/* ============================================================================
   STEM Math Studio — premium UI, scoped entirely under .ms-root
   ----------------------------------------------------------------------------
   A separate "app within the app". It borrows the whiteboard's shared theme
   tokens (--panel, --text, --accent, --chrome-shadow, …) so light/dark just
   works, then layers its own identity on top via locally-scoped --ms-* tokens.
   Nothing here leaks out: every selector is nested under .ms-root.
   ========================================================================== */

.ms-root {
  /* ---- Local identity tokens (light defaults) ---------------------------- */
  --ms-accent:      #7c5cff;                 /* violet — signature */
  --ms-accent-2:    #22d3ee;                 /* cyan   — signature */
  --ms-grad:        linear-gradient(135deg, #7c5cff 0%, #4f8cff 45%, #22d3ee 100%);
  --ms-grad-soft:   linear-gradient(135deg, rgba(124,92,255,.16), rgba(34,211,238,.16));
  --ms-surface:     #ffffff;                 /* panel body */
  --ms-surface-2:   #f4f6fb;                 /* keypad well */
  --ms-key:         #ffffff;                 /* number keys */
  --ms-key-edge:    rgba(15, 23, 42, .10);
  --ms-key-shadow:  0 1px 0 rgba(15,23,42,.04), 0 2px 5px rgba(15,23,42,.08);
  --ms-key-fn:      #eef1f8;                 /* function keys */
  --ms-key-op:      rgba(124, 92, 255, .12); /* operator keys */
  --ms-key-op-ink:  #5b3fe0;
  --ms-ink:         var(--text, #0f172a);
  --ms-ink-soft:    var(--muted, #64748b);
  --ms-display-bg:  #0f1222;                 /* the readout is always dark — a "screen" */
  --ms-display-ink: #f3f5ff;
  --ms-display-sub: #8b93c7;
  --ms-danger:      #ef4444;
  --ms-radius:      18px;
  --ms-radius-key:  13px;
  --ms-gap:         8px;
  --ms-ease:        cubic-bezier(.2, .7, .2, 1);
  --ms-font-mono:   ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", "Roboto Mono", Menlo, Consolas, monospace;

  position: fixed;
  z-index: 4000;                 /* above canvas + docks, below modals if any */
  top: 96px;
  right: 92px;
  width: 384px;
  /* height is content-driven but clamped; resize handle can grow it */
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--ms-ink);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  touch-action: none;
  animation: ms-pop .26s var(--ms-ease) both;
}

body.dark .ms-root {
  --ms-surface:     #171c2b;
  --ms-surface-2:   #10141f;
  --ms-key:         #212838;
  --ms-key-edge:    rgba(255, 255, 255, .08);
  --ms-key-shadow:  0 1px 0 rgba(255,255,255,.03), 0 2px 6px rgba(0,0,0,.4);
  --ms-key-fn:      #1b2130;
  --ms-key-op:      rgba(124, 92, 255, .22);
  --ms-key-op-ink:  #b7a6ff;
  --ms-display-bg:  #0a0d18;
  --ms-display-ink: #eef1ff;
  --ms-display-sub: #7982b5;
}

.ms-root.ms-min { width: 260px; }
.ms-root.ms-dragging, .ms-root.ms-resizing { animation: none; user-select: none; }
.ms-root.ms-dragging .ms-panel { transition: none; }

@keyframes ms-pop {
  from { opacity: 0; transform: translateY(10px) scale(.975); }
  to   { opacity: 1; transform: translateY(0)    scale(1); }
}

/* ---- Panel shell --------------------------------------------------------- */
.ms-panel {
  display: flex;
  flex-direction: column;
  border-radius: var(--ms-radius);
  background: var(--ms-surface);
  border: 1px solid var(--ms-key-edge);
  box-shadow:
    0 24px 60px rgba(15, 23, 42, .28),
    0 6px 18px rgba(15, 23, 42, .16),
    inset 0 1px 0 rgba(255, 255, 255, .5);
  overflow: hidden;
}
body.dark .ms-panel {
  box-shadow:
    0 28px 70px rgba(0, 0, 0, .6),
    0 8px 22px rgba(0, 0, 0, .4),
    inset 0 1px 0 rgba(255, 255, 255, .05);
}

/* ---- Header (drag handle) ------------------------------------------------ */
.ms-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 12px 11px 14px;
  cursor: grab;
  background:
    var(--ms-grad-soft),
    var(--ms-surface);
  border-bottom: 1px solid var(--ms-key-edge);
  backdrop-filter: blur(18px) saturate(160%);
}
.ms-header:active { cursor: grabbing; }

