/* =========================================================
   Equivalent Fractions Practice
   File:
   /interactive-learning-tools/equivalent-fractions/
   equivalent-fractions.css
   ========================================================= */

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

.equivalent-fractions-page *,
.equivalent-fractions-page *::before,
.equivalent-fractions-page *::after {
    box-sizing: border-box;
}


/* =========================================================
   Shared section styles
   ========================================================= */

.equivalent-overview,
.equivalent-practice-section,
.equivalent-reminders,
.equivalent-final-cta {
    padding: 5rem 0;
}

.equivalent-overview,
.equivalent-reminders {
    background: #f7f9fc;
}

.equivalent-practice-section,
.equivalent-final-cta {
    background: #ffffff;
}

.equivalent-section-heading {
    max-width: 760px;
    margin: 0 auto 2.25rem;
    text-align: center;
}

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

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

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


/* =========================================================
   Overview cards
   ========================================================= */

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

.equivalent-overview-card {
    position: relative;
    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);
}

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

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

.equivalent-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-size: 1rem;
    font-weight: 800;
}


/* =========================================================
   Main tool shell
   ========================================================= */

.equivalent-tool {
    max-width: 1050px;
    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);
}

.equivalent-tool-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
    border-bottom: 1px solid #dce3eb;
    background: #101827;
    color: #ffffff;
    padding: 1.75rem 2rem;
}

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

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


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

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

.equivalent-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;
}

.equivalent-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;
}

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


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

.equivalent-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;
}

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

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

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

#newProblemButton {
    min-height: 3rem;
    white-space: nowrap;
}


/* =========================================================
   Problem display
   ========================================================= */

.equivalent-problem-area {
    border-bottom: 1px solid #dce3eb;
    padding: 2.25rem 2rem;
    text-align: center;
}

.equivalent-problem-label {
    margin-bottom: 0.8rem;
    color: #657184;
    font-size: 0.85rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.equivalent-expression {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    color: #101827;
    font-size: clamp(1.7rem, 5vw, 2.8rem);
    font-weight: 800;
}

.equivalent-symbol {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2rem;
    color: #0f766e;
    font-size: 1.2em;
    font-weight: 800;
}


/* =========================================================
   Display fractions
   ========================================================= */

.display-fraction {
    display: inline-grid;
    grid-template-rows: auto auto;
    min-width: 3.5rem;
    line-height: 1.05;
    text-align: center;
}

.display-fraction .fraction-numerator {
    border-bottom: 3px solid currentColor;
    padding: 0 0.6rem 0.35rem;
}

.display-fraction .fraction-denominator {
    padding: 0.35rem 0.6rem 0;
}


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

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

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

.equivalent-fractions-page .btn-outline-teal {
    border-color: #0f766e;
    color: #0f766e;
}

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

/* =========================================================
   Progress tracker
   ========================================================= */

.equivalent-progress {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 0;
    border-bottom: 1px solid #dce3eb;
    background: #ffffff;
    padding: 1.75rem 2rem;
}

.equivalent-progress-step {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 90px;
    color: #8a95a6;
    text-align: center;
}

.equivalent-progress-step span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border: 2px solid #cfd8e3;
    border-radius: 50%;
    background: #ffffff;
    color: #7a8698;
    font-size: 0.95rem;
    font-weight: 800;
    transition:
        border-color 0.2s ease,
        background 0.2s ease,
        color 0.2s ease;
}

.equivalent-progress-step p {
    margin: 0.55rem 0 0;
    font-size: 0.8rem;
    font-weight: 700;
}

.equivalent-progress-step.active {
    color: #0f766e;
}

.equivalent-progress-step.active span {
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
}

.equivalent-progress-step.complete {
    color: #0f766e;
}

.equivalent-progress-step.complete span {
    border-color: #0f766e;
    background: #dff7f3;
    color: #0f766e;
}

.equivalent-progress-line {
    width: 110px;
    height: 2px;
    margin-top: 1.2rem;
    background: #d8e0e9;
}

.equivalent-progress-line.complete {
    background: #0f766e;
}


/* =========================================================
   Workspace shell
   ========================================================= */

