/* =========================================================
   Solving Proportions Practice
   File:
   /interactive-learning-tools/solving-proportions/
   solving-proportions.css
   ========================================================= */

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

.solving-proportions-page *,
.solving-proportions-page *::before,
.solving-proportions-page *::after {
    box-sizing: border-box;
}


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

.solving-proportions-overview,
.solving-proportions-tool-section,
.solving-proportions-strategies,
.solving-proportions-applications,
.solving-proportions-cta {
    padding: 5rem 0;
}

.solving-proportions-overview,
.solving-proportions-strategies {
    background: #f7f9fc;
}

.solving-proportions-tool-section,
.solving-proportions-applications,
.solving-proportions-cta {
    background: #ffffff;
}

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

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

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

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


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

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

.solving-proportions-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;
}

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

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

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

.solving-proportions-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
   ========================================================= */

.solving-proportions-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);
}

.solving-proportions-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;
}

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

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


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

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

.solving-proportions-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;
}

.solving-proportions-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;
}

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


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

.solving-proportions-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;
}

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

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

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

.solving-proportions-page #newProblemButton {
    min-height: 3rem;
    white-space: nowrap;
}


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

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

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

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

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


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

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

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

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

.solving-proportions-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;
}

.solving-proportions-difficulty-badge.easy {
    background: #dcfce7;
    color: #166534;
}

.solving-proportions-difficulty-badge.medium {
    background: #dbeafe;
    color: #1e40af;
}

.solving-proportions-difficulty-badge.hard {
    background: #fef3c7;
    color: #92400e;
}

.solving-proportions-problem-context {
    max-width: 820px;
    margin: 0 auto 0.45rem;
    color: #64748b;
    font-size: 0.98rem;
    font-weight: 600;
    line-height: 1.65;
    text-align: center;
}

.solving-proportions-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;
}

/* =========================================================
   Proportion Equation
   ========================================================= */

.solving-proportions-equation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(0.85rem, 3vw, 1.5rem);
    max-width: 500px;
    margin: 1.75rem auto 0;
    border: 1px solid #99d5cf;
    border-radius: 1rem;
    background: #f0fdfa;
    color: #101827;
    padding: 1.35rem 1.5rem;
}

.solving-proportions-fraction {
    display: inline-grid;
    grid-template-rows: repeat(2, auto);
    min-width: 4.5rem;
    text-align: center;
}

.solving-proportions-fraction-value {
    padding: 0.25rem 0.8rem;
    color: #101827;
    font-size: clamp(1.85rem, 5vw, 2.5rem);
    font-weight: 800;
    line-height: 1.1;
}

.solving-proportions-fraction-value:first-child {
    border-bottom: 3px solid #273449;
}

.solving-proportions-fraction-value.solving-proportions-unknown {
    color: #0f766e;
}

.solving-proportions-equals {
    color: #0f766e;
    font-size: clamp(1.8rem, 5vw, 2.35rem);
    font-weight: 800;
}

.solving-proportions-problem-context[hidden],
.solving-proportions-data-grid[hidden] {
    display: none !important;
}


/* =========================================================
   Problem Data
   ========================================================= */

.solving-proportions-data-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.85rem;
    max-width: 720px;
    margin: 1.5rem auto 0;
}

.solving-proportions-data-card {
    display: grid;
    gap: 0.25rem;
    align-content: center;
    min-height: 6.5rem;
    border: 1px solid #99d5cf;
    border-radius: 0.9rem;
    background: #f0fdfa;
    padding: 1rem 1.15rem;
    text-align: center;
}

.solving-proportions-data-label {
    color: #356b67;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.solving-proportions-data-value {
    color: #0f766e;
    font-size: clamp(1.45rem, 3vw, 1.85rem);
    font-weight: 800;
    line-height: 1.2;
}

.solving-proportions-data-detail {
    color: #52736f;
    font-size: 0.85rem;
    font-weight: 600;
}

.solving-proportions-data-detail:empty {
    display: none;
}


/* =========================================================
   One-Response Workspace
   ========================================================= */

.solving-proportions-workspace {
    background: #ffffff;
    padding: 2rem;
}

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

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

.solving-proportions-response-instruction {
    max-width: 780px;
    margin-bottom: 1.5rem;
    color: #5b6678;
    line-height: 1.7;
}

.solving-proportions-answer-panel {
    max-width: 760px;
    margin-bottom: 1.5rem;
    border: 1px solid #dce3eb;
    border-radius: 1rem;
    background: #f7f9fc;
    padding: 1.5rem;
    animation: solving-proportions-fade-in 0.24s ease;
}

.solving-proportions-answer-panel[hidden] {
    display: none !important;
}


/* =========================================================
   Numeric Answer Entry
   ========================================================= */

.solving-proportions-answer-entry {
    display: grid;
    grid-template-columns: auto minmax(150px, 240px) minmax(0, 1fr);
    gap: 0.5rem 0.75rem;
    align-items: center;
    max-width: 620px;
}

.solving-proportions-field-label {
    grid-column: 1 / -1;
    margin-bottom: 0;
    color: #273449;
    font-size: 0.9rem;
    font-weight: 800;
}

