ========================================================================= */
:root {
  --bp-cyan: #e599f7;
  --bp-blue: #f0c6ff;
  --bp-mark: #e599f7;
  --note-accent: #e599f7;
  --calc-col: 370px;
  --page-max: 1440px;
}

body {
  background-image:
    linear-gradient(rgba(255, 201, 77, 0.026) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 201, 77, 0.026) 1px, transparent 1px);
  background-size: 34px 34px, 34px 34px;
}

.hint { font-size: 0.76rem; color: var(--bp-ink-dim); line-height: 1.55; margin-top: 0.5rem; }
.hint b { color: var(--bp-cyan); }
.results-col { min-width: 0; }
.results-col svg { max-width: 100%; }

/* ------------------------------ the op list ------------------------------ */
/* The operations are a numbered LIST, and the number is the order they
   happen in. With transforms that is the single most important fact on the
   screen, so it gets a column of its own rather than being implied by
   vertical position alone. */
.op-list { display: flex; flex-direction: column; gap: 0.4rem; }
.op-row {
  display: grid; grid-template-columns: 1.1rem 1fr; gap: 0.45rem;
  align-items: start;
  border-left: 2px solid var(--bp-line); padding-left: 0.45rem;
}
.op-row.on { border-left-color: var(--bp-cyan); }
.op-num {
  font-family: var(--mono); font-size: 0.7rem; color: var(--bp-ink-dim);
  padding-top: 0.42rem; text-align: right;
}
.op-row.on .op-num { color: var(--bp-cyan); font-weight: 700; }
.op-body { display: flex; flex-direction: column; gap: 0.25rem; min-width: 0; }
.op-body select {
  width: 100%; font-family: var(--mono); font-size: 0.78rem;
  background: var(--bp-bg); color: var(--bp-ink);
  border: 1px solid var(--bp-line); border-radius: 6px; padding: 0.3rem 0.35rem;
}
.op-args { display: grid; gap: 0.25rem; }
.op-args input {
  width: 100%; font-family: var(--mono); font-size: 0.78rem;
  background: var(--bp-bg); color: var(--bp-ink);
  border: 1px solid var(--bp-line); border-radius: 6px;
  padding: 0.28rem 0.3rem; text-align: right; min-width: 0;
}
.op-args input:focus, .op-body select:focus { outline: none; border-color: var(--bp-cyan); }
.op-args label {
  font-family: var(--mono); font-size: 0.6rem; color: var(--bp-ink-dim);
  display: block; margin-bottom: 0.08rem;
}
.op-args > div { min-width: 0; }

/* ------------------------------ result cards ----------------------------- */
.vres {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.5rem; margin-bottom: 0.9rem;
}
.vres .card {
  border: 1px solid var(--bp-line); border-radius: 9px;
  background: var(--bp-panel); padding: 0.55rem 0.7rem;
}
.vres .card .k {
  font-family: var(--mono); font-size: 0.64rem; letter-spacing: 0.05em;
  text-transform: uppercase; color: var(--bp-ink-dim);
}
.vres .card .v {
  font-family: var(--mono); font-size: 1.1rem; font-weight: 700;
  color: var(--bp-cyan); margin-top: 0.15rem; overflow-wrap: anywhere;
}
.vres .card .x {
  font-family: var(--mono); font-size: 0.68rem; color: var(--bp-ink-dim);
  margin-top: 0.15rem; overflow-wrap: anywhere;
}

.vnote {
  border: 1px solid var(--bp-line); border-left-width: 4px;
  border-left-color: #ffd43b; border-radius: 9px;
  background: var(--bp-panel); padding: 0.5rem 0.8rem; margin-bottom: 0.8rem;
  font-size: 0.8rem; line-height: 1.55; color: var(--bp-ink-dim);
}
.vnote b { color: #ffd43b; }
.vnote.ok { border-left-color: #5fe3a1; }
.vnote.ok b { color: #5fe3a1; }

/* ------------------------- matrices in the output ------------------------ */
.mout { display: flex; flex-wrap: wrap; gap: 1.1rem; align-items: flex-start; }
.mout figure { margin: 0; }
.mout figcaption {
  font-family: var(--mono); font-size: 0.7rem; color: var(--bp-ink-dim);
  margin-bottom: 0.25rem; text-align: left;
}
.mbox {
  display: inline-grid; gap: 0.1rem 0.7rem;
  font-family: var(--mono); font-size: 0.8rem;
  padding: 0.4rem 0.6rem; border-left: 2px solid var(--bp-line2);
  border-right: 2px solid var(--bp-line2); border-radius: 3px;
  background: var(--bp-bg); text-align: right;
}
.mbox span.zero { color: var(--bp-ink-dim); opacity: 0.45; }
.mbox span.tr { color: #e599f7; }

.seg { display: inline-flex; border: 1px solid var(--bp-line); border-radius: 7px; overflow: hidden; }
.seg button {
  font-family: var(--mono); font-size: 0.72rem; cursor: pointer;
  background: transparent; color: var(--bp-ink-dim);
  border: none; padding: 0.3rem 0.65rem; transition: 0.16s;
}
.seg button.active { background: var(--bp-cyan); color: var(--bp-bg); font-weight: 700; }
.seg button:not(.active):hover { color: var(--bp-ink); }
.row-between { display: flex; align-items: center; justify-content: space-between; gap: 0.6rem; }
.res-table td.num { text-align: right; font-family: var(--mono); }

@media (max-width: 720px) {
  .op-args input, .op-body select { font-size: 0.72rem; }
}