.equivalent-workspace {
    padding: 2rem;
}

.equivalent-work-step {
    max-width: 820px;
    margin: 0 auto;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 2rem;
    box-shadow: 0 12px 30px rgba(16, 24, 39, 0.06);
}

.equivalent-work-step + .equivalent-work-step {
    margin-top: 1.25rem;
}

.equivalent-work-step.active {
    border-color: #7dd3c7;
    box-shadow:
        0 0 0 3px rgba(15, 118, 110, 0.08),
        0 14px 32px rgba(16, 24, 39, 0.08);
}

.equivalent-work-step[hidden] {
    display: none;
}

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

.equivalent-work-step h3 {
    margin-bottom: 0.75rem;
    color: #101827;
    font-size: clamp(1.35rem, 3vw, 1.8rem);
    font-weight: 800;
}

.equivalent-step-instruction {
    max-width: 700px;
    margin-bottom: 1.5rem;
    color: #5b6678;
    line-height: 1.7;
}


/* =========================================================
   Scale factor row
   ========================================================= */

.scale-factor-row {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.scale-factor-row > label {
    color: #273449;
    font-weight: 700;
}

.scale-factor-input-wrap {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
}

#scaleOperationSymbol {
    color: #0f766e;
    font-size: 1.6rem;
    font-weight: 800;
}

#scaleFactorInput {
    width: 90px;
    height: 56px;
    border: 2px solid #cfd8e3;
    border-radius: 0.75rem;
    background: #ffffff;
    color: #101827;
    font-size: 1.35rem;
    font-weight: 800;
    text-align: center;
}

#scaleFactorInput:focus {
    border-color: #0f766e;
    outline: none;
    box-shadow: 0 0 0 0.22rem rgba(15, 118, 110, 0.14);
}


/* =========================================================
   Fraction answer layout
   ========================================================= */

.equivalent-answer-row {
    display: grid;
    grid-template-columns:
        minmax(0, 1fr)
        auto
        minmax(0, 1fr);
    gap: 1.5rem;
    align-items: center;
    max-width: 620px;
    margin: 0 auto 1.75rem;
}

.equivalent-input-group {
    text-align: center;
}

.equivalent-input-group > label {
    display: block;
    margin-bottom: 0.7rem;
    color: #5b6678;
    font-size: 0.85rem;
    font-weight: 700;
}

.fraction-input {
    display: inline-grid;
    grid-template-rows: auto 3px auto;
    justify-items: center;
    gap: 0.35rem;
}

.fraction-input > span {
    display: block;
    width: 82px;
    height: 3px;
    background: #101827;
}

.fraction-input input {
    width: 82px;
    height: 54px;
    border: 2px solid #cfd8e3;
    border-radius: 0.65rem;
    background: #ffffff;
    color: #101827;
    font-size: 1.25rem;
    font-weight: 800;
    text-align: center;
}

.fraction-input input:focus {
    border-color: #0f766e;
    outline: none;
    box-shadow: 0 0 0 0.22rem rgba(15, 118, 110, 0.14);
}


/* =========================================================
   Input states
   ========================================================= */

.fraction-input input.is-correct,
#scaleFactorInput.is-correct {
    border-color: #15803d;
    background: #f0fdf4;
}

.fraction-input input.is-incorrect,
#scaleFactorInput.is-incorrect {
    border-color: #dc2626;
    background: #fef2f2;
}

.fraction-input input:disabled,
#scaleFactorInput:disabled {
    cursor: not-allowed;
    background: #f3f5f8;
    color: #687386;
    opacity: 1;
}


/* =========================================================
   Equivalent yes/no choices
   ========================================================= */

.equivalent-choice-group {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
    max-width: 650px;
    margin: 0 0 1.5rem;
    padding: 0;
    border: 0;
}

.equivalent-choice {
    position: relative;
    display: flex;
    align-items: center;
    min-height: 64px;
    cursor: pointer;
}

.equivalent-choice input {
    position: absolute;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}

.equivalent-choice span {
    display: flex;
    align-items: center;
    width: 100%;
    min-height: 64px;
    border: 2px solid #d4dce6;
    border-radius: 0.85rem;
    background: #ffffff;
    padding: 1rem 1.1rem;
    color: #273449;
    font-weight: 700;
    transition:
        border-color 0.2s ease,
        background 0.2s ease,
        color 0.2s ease,
        transform 0.2s ease;
}

