.tools-page {
    margin: 1.25rem 0 2rem;
}

.tools-page-header {
    align-items: end;
    display: flex;
    flex-wrap: wrap;
    gap: .75rem 1rem;
    justify-content: space-between;
    margin: .75rem 0 1rem;
}

.tools-page-title {
    color: #102a43;
    font-size: 1.85rem;
    line-height: 1.15;
    margin: 0;
}

.tools-page-subtitle {
    color: #52616f;
    margin: .35rem 0 0;
}

.student-tools-grid {
    display: grid;
    gap: 1rem;
    grid-template-areas:
        "scientific stack"
        "graph graph"
        "formula formula";
    grid-template-columns: minmax(300px, 440px) minmax(280px, 1fr);
    align-items: start;
}

.student-tool-panel {
    min-width: 0;
}

.student-tool-panel-wide {
    grid-area: graph;
    grid-column: 1 / -1;
}

.student-tool-panel-formula {
    grid-area: formula;
    grid-column: 1 / -1;
}

.student-tool-stack {
    display: grid;
    gap: 1rem;
    grid-area: stack;
    width: 100%;
}

.student-tool-panel-scientific {
    grid-area: scientific;
}

.student-tool-panel-fraction,
.student-tool-panel-unit {
    width: 100%;
}

.student-tool-box {
    background: #f8f7f3;
    border: 1px solid #d8d6cc;
    border-radius: 8px;
    color: #1f2937;
    padding: .9rem;
    width: 100%;
}

.student-tool-head {
    align-items: center;
    display: flex;
    gap: .75rem;
    justify-content: space-between;
    margin-bottom: .75rem;
}

.student-tool-head h2 {
    color: #102a43;
    font-size: 1.08rem;
    line-height: 1.25;
    margin: 0;
}

.student-tool-head span {
    background: #e0f2fe;
    border: 1px solid #bae6fd;
    border-radius: 999px;
    color: #155e75;
    font-size: .74rem;
    font-weight: 800;
    padding: .18rem .55rem;
    white-space: nowrap;
}

.tool-form-grid,
.graph-controls {
    display: grid;
    gap: .65rem;
}

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

.graph-controls {
    align-items: end;
    grid-template-columns: minmax(220px, 1.4fr) repeat(5, minmax(80px, .65fr)) auto;
}

.tool-form-grid label,
.graph-controls label,
.fraction-input-pair label,
.tool-select-label {
    color: #475569;
    display: grid;
    font-size: .78rem;
    font-weight: 800;
    gap: .25rem;
}

.tool-form-grid input,
.tool-form-grid select,
.graph-controls input,
.graph-controls select,
.fraction-input-pair input,
.tool-select-label select {
    background: #fff;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    color: #111827;
    font: 700 .95rem/1.35 system-ui, sans-serif;
    min-height: 2.55rem;
    min-width: 0;
    padding: .45rem .55rem;
    width: 100%;
}

.tool-form-grid input:focus,
.tool-form-grid select:focus,
.graph-controls input:focus,
.graph-controls select:focus,
.fraction-input-pair input:focus,
.tool-select-label select:focus {
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, .18);
    outline: none;
}

.tool-primary-button {
    align-items: center;
    background: #102a43;
    border: 1px solid #102a43;
    border-radius: 6px;
    color: #fff;
    display: inline-flex;
    font-weight: 800;
    justify-content: center;
    min-height: 2.55rem;
    padding: .5rem .85rem;
}

.tool-primary-button:hover {
    background: #155e75;
    border-color: #155e75;
}

.tool-result {
    background: #102a43;
    border-radius: 8px;
    color: #fff;
    display: block;
    font: 800 1.35rem/1.25 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    margin-top: .75rem;
    min-height: 3rem;
    overflow-wrap: anywhere;
    padding: .7rem .8rem;
}

.tool-subresult {
    color: #64748b;
    display: block;
    font: 700 .9rem/1.35 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    margin-top: .45rem;
    min-height: 1.25rem;
    overflow-wrap: anywhere;
}

.fraction-equation {
    align-items: end;
    display: grid;
    gap: .65rem;
    grid-template-columns: minmax(0, 1fr) 5.5rem minmax(0, 1fr);
}

.fraction-input-pair {
    display: grid;
    gap: .45rem;
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.fraction-tool .tool-primary-button {
    margin-top: .75rem;
    width: 100%;
}

.graph-expression-field {
    min-width: 0;
}

.graph-example-row {
    display: flex;
    flex-wrap: wrap;
    gap: .45rem;
    margin: .75rem 0;
}

.graph-example-row button {
    background: #eef2f7;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    color: #334155;
    font: 800 .84rem/1.2 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    min-height: 2.15rem;
    padding: .35rem .6rem;
}

.graph-example-row button:hover {
    background: #e0f2fe;
    border-color: #93c5fd;
}

