/* =========================================================
   Decimal Multiplication Practice
   File:
   /interactive-learning-tools/decimal-multiplication/
   decimal-multiplication.css
   ========================================================= */

.decimal-multiplication-page {
    background: #ffffff;
    color: #1f2937;
    font-family: "Inter", sans-serif;
}

.decimal-multiplication-page *,
.decimal-multiplication-page *::before,
.decimal-multiplication-page *::after {
    box-sizing: border-box;
}


/* =========================================================
   Shared Section Styles
   ========================================================= */

.decimal-multiplication-overview,
.decimal-multiplication-tool-section,
.decimal-multiplication-strategies,
.decimal-multiplication-comparison,
.decimal-multiplication-applications,
.decimal-multiplication-cta {
    padding: 5rem 0;
}

.decimal-multiplication-overview,
.decimal-multiplication-strategies,
.decimal-multiplication-applications {
    background: #f7f9fc;
}

.decimal-multiplication-tool-section,
.decimal-multiplication-comparison,
.decimal-multiplication-cta {
    background: #ffffff;
}

.decimal-multiplication-section-heading {
    max-width: 780px;
    margin: 0 auto 2.5rem;
    text-align: center;
}

.decimal-multiplication-section-heading h2 {
    margin-bottom: 1rem;
    color: #101827;
    font-size: clamp(1.75rem, 3vw, 2.4rem);
    font-weight: 800;
}

.decimal-multiplication-section-heading > p:last-child {
    margin-bottom: 0;
    color: #5b6678;
    font-size: 1.05rem;
    line-height: 1.75;
}

.decimal-multiplication-eyebrow {
    margin-bottom: 0.65rem;
    color: #0f766e;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}


/* =========================================================
   Overview Cards
   ========================================================= */

.decimal-multiplication-overview-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1rem;
}

.decimal-multiplication-overview-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.5rem;
    box-shadow: 0 12px 30px rgba(16, 24, 39, 0.05);
    transition:
        transform 0.2s ease,
        box-shadow 0.2s ease;
}

.decimal-multiplication-overview-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 16px 34px rgba(16, 24, 39, 0.08);
}

.decimal-multiplication-overview-card h3 {
    margin-bottom: 0.75rem;
    color: #101827;
    font-size: 1.1rem;
    font-weight: 800;
}

.decimal-multiplication-overview-card p {
    margin-bottom: 0;
    color: #5b6678;
    line-height: 1.65;
}

.decimal-multiplication-step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.65rem;
    height: 2.65rem;
    margin-bottom: 1rem;
    border-radius: 50%;
    background: #0f766e;
    color: #ffffff;
    font-weight: 800;
}


/* =========================================================
   Main Tool Shell
   ========================================================= */

.decimal-multiplication-tool {
    max-width: 1100px;
    margin: 0 auto;
    overflow: hidden;
    border: 1px solid #dce3eb;
    border-radius: 1.25rem;
    background: #ffffff;
    box-shadow: 0 22px 55px rgba(16, 24, 39, 0.1);
}

.decimal-multiplication-tool-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    border-bottom: 1px solid #273449;
    background: #101827;
    color: #ffffff;
    padding: 1.75rem 2rem;
}

.decimal-multiplication-tool-header h2 {
    margin-bottom: 0;
    color: #ffffff;
    font-size: clamp(1.45rem, 3vw, 2rem);
    font-weight: 800;
}

.decimal-multiplication-tool-header
.decimal-multiplication-eyebrow {
    color: #5eead4;
}


/* =========================================================
   Scoreboard
   ========================================================= */

.decimal-multiplication-scoreboard {
    display: grid;
    grid-template-columns: repeat(3, minmax(80px, 1fr));
    gap: 0.75rem;
}

.decimal-multiplication-score-item {
    min-width: 90px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 0.8rem;
    background: rgba(255, 255, 255, 0.08);
    padding: 0.75rem 0.9rem;
    text-align: center;
}

.decimal-multiplication-score-label {
    display: block;
    margin-bottom: 0.2rem;
    color: rgba(255, 255, 255, 0.72);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.decimal-multiplication-score-item strong {
    color: #ffffff;
    font-size: 1.4rem;
    font-weight: 800;
}


/* =========================================================
   Settings
   ========================================================= */