.ms-brand { display: flex; align-items: center; gap: 9px; min-width: 0; }
.ms-logo {
  width: 26px; height: 26px; flex: none;
  border-radius: 8px;
  background: var(--ms-grad);
  box-shadow: 0 2px 8px rgba(124, 92, 255, .5), inset 0 1px 0 rgba(255,255,255,.4);
  display: grid; place-items: center;
  color: #fff; font-weight: 800; font-size: 15px; line-height: 1;
  letter-spacing: -.02em;
}
.ms-titles { display: flex; flex-direction: column; min-width: 0; }
.ms-title {
  font-weight: 750; font-size: 13.5px; letter-spacing: -.01em; line-height: 1.15;
  white-space: nowrap;
}
.ms-sub {
  font-size: 10.5px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase;
  color: var(--ms-ink-soft);
  background: linear-gradient(90deg, var(--ms-accent), var(--ms-accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.ms-spacer { flex: 1 1 auto; }

.ms-winbtns { display: flex; gap: 4px; }
.ms-winbtn {
  width: 26px; height: 26px; flex: none;
  display: grid; place-items: center;
  border: 0; border-radius: 8px;
  background: transparent;
  color: var(--ms-ink-soft);
  cursor: pointer;
  transition: background .15s var(--ms-ease), color .15s var(--ms-ease), transform .12s var(--ms-ease);
}
.ms-winbtn:hover { background: var(--chrome-hover, rgba(15,23,42,.06)); color: var(--ms-ink); }
.ms-winbtn:active { transform: scale(.9); }
.ms-winbtn.ms-close:hover { background: rgba(239, 68, 68, .14); color: var(--ms-danger); }
.ms-winbtn svg { width: 15px; height: 15px; }

/* ---- Module switcher (chips) --------------------------------------------- */
.ms-modules {
  display: flex; gap: 4px; padding: 8px 10px;
  overflow-x: auto; scrollbar-width: none;
  border-bottom: 1px solid var(--ms-key-edge);
  background: var(--ms-surface);
}
.ms-modules::-webkit-scrollbar { display: none; }
.ms-chip {
  flex: none;
  font: 600 11.5px/1 'Inter', sans-serif;
  letter-spacing: .01em;
  padding: 7px 11px;
  border-radius: 999px;
  border: 1px solid var(--ms-key-edge);
  background: var(--ms-surface-2);
  color: var(--ms-ink-soft);
  cursor: pointer;
  white-space: nowrap;
  transition: all .16s var(--ms-ease);
}
.ms-chip:hover { color: var(--ms-ink); border-color: color-mix(in srgb, var(--ms-accent) 40%, transparent); }
.ms-chip.ms-on {
  color: #fff;
  background: var(--ms-grad);
  border-color: transparent;
  box-shadow: 0 3px 10px rgba(124, 92, 255, .38);
}
.ms-chip[disabled] { opacity: .5; cursor: not-allowed; }

/* ---- Body ---------------------------------------------------------------- */
.ms-body { display: flex; flex-direction: column; padding: 12px; gap: 12px; }
.ms-min .ms-body, .ms-min .ms-modules { display: none; }

/* ---- Display "screen" ---------------------------------------------------- */
.ms-display {
  position: relative;
  background:
    radial-gradient(120% 100% at 100% 0%, rgba(124,92,255,.22), transparent 60%),
    radial-gradient(120% 120% at 0% 100%, rgba(34,211,238,.16), transparent 55%),
    var(--ms-display-bg);
  border-radius: 14px;
  padding: 14px 15px 12px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.06), inset 0 0 0 1px rgba(255,255,255,.04),
              0 8px 20px rgba(15, 23, 42, .18);
  overflow: hidden;
}
.ms-display::after {   /* faint scanline sheen */
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: linear-gradient(180deg, rgba(255,255,255,.05), transparent 30%);
}
.ms-expr {
  width: 100%;
  background: transparent; border: 0; outline: 0;
  color: var(--ms-display-ink);
  font: 500 20px/1.3 var(--ms-font-mono);
  letter-spacing: .01em;
  caret-color: var(--ms-accent-2);
  resize: none; overflow: hidden;
  min-height: 26px;
}
.ms-expr::placeholder { color: var(--ms-display-sub); }
.ms-result {
  margin-top: 8px; min-height: 26px;
  text-align: right;
  color: #fff;
  font-family: var(--ms-font-mono);
  font-size: 24px; font-weight: 600;
  letter-spacing: .01em;
  word-break: break-all;
  transition: color .15s var(--ms-ease);
}
.ms-result .ms-eq { color: var(--ms-display-sub); margin-right: 6px; font-weight: 500; }
.ms-result.ms-err { color: #ff8a8a; font-size: 14px; font-weight: 500; }
.ms-metarow {
  display: flex; align-items: center; gap: 8px; margin-top: 10px;
}
.ms-badge {
  font: 700 10px/1 'Inter', sans-serif; letter-spacing: .08em; text-transform: uppercase;
  padding: 4px 7px; border-radius: 6px;
  color: var(--ms-display-sub);
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.08);
  cursor: pointer; user-select: none;
  transition: all .15s var(--ms-ease);
}
.ms-badge.ms-on { color: #0a0d18; background: var(--ms-accent-2); border-color: transparent; }
.ms-badge.ms-mem { color: var(--ms-accent-2); }
.ms-badge.ms-mem[data-empty="1"] { opacity: .35; }
/* precision selector — fixed-ish width so cycling 2 DP / FULL doesn't jitter */
.ms-badge.ms-precbtn { color: var(--ms-accent-2); white-space: nowrap; min-width: 44px; text-align: center; }
.ms-metarow .ms-spacer { flex: 1; }

