/* =========================================================
   COORDINATE PLANE PRACTICE PAGE
   ========================================================= */

:root
{
    --cp-navy: #102a43;
    --cp-navy-dark: #081c2f;
    --cp-blue: #1f6f8b;
    --cp-teal: #159a9c;
    --cp-teal-dark: #117b7d;
    --cp-green: #198754;
    --cp-green-dark: #157347;
    --cp-red: #c0392b;
    --cp-orange: #d97706;
    --cp-purple: #6f42c1;
    --cp-light: #f5f8fb;
    --cp-lighter: #fbfcfe;
    --cp-border: #dbe5ee;
    --cp-text: #243b53;
    --cp-muted: #627d98;
    --cp-white: #ffffff;

    --cp-shadow:
        0 18px 45px rgba(16, 42, 67, 0.12);

    --cp-shadow-small:
        0 8px 24px rgba(16, 42, 67, 0.09);
}


/* =========================================================
   GENERAL PAGE
   ========================================================= */

.cp-practice-page
{
    background: var(--cp-white);
    color: var(--cp-text);

    font-family: "Inter", sans-serif;
}


.cp-practice-page *,
.cp-practice-page *::before,
.cp-practice-page *::after
{
    box-sizing: border-box;
}


.cp-practice-page button,
.cp-practice-page input,
.cp-practice-page select
{
    font-family: inherit;
}


.cp-practice-page button
{
    cursor: pointer;
}


/* =========================================================
   PRACTICE SECTION
   ========================================================= */

.cp-section
{
    position: relative;

    padding: 5rem 1.5rem;

    background:
        radial-gradient(
            circle at top left,
            rgba(21, 154, 156, 0.08),
            transparent 32rem
        ),
        linear-gradient(
            180deg,
            #ffffff 0%,
            #f5f8fb 100%
        );
}


.cp-app
{
    width: min(100%, 1080px);

    margin: 0 auto;
}


/* =========================================================
   TOOLBAR
   ========================================================= */

.cp-toolbar
{
    display: flex;
    align-items: flex-end;
    justify-content: space-between;

    gap: 2rem;

    margin-bottom: 2rem;
}


.cp-toolbar-heading
{
    max-width: 700px;
}


.cp-toolbar-heading h2
{
    margin: 0 0 0.75rem;

    color: var(--cp-navy);

    font-size: clamp(1.65rem, 3.2vw, 2.2rem);
    font-weight: 800;
    line-height: 1.15;
}


.cp-toolbar-heading p:last-child
{
    max-width: 660px;

    margin: 0;

    color: var(--cp-muted);

    font-size: 1rem;
    line-height: 1.7;
}


.cp-eyebrow
{
    margin: 0 0 0.5rem;

    color: var(--cp-teal-dark);

    font-size: 0.78rem;
    font-weight: 800;

    letter-spacing: 0.12em;

    text-transform: uppercase;
}


.cp-controls
{
    flex: 0 0 auto;
}


.cp-control-group
{
    min-width: 190px;
}


.cp-control-group label
{
    display: block;

    margin-bottom: 0.45rem;

    color: var(--cp-navy);

    font-size: 0.85rem;
    font-weight: 700;
}


.cp-select
{
    width: 100%;
    min-height: 48px;

    padding: 0.7rem 2.5rem 0.7rem 0.95rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.75rem;

    background-color: var(--cp-white);
    color: var(--cp-navy);

    font-size: 0.95rem;
    font-weight: 700;

    outline: none;

    box-shadow: var(--cp-shadow-small);

    transition:
        border-color 0.2s ease,
        box-shadow 0.2s ease,
        transform 0.2s ease;
}


.cp-select:hover
{
    border-color:
        rgba(21, 154, 156, 0.6);
}


.cp-select:focus
{
    border-color: var(--cp-teal);

    box-shadow:
        0 0 0 4px rgba(21, 154, 156, 0.14),
        var(--cp-shadow-small);
}


/* =========================================================
   MODE SELECTOR
   ========================================================= */