.decimal-multiplication-settings {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr)) auto;
    gap: 1rem;
    align-items: end;
    border-bottom: 1px solid #dce3eb;
    background: #f7f9fc;
    padding: 1.5rem 2rem;
}

.decimal-multiplication-setting-group label {
    display: block;
    margin-bottom: 0.45rem;
    color: #273449;
    font-size: 0.9rem;
    font-weight: 700;
}

.decimal-multiplication-setting-group .form-select {
    min-height: 3rem;
    border-color: #cfd8e3;
    border-radius: 0.75rem;
    background-color: #ffffff;
}

.decimal-multiplication-setting-group .form-select:focus {
    border-color: #0f766e;
    box-shadow: 0 0 0 0.2rem rgba(15, 118, 110, 0.14);
}

.decimal-multiplication-setting-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.decimal-multiplication-setting-actions .btn {
    min-height: 3rem;
    white-space: nowrap;
}


/* =========================================================
   Buttons
   ========================================================= */

.decimal-multiplication-page .btn-teal {
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
}

.decimal-multiplication-page .btn-teal:hover,
.decimal-multiplication-page .btn-teal:focus {
    border-color: #0b5f59;
    background: #0b5f59;
    color: #ffffff;
}

.decimal-multiplication-page .btn-outline-teal {
    border-color: #0f766e;
    background: transparent;
    color: #0f766e;
}

.decimal-multiplication-page .btn-outline-teal:hover,
.decimal-multiplication-page .btn-outline-teal:focus {
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
}


/* =========================================================
   Problem Display
   ========================================================= */

.decimal-multiplication-problem-area {
    border-bottom: 1px solid #dce3eb;
    background: #ffffff;
    padding: 2.25rem 2rem;
}

.decimal-multiplication-problem-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.65rem;
    margin-bottom: 1rem;
}

.decimal-multiplication-problem-label {
    margin-bottom: 0;
    color: #0f766e;
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.09em;
    text-transform: uppercase;
}

.decimal-multiplication-difficulty-badge,
.decimal-multiplication-stage-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    padding: 0.32rem 0.7rem;
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.decimal-multiplication-difficulty-badge {
    background: #e2e8f0;
    color: #475569;
}

.decimal-multiplication-difficulty-badge.easy {
    background: #dcfce7;
    color: #166534;
}

.decimal-multiplication-difficulty-badge.medium {
    background: #dbeafe;
    color: #1e40af;
}

.decimal-multiplication-difficulty-badge.hard {
    background: #fef3c7;
    color: #92400e;
}

.decimal-multiplication-stage-badge {
    background: #ede9fe;
    color: #5b21b6;
}

.decimal-multiplication-problem-text {
    max-width: 850px;
    margin: 0 auto;
    color: #101827;
    font-size: clamp(1.15rem, 2.4vw, 1.45rem);
    font-weight: 700;
    line-height: 1.7;
    text-align: center;
}

.decimal-multiplication-original-problem {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    width: fit-content;
    margin: 1.25rem auto 0;
    border: 1px solid #99d5cf;
    border-radius: 0.85rem;
    background: #f0fdfa;
    color: #101827;
    padding: 0.85rem 1.25rem;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.55rem, 4vw, 2rem);
    font-variant-numeric: tabular-nums;
    font-weight: 800;
}

.decimal-multiplication-original-problem > span:nth-child(2) {
    color: #0f766e;
    font-family: "Inter", sans-serif;
}

.decimal-multiplication-whole-number-note {
    max-width: 680px;
    margin: 0.9rem auto 0;
    color: #52736f;
    font-size: 0.9rem;
    font-weight: 650;
    line-height: 1.55;
    text-align: center;
}


/* =========================================================
   Vertical Multiplication Board
   ========================================================= */

.decimal-multiplication-board-wrap {
    display: flex;
    justify-content: center;
    max-width: 720px;
    margin: 1.5rem auto 0;
    overflow-x: auto;
    border: 1px solid #99d5cf;
    border-radius: 1rem;
    background:
        linear-gradient(180deg, #f0fdfa 0%, #ffffff 48%);
    padding: 1.25rem 1.4rem 1.4rem;
    scrollbar-width: thin;
    scrollbar-color: #99d5cf transparent;
}

.decimal-multiplication-board {
    width: min(100%, 610px);
    min-width: 340px;
    margin: 0 auto;
    border-spacing: 0;
    border-collapse: separate;
    table-layout: fixed;
}