/* ---- History tape -------------------------------------------------------- */
.ms-tape {
  max-height: 92px; overflow-y: auto;
  display: none; flex-direction: column-reverse; gap: 2px;
  padding: 4px 2px; scrollbar-width: thin;
}
.ms-tape.ms-show { display: flex; }
.ms-tape-row {
  display: flex; justify-content: space-between; gap: 12px;
  padding: 5px 8px; border-radius: 8px; cursor: pointer;
  font-family: var(--ms-font-mono); font-size: 12px;
  color: var(--ms-ink-soft);
  transition: background .12s var(--ms-ease);
}
.ms-tape-row:hover { background: var(--ms-key-op); color: var(--ms-ink); }
.ms-tape-row b { color: var(--ms-ink); font-weight: 600; }

/* ---- Keypad -------------------------------------------------------------- */
.ms-keypad {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--ms-gap);
  background: var(--ms-surface-2);
  padding: 10px;
  border-radius: 14px;
  border: 1px solid var(--ms-key-edge);
}
.ms-key {
  position: relative;
  appearance: none; border: 1px solid var(--ms-key-edge);
  background: var(--ms-key);
  color: var(--ms-ink);
  border-radius: var(--ms-radius-key);
  height: 44px;
  font: 600 15px/1 'Inter', sans-serif;
  letter-spacing: -.01em;
  cursor: pointer;
  box-shadow: var(--ms-key-shadow);
  transition: transform .09s var(--ms-ease), box-shadow .15s var(--ms-ease),
              background .15s var(--ms-ease), border-color .15s var(--ms-ease), filter .15s;
  user-select: none;
}
.ms-key.ms-num { font-family: var(--ms-font-mono); font-size: 17px; font-weight: 600; }
.ms-key:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(15,23,42,.14); }
.ms-key:active { transform: translateY(0) scale(.95); box-shadow: 0 1px 3px rgba(15,23,42,.16); filter: brightness(.98); }
.ms-key:focus-visible { outline: 2px solid var(--ms-accent); outline-offset: 2px; }

/* function keys (sin, cos, √, x², …) */
.ms-key.ms-fn { background: var(--ms-key-fn); font-size: 13.5px; color: var(--ms-ink-soft); }
.ms-key.ms-fn:hover { color: var(--ms-ink); }
.ms-key.ms-fn sup, .ms-key sup { font-size: .68em; }
.ms-key .ms-sub2 { font-size: .7em; vertical-align: sub; }

/* operator keys (+ − × ÷) */
.ms-key.ms-op {
  background: var(--ms-key-op); color: var(--ms-key-op-ink);
  font-family: var(--ms-font-mono); font-size: 19px; font-weight: 700;
  border-color: color-mix(in srgb, var(--ms-accent) 24%, transparent);
}
/* clear / danger */
.ms-key.ms-clear { color: var(--ms-danger); background: color-mix(in srgb, var(--ms-danger) 10%, var(--ms-key)); }
.ms-key.ms-clear:hover { background: color-mix(in srgb, var(--ms-danger) 18%, var(--ms-key)); }

/* memory + 2nd modifier */
.ms-key.ms-mod { font-size: 12px; font-weight: 700; letter-spacing: .02em; text-transform: uppercase; color: var(--ms-ink-soft); }
.ms-key.ms-mod.ms-on { color: #fff; background: var(--ms-grad); border-color: transparent; box-shadow: 0 3px 12px rgba(124,92,255,.4); }

/* equals — the hero key, glows with the signature gradient */
.ms-key.ms-eq {
  background: var(--ms-grad);
  color: #fff;
  border-color: transparent;
  font-family: var(--ms-font-mono);
  font-size: 22px; font-weight: 700;
  box-shadow: 0 6px 18px rgba(124, 92, 255, .45), inset 0 1px 0 rgba(255,255,255,.3);
}
.ms-key.ms-eq:hover { transform: translateY(-1px); box-shadow: 0 10px 26px rgba(124, 92, 255, .55); filter: brightness(1.04); }
.ms-key.ms-eq:active { transform: scale(.97); }