.solving-proportions-answer-prefix {
    min-width: 0.8rem;
    color: #0f766e;
    font-size: 1.2rem;
    font-weight: 800;
    text-align: right;
}

.solving-proportions-number-input {
    width: 100%;
    min-height: 3.15rem;
    border: 2px solid #cfd8e3;
    border-radius: 0.75rem;
    background: #ffffff;
    color: #101827;
    font-size: 1.15rem;
    font-weight: 800;
    text-align: center;
}

.solving-proportions-number-input:focus {
    border-color: #0f766e;
    box-shadow: 0 0 0 0.2rem rgba(15, 118, 110, 0.14);
}

.solving-proportions-number-input.correct,
.solving-proportions-number-input.input-correct {
    border-color: #15803d;
    background: #f0fdf4;
}

.solving-proportions-number-input.incorrect,
.solving-proportions-number-input.input-incorrect {
    border-color: #dc2626;
    background: #fef2f2;
}

.solving-proportions-answer-unit {
    color: #475569;
    font-weight: 700;
    line-height: 1.5;
}

.solving-proportions-answer-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}


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

.solving-proportions-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;
}

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

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

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

.solving-proportions-feedback[hidden] {
    display: none !important;
}

.solving-proportions-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;
}

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

.solving-proportions-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;
}

.solving-proportions-hint[hidden] {
    display: none !important;
}


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

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

.solving-proportions-completion[hidden] {
    display: none !important;
}

.solving-proportions-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;
}

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

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

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

.solving-proportions-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;
}

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

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

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

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

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

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

.solving-proportions-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;
}

.solving-proportions-strategy-icon svg {
    width: 1.25rem;
    height: 1.25rem;
}

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

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


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

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

.solving-proportions-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);
}

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

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


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

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

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

.solving-proportions-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
   ========================================================= */

.solving-proportions-page button:disabled {
    cursor: not-allowed;
    opacity: 0.68;
}

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


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

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

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

@media (prefers-reduced-motion: reduce) {
    .solving-proportions-overview-card,
    .solving-proportions-answer-panel,
    .solving-proportions-completion {
        animation: none;
        transition: none;
    }

    .solving-proportions-overview-card:hover {
        transform: none;
    }
}


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

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

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

    .solving-proportions-scoreboard {
        width: 100%;
    }

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

    .solving-proportions-page #newProblemButton {
        grid-column: 1 / -1;
        width: 100%;
    }
}


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

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

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

    .solving-proportions-settings {
        grid-template-columns: 1fr;
    }

    .solving-proportions-page #newProblemButton {
        grid-column: auto;
    }

    .solving-proportions-answer-entry {
        grid-template-columns: auto minmax(0, 1fr) minmax(0, auto);
    }

    .solving-proportions-answer-actions .btn {
        flex: 1 1 160px;
    }

    .solving-proportions-feedback,
    .solving-proportions-hint-button,
    .solving-proportions-hint,
    .solving-proportions-completion {
        margin-right: 1.25rem;
        margin-left: 1.25rem;
    }

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


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

@media (max-width: 480px) {
    .solving-proportions-overview-grid,
    .solving-proportions-strategy-grid,
    .solving-proportions-application-grid,
    .solving-proportions-data-grid {
        grid-template-columns: 1fr;
    }

    .solving-proportions-tool {
        border-radius: 1rem;
    }

    .solving-proportions-tool-header {
        padding: 1.35rem 1rem;
    }

    .solving-proportions-scoreboard {
        gap: 0.4rem;
    }

    .solving-proportions-score-item {
        min-width: 0;
        padding: 0.65rem 0.35rem;
    }

    .solving-proportions-score-label {
        font-size: 0.62rem;
    }

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

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

    .solving-proportions-problem-header {
        align-items: center;
        flex-direction: column;
    }

    .solving-proportions-problem-text {
        font-size: 1.08rem;
    }

    .solving-proportions-data-card {
        min-height: 5.4rem;
    }

    .solving-proportions-answer-panel {
        padding: 1.15rem;
    }

    .solving-proportions-answer-entry {
        grid-template-columns: auto minmax(0, 1fr) auto;
        gap: 0.5rem;
    }

    .solving-proportions-feedback,
    .solving-proportions-hint-button,
    .solving-proportions-hint,
    .solving-proportions-completion {
        margin-right: 1rem;
        margin-left: 1rem;
    }

    .solving-proportions-completion {
        padding: 1.35rem 1rem;
    }

    .solving-proportions-cta-card {
        padding: 1.75rem 1rem;
    }
}

/* =========================================================
   Calculator Button
   ========================================================= */

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

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

.solving-proportions-calculator-trigger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.solving-proportions-calculator-trigger svg {
    width: 1rem;
    height: 1rem;
}


/* =========================================================
   Floating Calculator
   ========================================================= */