.decimal-multiplication-board th,
.decimal-multiplication-board td {
    width: auto;
    min-width: 0;
    border: 0;
    padding: 0.22rem 0.1rem;
    text-align: center;
    vertical-align: middle;
}

.decimal-multiplication-board th:first-child,
.decimal-multiplication-board td:first-child {
    width: 2.7rem;
}

.decimal-multiplication-number-row th,
.decimal-multiplication-number-row td {
    height: 3.15rem;
    color: #101827;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.55rem, 4vw, 2.05rem);
    font-variant-numeric: tabular-nums;
    font-weight: 800;
    line-height: 1;
}

.decimal-multiplication-operation-cell {
    color: #0f766e !important;
    font-family: "Inter", sans-serif !important;
    font-size: clamp(1.65rem, 4vw, 2.1rem) !important;
}

.decimal-multiplication-bottom-factor-row td {
    padding-top: 0.3rem;
}

.decimal-multiplication-rule-row td {
    height: 0.75rem;
    padding: 0 0.1rem;
}

.decimal-multiplication-rule {
    display: block;
    width: 100%;
    border-top: 3px solid #273449;
}

.decimal-multiplication-partial-row th,
.decimal-multiplication-partial-row td,
.decimal-multiplication-product-row th,
.decimal-multiplication-product-row td {
    height: 3.65rem;
    padding-top: 0.3rem;
    padding-bottom: 0.3rem;
}

.decimal-multiplication-partial-row +
.decimal-multiplication-partial-row td,
.decimal-multiplication-partial-row +
.decimal-multiplication-partial-row th {
    border-top: 1px dashed #d6e7e5;
}

.decimal-multiplication-partial-operation {
    color: #0f766e;
    font-size: 1.4rem;
    font-weight: 800;
}

.decimal-multiplication-product-rule-row td {
    padding-top: 0.35rem;
}

.decimal-multiplication-product-row {
    background: rgba(236, 253, 245, 0.55);
}

.decimal-multiplication-product-row th:first-child {
    border-radius: 0.65rem 0 0 0.65rem;
}

.decimal-multiplication-product-row td:last-child {
    border-radius: 0 0.65rem 0.65rem 0;
}

.decimal-multiplication-digit-input {
    display: block;
    width: calc(100% - 0.28rem);
    min-width: 0;
    max-width: 3.85rem;
    height: 3rem;
    margin: 0 auto;
    border: 2px solid #5ab8af;
    border-radius: 0.58rem;
    background: #ffffff;
    color: #101827;
    caret-color: #0f766e;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.25rem, 3.5vw, 1.75rem);
    font-variant-numeric: tabular-nums;
    font-weight: 800;
    line-height: 1;
    text-align: center;
    transition:
        border-color 0.16s ease,
        background 0.16s ease,
        box-shadow 0.16s ease,
        transform 0.16s ease;
}

.decimal-multiplication-product-input {
    border-color: #22a06b;
    background: #fbfffc;
}

.decimal-multiplication-digit-input:hover {
    border-color: #0f766e;
    background: #f8fffe;
}

.decimal-multiplication-digit-input:focus {
    border-color: #0f766e;
    background: #ffffff;
    outline: 0;
    box-shadow:
        0 0 0 0.22rem rgba(15, 118, 110, 0.16),
        0 5px 14px rgba(15, 118, 110, 0.12);
    transform: translateY(-1px);
}

.decimal-multiplication-digit-input.correct,
.decimal-multiplication-digit-input.input-correct {
    border-color: #15803d;
    background: #f0fdf4;
    color: #166534;
    box-shadow: 0 0 0 0.18rem rgba(21, 128, 61, 0.12);
}

.decimal-multiplication-digit-input.incorrect,
.decimal-multiplication-digit-input.input-incorrect {
    border-color: #dc2626;
    background: #fef2f2;
    color: #991b1b;
    box-shadow: 0 0 0 0.18rem rgba(220, 38, 38, 0.1);
}

.decimal-multiplication-digit-input.hint-target {
    border-color: #d97706;
    background: #fffbeb;
    box-shadow: 0 0 0 0.2rem rgba(217, 119, 6, 0.14);
}

.decimal-multiplication-digit-input:disabled {
    cursor: default;
    opacity: 0.72;
}

.decimal-multiplication-digit-input[hidden],
.decimal-multiplication-board [hidden] {
    display: none !important;
}