.cp-mode-selector
{
    margin-bottom: 1.7rem;

    padding: 1.25rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background: var(--cp-white);

    box-shadow: var(--cp-shadow-small);
}


.cp-mode-heading
{
    display: flex;
    align-items: baseline;
    justify-content: space-between;

    gap: 1rem;

    margin-bottom: 0.9rem;
}


.cp-mode-label
{
    color: var(--cp-navy);

    font-size: 0.9rem;
    font-weight: 800;
}


.cp-mode-help
{
    color: var(--cp-muted);

    font-size: 0.8rem;
}


.cp-mode-tabs
{
    display: grid;

    grid-template-columns:
        repeat(6, minmax(0, 1fr));

    gap: 0.7rem;
}


.cp-mode-button
{
    display: flex;
    align-items: center;
    justify-content: center;

    gap: 0.55rem;

    min-height: 64px;

    padding: 0.8rem 0.65rem;

    border: 2px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-lighter);
    color: var(--cp-navy);

    font-size: 0.76rem;
    font-weight: 800;

    line-height: 1.3;
    text-align: center;

    transition:
        transform 0.2s ease,
        border-color 0.2s ease,
        background-color 0.2s ease,
        color 0.2s ease,
        box-shadow 0.2s ease;
}


.cp-mode-button svg
{
    flex: 0 0 auto;

    width: 18px;
    height: 18px;
}


.cp-mode-button:hover
{
    transform: translateY(-1px);

    border-color:
        rgba(21, 154, 156, 0.5);

    background:
        rgba(21, 154, 156, 0.055);

    color: var(--cp-teal-dark);
}


.cp-mode-button.is-active
{
    border-color: var(--cp-teal);

    background:
        linear-gradient(
            135deg,
            rgba(21, 154, 156, 0.13),
            rgba(31, 111, 139, 0.07)
        );

    color: var(--cp-teal-dark);

    box-shadow:
        0 6px 18px rgba(21, 154, 156, 0.14);
}


/* =========================================================
   ROUND PROGRESS
   ========================================================= */

.cp-progress-area
{
    margin-bottom: 1.25rem;
}


.cp-progress-text
{
    display: flex;
    justify-content: space-between;

    gap: 1rem;

    margin-bottom: 0.6rem;

    color: var(--cp-navy);

    font-size: 0.88rem;
    font-weight: 700;
}


.cp-progress-track
{
    width: 100%;
    height: 12px;

    overflow: hidden;

    border-radius: 999px;

    background: #dfe9f1;
}


.cp-progress-bar
{
    width: 10%;
    height: 100%;

    border-radius: inherit;

    background:
        linear-gradient(
            90deg,
            var(--cp-teal),
            var(--cp-blue)
        );

    transition:
        width 0.35s ease;
}


/* =========================================================
   MAIN PRACTICE CARD
   ========================================================= */

.cp-card
{
    padding:
        clamp(1.4rem, 4vw, 2.5rem);

    border:
        1px solid rgba(219, 229, 238, 0.9);

    border-radius: 1.35rem;

    background: var(--cp-white);

    box-shadow: var(--cp-shadow);
}


.cp-card-top
{
    display: flex;
    align-items: flex-start;
    justify-content: space-between;

    gap: 1rem;

    margin-bottom: 1.5rem;
}


.cp-card-label
{
    margin: 0 0 0.3rem;

    color: var(--cp-navy);

    font-size: 0.95rem;
    font-weight: 800;
}


.cp-step-instruction
{
    margin: 0;

    color: var(--cp-muted);

    font-size: 0.92rem;
    line-height: 1.5;
}


.cp-card-badges
{
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex-wrap: wrap;

    gap: 0.5rem;
}


.cp-mode-badge,
.cp-difficulty-badge
{
    display: inline-flex;
    align-items: center;
    justify-content: center;

    min-height: 34px;

    padding: 0.45rem 0.8rem;

    border-radius: 999px;

    font-size: 0.75rem;
    font-weight: 800;

    letter-spacing: 0.03em;

    white-space: nowrap;
}


.cp-mode-badge
{
    background:
        rgba(31, 111, 139, 0.11);

    color: var(--cp-blue);
}


.cp-difficulty-badge
{
    background:
        rgba(21, 154, 156, 0.11);

    color: var(--cp-teal-dark);
}


/* =========================================================
   CURRENT PROBLEM
   ========================================================= */