.solving-proportions-calculator {
    position: fixed;
    right: max(1.25rem, env(safe-area-inset-right));
    bottom: max(1.25rem, env(safe-area-inset-bottom));
    z-index: 1080;
    width: min(370px, calc(100vw - 2rem));
    max-height: calc(100vh - 2rem);
    overflow-y: auto;
    border: 1px solid #cbd5e1;
    border-radius: 1.15rem;
    background: #ffffff;
    padding: 1.25rem;
    box-shadow:
        0 24px 60px rgba(15, 23, 42, 0.24),
        0 8px 20px rgba(15, 23, 42, 0.12);
    animation: solving-proportions-calculator-in 0.2s ease;
}

.solving-proportions-calculator[hidden] {
    display: none !important;
}


/* =========================================================
   Calculator Header
   ========================================================= */

.solving-proportions-calculator-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1rem;
}

.solving-proportions-calculator-eyebrow {
    margin-bottom: 0.2rem;
    color: #0f766e;
    font-size: 0.7rem;
    font-weight: 800;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.solving-proportions-calculator-header h3 {
    margin-bottom: 0;
    color: #101827;
    font-size: 1.15rem;
    font-weight: 800;
}

.solving-proportions-calculator-close {
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    width: 2.4rem;
    height: 2.4rem;
    border: 1px solid #dce3eb;
    border-radius: 50%;
    background: #f8fafc;
    color: #475569;
    cursor: pointer;
    transition:
        border-color 0.2s ease,
        background 0.2s ease,
        color 0.2s ease;
}

.solving-proportions-calculator-close:hover {
    border-color: #0f766e;
    background: #f0fdfa;
    color: #0f766e;
}

.solving-proportions-calculator-close svg {
    width: 1.1rem;
    height: 1.1rem;
}


/* =========================================================
   Calculator Display
   ========================================================= */

.solving-proportions-calculator-screen {
    display: flex;
    min-height: 6rem;
    margin-bottom: 1rem;
    overflow: hidden;
    border-radius: 0.85rem;
    background: #101827;
    padding: 0.9rem 1rem;
    text-align: right;
    flex-direction: column;
    justify-content: flex-end;
}

.solving-proportions-calculator-expression {
    display: block;
    min-height: 1.25rem;
    margin-bottom: 0.25rem;
    overflow-wrap: anywhere;
    color: rgba(255, 255, 255, 0.62);
    font-size: 0.85rem;
    font-weight: 600;
}

.solving-proportions-calculator-display {
    display: block;
    overflow-wrap: anywhere;
    color: #ffffff;
    font-size: clamp(1.65rem, 6vw, 2.15rem);
    font-weight: 800;
    line-height: 1.2;
}


/* =========================================================
   Calculator Keypad
   ========================================================= */

.solving-proportions-calculator-keypad {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.55rem;
}

.solving-proportions-calculator-key {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 3.1rem;
    border: 1px solid #dce3eb;
    border-radius: 0.75rem;
    background: #f8fafc;
    color: #1e293b;
    font-size: 1.05rem;
    font-weight: 800;
    cursor: pointer;
    user-select: none;
    transition:
        transform 0.1s ease,
        border-color 0.2s ease,
        background 0.2s ease;
}

.solving-proportions-calculator-key:hover {
    border-color: #99d5cf;
    background: #f0fdfa;
}

.solving-proportions-calculator-key:active {
    transform: translateY(1px);
}

.solving-proportions-calculator-key-operator {
    border-color: #99d5cf;
    background: #e6fffb;
    color: #0f766e;
}

.solving-proportions-calculator-key-clear {
    border-color: #fed7aa;
    background: #fff7ed;
    color: #c2410c;
}

.solving-proportions-calculator-key-equals {
    grid-row: span 2;
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
}

.solving-proportions-calculator-key-equals:hover {
    border-color: #0b5f59;
    background: #0b5f59;
}

.solving-proportions-calculator-key-zero {
    grid-column: span 2;
}

.solving-proportions-calculator-note {
    margin: 0.9rem 0 0;
    color: #64748b;
    font-size: 0.78rem;
    line-height: 1.5;
}


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

@keyframes solving-proportions-calculator-in {
    from {
        transform: translateY(10px);
        opacity: 0;
    }

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

@media (prefers-reduced-motion: reduce) {
    .solving-proportions-calculator,
    .solving-proportions-calculator-key {
        animation: none;
        transition: none;
    }
}


/* =========================================================
   Responsive Styles
   ========================================================= */

@media (max-width: 992px) {
    .solving-proportions-setting-actions {
        grid-column: 1 / -1;
        width: 100%;
    }

    .solving-proportions-setting-actions .btn {
        flex: 1 1 0;
    }
}

@media (max-width: 480px) {
    .solving-proportions-calculator {
        right: 0.75rem;
        bottom: max(0.75rem, env(safe-area-inset-bottom));
        width: calc(100vw - 1.5rem);
        max-height: calc(100vh - 1.5rem);
        padding: 1rem;
    }

    .solving-proportions-setting-actions {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .solving-proportions-setting-actions .btn {
        width: 100%;
        padding-right: 0.65rem;
        padding-left: 0.65rem;
    }

    .solving-proportions-calculator-key {
        min-height: 3rem;
    }
}