.decimal-multiplication-fixed-zero {
    color: #2563eb;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.3rem, 3.5vw, 1.8rem);
    font-weight: 800;
}

.decimal-multiplication-partial-note {
    max-width: 680px;
    margin: 0.95rem auto 0;
    color: #52736f;
    font-size: 0.86rem;
    font-weight: 600;
    line-height: 1.55;
    text-align: center;
}

.decimal-multiplication-partial-note:empty,
.decimal-multiplication-partial-note[hidden] {
    display: none !important;
}


/* =========================================================
   Workspaces and Answer Controls
   ========================================================= */

.decimal-multiplication-workspace,
.decimal-multiplication-decimal-workspace {
    border-top: 1px solid #edf2f7;
    background: #f8fafc;
    padding: 1.7rem 2rem 2rem;
    text-align: center;
}

.decimal-multiplication-decimal-workspace {
    margin: 0 2rem 2rem;
    overflow: hidden;
    border: 1px solid #c4b5fd;
    border-radius: 1rem;
    background: #faf8ff;
    animation: decimal-multiplication-fade-in 0.24s ease;
}

.decimal-multiplication-decimal-workspace[hidden] {
    display: none !important;
}

.decimal-multiplication-work-label {
    margin-bottom: 0.5rem;
    color: #0f766e;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.decimal-multiplication-workspace h3,
.decimal-multiplication-decimal-workspace h3 {
    margin-bottom: 0.75rem;
    color: #101827;
    font-size: clamp(1.35rem, 3vw, 1.75rem);
    font-weight: 800;
}

.decimal-multiplication-response-instruction {
    max-width: 780px;
    margin: 0 auto 1.35rem;
    color: #5b6678;
    line-height: 1.7;
}

.decimal-multiplication-answer-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
}


/* =========================================================
   Decimal-Place Count and Product Builder
   ========================================================= */

.decimal-multiplication-place-count-card {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.65rem;
    width: fit-content;
    max-width: 100%;
    margin: 1.1rem auto 1.35rem;
    border: 1px solid #ddd6fe;
    border-radius: 0.9rem;
    background: #ffffff;
    color: #4c1d95;
    padding: 0.85rem 1rem;
    font-size: 1.15rem;
    font-weight: 800;
}

.decimal-multiplication-place-count-input {
    width: 3.15rem;
    height: 2.85rem;
    border: 2px solid #8b5cf6;
    border-radius: 0.6rem;
    background: #ffffff;
    color: #101827;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: 1.35rem;
    font-weight: 800;
    line-height: 1;
    text-align: center;
}

.decimal-multiplication-place-count-input:focus {
    border-color: #6d28d9;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(124, 58, 237, 0.15);
}

.decimal-multiplication-place-count-input.correct,
.decimal-multiplication-place-count-input.input-correct {
    border-color: #15803d;
    background: #f0fdf4;
    color: #166534;
}

.decimal-multiplication-place-count-input.incorrect,
.decimal-multiplication-place-count-input.input-incorrect {
    border-color: #dc2626;
    background: #fef2f2;
    color: #991b1b;
}

.decimal-multiplication-place-count-input.hint-target {
    border-color: #d97706;
    background: #fffbeb;
}

.decimal-multiplication-place-count-label {
    color: #6b4fa0;
    font-size: 0.86rem;
    font-weight: 700;
}

.decimal-multiplication-product-builder {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 760px;
    margin: 0 auto 0.75rem;
    overflow-x: auto;
    border: 1px solid #ddd6fe;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1rem;
    scrollbar-width: thin;
    scrollbar-color: #c4b5fd transparent;
}

.decimal-multiplication-product-digit {
    flex: 0 0 auto;
    color: #101827;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.8rem, 5vw, 2.5rem);
    font-variant-numeric: tabular-nums;
    font-weight: 800;
    line-height: 1;
}

.decimal-multiplication-decimal-slot {
    display: inline-flex;
    flex: 0 0 1.4rem;
    align-items: flex-end;
    justify-content: center;
    width: 1.4rem;
    height: 2.9rem;
    margin: 0 0.08rem;
    border: 1px dashed transparent;
    border-radius: 0.45rem;
    background: transparent;
    color: #c4b5fd;
    padding: 0 0 0.2rem;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
    cursor: pointer;
    transition:
        border-color 0.16s ease,
        background 0.16s ease,
        color 0.16s ease,
        transform 0.16s ease;
}