.equivalent-choice span::before {
    content: "";
    width: 1.2rem;
    height: 1.2rem;
    margin-right: 0.75rem;
    border: 2px solid #aab5c3;
    border-radius: 50%;
    background: #ffffff;
    box-shadow: inset 0 0 0 4px #ffffff;
}

.equivalent-choice:hover span {
    border-color: #7dd3c7;
    background: #f3fbfa;
    transform: translateY(-1px);
}

.equivalent-choice input:focus-visible + span {
    outline: 3px solid rgba(15, 118, 110, 0.18);
    outline-offset: 2px;
}

.equivalent-choice input:checked + span {
    border-color: #0f766e;
    background: #ecfdf8;
    color: #0f5f59;
}

.equivalent-choice input:checked + span::before {
    border-color: #0f766e;
    background: #0f766e;
}

.equivalent-choice input:disabled + span {
    cursor: not-allowed;
    opacity: 0.7;
}


/* =========================================================
   Step buttons
   ========================================================= */

.equivalent-work-step .btn {
    min-width: 140px;
    min-height: 48px;
    border-radius: 0.7rem;
}

.equivalent-work-step .btn:disabled {
    cursor: not-allowed;
    opacity: 0.65;
}


/* =========================================================
   Shared feedback
   ========================================================= */

.equivalent-feedback {
    max-width: 820px;
    margin: 1rem auto 0;
    border: 1px solid transparent;
    border-radius: 0.85rem;
    padding: 1rem 1.1rem;
    font-weight: 700;
    line-height: 1.6;
}

.equivalent-feedback[hidden] {
    display: none;
}

.equivalent-feedback.success {
    border-color: #86efac;
    background: #f0fdf4;
    color: #166534;
}

.equivalent-feedback.error {
    border-color: #fecaca;
    background: #fef2f2;
    color: #991b1b;
}

.equivalent-feedback.info {
    border-color: #bae6fd;
    background: #f0f9ff;
    color: #075985;
}


/* =========================================================
   Hint button and hint box
   ========================================================= */

.equivalent-hint-button {
    display: block;
    margin: 1.25rem auto 0;
    border: 0;
    background: transparent;
    color: #0f766e;
    font-weight: 800;
    text-decoration: underline;
    text-underline-offset: 0.2rem;
}

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

.equivalent-hint {
    max-width: 820px;
    margin: 0.9rem auto 0;
    border-left: 4px solid #0f766e;
    border-radius: 0.5rem;
    background: #f1fbf9;
    padding: 1rem 1.1rem;
    color: #315b57;
    line-height: 1.65;
}

.equivalent-hint[hidden] {
    display: none;
}

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

.equivalent-completion {
    max-width: 820px;
    margin: 1.5rem auto 0;
    border: 1px solid #a7f3d0;
    border-radius: 1rem;
    background: #ecfdf5;
    padding: 2rem;
    text-align: center;
}

.equivalent-completion[hidden] {
    display: none;
}

.equivalent-completion-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 4rem;
    height: 4rem;
    margin-bottom: 1rem;
    border-radius: 50%;
    background: #0f766e;
    color: #ffffff;
    font-size: 2rem;
    font-weight: 800;
}

.equivalent-completion h3 {
    margin-bottom: 0.6rem;
    color: #14532d;
    font-size: 1.7rem;
    font-weight: 800;
}

.equivalent-completion p {
    margin-bottom: 1rem;
    color: #32644a;
    line-height: 1.65;
}

.equivalent-final-answer {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.85rem;
    margin: 1.25rem 0 1.5rem;
    color: #101827;
    font-size: 1.7rem;
    font-weight: 800;
}

.equivalent-final-answer .display-fraction {
    min-width: 3rem;
}

.equivalent-final-answer .fraction-numerator {
    border-bottom-width: 2px;
}


/* =========================================================
   Correct and completed step states
   ========================================================= */

.equivalent-work-step.complete {
    border-color: #86efac;
    background: #f8fff9;
}