.graph-canvas {
    aspect-ratio: 12 / 7;
    background: #fff;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    display: block;
    height: auto;
    width: 100%;
}

.formula-section-grid {
    display: grid;
    gap: .75rem;
}

.formula-section {
    background: #fbfaf7;
    border: 1px solid #e2e0d7;
    border-radius: 8px;
    overflow: hidden;
}

.formula-section summary {
    align-items: center;
    color: #102a43;
    cursor: pointer;
    display: flex;
    font-weight: 850;
    justify-content: space-between;
    list-style: none;
    min-height: 2.85rem;
    padding: .65rem .8rem;
}

.formula-section summary::-webkit-details-marker {
    display: none;
}

.formula-section summary::after {
    align-items: center;
    background: #e0f2fe;
    border-radius: 999px;
    color: #155e75;
    content: "+";
    display: inline-flex;
    font-weight: 900;
    height: 1.35rem;
    justify-content: center;
    width: 1.35rem;
}

.formula-section[open] summary {
    border-bottom: 1px solid #e2e0d7;
}

.formula-section[open] summary::after {
    content: "-";
}

.formula-card-grid {
    display: grid;
    gap: .65rem;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    padding: .75rem;
}

.formula-card {
    background: #fff;
    border: 1px solid #d8e1ea;
    border-radius: 8px;
    display: grid;
    gap: .28rem;
    min-height: 6.75rem;
    padding: .75rem;
}

.formula-card strong {
    color: #102a43;
    font-size: .92rem;
    line-height: 1.25;
}

.formula-card span {
    color: #111827;
    font-size: 1.02rem;
    font-weight: 750;
    line-height: 1.35;
    overflow-wrap: anywhere;
}

.formula-card small {
    color: #64748b;
    font-size: .8rem;
    line-height: 1.35;
}

.formula-save-form {
    margin: .35rem 0 0;
}

.formula-save-button {
    align-items: center;
    background: #fff;
    border: 1px solid #cbd5e1;
    border-radius: 999px;
    color: #334155;
    cursor: pointer;
    display: inline-flex;
    font: 800 .78rem/1.2 system-ui, sans-serif;
    justify-content: center;
    min-height: 2rem;
    padding: .35rem .7rem;
}

.formula-save-button:hover {
    background: #f8fafc;
    border-color: #94a3b8;
}

.formula-save-button.is-saved {
    background: #fff7df;
    border-color: #e9c986;
    color: #6f541f;
}

.tool-note-list {
    background: #f8f7f3;
    border: 1px solid #e2e0d7;
    border-radius: 8px;
    color: #374151;
    margin: 0;
    padding: 1rem 1.15rem;
}

.tool-note-list h2 {
    color: #102a43;
    font-size: 1.08rem;
    margin: 0 0 .6rem;
}

.tool-note-list p {
    margin: .45rem 0;
}

.scientific-calculator {
    background: #f8f7f3;
    border: 1px solid #d8d6cc;
    border-radius: 8px;
    color: #1f2937;
    max-width: 440px;
    padding: .85rem;
    width: 100%;
}

.calculator-display {
    background: #102a43;
    border-radius: 8px;
    color: #f8fafc;
    padding: .75rem;
}

.calculator-display-top {
    align-items: center;
    display: flex;
    gap: .75rem;
    justify-content: space-between;
    margin-bottom: .45rem;
}

.calculator-field-label {
    color: #dbeafe;
    font-size: .75rem;
    font-weight: 800;
    letter-spacing: .06em;
    text-transform: uppercase;
}

.calculator-mode-toggle {
    background: #f59e0b;
    border: 1px solid #fbbf24;
    border-radius: 6px;
    color: #111827;
    font-size: .78rem;
    font-weight: 800;
    min-height: 2rem;
    padding: .25rem .6rem;
}

.calculator-expression {
    background: #fbfaf7;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    color: #111827;
    font: 700 1.05rem/1.4 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    min-height: 2.8rem;
    padding: .55rem .65rem;
    width: 100%;
}

.calculator-expression:focus {
    border-color: #f59e0b;
    box-shadow: 0 0 0 3px rgba(245, 158, 11, .25);
    outline: none;
}

.calculator-output {
    color: #f8fafc;
    display: block;
    font: 800 1.45rem/1.25 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    min-height: 2.15rem;
    overflow-wrap: anywhere;
    padding-top: .45rem;
    text-align: right;
}

.scientific-calculator.has-error .calculator-output {
    color: #fecaca;
}

.calculator-key-grid {
    display: grid;
    gap: .45rem;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    margin-top: .65rem;
}

.calculator-key {
    align-items: center;
    background: #fff;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    color: #1f2937;
    display: inline-flex;
    font: 800 .92rem/1 system-ui, sans-serif;
    justify-content: center;
    min-height: 2.65rem;
    min-width: 0;
    overflow: hidden;
    padding: .25rem;
    text-align: center;
    white-space: nowrap;
}