.decimal-multiplication-decimal-slot:hover,
.decimal-multiplication-decimal-slot:focus-visible {
    border-color: #8b5cf6;
    background: #f5f3ff;
    color: #7c3aed;
    outline: 0;
}

.decimal-multiplication-decimal-slot.is-selected,
.decimal-multiplication-decimal-slot[aria-pressed="true"] {
    border-color: #6d28d9;
    background: #ede9fe;
    color: #5b21b6;
    box-shadow: 0 0 0 0.18rem rgba(124, 58, 237, 0.13);
    transform: translateY(-1px);
}

.decimal-multiplication-decimal-slot.correct {
    border-color: #15803d;
    background: #dcfce7;
    color: #166534;
}

.decimal-multiplication-decimal-slot.incorrect {
    border-color: #dc2626;
    background: #fee2e2;
    color: #991b1b;
}

.decimal-multiplication-decimal-slot.hint-target {
    border-color: #d97706;
    background: #fffbeb;
    color: #b45309;
}

.decimal-multiplication-placement-instruction {
    margin: 0 auto 1.3rem;
    color: #6b4fa0;
    font-size: 0.86rem;
    font-weight: 600;
    line-height: 1.55;
}


/* =========================================================
   Feedback and Hint
   ========================================================= */

.decimal-multiplication-feedback {
    margin: 0 2rem 1rem;
    border: 1px solid #cbd5e1;
    border-radius: 0.85rem;
    background: #f8fafc;
    color: #334155;
    padding: 1rem 1.15rem;
    font-weight: 600;
    line-height: 1.6;
}

.decimal-multiplication-feedback.success {
    border-color: #86cda9;
    background: #f0fdf4;
    color: #166534;
}

.decimal-multiplication-feedback.error {
    border-color: #f0a7a7;
    background: #fef2f2;
    color: #991b1b;
}

.decimal-multiplication-feedback.info {
    border-color: #93c5fd;
    background: #eff6ff;
    color: #1e40af;
}

.decimal-multiplication-feedback[hidden] {
    display: none !important;
}

.decimal-multiplication-hint-button {
    margin: 0 2rem 1rem;
    border: 0;
    background: transparent;
    color: #0f766e;
    padding: 0;
    font-weight: 800;
    text-decoration: underline;
    text-underline-offset: 0.2rem;
}

.decimal-multiplication-hint-button:hover,
.decimal-multiplication-hint-button:focus {
    color: #0b5f59;
}

.decimal-multiplication-hint {
    margin: 0 2rem 1.5rem;
    border-left: 4px solid #0f766e;
    border-radius: 0.75rem;
    background: #f0fdfa;
    color: #355d59;
    padding: 1rem 1.15rem;
    line-height: 1.65;
}

.decimal-multiplication-hint[hidden] {
    display: none !important;
}


/* =========================================================
   Completion
   ========================================================= */

.decimal-multiplication-completion {
    margin: 0 2rem 2rem;
    border: 1px solid #86cda9;
    border-radius: 1rem;
    background: #f0fdf4;
    padding: 1.75rem;
    text-align: center;
    animation: decimal-multiplication-fade-in 0.24s ease;
}

.decimal-multiplication-completion[hidden] {
    display: none !important;
}

.decimal-multiplication-completion-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3.5rem;
    height: 3.5rem;
    margin-bottom: 1rem;
    border-radius: 50%;
    background: #15803d;
    color: #ffffff;
    font-size: 1.65rem;
    font-weight: 800;
}

.decimal-multiplication-completion h3 {
    margin-bottom: 0.65rem;
    color: #14532d;
    font-size: 1.6rem;
    font-weight: 800;
}

.decimal-multiplication-completion > p {
    color: #3f624b;
    line-height: 1.65;
}

.decimal-multiplication-final-summary {
    display: grid;
    gap: 0.7rem;
    max-width: 760px;
    margin: 1.35rem auto;
    text-align: left;
}

.decimal-multiplication-summary-row {
    display: grid;
    grid-template-columns: minmax(120px, 155px) 1fr;
    gap: 1rem;
    border: 1px solid #bbf7d0;
    border-radius: 0.75rem;
    background: #ffffff;
    padding: 0.85rem 1rem;
}

.decimal-multiplication-summary-row span {
    color: #15803d;
    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.decimal-multiplication-summary-row strong {
    color: #173f2b;
    line-height: 1.55;
}