/* wide key (0 or Ans) */
.ms-key.ms-wide { grid-column: span 2; }

/* subtle ripple flash on activate (added/removed via JS) */
.ms-key.ms-flash::before {
  content: ""; position: absolute; inset: 0; border-radius: inherit;
  background: radial-gradient(circle at center, rgba(124,92,255,.5), transparent 70%);
  animation: ms-ripple .4s var(--ms-ease);
  pointer-events: none;
}
@keyframes ms-ripple { from { opacity: .8; transform: scale(.4); } to { opacity: 0; transform: scale(1.1); } }

/* ---- Resize handle ------------------------------------------------------- */
.ms-resize {
  position: absolute; right: 3px; bottom: 3px; width: 18px; height: 18px;
  cursor: nwse-resize; opacity: .5;
  background:
    linear-gradient(135deg, transparent 46%, var(--ms-ink-soft) 46%, var(--ms-ink-soft) 54%, transparent 54%),
    linear-gradient(135deg, transparent 66%, var(--ms-ink-soft) 66%, var(--ms-ink-soft) 74%, transparent 74%);
}
.ms-resize:hover { opacity: .9; }
.ms-min .ms-resize { display: none; }
/* Edge resize handles: east (width) + south (height). Thin invisible strips
   along the panel edges so horizontal / vertical resizing is easy to grab. */
.ms-resize-e {
  position: absolute; top: 40px; bottom: 22px; right: 0; width: 8px;
  cursor: ew-resize; z-index: 3;
}
.ms-resize-s {
  position: absolute; left: 22px; right: 22px; bottom: 0; height: 8px;
  cursor: ns-resize; z-index: 3;
}
.ms-min .ms-resize-e, .ms-min .ms-resize-s { display: none; }

/* ---- Math-field inputs (MathLive) --------------------------------------- */
.ms-mathfield {
  width: 100%;
  box-sizing: border-box;
  font-size: 20px;
}
/* hide MathLive's built-in menu + virtual-keyboard toggles — we ship our own */
.ms-root math-field::part(menu-toggle),
.ms-root math-field::part(virtual-keyboard-toggle) { display: none; }

/* the Scientific expression field sits on the dark "screen" */
.ms-mf-host { position: relative; z-index: 1; }
.ms-mathfield.ms-expr-field {
  --caret-color: var(--ms-accent-2);
  --selection-background-color: rgba(124, 92, 255, .35);
  color: var(--ms-display-ink);
  background: transparent;
  border: 0;
  font-size: 22px;
  min-height: 30px;
  padding: 0;
}
.ms-mathfield.ms-mf-fallback {
  border: 0; outline: 0; background: transparent;
  color: var(--ms-display-ink);
  font: 500 20px/1.3 var(--ms-font-mono);
  width: 100%;
}
.ms-eq-mfhost .ms-mf-fallback { color: var(--ms-ink); font-size: 14px; }

/* ---- Memory cluster (Scientific display) -------------------------------- */
.ms-memcluster { display: inline-flex; gap: 4px; }
.ms-membtn {
  appearance: none; border: 1px solid rgba(255, 255, 255, .14);
  background: rgba(255, 255, 255, .06); color: var(--ms-display-sub);
  border-radius: 7px; padding: 2px 7px; cursor: pointer;
  font: 700 10.5px/1 'Inter', sans-serif; letter-spacing: .02em;
  transition: background .15s var(--ms-ease), color .15s var(--ms-ease);
}
.ms-membtn:hover { background: rgba(124, 92, 255, .28); color: #fff; }
.ms-membtn:active { transform: scale(.94); }
/* the meta badges are <button>s now — reset native chrome */
.ms-badge { appearance: none; font-family: inherit; }

/* ---- Shared LaTeX keyboard (footer, all modules) ------------------------ */
.ms-keyboard {
  margin: 0 12px 12px;
  background: var(--ms-surface-2);
  border: 1px solid var(--ms-key-edge);
  border-radius: 16px;
  padding: 8px;
  display: flex; flex-direction: column; gap: 8px;
}
.ms-min .ms-keyboard { display: none; }
.ms-kbtabs { display: flex; align-items: center; gap: 6px; }
.ms-kbspacer { flex: 1 1 auto; }
.ms-kbtab {
  appearance: none; border: 1px solid var(--ms-key-edge);
  background: var(--ms-key-fn); color: var(--ms-ink-soft);
  border-radius: 10px; padding: 5px 14px; cursor: pointer;
  font: 700 12.5px/1 'Inter', sans-serif; letter-spacing: .01em;
  transition: color .15s var(--ms-ease), background .15s var(--ms-ease);
}
.ms-kbtab:hover { color: var(--ms-ink); }
.ms-kbtab.ms-on { background: var(--ms-grad); color: #fff; border-color: transparent; box-shadow: 0 3px 10px rgba(124, 92, 255, .34); }
/* pin button keeps its square shape + houses the SVG */
.ms-kb-pin { display: grid; place-items: center; padding: 5px; width: 30px; }
.ms-kb-pin svg { display: block; transform: rotate(0deg); transition: transform .18s var(--ms-ease); }
.ms-kb-pin.ms-on svg { transform: rotate(-20deg); }
/* manual hide/show toggle — chevron flips when the keypad is collapsed */
.ms-kb-toggle { display: grid; place-items: center; padding: 5px; width: 30px; }
.ms-kb-toggle svg { display: block; transition: transform .2s var(--ms-ease); }
.ms-kb-toggle.ms-on svg { transform: rotate(180deg); }

