:root {
  --dm-accent: #0056b3;
  --dm-accent-soft: rgba(0, 86, 179, 0.14);
  --dm-surface: #f7fbff;
  --dm-surface-strong: #eef5ff;
  --dm-border: #d6e1ef;
  --dm-text: #122033;
  --dm-muted: #526173;
  --dm-guide: #9db4d0;
  --dm-write: #ffd76a;
  --dm-answer: #0a7a4b;
  --dm-target: rgba(255, 215, 106, 0.3);
}

:root.dark {
  --dm-surface: #0f1722;
  --dm-surface-strong: #152234;
  --dm-border: #233247;
  --dm-text: #e5eef8;
  --dm-muted: #b8c5d4;
  --dm-guide: #5c708c;
  --dm-write: #8a6a00;
  --dm-answer: #5bd49d;
  --dm-target: rgba(255, 215, 106, 0.18);
}

.decimal-multiplication .eyebrow {
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--dm-accent);
  font-weight: 800;
  margin-bottom: 6px;
}

.decimal-multiplication .dm-grid {
  display: grid;
  gap: 16px;
}

.decimal-multiplication .dm-grid.two-col {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  align-items: start;
}

.decimal-multiplication .dm-field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 12px;
}

.decimal-multiplication .dm-field,
.decimal-multiplication .dm-options,
.decimal-multiplication .dm-panel {
  background: var(--dm-surface);
  border: 1px solid var(--dm-border);
  border-radius: 14px;
  padding: 12px;
}

.decimal-multiplication .dm-field .label,
.decimal-multiplication .dm-options .label {
  display: block;
  font-weight: 700;
  color: var(--dm-text);
  margin-bottom: 6px;
}

.decimal-multiplication .dm-options .checkbox {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  margin-top: 8px;
  color: var(--dm-text);
}

.decimal-multiplication .dm-actions,
.decimal-multiplication .chip-row,
.decimal-multiplication .step-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.decimal-multiplication .dm-actions .button {
  min-width: 120px;
}

.decimal-multiplication .chip {
  border: 1px solid var(--dm-border);
  background: var(--dm-surface-strong);
  color: var(--dm-text);
  padding: 8px 12px;
  border-radius: 999px;
  font-weight: 700;
  cursor: pointer;
}

.decimal-multiplication .chip:hover,
.decimal-multiplication .chip:focus-visible {
  border-color: var(--dm-accent);
  outline: none;
}

.decimal-multiplication .result-panel {
  background: linear-gradient(180deg, rgba(0, 86, 179, 0.08) 0%, rgba(0, 86, 179, 0.02) 100%);
  border: 1px solid var(--dm-border);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 16px 40px rgba(0, 86, 179, 0.12);
}

.decimal-multiplication .result-value {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 900;
  color: var(--dm-text);
  line-height: 1.1;
  word-break: break-word;
}

.decimal-multiplication #result-note {
  margin-top: 10px;
  display: grid;
  gap: 6px;
}

.decimal-multiplication .result-line {
  color: var(--dm-muted);
}

.decimal-multiplication .check-panel {
  margin-top: 12px;
  display: grid;
  gap: 10px;
  padding: 12px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--dm-border);
  border-radius: 14px;
}

.decimal-multiplication .check-panel__title,
.decimal-multiplication .check-card__title {
  font-weight: 800;
  color: var(--dm-text);
}

.decimal-multiplication .check-panel__cards {
  display: grid;
  gap: 10px;
}

.decimal-multiplication .check-card {
  display: grid;
  gap: 6px;
  padding: 10px;
  background: var(--dm-surface);
  border: 1px solid var(--dm-border);
  border-radius: 12px;
}

.decimal-multiplication .check-card--approx {
  background: var(--dm-surface-strong);
}

.decimal-multiplication .check-card__expression {
  font-weight: 700;
  color: var(--dm-text);
  word-break: break-word;
}

.decimal-multiplication .check-card__note {
  color: var(--dm-muted);
}

.decimal-multiplication.is-teacher .check-card {
  border-width: 2px;
}

.decimal-multiplication .layout-shell {
  background: #fff;
  border: 1px solid var(--dm-border);
  border-radius: 14px;
  padding: 12px;
  overflow-x: auto;
}

.decimal-multiplication .layout-shell .dm-layout {
  min-width: max-content;
}

.decimal-multiplication .steps-list {
  margin: 0;
  padding-inline-start: 20px;
  display: grid;
  gap: 8px;
}

.decimal-multiplication .steps-list li {
  background: var(--dm-surface);
  border: 1px solid var(--dm-border);
  border-radius: 10px;
  padding: 8px 10px;
  line-height: 1.6;
}

.decimal-multiplication .steps-list li.active-step {
  background: var(--dm-accent-soft);
  border-color: var(--dm-accent);
  font-weight: 700;
}