.decimal-multiplication-completion-explanation {
    max-width: 760px;
    margin: 0 auto 1.35rem;
    color: #3f624b;
    line-height: 1.7;
}


/* =========================================================
   Strategy Cards
   ========================================================= */

.decimal-multiplication-strategy-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1rem;
}

.decimal-multiplication-strategy-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.5rem;
}

.decimal-multiplication-strategy-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.8rem;
    height: 2.8rem;
    margin-bottom: 1rem;
    border-radius: 0.8rem;
    background: #e6fffb;
    color: #0f766e;
}

.decimal-multiplication-strategy-icon svg {
    width: 1.25rem;
    height: 1.25rem;
}

.decimal-multiplication-strategy-card h3 {
    margin-bottom: 0.65rem;
    color: #101827;
    font-size: 1.05rem;
    font-weight: 800;
}

.decimal-multiplication-strategy-card p {
    margin-bottom: 0;
    color: #5b6678;
    line-height: 1.65;
}


/* =========================================================
   Comparison Cards
   ========================================================= */

.decimal-multiplication-comparison-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
    max-width: 900px;
    margin: 0 auto;
}

.decimal-multiplication-comparison-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-top: 4px solid #2563eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.5rem;
    box-shadow: 0 10px 24px rgba(16, 24, 39, 0.04);
}

.decimal-multiplication-comparison-card:last-child {
    border-top-color: #0f766e;
}

.decimal-multiplication-method-badge {
    display: inline-flex;
    margin-bottom: 1rem;
    border-radius: 999px;
    padding: 0.35rem 0.75rem;
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.decimal-multiplication-method-badge.addition {
    background: #dbeafe;
    color: #1e40af;
}

.decimal-multiplication-method-badge.multiplication {
    background: #ccfbf1;
    color: #115e59;
}

.decimal-multiplication-comparison-card h3 {
    margin-bottom: 0.75rem;
    color: #101827;
    font-size: 1.18rem;
    font-weight: 800;
}

.decimal-multiplication-comparison-card p {
    color: #5b6678;
    line-height: 1.65;
}

.decimal-multiplication-comparison-example {
    border-radius: 0.75rem;
    background: #101827;
    color: #ffffff;
    padding: 0.9rem 1rem;
    font-size: 1.05rem;
    font-variant-numeric: tabular-nums;
    font-weight: 800;
    text-align: center;
}


/* =========================================================
   Application Cards
   ========================================================= */

.decimal-multiplication-application-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1rem;
}

.decimal-multiplication-application-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.5rem;
    box-shadow: 0 10px 24px rgba(16, 24, 39, 0.04);
}

.decimal-multiplication-application-card h3 {
    margin-bottom: 0.65rem;
    color: #101827;
    font-size: 1.05rem;
    font-weight: 800;
}

.decimal-multiplication-application-card p {
    margin-bottom: 0;
    color: #5b6678;
    line-height: 1.65;
}


/* =========================================================
   Bottom CTA
   ========================================================= */

.decimal-multiplication-cta-card {
    border-radius: 1.25rem;
    background: #101827;
    color: #ffffff;
    padding: 2.25rem;
    text-align: center;
}

.decimal-multiplication-cta-card h2 {
    margin-bottom: 0.8rem;
    color: #ffffff;
    font-size: clamp(1.65rem, 3vw, 2.2rem);
    font-weight: 800;
}

.decimal-multiplication-cta-card p {
    max-width: 720px;
    margin: 0 auto 1.4rem;
    color: rgba(255, 255, 255, 0.78);
    line-height: 1.7;
}


/* =========================================================
   Disabled, Hidden, and Focus States
   ========================================================= */

.decimal-multiplication-page button:disabled {
    cursor: not-allowed;
    opacity: 0.68;
}

.decimal-multiplication-page button:focus-visible,
.decimal-multiplication-page select:focus-visible,
.decimal-multiplication-page input:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.28);
    outline-offset: 2px;
}

.decimal-multiplication-page
.decimal-multiplication-digit-input:focus-visible,
.decimal-multiplication-page
.decimal-multiplication-place-count-input:focus-visible {
    outline: 0;
}

.decimal-multiplication-page [hidden] {
    display: none !important;
}


/* =========================================================
   Animation
   ========================================================= */