/* body wraps the key grid + arrow nav; it's what collapses on idle */
.ms-kbbody {
  display: flex; gap: 8px; align-items: stretch;
  overflow: hidden;
  max-height: 320px; opacity: 1;
  transition: max-height .28s var(--ms-ease), opacity .2s var(--ms-ease), margin-top .28s var(--ms-ease);
}
.ms-keyboard.ms-kb-collapsed .ms-kbbody {
  max-height: 0; opacity: 0; margin-top: -8px; pointer-events: none;
}
.ms-kbgrid {
  flex: 1; min-width: 0;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--ms-gap);
}
.ms-kbgrid .ms-key { height: 40px; }

/* arrow-key navigation cluster — a 2-wide column on the keypad's right */
.ms-kbnav {
  flex: none; width: 74px;
  display: grid; grid-template-columns: 1fr 1fr;
  grid-template-areas: "up up" "left right" "down down";
  gap: var(--ms-gap);
}
.ms-key.ms-nav {
  height: auto; font-size: 15px; font-weight: 700;
  color: var(--ms-key-op-ink); background: var(--ms-key-op);
  border-color: color-mix(in srgb, var(--ms-accent) 22%, transparent);
}
.ms-key.ms-nav:nth-child(1) { grid-area: left; }
.ms-key.ms-nav:nth-child(2) { grid-area: up; }
.ms-key.ms-nav:nth-child(3) { grid-area: down; }
.ms-key.ms-nav:nth-child(4) { grid-area: right; }
.ms-key.ms-const { color: var(--ms-key-op-ink); font-weight: 700; }
.ms-key.ms-var { font-family: var(--ms-font-mono); font-style: italic; color: var(--ms-ink); }

/* ---- Module views -------------------------------------------------------- */
.ms-view { display: none; }
.ms-view.ms-active { display: flex; flex-direction: column; gap: 12px; }

/* ========================================================================== */
/*  Graphing module                                                            */
/* ========================================================================== */
.ms-graph {
  display: flex;
  gap: 10px;
  height: min(58vh, 460px);
  min-height: 330px;
}
.ms-graph-side {
  width: 150px; flex: none;
  display: flex; flex-direction: column; gap: 8px;
  min-width: 0;
}
/* Draggable divider between the function list and the plot. */
.ms-graph-divider {
  flex: none; width: 6px; align-self: stretch;
  margin: 0 -3px; cursor: ew-resize; border-radius: 3px;
  background: transparent; position: relative; z-index: 2;
  transition: background .15s var(--ms-ease);
}
.ms-graph-divider::before {
  content: ""; position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 2px; height: 30px; border-radius: 2px;
  background: var(--ms-key-edge);
}
.ms-graph-divider:hover, .ms-graph-divider.ms-dragging {
  background: color-mix(in srgb, var(--ms-accent) 22%, transparent);
}
.ms-eqlist { display: flex; flex-direction: column; gap: 6px; overflow-y: auto; }
.ms-eq-row {
  display: flex; align-items: center; gap: 5px;
  background: var(--ms-key-fn);
  border: 1px solid var(--ms-key-edge);
  border-radius: 10px; padding: 5px 6px;
}
.ms-eq-row.ms-eq-err { border-color: color-mix(in srgb, var(--ms-danger) 55%, var(--ms-key-edge)); }
.ms-eq-color {
  width: 16px; height: 16px; flex: none; border-radius: 5px;
  border: 2px solid; cursor: pointer; padding: 0;
}
.ms-eq-yeq { color: var(--ms-ink-soft); font: 600 12px var(--ms-font-mono); flex: none; }
.ms-eq-mfhost { flex: 1; min-width: 0; display: flex; }
.ms-eq-field { flex: 1; min-width: 0; font-size: 15px; --caret-color: var(--ms-accent); }
.ms-eq-field.ms-mf-fallback {
  border: 0; outline: 0; background: transparent;
  color: var(--ms-ink); font: 500 13px var(--ms-font-mono);
}
.ms-eq-del {
  flex: none; border: 0; background: transparent; cursor: pointer;
  color: var(--ms-ink-soft); font-size: 16px; line-height: 1; padding: 0 2px;
}
.ms-eq-del:hover { color: var(--ms-danger); }
.ms-eq-add {
  border: 1px dashed var(--ms-key-edge); background: transparent;
  color: var(--ms-ink-soft); border-radius: 10px; padding: 7px;
  cursor: pointer; font-size: 12.5px; font-weight: 600;
  transition: border-color .15s var(--ms-ease), color .15s var(--ms-ease);
}
.ms-eq-add:hover { color: var(--ms-accent); border-color: color-mix(in srgb, var(--ms-accent) 45%, transparent); }