.equivalent-work-step.complete .equivalent-work-label {
    color: #15803d;
}

.equivalent-work-step.complete::after {
    content: "Completed";
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-top: 1rem;
    border-radius: 999px;
    background: #dcfce7;
    padding: 0.35rem 0.75rem;
    color: #166534;
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.equivalent-work-step.complete button {
    display: none;
}


/* =========================================================
   Reminder section
   ========================================================= */

.equivalent-reminders-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
}

.equivalent-reminder-card {
    min-height: 100%;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.75rem;
    box-shadow: 0 12px 30px rgba(16, 24, 39, 0.05);
}

.equivalent-reminder-card h3 {
    margin-bottom: 0.75rem;
    color: #101827;
    font-size: 1.15rem;
    font-weight: 800;
}

.equivalent-reminder-card p {
    margin-bottom: 1.25rem;
    color: #5b6678;
    line-height: 1.65;
}

.equivalent-example {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    min-height: 95px;
    border-radius: 0.85rem;
    background: #f1f7f7;
    padding: 1rem;
    color: #0f5f59;
    font-size: 1.25rem;
    font-weight: 800;
}

.equivalent-example .display-fraction {
    min-width: 3.25rem;
}

.equivalent-example .fraction-numerator {
    border-bottom-width: 2px;
}


/* =========================================================
   Final call to action
   ========================================================= */

.equivalent-final-cta-card {
    max-width: 920px;
    margin: 0 auto;
    border-radius: 1.25rem;
    background: #101827;
    padding: 3rem;
    color: #ffffff;
    text-align: center;
    box-shadow: 0 22px 55px rgba(16, 24, 39, 0.16);
}

.equivalent-final-cta-card .equivalent-eyebrow {
    color: #5eead4;
}

.equivalent-final-cta-card h2 {
    margin-bottom: 1rem;
    color: #ffffff;
    font-size: clamp(1.75rem, 3vw, 2.35rem);
    font-weight: 800;
}

.equivalent-final-cta-card p {
    max-width: 700px;
    margin: 0 auto 1.5rem;
    color: rgba(255, 255, 255, 0.78);
    font-size: 1.05rem;
    line-height: 1.75;
}


/* =========================================================
   Accessibility and keyboard focus
   ========================================================= */

.equivalent-fractions-page button:focus-visible,
.equivalent-fractions-page select:focus-visible,
.equivalent-fractions-page input:focus-visible,
.equivalent-fractions-page a:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.35);
    outline-offset: 3px;
}

.equivalent-fractions-page input[type="number"] {
    appearance: textfield;
    -moz-appearance: textfield;
}

.equivalent-fractions-page input[type="number"]::-webkit-inner-spin-button,
.equivalent-fractions-page input[type="number"]::-webkit-outer-spin-button {
    margin: 0;
    -webkit-appearance: none;
}


/* =========================================================
   Hidden and disabled states
   ========================================================= */

.equivalent-fractions-page [hidden] {
    display: none !important;
}

.equivalent-fractions-page .is-hidden {
    display: none !important;
}

.equivalent-fractions-page .is-disabled {
    cursor: not-allowed;
    opacity: 0.6;
    pointer-events: none;
}


/* =========================================================
   Optional shake animation for incorrect answers
   ========================================================= */

.equivalent-shake {
    animation: equivalent-shake 0.35s ease;
}

@keyframes equivalent-shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-6px);
    }

    50% {
        transform: translateX(6px);
    }

    75% {
        transform: translateX(-3px);
    }
}


/* =========================================================
   Optional success animation
   ========================================================= */

.equivalent-pop {
    animation: equivalent-pop 0.32s ease;
}

@keyframes equivalent-pop {

    0% {
        transform: scale(0.96);
        opacity: 0.6;
    }

    70% {
        transform: scale(1.025);
        opacity: 1;
    }

    100% {
        transform: scale(1);
    }
}


/* =========================================================
   Loading state
   ========================================================= */

.equivalent-tool.is-loading {
    position: relative;
    pointer-events: none;
}

.equivalent-tool.is-loading::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 20;
    background: rgba(255, 255, 255, 0.72);
}