.cp-current-problem-area
{
    margin-bottom: 1.5rem;

    padding: 1.35rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background:
        linear-gradient(
            135deg,
            rgba(21, 154, 156, 0.055),
            rgba(31, 111, 139, 0.03)
        );
}


.cp-problem-label
{
    display: block;

    margin-bottom: 0.75rem;

    color: var(--cp-muted);

    font-size: 0.76rem;
    font-weight: 800;

    letter-spacing: 0.08em;

    text-transform: uppercase;
}


.cp-problem-display
{
    color: var(--cp-navy-dark);

    font-size:
        clamp(1.4rem, 4vw, 2rem);

    font-weight: 800;
    line-height: 1.55;

    text-align: center;

    overflow-wrap: anywhere;
}


/* =========================================================
   THREE STEP PROGRESS
   ========================================================= */

.cp-step-progress
{
    display: grid;

    grid-template-columns:
        auto minmax(20px, 1fr)
        auto minmax(20px, 1fr)
        auto;

    align-items: center;

    gap: 0.55rem;

    margin: 1.8rem 0;
}


.cp-step-marker
{
    display: flex;
    flex-direction: column;
    align-items: center;

    gap: 0.35rem;

    min-width: 72px;

    text-align: center;
}


.cp-step-marker span
{
    display: flex;
    align-items: center;
    justify-content: center;

    width: 38px;
    height: 38px;

    border: 2px solid var(--cp-border);
    border-radius: 50%;

    background: var(--cp-white);
    color: var(--cp-muted);

    font-size: 0.84rem;
    font-weight: 800;

    transition:
        border-color 0.25s ease,
        background-color 0.25s ease,
        color 0.25s ease,
        transform 0.25s ease;
}


.cp-step-marker small
{
    color: var(--cp-muted);

    font-size: 0.68rem;
    font-weight: 700;

    line-height: 1.2;
}


.cp-step-marker.is-active span
{
    border-color: var(--cp-teal);

    background: var(--cp-teal);
    color: var(--cp-white);

    transform: scale(1.05);
}


.cp-step-marker.is-active small
{
    color: var(--cp-teal-dark);

    font-weight: 800;
}


.cp-step-marker.is-complete span
{
    border-color: var(--cp-green);

    background: var(--cp-green);
    color: var(--cp-white);
}


.cp-step-marker.is-complete small
{
    color: var(--cp-green);
}


.cp-step-connector
{
    height: 3px;

    border-radius: 999px;

    background: var(--cp-border);

    transition:
        background-color 0.25s ease;
}


.cp-step-connector.is-complete
{
    background: var(--cp-green);
}


/* =========================================================
   ACTIVE WORK AREA
   ========================================================= */

.cp-work-area
{
    margin-top: 1rem;

    padding:
        clamp(1.25rem, 3vw, 1.8rem);

    border:
        2px solid rgba(21, 154, 156, 0.2);

    border-radius: 1rem;

    background:
        linear-gradient(
            135deg,
            rgba(21, 154, 156, 0.065),
            rgba(31, 111, 139, 0.035)
        );
}


.cp-work-step-number
{
    margin: 0 0 0.35rem;

    color: var(--cp-teal-dark);

    font-size: 0.76rem;
    font-weight: 800;

    letter-spacing: 0.1em;

    text-transform: uppercase;
}


.cp-work-area h3
{
    margin: 0 0 0.55rem;

    color: var(--cp-navy);

    font-size:
        clamp(1.2rem, 3vw, 1.55rem);

    font-weight: 800;
    line-height: 1.3;
}


.cp-work-description
{
    margin: 0 0 1.3rem;

    color: var(--cp-muted);

    font-size: 0.9rem;
    line-height: 1.65;
}


/* =========================================================
   PROBLEM REMINDER
   ========================================================= */

