mathew/frontend/app/assets/css/_calculator.scss

@use 'mixins' as *;

// ---------- Graphing calculator (/calculator) ----------

// desktop: the plane owns the space beside the sidebar the way the link
// map does — a full surface with the function dock and the zoom buttons
// floating over it. (The page transition only fades, so no transform
// steals the fixed positioning.)
.calc-stage {
  position: fixed;
  inset: 0 0 0 var(--sidebar-w);
  transition: left 0.22s ease;
  z-index: 1;
  background: var(--bg);
}

// the plane fills the stage
.plot-wrap {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: var(--surface);
}

.plot-canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none; // the plane owns drags and pinches, not the page
}

// the function dock, pinned to the plane's left edge
.calc-dock {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 2;
  display: flex;
  flex-direction: column;
  width: clamp(260px, 24vw, 320px);
  padding: 18px 16px;
  border-right: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg-elev) 92%, transparent);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
  overflow-y: auto;
}

.calc-dock-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin: 0 0 14px;
}

.calc-dock-title {
  @include eyebrow(0.74rem, 750, 0.09em);
  margin: 0;
}

.calc-rows {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.calc-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

// the curve's hue; a press hands it on to the next one in the palette
.calc-swatch {
  flex: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid color-mix(in srgb, var(--text) 12%, transparent);
  transition: transform 0.15s;

  &:hover { transform: scale(1.2); }
}

.calc-input-box {
  flex: 1;
  display: flex;
  align-items: center;
  min-width: 0;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  transition: border-color 0.15s, box-shadow 0.15s;

  &:focus-within {
    border-color: var(--accent);
    box-shadow: var(--ring);
  }

  .calc-item.invalid & {
    border-color: color-mix(in srgb, var(--danger) 55%, transparent);
  }
}

// the "y =" the field answers to, set like the math it introduces
.calc-y {
  flex: none;
  padding: 0 2px 0 10px;
  color: var(--faint);
  font: italic 0.95rem/1 'Computer Modern', Georgia, serif;
}

.calc-input {
  flex: 1;
  min-width: 0;
  padding: 9px 10px 9px 6px;
  border: 0;
  outline: none;
  background: transparent;
  color: var(--text);
  font: 0.95rem/1.2 'Computer Modern', Georgia, serif;

  &::placeholder { color: var(--faint); opacity: 0.75; }

  &.input-error { color: var(--danger); }
}

.calc-remove:hover {
  color: var(--danger);
  background: color-mix(in srgb, var(--danger) 10%, transparent);
}

.calc-error {
  display: block;
  margin: 5px 2px 1px;
  color: var(--danger);
  font-size: 0.78rem;
}

.calc-add { margin-top: 12px; }

// the fold: the dock slides out to the left, under the app sidebar, and a
// quiet card takes its place at the plane's top-left corner
.calc-dock-enter-active,
.calc-dock-leave-active { transition: transform 0.22s ease; }

.calc-dock-enter-from,
.calc-dock-leave-to { transform: translateX(-105%); }

.calc-dock-open {
  position: absolute;
  top: 10px;
  left: 12px;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: color-mix(in srgb, var(--bg-elev) 84%, transparent);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 650;
  white-space: nowrap;
  transition: color 0.15s, background-color 0.15s;

  &:hover { color: var(--text); background: var(--surface-2); }
}

// the button row floating on the plane's top-right corner — clear of the dock
.plot-toolbar {
  position: absolute;
  top: 10px;
  right: 12px;
  z-index: 2;
  display: flex;
  gap: 2px;
  padding: 4px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: color-mix(in srgb, var(--bg-elev) 84%, transparent);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}

// where the cursor stands, bottom-right so the dock never covers it
.plot-readout {
  position: absolute;
  bottom: 10px;
  right: 12px;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: color-mix(in srgb, var(--bg-elev) 84%, transparent);
  backdrop-filter: blur(10px);
  color: var(--muted);
  font: 0.78rem/1.3 'Computer Modern', Georgia, serif;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

// the top bar is in the flow here, so the calculator folds into panels of
// the page: the dock first, then the plane as its own card
@media (max-width: 900px) {
  .calc-stage {
    position: static;
    inset: auto;
    display: flex;
    flex-direction: column;
    background: transparent;
  }

  .calc-dock {
    position: static;
    order: 1;
    width: auto;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: var(--bg-elev);
    backdrop-filter: none;
    box-shadow: var(--shadow-sm);
    overflow: visible;
  }

  .plot-wrap {
    position: static;
    order: 2;
    width: 100%;
    height: min(66dvh, 560px);
    border: 1px solid var(--border);
    border-radius: 14px;
  }

  .plot-toolbar { top: 8px; right: 8px; }

  // during the fold the dock lifts out of the flow, so the plane takes the
  // width back at once rather than after the slide
  .calc-dock-leave-active { position: absolute; left: 0; right: 0; }
}