.equivalent-tool.is-loading::before {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    z-index: 21;
    width: 2.75rem;
    height: 2.75rem;
    margin: -1.375rem 0 0 -1.375rem;
    border: 4px solid #d6e3e1;
    border-top-color: #0f766e;
    border-radius: 50%;
    animation: equivalent-spin 0.8s linear infinite;
}

@keyframes equivalent-spin {

    to {
        transform: rotate(360deg);
    }
}

/* =========================================================
   Responsive: tablets
   ========================================================= */

@media (max-width: 991.98px) {

    .equivalent-overview-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

    .equivalent-scoreboard {
        width: 100%;
    }

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

    #newProblemButton {
        grid-column: 1 / -1;
        justify-self: start;
    }

    .equivalent-reminders-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .equivalent-reminder-card:last-child {
        grid-column: 1 / -1;
    }

}


/* =========================================================
   Responsive: phones
   ========================================================= */

@media (max-width: 767.98px) {

    .equivalent-overview,
    .equivalent-practice-section,
    .equivalent-reminders,
    .equivalent-final-cta {
        padding: 3.5rem 0;
    }

    .equivalent-section-heading {
        margin-bottom: 1.75rem;
    }

    .equivalent-section-heading h2 {
        font-size: 1.75rem;
    }

    .equivalent-overview-grid {
        grid-template-columns: 1fr;
    }

    .equivalent-overview-card {
        padding: 1.35rem;
    }


    /* Tool shell */

    .equivalent-tool {
        border-radius: 1rem;
    }

    .equivalent-tool-header {
        gap: 1.25rem;
        padding: 1.5rem;
    }

    .equivalent-scoreboard {
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 0.5rem;
    }

    .equivalent-score-item {
        min-width: 0;
        padding: 0.65rem 0.4rem;
    }

    .equivalent-score-label {
        font-size: 0.65rem;
    }

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


    /* Settings */

    .equivalent-settings {
        grid-template-columns: 1fr;
        padding: 1.25rem 1.5rem;
    }

    #newProblemButton {
        grid-column: auto;
        width: 100%;
    }


    /* Problem display */

    .equivalent-problem-area {
        padding: 1.75rem 1.25rem;
    }

    .equivalent-expression {
        gap: 0.75rem;
        font-size: 2rem;
    }

    .display-fraction {
        min-width: 3rem;
    }

    .display-fraction .fraction-numerator {
        padding-right: 0.45rem;
        padding-left: 0.45rem;
    }

    .display-fraction .fraction-denominator {
        padding-right: 0.45rem;
        padding-left: 0.45rem;
    }


    /* Progress */

    .equivalent-progress {
        padding: 1.35rem 0.75rem;
    }

    .equivalent-progress-step {
        min-width: 64px;
    }

    .equivalent-progress-step span {
        width: 2.15rem;
        height: 2.15rem;
        font-size: 0.85rem;
    }

    .equivalent-progress-step p {
        font-size: 0.7rem;
    }

    .equivalent-progress-line {
        width: 55px;
        margin-top: 1.05rem;
    }


    /* Workspace */

    .equivalent-workspace {
        padding: 1.25rem;
    }

    .equivalent-work-step {
        padding: 1.5rem;
    }

    .equivalent-work-step h3 {
        font-size: 1.4rem;
    }

    .equivalent-step-instruction {
        margin-bottom: 1.25rem;
    }


    /* Scale factor */

    .scale-factor-row {
        align-items: flex-start;
        flex-direction: column;
        gap: 0.65rem;
    }


    /* Fraction answer row */

    .equivalent-answer-row {
        grid-template-columns:
            minmax(0, 1fr)
            auto
            minmax(0, 1fr);
        gap: 0.75rem;
    }

    .equivalent-input-group > label {
        font-size: 0.75rem;
    }

    .fraction-input input {
        width: 70px;
        height: 50px;
        font-size: 1.15rem;
    }

    .fraction-input > span {
        width: 70px;
    }

    .equivalent-answer-row > .equivalent-symbol {
        min-width: 1.4rem;
        font-size: 1.6rem;
    }


