/* =========================================================
   Decimal Addition and Subtraction Practice
   File:
   /interactive-learning-tools/decimal-addition-subtraction/
   decimal-addition-subtraction.css
   ========================================================= */

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

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


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

.decimal-addition-subtraction-overview,
.decimal-addition-subtraction-tool-section,
.decimal-addition-subtraction-strategies,
.decimal-addition-subtraction-operations,
.decimal-addition-subtraction-applications,
.decimal-addition-subtraction-cta {
    padding: 5rem 0;
}

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

.decimal-addition-subtraction-tool-section,
.decimal-addition-subtraction-operations,
.decimal-addition-subtraction-cta {
    background: #ffffff;
}

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

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

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

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


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

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

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

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

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

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

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


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

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

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


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

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

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

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

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

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


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

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

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

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

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


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

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

.decimal-addition-subtraction-problem-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

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

.decimal-addition-subtraction-difficulty-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 999px;
    background: #e2e8f0;
    color: #475569;
    padding: 0.32rem 0.7rem;
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

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

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

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

.decimal-addition-subtraction-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;
}


/* =========================================================
   Fixed Place-Value Board
   ========================================================= */

.decimal-addition-subtraction-board-wrap {
    display: flex;
    justify-content: center;
    max-width: 650px;
    margin: 1.65rem auto 0;
    overflow-x: auto;
    border: 1px solid #99d5cf;
    border-radius: 1rem;
    background:
        linear-gradient(180deg, #f0fdfa 0%, #ffffff 48%);
    padding: 1.2rem 1.35rem 1.35rem;
    scrollbar-width: thin;
    scrollbar-color: #99d5cf transparent;
}

.decimal-addition-subtraction-board {
    width: min(100%, 500px);
    min-width: 300px;
    margin: 0 auto;
    border-spacing: 0;
    border-collapse: separate;
    table-layout: fixed;
}

.decimal-addition-subtraction-board th,
.decimal-addition-subtraction-board td {
    width: auto;
    min-width: 0;
    border: 0;
    padding: 0.28rem 0.12rem;
    text-align: center;
    vertical-align: middle;
}

.decimal-addition-subtraction-board th:first-child,
.decimal-addition-subtraction-board td:first-child {
    width: 2.5rem;
}

.decimal-addition-subtraction-board th:nth-child(6),
.decimal-addition-subtraction-board td:nth-child(6) {
    width: 1.25rem;
}

.decimal-addition-subtraction-place-value-row th {
    height: 2.25rem;
    border-bottom: 1px solid #bfe8e3;
    color: #52736f;
    font-size: clamp(0.55rem, 1.4vw, 0.7rem);
    font-weight: 800;
    line-height: 1.1;
    white-space: nowrap;
}

.decimal-addition-subtraction-operation-heading {
    background: transparent;
}

.decimal-addition-subtraction-decimal-heading,
.decimal-addition-subtraction-decimal-cell {
    background: rgba(20, 184, 166, 0.1);
    color: #0f766e;
}

.decimal-addition-subtraction-number-row td {
    height: 3.25rem;
    color: #101827;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.55rem, 5vw, 2.15rem);
    font-variant-numeric: tabular-nums;
    font-weight: 800;
    line-height: 1;
}

.decimal-addition-subtraction-operation-cell {
    color: #0f766e !important;
    font-family: "Inter", sans-serif !important;
    font-size: clamp(1.65rem, 5vw, 2.1rem) !important;
}

.decimal-addition-subtraction-bottom-row td {
    padding-top: 0.35rem;
}

.decimal-addition-subtraction-decimal-cell {
    border-radius: 0.35rem;
    font-family: "Inter", sans-serif !important;
}

.decimal-addition-subtraction-placeholder-zero {
    color: #2563eb !important;
    text-decoration: underline dotted #60a5fa 2px;
    text-underline-offset: 0.25rem;
}

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

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

.decimal-addition-subtraction-result-row td {
    height: 3.7rem;
    color: #0f766e;
    padding-top: 0.3rem;
    padding-bottom: 0.3rem;
}

.decimal-addition-subtraction-answer-cell {
    position: relative;
}

.decimal-addition-subtraction-answer-cell.is-inactive {
    background: transparent;
}

.decimal-addition-subtraction-digit-input {
    display: block;
    width: calc(100% - 0.35rem);
    min-width: 0;
    max-width: 3.7rem;
    height: 3rem;
    margin: 0 auto;
    border: 2px solid #5ab8af;
    border-radius: 0.6rem;
    background: #ffffff;
    color: #101827;
    caret-color: #0f766e;
    font-family:
        "SFMono-Regular",
        Consolas,
        "Liberation Mono",
        Menlo,
        monospace;
    font-size: clamp(1.35rem, 4vw, 1.85rem);
    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-addition-subtraction-digit-input:hover {
    border-color: #0f766e;
    background: #f8fffe;
}

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

.decimal-addition-subtraction-digit-input:disabled {
    cursor: default;
    opacity: 0.6;
}

.decimal-addition-subtraction-digit-input[hidden] {
    display: none !important;
}