.ms-graph-main { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.ms-graph-toolbar { display: flex; align-items: center; gap: 6px; }
.ms-gbtn {
  border: 1px solid var(--ms-key-edge); background: var(--ms-key-fn);
  color: var(--ms-ink-soft); border-radius: 9px; min-width: 30px; height: 28px;
  padding: 0 9px; cursor: pointer; font-size: 13px; font-weight: 600;
  transition: transform .1s var(--ms-ease), color .15s var(--ms-ease);
}
.ms-gbtn:hover { color: var(--ms-ink); }
.ms-gbtn:active { transform: scale(.94); }
.ms-gbtn.ms-on { background: var(--ms-grad); color: #fff; border-color: transparent; }
.ms-graph-coord {
  margin-left: auto; color: var(--ms-ink-soft);
  font: 500 12px var(--ms-font-mono); white-space: nowrap;
}
.ms-graph-canvas {
  flex: 1; width: 100%; min-height: 0; display: block;
  background: var(--ms-surface);
  border: 1px solid var(--ms-key-edge); border-radius: 12px;
  cursor: crosshair; touch-action: none;
}
.ms-graph-table { display: none; max-height: 150px; overflow: auto; }
.ms-graph-table.ms-show { display: block; }
.ms-graph-table table { width: 100%; border-collapse: collapse; font: 500 12px var(--ms-font-mono); }
.ms-graph-table th, .ms-graph-table td {
  border: 1px solid var(--ms-key-edge); padding: 3px 8px; text-align: right;
  color: var(--ms-ink);
}
.ms-graph-table th { color: var(--ms-ink-soft); position: sticky; top: 0; background: var(--ms-surface-2); }
.ms-graph-empty { color: var(--ms-ink-soft); font-size: 12.5px; padding: 8px; }

/* ---- Function analyser --------------------------------------------------- */
.ms-an-bar { display: flex; flex-direction: column; gap: 6px; }
.ms-an-chips { display: flex; flex-wrap: wrap; gap: 5px; }
/* Function-target picker ("on yN") — shown when 2+ curves are plotted so
   tangent / area / roots / extrema can attach to a chosen function. */
.ms-an-target-wrap {
  display: inline-flex; align-items: center;
  font: 600 11.5px/1 var(--ms-font-mono); color: var(--ms-ink-soft);
}
.ms-an-target {
  appearance: none; -webkit-appearance: none;
  border: 1px solid var(--ms-key-edge); border-radius: 7px;
  background: var(--ms-surface); color: var(--ms-ink);
  padding: 3px 22px 3px 8px; cursor: pointer;
  font: 600 11.5px/1 var(--ms-font-mono);
  background-image: linear-gradient(45deg, transparent 50%, var(--ms-ink-soft) 50%), linear-gradient(135deg, var(--ms-ink-soft) 50%, transparent 50%);
  background-position: right 9px center, right 5px center;
  background-size: 4px 4px, 4px 4px; background-repeat: no-repeat;
}
.ms-an-target:focus { outline: none; border-color: color-mix(in srgb, var(--ms-accent) 55%, transparent); }
.ms-an-chip {
  appearance: none; border: 1px solid var(--ms-key-edge);
  background: var(--ms-key-fn); color: var(--ms-ink-soft);
  border-radius: 999px; padding: 4px 10px; cursor: pointer;
  font: 600 11px/1 'Inter', sans-serif; letter-spacing: .01em;
  transition: color .15s var(--ms-ease), background .15s var(--ms-ease), border-color .15s var(--ms-ease);
}
.ms-an-chip:hover { color: var(--ms-ink); border-color: color-mix(in srgb, var(--ms-accent) 40%, transparent); }
.ms-an-chip.ms-on { color: #fff; background: var(--ms-grad); border-color: transparent; box-shadow: 0 2px 8px rgba(124, 92, 255, .34); }
.ms-an-chip.ms-an-addbtn { color: var(--ms-accent); border-style: dashed; }
.ms-an-chip.ms-an-addbtn:hover { background: var(--ms-key-op); }