    /* Choices */

    .equivalent-choice-group {
        grid-template-columns: 1fr;
    }


    /* Buttons */

    .equivalent-work-step .btn {
        width: 100%;
    }


    /* Feedback and hints */

    .equivalent-feedback,
    .equivalent-hint {
        font-size: 0.95rem;
    }


    /* Completion */

    .equivalent-completion {
        padding: 1.5rem;
    }

    .equivalent-completion-icon {
        width: 3.5rem;
        height: 3.5rem;
        font-size: 1.75rem;
    }

    .equivalent-final-answer {
        font-size: 1.45rem;
    }


    /* Reminder cards */

    .equivalent-reminders-grid {
        grid-template-columns: 1fr;
    }

    .equivalent-reminder-card:last-child {
        grid-column: auto;
    }

    .equivalent-reminder-card {
        padding: 1.5rem;
    }


    /* Final CTA */

    .equivalent-final-cta-card {
        padding: 2rem 1.5rem;
    }

}


/* =========================================================
   Responsive: very small phones
   ========================================================= */

@media (max-width: 479.98px) {

    .equivalent-tool-header {
        padding: 1.25rem;
    }

    .equivalent-scoreboard {
        gap: 0.35rem;
    }

    .equivalent-score-item {
        padding: 0.6rem 0.25rem;
    }

    .equivalent-score-label {
        letter-spacing: 0.02em;
    }

    .equivalent-settings {
        padding: 1.1rem 1.25rem;
    }

    .equivalent-problem-area {
        padding: 1.5rem 1rem;
    }

    .equivalent-expression {
        gap: 0.55rem;
        font-size: 1.75rem;
    }

    .equivalent-progress-step {
        min-width: 54px;
    }

    .equivalent-progress-line {
        width: 34px;
    }

    .equivalent-progress-step p {
        font-size: 0.65rem;
    }

    .equivalent-workspace {
        padding: 1rem;
    }

    .equivalent-work-step {
        padding: 1.25rem;
    }

    .equivalent-answer-row {
        gap: 0.45rem;
    }

    .fraction-input input {
        width: 62px;
        height: 47px;
        font-size: 1.05rem;
    }

    .fraction-input > span {
        width: 62px;
    }

    #scaleFactorInput {
        width: 80px;
        height: 52px;
    }

    .equivalent-choice span {
        padding: 0.9rem;
        font-size: 0.92rem;
    }

    .equivalent-example {
        font-size: 1.1rem;
    }

}


/* =========================================================
   Reduced motion
   ========================================================= */

@media (prefers-reduced-motion: reduce) {

    .equivalent-fractions-page *,
    .equivalent-fractions-page *::before,
    .equivalent-fractions-page *::after {
        scroll-behavior: auto !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

}


/* =========================================================
   Print
   ========================================================= */

@media print {

    .equivalent-fractions-page .navbar,
    .equivalent-fractions-page footer,
    .equivalent-settings,
    .equivalent-scoreboard,
    .equivalent-progress,
    .equivalent-hint-button,
    .equivalent-final-cta {
        display: none !important;
    }

    .equivalent-tool {
        border: 1px solid #000000;
        box-shadow: none;
    }

    .equivalent-tool-header {
        background: #ffffff;
        color: #000000;
    }

    .equivalent-tool-header h2 {
        color: #000000;
    }

    .equivalent-work-step {
        box-shadow: none;
        break-inside: avoid;
    }

}

.display-fraction {
    display: inline-grid;
    grid-template-rows: auto auto;
    justify-items: center;
    min-width: 4rem;
}

.fraction-numerator {
    width: 100%;
    border-bottom: 3px solid currentColor;
    padding: .15rem .5rem .35rem;
}

.fraction-denominator {
    width: 100%;
    padding: .35rem .5rem .15rem;
}

.fraction-input > span {
    height: 4px;
    border-radius: 3px;
}

.equivalent-missing-value {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.5rem;
    min-height: 2.5rem;
    border: 2px dashed #0f766e;
    border-radius: 0.5rem;
    background: #ecfdf8;
    color: #0f766e;
}

/* ==========================================================
   Missing Value
   ========================================================== */