.decimal-multiplication .input-hint.error {
  color: #b3261e;
}

.decimal-multiplication .dm-layout {
  display: grid;
  gap: 3px;
}

.decimal-multiplication .dm-row {
  display: grid;
  grid-template-columns: 1.75rem auto;
  align-items: center;
  gap: 8px;
}

.decimal-multiplication .dm-operator {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 1.75rem;
  font-weight: 800;
  color: var(--dm-text);
}

.decimal-multiplication .dm-operator--times,
.decimal-multiplication .dm-operator--plus {
  color: var(--dm-accent);
}

.decimal-multiplication .dm-digits {
  display: grid;
  grid-template-columns: repeat(var(--dm-cols, 1), minmax(1.8rem, 1.8rem));
  gap: 2px;
}

.decimal-multiplication .dm-rule {
  border-top: 3px solid var(--dm-text);
  width: calc(var(--dm-cols, 1) * 1.8rem + (var(--dm-cols, 1) - 1) * 2px);
}

.decimal-multiplication .dm-cell {
  min-height: 1.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  color: var(--dm-text);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.decimal-multiplication .has-guides .dm-cell {
  border: 1px dashed var(--dm-guide);
}

.decimal-multiplication .dm-cell--carry {
  font-size: 0.9rem;
  color: var(--dm-accent);
  font-weight: 800;
}

.decimal-multiplication .dm-cell--row-active {
  background: rgba(0, 86, 179, 0.06);
}

.decimal-multiplication .dm-cell--addition {
  background: rgba(10, 122, 75, 0.12);
  outline: 2px solid rgba(10, 122, 75, 0.32);
  outline-offset: -1px;
}

.decimal-multiplication .dm-cell--write {
  background: rgba(255, 215, 106, 0.45);
  outline: 2px solid rgba(138, 106, 0, 0.7);
  outline-offset: -1px;
}

.decimal-multiplication .dm-cell--answer {
  color: var(--dm-answer);
}

.decimal-multiplication .dm-cell.is-active {
  background: var(--dm-accent-soft);
  outline: 2px solid rgba(0, 86, 179, 0.48);
  outline-offset: -1px;
  text-decoration: underline;
  text-underline-offset: 0.12em;
}

.decimal-multiplication .dm-placement {
  display: grid;
  gap: 12px;
}

.decimal-multiplication .dm-count-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
}

.decimal-multiplication .dm-count-card {
  border: 1px solid var(--dm-border);
  border-radius: 12px;
  padding: 10px;
  background: var(--dm-surface);
}

.decimal-multiplication .dm-count-card.is-active {
  background: var(--dm-accent-soft);
  border-color: var(--dm-accent);
}

.decimal-multiplication .dm-count-label {
  color: var(--dm-muted);
  font-size: 0.92rem;
}

.decimal-multiplication .dm-count-value {
  color: var(--dm-text);
  font-weight: 800;
  font-size: 1.2rem;
}

.decimal-multiplication .dm-placement-block {
  border: 1px solid var(--dm-border);
  border-radius: 12px;
  padding: 12px;
  background: var(--dm-surface);
  display: grid;
  gap: 8px;
}

.decimal-multiplication .dm-placement-block.is-active {
  border-color: var(--dm-accent);
  box-shadow: inset 0 0 0 1px rgba(0, 86, 179, 0.18);
}

.decimal-multiplication .dm-placement-label {
  color: var(--dm-muted);
  font-weight: 700;
}

.decimal-multiplication .dm-place-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  font-family: Menlo, 'Roboto Mono', monospace;
}

.decimal-multiplication .dm-place-digit {
  min-width: 1.8rem;
  min-height: 1.8rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px dashed var(--dm-guide);
  border-radius: 8px;
  font-weight: 700;
  color: var(--dm-text);
}

.decimal-multiplication .dm-place-digit--target {
  background: var(--dm-target);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

.decimal-multiplication .dm-place-digit.is-active {
  outline: 2px solid rgba(0, 86, 179, 0.48);
  outline-offset: -1px;
}

.decimal-multiplication .dm-placement-value,
.decimal-multiplication .dm-placement-trimmed {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--dm-text);
  word-break: break-word;
}

.decimal-multiplication .dm-placement-trimmed {
  color: var(--dm-answer);
}

.decimal-multiplication .dm-placement-trimmed.is-active {
  text-decoration: underline;
  text-underline-offset: 0.12em;
}

.decimal-multiplication.is-teacher .layout-shell,
.decimal-multiplication.is-teacher .dm-layout.is-teacher {
  border-width: 2px;
}

.decimal-multiplication.is-teacher .dm-cell,
.decimal-multiplication.is-teacher .steps-list li,
.decimal-multiplication.is-teacher .dm-place-digit {
  font-size: 1.05rem;
}

@media (min-width: 1080px) {
  .decimal-multiplication .dm-grid.two-col {
    grid-template-columns: minmax(360px, 520px) 1fr;
  }
}