.ms-an-inputs {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  font: 600 11.5px/1 var(--ms-font-mono); color: var(--ms-ink-soft);
}
.ms-an-grp { display: inline-flex; align-items: center; gap: 6px; }
.ms-an-inputs label { display: inline-flex; align-items: center; gap: 3px; }
.ms-an-num {
  width: 56px; box-sizing: border-box;
  border: 1px solid var(--ms-key-edge); border-radius: 7px;
  background: var(--ms-surface); color: var(--ms-ink);
  padding: 3px 6px; font: 600 11.5px/1 var(--ms-font-mono);
  outline: none; transition: border-color .15s var(--ms-ease);
}
.ms-an-num:focus { border-color: color-mix(in srgb, var(--ms-accent) 55%, transparent); }
/* trim the number spinners so the fields stay compact */
.ms-an-num::-webkit-outer-spin-button, .ms-an-num::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.ms-an-num { -moz-appearance: textfield; }
.ms-an-clearpts {
  appearance: none; border: 1px solid var(--ms-key-edge); background: transparent;
  color: var(--ms-ink-soft); border-radius: 7px; padding: 3px 9px; cursor: pointer;
  font: 600 11px/1 'Inter', sans-serif;
}
.ms-an-clearpts:hover { color: var(--ms-danger); border-color: color-mix(in srgb, var(--ms-danger) 45%, transparent); }

.ms-an-readout {
  font: 500 11.5px/1.5 var(--ms-font-mono);
  color: var(--ms-ink);
  background: var(--ms-key-op);
  border: 1px solid color-mix(in srgb, var(--ms-accent) 20%, transparent);
  border-radius: 9px; padding: 6px 9px;
  word-break: break-word;
}

/* ========================================================================== */
/*  CAS module                                                                 */
/* ========================================================================== */
.ms-cas-display { display: flex; flex-direction: column; gap: 12px; }
/* Input sits on the same dark "screen" as the Scientific field + CAS result,
   so the light (--ms-display-ink) typeset text is legible. */
.ms-cas-inhost {
  display: flex; min-height: 40px;
  background:
    radial-gradient(120% 100% at 100% 0%, rgba(124,92,255,.22), transparent 60%),
    radial-gradient(120% 120% at 0% 100%, rgba(34,211,238,.16), transparent 55%),
    var(--ms-display-bg);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 12px; padding: 10px 12px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.06);
}
.ms-cas-field { flex: 1; min-width: 0; font-size: 19px; background: transparent; --caret-color: var(--ms-accent-2); --selection-background-color: rgba(124, 92, 255, .35); color: var(--ms-display-ink); }
.ms-cas-field.ms-mf-fallback {
  border: 0; outline: 0; background: transparent;
  color: var(--ms-display-ink); font: 500 16px var(--ms-font-mono);
}
.ms-cas-field.ms-mf-fallback::placeholder { color: var(--ms-display-sub); }
.ms-cas-ops { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.ms-cas-op {
  border: 1px solid var(--ms-key-edge); background: var(--ms-key-fn);
  color: var(--ms-ink); border-radius: 10px; height: 32px; padding: 0 12px;
  cursor: pointer; font-size: 13px; font-weight: 600;
  transition: transform .12s var(--ms-ease), border-color .15s var(--ms-ease), background .15s var(--ms-ease);
}
.ms-cas-op:hover { border-color: color-mix(in srgb, var(--ms-accent) 45%, transparent); background: var(--ms-key-op); color: var(--ms-key-op-ink); }
.ms-cas-op:active { transform: scale(.95); }
.ms-cas-var {
  display: inline-flex; align-items: center; gap: 6px; margin-left: auto;
  color: var(--ms-ink-soft); font-size: 12.5px; font-weight: 600;
}
.ms-cas-varin {
  width: 34px; text-align: center;
  border: 1px solid var(--ms-key-edge); background: var(--ms-surface);
  color: var(--ms-ink); border-radius: 8px; height: 28px;
  font: 600 14px var(--ms-font-mono);
}
.ms-cas-varin:focus { outline: 0; border-color: var(--ms-accent); }
.ms-cas-resultwrap {
  display: flex; flex-direction: column; gap: 6px;
  background: var(--ms-display-bg);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 14px; padding: 12px 14px; min-height: 58px;
}
.ms-cas-reslabel {
  color: var(--ms-display-sub); font-size: 11px; font-weight: 700;
  letter-spacing: .06em; text-transform: uppercase;
}
.ms-cas-reslabel:empty { display: none; }
.ms-cas-reshost { display: flex; min-height: 26px; }
.ms-cas-resfield {
  flex: 1; min-width: 0; font-size: 21px; background: transparent; color: var(--ms-display-ink);
  --caret-color: transparent;
}
.ms-cas-resfield.ms-mf-fallback {
  border: 0; outline: 0; background: transparent;
  color: var(--ms-display-ink); font: 500 17px var(--ms-font-mono);
}
.ms-cas-use {
  align-self: flex-start; margin-top: 2px;
  border: 1px solid rgba(255,255,255,.16); background: rgba(255,255,255,.06);
  color: var(--ms-display-ink); border-radius: 8px; height: 26px; padding: 0 10px;
  cursor: pointer; font-size: 12px; font-weight: 600;
  transition: background .15s var(--ms-ease);
}
.ms-cas-use:hover { background: rgba(124,92,255,.30); }
/* active operation button (used by Calculus op selector) */
.ms-cas-op.ms-on {
  background: var(--ms-grad); color: #fff; border-color: transparent;
}