.equivalent-missing-value {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.75rem;
    min-height: 2.75rem;
    padding: 0.25rem;
    border: 2px dashed #0f766e;
    border-radius: 0.5rem;
    background: #ecfdf5;
    color: #0f766e;
    font-weight: 700;
}


/* ==========================================================
   Correct and Incorrect Inputs
   ========================================================== */

.equivalent-fraction-input.is-correct,
.equivalent-scale-input.is-correct {
    border-color: #15803d;
    background: #f0fdf4;
    color: #166534;
    box-shadow: 0 0 0 3px rgba(21, 128, 61, 0.12);
}

.equivalent-fraction-input.is-incorrect,
.equivalent-scale-input.is-incorrect {
    border-color: #dc2626;
    background: #fef2f2;
    color: #991b1b;
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.12);
}


/* ==========================================================
   Feedback States
   ========================================================== */

.equivalent-feedback {
    margin-top: 1rem;
    padding: 0.9rem 1rem;
    border-radius: 0.75rem;
    font-weight: 600;
    line-height: 1.5;
}

.equivalent-feedback.info {
    border: 1px solid #93c5fd;
    background: #eff6ff;
    color: #1e40af;
}

.equivalent-feedback.success {
    border: 1px solid #86efac;
    background: #f0fdf4;
    color: #166534;
}

.equivalent-feedback.error {
    border: 1px solid #fca5a5;
    background: #fef2f2;
    color: #991b1b;
}


/* ==========================================================
   Hint Box
   ========================================================== */

.equivalent-hint {
    margin-top: 1rem;
    padding: 1rem;
    border-left: 4px solid #d97706;
    border-radius: 0.5rem;
    background: #fffbeb;
    color: #78350f;
    line-height: 1.55;
}


/* ==========================================================
   Active and Completed Steps
   ========================================================== */

.equivalent-step-card.active {
    border-color: #0f766e;
    box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.1);
}

.equivalent-step-card.complete {
    border-color: #22c55e;
    background: #f0fdf4;
}

.equivalent-step-card.complete .equivalent-step-number {
    background: #15803d;
    color: #ffffff;
}


/* ==========================================================
   Progress Tracker States
   ========================================================== */

.equivalent-progress-step.active .equivalent-progress-circle {
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
    transform: scale(1.08);
}

.equivalent-progress-step.complete .equivalent-progress-circle {
    border-color: #15803d;
    background: #15803d;
    color: #ffffff;
}

.equivalent-progress-step.complete .equivalent-progress-circle::after {
    content: "✓";
}

.equivalent-progress-step.complete .equivalent-progress-number {
    display: none;
}

.equivalent-progress-line.complete {
    background: #15803d;
}


/* ==========================================================
   Final Answer
   ========================================================== */

.equivalent-final-answer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.25rem;
    margin-top: 1.25rem;
    font-size: 1.4rem;
}

.equivalent-symbol {
    font-size: 2rem;
    font-weight: 700;
    color: #0f766e;
}


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

.equivalent-pop {
    animation: equivalentPop 0.35s ease;
}

@keyframes equivalentPop {
    0% {
        opacity: 0;
        transform: translateY(8px) scale(0.98);
    }

    100% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}


/* ==========================================================
   Incorrect Answer Shake
   ========================================================== */

.equivalent-shake {
    animation: equivalentShake 0.4s ease;
}

@keyframes equivalentShake {
    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-6px);
    }

    50% {
        transform: translateX(6px);
    }

    75% {
        transform: translateX(-3px);
    }
}


/* ==========================================================
   Disabled Inputs
   ========================================================== */

.equivalent-fraction-input:disabled,
.equivalent-scale-input:disabled {
    cursor: not-allowed;
    opacity: 1;
}

.equivalent-fraction-input:disabled {
    background: #f8fafc;
    color: #334155;
}


/* ==========================================================
   Hidden Elements
   ========================================================== */

[hidden] {
    display: none !important;
}


/* ==========================================================
   Reduced Motion
   ========================================================== */

@media (prefers-reduced-motion: reduce) {
    .equivalent-pop,
    .equivalent-shake {
        animation: none;
    }

    .equivalent-progress-circle {
        transition: none;
    }
}