.balance-lab { --balance-accent: #c8b6f2; --balance-gold: #f0cc89; --card-footer-color: #b1a5c7; display: flex; flex-direction: column; gap: var(--card-footer-gap); width: 100%; height: 100%; min-height: 0; padding: var(--format-top) max(var(--edge), env(safe-area-inset-right)) var(--content-bottom) max(var(--edge), env(safe-area-inset-left)); color: #faf6ff; background: radial-gradient(ellipse at 85% 12%, #64508655, transparent 65%), #29253f; }
.balance-lab button, .balance-lab input, .balance-explanation button { font: inherit; -webkit-tap-highlight-color: transparent; }
.balance-lab button { cursor: pointer; }
.balance-lab button:focus-visible, .balance-lab input:focus-visible, .balance-lab__scroll:focus-visible { outline: 2px solid var(--balance-gold); outline-offset: 3px; }
.balance-lab button:disabled { opacity: .4; cursor: default; }
.balance-lab__scroll { flex: 1; min-height: 0; overflow-y: auto; scrollbar-width: thin; scrollbar-color: #6e5e84 transparent; }
.balance-lab__scroll.is-scrollable { touch-action: pan-y; }
.balance-lab__body { display: flex; flex-direction: column; gap: 18px; width: 100%; max-width: 600px; min-height: 100%; margin-inline: auto; padding: 8px 0 2px; }
.balance-lab__intro { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.balance-lab__intro > div { min-width: 0; }
.balance-lab__eyebrow { margin: 0 0 6px; color: #c0b0d5; font-size: 9px; font-weight: 650; letter-spacing: .12em; }
.balance-lab__title { margin: 0; font-size: clamp(26px, 3.4vw, 36px); line-height: 1.12; font-weight: 650; letter-spacing: -.04em; overflow-wrap: anywhere; }
.balance-lab__reset { display: grid; place-items: center; flex: none; width: 44px; height: 44px; padding: 0; border: 1px solid #7d6a9266; border-radius: 50%; color: #ded0ef; background: transparent; }
.balance-lab__reset svg { width: 21px; height: 21px; }
.balance-lab__workspace { display: flex; flex: none; flex-direction: column; gap: 18px; padding: 4px 0 0; }
.balance-lab__equation { margin: 0; color: #f2e0b9; font: 500 clamp(28px, 6vw, 38px)/1.3 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; text-align: center; letter-spacing: -.05em; overflow-wrap: anywhere; }
.balance-lab__equation.is-long { font-size: clamp(16px, 3.8vw, 24px); }
.balance-lab__figure { margin: 0; padding: 8px; border-radius: 22px; color: #534665; background: #f7f3f9; }
.balance-visual { display: block; width: 100%; height: clamp(154px, 26dvh, 254px); overflow: visible; }
.balance-visual__beam { transition: transform 650ms cubic-bezier(.2,.8,.2,1); }
.balance-visual__tile { stroke-width: 1.5; }
.balance-visual__tile.is-x { fill: #b89bdd; stroke: #9d7ac6; }
.balance-visual__tile.is-unit { fill: #f2d39b; stroke: #d9b371; }
.balance-visual__tile.is-negative { fill: #f7f3f9; stroke-dasharray: 3 2; }
.balance-visual__tile-label { fill: #3e3156; font: 600 19px ui-monospace, SFMono-Regular, Menlo, monospace; }
.balance-lab__changes { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; padding: 0 3% 6px; }
.balance-lab__change { justify-self: center; color: #674188; font: 600 13px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace; text-align: center; }
.balance-lab__feedback { padding: 0 2px; }
.balance-lab__success-icon { display: block; width: 34px; height: 34px; grid-row: 1 / 3; color: var(--balance-gold); }
.balance-lab__success-icon svg { display: block; width: 100%; height: 100%; }
.balance-lab__proof { grid-column: 1 / -1; margin: 4px 0 0; color: #f2ddb7; font-size: 12px; line-height: 1.5; }
.balance-lab__feedback-title { display: block; font-size: 14px; font-weight: 500; line-height: 1.45; color: #e0d0f6; }
.balance-lab__feedback-copy { margin: 5px 0 0; font-size: 12px; line-height: 1.5; color: #bfb0d2; }
.balance-lab.is-solved .balance-lab__feedback-title { color: #f0cc89; }
.balance-lab.is-solved .balance-lab__feedback { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 6px 12px; padding: 16px; border: 1px solid #f0cc8955; border-radius: 16px; background: #ffffff08; }
.balance-lab.is-solved .balance-lab__feedback-title { font-size: 20px; font-weight: 650; }
.balance-lab.is-solved .balance-lab__feedback-copy { margin: 0; }
.balance-lab.is-solved .balance-lab__figure { box-shadow: inset 0 0 0 2px var(--balance-gold); }
.balance-lab__controls { display: flex; flex: 1; flex-direction: column; gap: 8px; }
.balance-lab__input-row { display: grid; grid-template-columns: minmax(0, 1fr) clamp(64px, 20%, 84px); gap: 8px; align-items: center; }