@keyframes decimal-multiplication-fade-in {
    from {
        transform: translateY(5px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@media (prefers-reduced-motion: reduce) {
    .decimal-multiplication-overview-card,
    .decimal-multiplication-digit-input,
    .decimal-multiplication-decimal-slot,
    .decimal-multiplication-decimal-workspace,
    .decimal-multiplication-completion {
        animation: none;
        transition: none;
    }

    .decimal-multiplication-overview-card:hover,
    .decimal-multiplication-decimal-slot.is-selected,
    .decimal-multiplication-decimal-slot[aria-pressed="true"] {
        transform: none;
    }
}


/* =========================================================
   Responsive: Tablet
   ========================================================= */

@media (max-width: 992px) {
    .decimal-multiplication-overview-grid,
    .decimal-multiplication-strategy-grid,
    .decimal-multiplication-application-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .decimal-multiplication-tool-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .decimal-multiplication-scoreboard {
        width: 100%;
    }

    .decimal-multiplication-settings {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .decimal-multiplication-setting-actions {
        grid-column: 1 / -1;
        width: 100%;
    }

    .decimal-multiplication-setting-actions .btn {
        flex: 1 1 0;
    }
}


/* =========================================================
   Responsive: Mobile
   ========================================================= */

@media (max-width: 768px) {
    .decimal-multiplication-overview,
    .decimal-multiplication-tool-section,
    .decimal-multiplication-strategies,
    .decimal-multiplication-comparison,
    .decimal-multiplication-applications,
    .decimal-multiplication-cta {
        padding: 3.5rem 0;
    }

    .decimal-multiplication-tool-header,
    .decimal-multiplication-settings,
    .decimal-multiplication-problem-area,
    .decimal-multiplication-workspace {
        padding-right: 1.25rem;
        padding-left: 1.25rem;
    }

    .decimal-multiplication-settings {
        grid-template-columns: 1fr;
    }

    .decimal-multiplication-setting-actions {
        grid-column: auto;
    }

    .decimal-multiplication-board-wrap {
        justify-content: flex-start;
        padding-right: 0.75rem;
        padding-left: 0.75rem;
    }

    .decimal-multiplication-board {
        width: 100%;
        min-width: 320px;
    }

    .decimal-multiplication-answer-actions .btn {
        flex: 1 1 160px;
    }

    .decimal-multiplication-feedback,
    .decimal-multiplication-hint-button,
    .decimal-multiplication-hint,
    .decimal-multiplication-completion,
    .decimal-multiplication-decimal-workspace {
        margin-right: 1.25rem;
        margin-left: 1.25rem;
    }

    .decimal-multiplication-summary-row {
        grid-template-columns: 1fr;
        gap: 0.35rem;
    }

    .decimal-multiplication-product-builder {
        justify-content: flex-start;
    }
}


/* =========================================================
   Responsive: Small Mobile
   ========================================================= */

@media (max-width: 480px) {
    .decimal-multiplication-overview-grid,
    .decimal-multiplication-strategy-grid,
    .decimal-multiplication-comparison-grid,
    .decimal-multiplication-application-grid {
        grid-template-columns: 1fr;
    }

    .decimal-multiplication-tool {
        border-radius: 1rem;
    }

    .decimal-multiplication-tool-header {
        padding: 1.35rem 1rem;
    }

    .decimal-multiplication-scoreboard {
        gap: 0.4rem;
    }

    .decimal-multiplication-score-item {
        min-width: 0;
        padding: 0.65rem 0.35rem;
    }

    .decimal-multiplication-score-label {
        font-size: 0.62rem;
    }

    .decimal-multiplication-score-item strong {
        font-size: 1.2rem;
    }

    .decimal-multiplication-settings,
    .decimal-multiplication-problem-area,
    .decimal-multiplication-workspace {
        padding-right: 1rem;
        padding-left: 1rem;
    }

    .decimal-multiplication-setting-actions {
        display: grid;
        grid-template-columns: 1fr;
    }

    .decimal-multiplication-setting-actions .btn {
        width: 100%;
    }

    .decimal-multiplication-problem-header {
        align-items: center;
        flex-direction: column;
    }

    .decimal-multiplication-problem-text {
        font-size: 1.08rem;
    }

    .decimal-multiplication-original-problem {
        gap: 0.55rem;
        padding: 0.7rem 0.9rem;
        font-size: 1.5rem;
    }