.calculator-key:hover {
    background: #eef6ff;
    border-color: #93c5fd;
}

.calculator-key:focus-visible {
    outline: 3px solid rgba(37, 99, 235, .28);
    outline-offset: 1px;
}

.calculator-key.is-function {
    background: #eef2f7;
    color: #102a43;
}

.calculator-key.is-operator {
    background: #e0f2fe;
    color: #155e75;
}

.calculator-key.is-danger {
    background: #fef2f2;
    border-color: #fecaca;
    color: #991b1b;
}

.calculator-key.is-equal {
    background: #15803d;
    border-color: #15803d;
    color: #fff;
    grid-column: span 2;
}

.calculator-key.is-equal:hover {
    background: #166534;
    border-color: #166534;
}

.calculator-history {
    display: grid;
    gap: .35rem;
    margin-top: .7rem;
}

.calculator-history:empty {
    display: none;
}

.calculator-history-button {
    background: #fbfaf7;
    border: 1px solid #e2e0d7;
    border-radius: 6px;
    color: #334155;
    cursor: pointer;
    display: grid;
    font: inherit;
    gap: .1rem;
    padding: .45rem .55rem;
    text-align: left;
}

.calculator-history-button:hover {
    background: #fff;
    border-color: #cbd5e1;
}

.calculator-history-expression {
    color: #64748b;
    font-size: .78rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.calculator-history-result {
    color: #102a43;
    font: 800 .9rem/1.25 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    overflow-wrap: anywhere;
}

.calculator-launcher {
    bottom: 1rem;
    position: fixed;
    right: 1rem;
    z-index: 420;
}

.calculator-open-button {
    align-items: center;
    background: #102a43;
    border: 1px solid rgba(255, 255, 255, .2);
    border-radius: 8px;
    box-shadow: 0 12px 28px rgba(15, 23, 42, .24);
    color: #fff;
    display: inline-flex;
    font-weight: 800;
    gap: .45rem;
    min-height: 2.75rem;
    padding: .55rem .85rem;
}

.calculator-open-button:hover {
    background: #155e75;
}

.calculator-open-icon {
    align-items: center;
    background: #f59e0b;
    border-radius: 6px;
    color: #111827;
    display: inline-flex;
    font: 900 1rem/1 ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
    height: 1.55rem;
    justify-content: center;
    width: 1.55rem;
}

.calculator-modal-backdrop {
    align-items: flex-start;
    background: rgba(15, 23, 42, .52);
    display: flex;
    inset: 0;
    justify-content: flex-end;
    padding: 1rem;
    position: fixed;
    z-index: 600;
}

.calculator-modal-backdrop[hidden] {
    display: none;
}

.calculator-modal {
    background: #fbfaf7;
    border: 1px solid #d8d6cc;
    border-radius: 8px;
    box-shadow: 0 24px 60px rgba(15, 23, 42, .35);
    max-height: calc(100vh - 2rem);
    overflow: auto;
    padding: .85rem;
    width: min(440px, 100%);
}

.calculator-modal-header {
    align-items: center;
    display: flex;
    gap: .75rem;
    justify-content: space-between;
    margin-bottom: .65rem;
}

.calculator-modal-title {
    color: #102a43;
    font-size: 1.05rem;
    line-height: 1.25;
    margin: 0;
}

.calculator-close-button {
    align-items: center;
    background: #eef2f7;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    color: #334155;
    display: inline-flex;
    font-size: 1.25rem;
    font-weight: 900;
    height: 2.2rem;
    justify-content: center;
    line-height: 1;
    padding: 0;
    width: 2.2rem;
}

.calculator-close-button:hover {
    background: #e2e8f0;
}

.calculator-modal .scientific-calculator {
    border: 0;
    max-width: none;
    padding: 0;
}

@media (max-width: 780px) {
    .student-tools-grid {
        grid-template-areas:
            "scientific"
            "stack"
            "graph"
            "formula";
        grid-template-columns: 1fr;
    }

    .student-tool-panel-wide {
        grid-column: auto;
    }

    .student-tool-panel-formula {
        grid-column: auto;
    }

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

    .graph-expression-field,
    .graph-controls .tool-primary-button {
        grid-column: 1 / -1;
    }
}

@media (max-width: 520px) {
    .calculator-key-grid {
        gap: .35rem;
    }

    .calculator-key {
        font-size: .82rem;
        min-height: 2.45rem;
    }

    .calculator-launcher {
        bottom: .75rem;
        right: .75rem;
    }

    .calculator-open-button {
        min-height: 2.55rem;
        padding: .45rem .65rem;
    }

    .tool-form-grid,
    .fraction-equation,
    .fraction-input-pair,
    .graph-controls {
        grid-template-columns: 1fr;
    }

    .graph-expression-field,
    .graph-controls .tool-primary-button {
        grid-column: auto;
    }
}