.balance-lab__dock { display: grid; margin-block-start: auto; padding-block-start: 12px; }
.balance-lab__operations { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 3px; padding: 4px; border-radius: 15px; background: #ffffff0a; }
.balance-lab__operation { min-height: 44px; padding: 8px 5px; border: 0; border-radius: 11px; background: transparent; color: #dfd0ee; font-size: 12px !important; }
.balance-lab__operation[aria-pressed="true"] { color: #2d2244; background: #c8b6f2; font-weight: 650; }
.balance-lab__quantity { position: relative; }
.balance-lab__quantity label { position: absolute; top: 6px; inset-inline: 0; margin: 0; color: #c2b1d5; font-size: 9px; text-align: center; pointer-events: none; }
.balance-lab__amount { width: 100%; height: 52px; padding: 19px 10px 2px; border: 1px solid #8c779f88; border-radius: 13px; background: transparent; color: #f2e8ff; font: 500 20px ui-monospace, SFMono-Regular, Menlo, monospace !important; text-align: center; color-scheme: dark; }
.balance-lab__apply { width: 100%; min-height: 48px; padding: 10px 14px; border: 1px solid #f0cc89; border-radius: 14px; background: #f0cc89; color: #342a40; font-size: 14px !important; font-weight: 650 !important; }
.balance-lab__error { margin: 0; color: #ffcfca; font-size: 12px; line-height: 1.45; }
.balance-lab__tools { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-block-start: -4px; }
.balance-lab__why { margin-inline-end: auto; }
.balance-lab__undo, .balance-lab__why { min-height: 44px; padding: 7px 0; border: 0; background: transparent; font-size: 11px !important; color: #c9b7df; text-align: left; }
.balance-lab__why { text-decoration: underline; text-underline-offset: 4px; }
.balance-explanation { --sheet-surface: #f6f0f9; --sheet-ink: #49365e; --sheet-muted: #806c95; --sheet-border: #e2d6ec; --sheet-control: #e9def2; --sheet-control-ink: #614778; --sheet-focus: #79569a; --sheet-handle: #cfbddc; --sheet-backdrop: #21173377; }
.balance-explanation__body { padding: 20px max(var(--edge), 20px); }
.balance-explanation__intro, .balance-explanation__copy { margin: 0; font-size: 14px; line-height: 1.6; }
.balance-explanation__intro { color: #806c95; font-size: 12px; }
.balance-explanation__equation { margin: 20px 0 0; font: 500 26px/1.3 ui-monospace, SFMono-Regular, Menlo, monospace; text-align: center; }
.balance-explanation .balance-visual { width: 100%; height: 205px; margin-block: 8px 16px; }
.balance-explanation__copy { padding: 14px; border-radius: 12px; background: #eae0f3; }
.balance-explanation__note { margin: 16px 0 0; font-size: 12px; line-height: 1.6; color: #806c95; }
.balance-explanation__actions { padding: 14px max(var(--edge), 20px) var(--content-bottom); border-top: 1px solid var(--sheet-border); }
.balance-explanation__try { width: 100%; min-height: 48px; padding: 12px; border: 0; border-radius: 12px; background: #75508f; color: #fff; font-size: 13px !important; cursor: pointer; }
@media (max-height: 740px) {
  .balance-lab__body { gap: 9px; }
  .balance-lab__title { font-size: 25px; }
  .balance-lab__workspace { gap: 10px; padding-block: 4px; }
  .balance-lab__equation { font-size: 28px; }
  .balance-lab__figure { padding-block: 7px; }
  .balance-lab .balance-visual { height: 145px; }
  .balance-lab__controls { gap: 7px; }
  .balance-lab__feedback-copy { margin-top: 3px; }
  .balance-lab.is-solved .balance-visual { height: 125px; }
  .balance-lab.is-solved .balance-lab__feedback { grid-template-columns: 28px minmax(0, 1fr); gap: 5px 10px; padding: 12px; }
  .balance-lab.is-solved .balance-lab__success-icon { width: 28px; height: 28px; }
  .balance-lab.is-solved .balance-lab__feedback-title { font-size: 18px; }
}
@media (max-width: 699px) and (max-height: 600px) {
  .balance-lab__body { gap: 6px; padding-block: 2px; }
  .balance-lab__title { font-size: 23px; }
  .balance-lab .balance-visual { height: 116px; }
  .balance-lab__equation { font-size: 26px; }
  .balance-lab__feedback-copy { font-size: 11px; }
  .balance-lab__feedback-title { font-size: 13px; }
  .balance-lab__apply { min-height: 44px; }
  .balance-lab.is-solved .balance-visual { height: 96px; }
  .balance-lab.is-solved .balance-lab__feedback { padding: 10px; }
  .balance-lab__proof { font-size: 11px; }
}
@media (prefers-reduced-motion: reduce) { .balance-visual__beam { transition: none; } }
@media (hover: hover) { .balance-lab__reset:hover, .balance-lab__operation[aria-pressed="false"]:hover { background: #ffffff14; } .balance-lab__apply:hover { background: #f6dab0; } }