    .decimal-multiplication-board-wrap {
        padding: 0.85rem 0.25rem 1rem;
    }

    .decimal-multiplication-board {
        min-width: 300px;
    }

    .decimal-multiplication-board th:first-child,
    .decimal-multiplication-board td:first-child {
        width: 1.75rem;
    }

    .decimal-multiplication-number-row th,
    .decimal-multiplication-number-row td {
        height: 2.65rem;
        font-size: 1.45rem;
    }

    .decimal-multiplication-partial-row th,
    .decimal-multiplication-partial-row td,
    .decimal-multiplication-product-row th,
    .decimal-multiplication-product-row td {
        height: 3rem;
        padding-right: 0.03rem;
        padding-left: 0.03rem;
    }

    .decimal-multiplication-digit-input {
        width: calc(100% - 0.06rem);
        height: 2.3rem;
        border-radius: 0.42rem;
        font-size: 1.15rem;
    }

    .decimal-multiplication-feedback,
    .decimal-multiplication-hint-button,
    .decimal-multiplication-hint,
    .decimal-multiplication-completion,
    .decimal-multiplication-decimal-workspace {
        margin-right: 1rem;
        margin-left: 1rem;
    }

    .decimal-multiplication-decimal-workspace,
    .decimal-multiplication-completion {
        padding: 1.35rem 1rem;
    }

    .decimal-multiplication-place-count-card {
        gap: 0.45rem;
        padding: 0.75rem;
        font-size: 1rem;
    }

    .decimal-multiplication-place-count-input {
        width: 2.8rem;
        height: 2.55rem;
        font-size: 1.2rem;
    }

    .decimal-multiplication-product-builder {
        padding: 0.85rem 0.55rem;
    }

    .decimal-multiplication-product-digit {
        font-size: 1.75rem;
    }

    .decimal-multiplication-decimal-slot {
        flex-basis: 1.15rem;
        width: 1.15rem;
        height: 2.35rem;
        font-size: 1.65rem;
    }

    .decimal-multiplication-cta-card {
        padding: 1.75rem 1rem;
    }

    .decimal-multiplication-carry-row th,
	.decimal-multiplication-carry-row td {
	    height: 2rem;
	    padding-right: 0.02rem;
	    padding-left: 0.02rem;
	}

	.decimal-multiplication-carry-input {
	    width: 1.7rem;
	    height: 1.55rem;
	    border-radius: 0.32rem;
	    font-size: 0.7rem;
	}
}

/* Compact the multiplication columns around the active digits */

.decimal-multiplication-board {
    width: auto;
    min-width: 0;
    table-layout: auto;
}

.decimal-multiplication-board th:not(:first-child),
.decimal-multiplication-board td:not(:first-child) {
    width: 4.15rem;
}

.decimal-multiplication-board td:empty {
    width: 0;
    padding-right: 0;
    padding-left: 0;
}

.decimal-multiplication-digit-input {
    width: 3.65rem;
    max-width: 3.65rem;
}

@media (max-width: 480px) {
    .decimal-multiplication-board th:not(:first-child),
    .decimal-multiplication-board td:not(:first-child) {
        width: 2.8rem;
    }

    .decimal-multiplication-digit-input {
        width: 2.45rem;
        max-width: 2.45rem;
    }
}

.decimal-multiplication-carry-row th,
.decimal-multiplication-carry-row td {
    height: 2.4rem;
    padding-top: 0.2rem;
    padding-bottom: 0.2rem;
}

.decimal-multiplication-carry-input {
    display: block;
    width: 2.15rem;
    height: 1.8rem;
    box-sizing: border-box;
    margin: 0 auto;
    border: 1px solid #e9b55d;
    border-radius: 0.4rem;
    outline: none;
    background: #fffbeb;
    color: #92400e;
    caret-color: #d97706;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: 0.82rem;
    font-weight: 800;
    line-height: 1;
    text-align: center;
    transition:
        border-color 0.18s ease,
        background-color 0.18s ease,
        box-shadow 0.18s ease;
}

.decimal-multiplication-carry-input:focus {
    border-color: #d97706;
    background: #ffffff;
    box-shadow:
        0 0 0 0.16rem rgba(217, 119, 6, 0.16);
}

.decimal-multiplication-carry-input.hint-target {
    border-color: #d97706;
    background: #fef3c7;
    box-shadow:
        0 0 0 0.18rem rgba(217, 119, 6, 0.2);
}