/* ========================================================================== */
/*  Calculus module                                                            */
/* ========================================================================== */
.ms-calc-ops { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.ms-calc-params {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  font: 600 12px/1 var(--ms-font-mono); color: var(--ms-display-sub);
}
.ms-calc-num { display: inline-flex; align-items: center; gap: 5px; }
.ms-calc-num input, .ms-calc-dir {
  border: 1px solid var(--ms-key-edge); border-radius: 7px;
  background: var(--ms-surface); color: var(--ms-ink);
  padding: 4px 7px; font: 600 12.5px/1 var(--ms-font-mono);
  outline: none; transition: border-color .15s var(--ms-ease);
}
.ms-calc-num input:focus, .ms-calc-dir:focus { border-color: color-mix(in srgb, var(--ms-accent) 55%, transparent); }
.ms-calc-dir { cursor: pointer; }
/* Advanced CAS (SymPy) affordance + step hints */
.ms-calc-adv {
  display: none; align-self: flex-start; margin-top: 8px;
  border: 1px solid color-mix(in srgb, var(--ms-accent) 45%, transparent);
  background: rgba(124,92,255,.16); color: var(--ms-display-ink);
  border-radius: 8px; height: 28px; padding: 0 12px;
  cursor: pointer; font-size: 12.5px; font-weight: 600;
  transition: background .15s var(--ms-ease);
}
.ms-calc-adv:hover { background: rgba(124,92,255,.30); }
.ms-calc-adv:disabled { opacity: .6; cursor: default; }
.ms-calc-steps { display: none; margin-top: 8px; }
.ms-calc-step {
  color: var(--ms-display-sub); font-size: 12px; line-height: 1.5;
  padding: 1px 0;
}

/* ========================================================================== */
/*  Diff Eq module                                                             */
/* ========================================================================== */
.ms-ode-inwrap {
  display: flex; align-items: center; gap: 10px; padding: 10px 12px;
}
.ms-ode-lhs { color: var(--ms-display-sub); font: 700 15px var(--ms-font-mono); flex: none; }
.ms-ode-inhost { flex: 1; min-width: 0; display: flex; }
.ms-ode-field {
  flex: 1; min-width: 0; font-size: 18px; background: transparent;
  color: var(--ms-display-ink); --caret-color: var(--ms-accent-2);
}
.ms-ode-field.ms-mf-fallback {
  border: 0; outline: 0; background: transparent;
  color: var(--ms-display-ink); font: 500 15px var(--ms-font-mono);
}
.ms-ode-params {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 10px;
  font: 600 12px/1 var(--ms-font-mono); color: var(--ms-ink-soft);
}
.ms-ode-go { margin-left: auto; height: 30px; }
.ms-ode-body { display: flex; flex-direction: column; gap: 10px; margin-top: 10px; }
.ms-ode-canvas {
  width: 100%; height: 240px; display: block;
  background: var(--ms-surface); border: 1px solid var(--ms-key-edge);
  border-radius: 12px;
}
.ms-ode-tablewrap {
  max-height: 190px; overflow-y: auto; border: 1px solid var(--ms-key-edge);
  border-radius: 10px; scrollbar-width: thin;
}
.ms-ode-table { width: 100%; border-collapse: collapse; font: 500 12px var(--ms-font-mono); }
.ms-ode-table th, .ms-ode-table td {
  padding: 5px 10px; text-align: right; border-bottom: 1px solid var(--ms-key-edge);
  color: var(--ms-ink); white-space: nowrap;
}
.ms-ode-table th {
  position: sticky; top: 0; background: var(--ms-surface-2);
  color: var(--ms-ink-soft); font-weight: 700; text-align: right;
}
.ms-ode-table td:first-child, .ms-ode-table th:first-child { text-align: left; color: var(--ms-ink-soft); }
.ms-ode-table tbody tr:hover { background: var(--ms-key-op); }
.ms-ode-empty { padding: 16px; text-align: center; color: var(--ms-ink-soft); font-size: 13px; }

/* ---- Accessibility / reduced motion ------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .ms-root, .ms-key, .ms-winbtn, .ms-chip { animation: none !important; transition: none !important; }
}