.decimal-addition-subtraction-board [hidden] {
    display: none !important;
}

.decimal-addition-subtraction-alignment-note {
    max-width: 620px;
    margin: 0.9rem auto 0;
    color: #52736f;
    font-size: 0.86rem;
    font-weight: 600;
    line-height: 1.55;
    text-align: center;
}

.decimal-addition-subtraction-alignment-note:empty,
.decimal-addition-subtraction-alignment-note[hidden] {
    display: none !important;
}


/* =========================================================
   Direct-Entry Controls
   ========================================================= */

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

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

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

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

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


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

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

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

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

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

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

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


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

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

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

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

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

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

.decimal-addition-subtraction-summary-row {
    display: grid;
    grid-template-columns: minmax(100px, 135px) 1fr;
    gap: 1rem;
    border: 1px solid #bbf7d0;
    border-radius: 0.75rem;
    background: #ffffff;
    padding: 0.85rem 1rem;
}

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

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

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


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

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

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

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

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

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


/* =========================================================
   Addition and Subtraction Cards
   ========================================================= */

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

.decimal-addition-subtraction-operation-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-top: 4px solid #0f766e;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.5rem;
    box-shadow: 0 10px 24px rgba(16, 24, 39, 0.04);
}

.decimal-addition-subtraction-operation-card:last-child {
    border-top-color: #2563eb;
}

.decimal-addition-subtraction-operation-badge {
    display: inline-flex;
    margin-bottom: 1rem;
    border-radius: 999px;
    background: #ccfbf1;
    color: #115e59;
    padding: 0.35rem 0.75rem;
    font-size: 0.76rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.decimal-addition-subtraction-operation-badge.subtraction {
    background: #dbeafe;
    color: #1e40af;
}

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

.decimal-addition-subtraction-operation-card p {
    color: #5b6678;
    line-height: 1.65;
}

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

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

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


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

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

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

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


/* =========================================================
   Disabled and Focus States
   ========================================================= */

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

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

.decimal-addition-subtraction-page
.decimal-addition-subtraction-digit-input:focus-visible {
    outline: 0;
    box-shadow:
        0 0 0 0.22rem rgba(15, 118, 110, 0.16),
        0 5px 14px rgba(15, 118, 110, 0.12);
}


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

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

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

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

    .decimal-addition-subtraction-overview-card:hover {
        transform: none;
    }
}

.decimal-addition-subtraction-regrouping-row td {
    height: 2.4rem;
    padding-top: 0.2rem;
    padding-bottom: 0.2rem;
}

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

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

.decimal-addition-subtraction-regrouping-row td.is-inactive {
    visibility: hidden;
}


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

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

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

    .decimal-addition-subtraction-scoreboard {
        width: 100%;
    }

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

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

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


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

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

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

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

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

    .decimal-addition-subtraction-board-wrap {
        padding-right: 0.75rem;
        padding-left: 0.75rem;
    }

    .decimal-addition-subtraction-board {
        width: 100%;
    }

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

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

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


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

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

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

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

    .decimal-addition-subtraction-scoreboard {
        gap: 0.4rem;
    }

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

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

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

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

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

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

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

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

    .decimal-addition-subtraction-board-wrap {
        padding: 0.85rem 0.35rem 1rem;
    }

    .decimal-addition-subtraction-board {
        min-width: 280px;
    }

    .decimal-addition-subtraction-board th:first-child,
    .decimal-addition-subtraction-board td:first-child {
        width: 1.9rem;
    }

    .decimal-addition-subtraction-board th:nth-child(6),
    .decimal-addition-subtraction-board td:nth-child(6) {
        width: 0.9rem;
    }

    .decimal-addition-subtraction-place-value-row th {
        height: 3.8rem;
        font-size: 0.55rem;
        white-space: normal;
        writing-mode: vertical-rl;
        transform: rotate(180deg);
    }

    .decimal-addition-subtraction-place-value-row
    .decimal-addition-subtraction-operation-heading,
    .decimal-addition-subtraction-place-value-row
    .decimal-addition-subtraction-decimal-heading {
        writing-mode: horizontal-tb;
        transform: none;
    }

    .decimal-addition-subtraction-number-row td {
        height: 2.8rem;
        font-size: 1.55rem;
    }

    .decimal-addition-subtraction-regrouping-row td {
        height: 1.7rem;
        font-size: 0.78rem;
    }

    .decimal-addition-subtraction-result-row td {
        height: 3rem;
        padding-right: 0.04rem;
        padding-left: 0.04rem;
    }

    .decimal-addition-subtraction-digit-input {
        width: calc(100% - 0.08rem);
        height: 2.35rem;
        border-radius: 0.45rem;
        font-size: 1.25rem;
    }

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

    .decimal-addition-subtraction-completion {
        padding: 1.35rem 1rem;
    }

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

    .decimal-addition-subtraction-regrouping-row td {
	    height: 2rem;
	    padding-right: 0.02rem;
	    padding-left: 0.02rem;
	}

	.decimal-addition-subtraction-scratch-input {
	    width: 1.7rem;
	    height: 1.55rem;
	    border-radius: 0.32rem;
	    font-size: 0.7rem;
	}

}