.cp-problem-reminder
{
    margin: 1.2rem 0 1.4rem;

    padding: 1.1rem 1.3rem;

    border:
        1px solid rgba(21, 154, 156, 0.22);

    border-radius: 0.9rem;

    background: var(--cp-white);
    color: var(--cp-navy-dark);

    font-size:
        clamp(1.1rem, 3.5vw, 1.45rem);

    font-weight: 700;
    line-height: 1.6;

    text-align: center;

    box-shadow: var(--cp-shadow-small);
}


.cp-problem-reminder strong
{
    color: var(--cp-teal-dark);

    font-size:
        clamp(1.35rem, 4vw, 1.8rem);
}


/* =========================================================
   COORDINATE GRAPH SHELL
   ========================================================= */

.cp-graph-shell
{
    margin-top: 1.4rem;

    padding: 1rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background: var(--cp-white);

    box-shadow: var(--cp-shadow-small);
}


.cp-graph-heading
{
    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 1rem;

    margin-bottom: 0.9rem;
}


.cp-graph-heading > div:first-child
{
    display: flex;
    flex-direction: column;

    gap: 0.2rem;
}


.cp-graph-label
{
    color: var(--cp-muted);

    font-size: 0.72rem;
    font-weight: 800;

    letter-spacing: 0.08em;

    text-transform: uppercase;
}


.cp-graph-heading strong
{
    color: var(--cp-navy);

    font-size: 0.9rem;
    font-weight: 800;
}


.cp-coordinate-readout
{
    flex: 0 0 auto;

    min-width: 130px;

    padding: 0.5rem 0.7rem;

    border: 1px solid var(--cp-border);
    border-radius: 999px;

    background: var(--cp-lighter);
    color: var(--cp-teal-dark);

    font-size: 0.8rem;
    font-weight: 800;

    text-align: center;
}


/* =========================================================
   GRAPH
   ========================================================= */

.cp-graph-wrapper
{
    position: relative;

    width: min(100%, 720px);

    margin: 0 auto;
}


.cp-graph
{
    width: 100%;
    height: 560px;

    margin: 0;

    border:
        1px solid var(--cp-border) !important;

    border-radius: 0.9rem;

    background: #ffffff;

    box-shadow:
        inset 0 0 0 1px rgba(16, 42, 67, 0.015);

    touch-action: none;
}


/*
 * JSXGraph sometimes exposes its own cursor.
 * Keep plotting interactions visually obvious.
 */
.cp-graph.is-interactive
{
    cursor: crosshair;
}


.cp-graph.is-readonly
{
    cursor: default;
}


/* =========================================================
   FIXED GRAPH LEGEND
   ========================================================= */

.cp-graph-legend
{
    position: absolute;

    top: 14px;
    right: 14px;

    z-index: 30;

    display: grid;

    gap: 0.5rem;

    padding: 0.65rem 0.8rem;

    border:
        1px solid rgba(219, 229, 238, 0.95);

    border-radius: 0.7rem;

    background:
        rgba(255, 255, 255, 0.95);

    color: var(--cp-navy);

    font-size: 0.75rem;
    font-weight: 750;

    line-height: 1.2;

    pointer-events: none;

    box-shadow:
        0 4px 14px rgba(16, 42, 67, 0.1);
}


.cp-graph-legend[hidden]
{
    display: none !important;
}


.cp-graph-legend-item
{
    display: flex;
    align-items: center;

    gap: 0.55rem;

    white-space: nowrap;
}


.cp-legend-point
{
    display: inline-block;

    flex: 0 0 auto;

    width: 12px;
    height: 12px;

    border: 3px solid var(--cp-teal);
    border-radius: 50%;

    background: var(--cp-white);
}


.cp-legend-point-target
{
    border-color: var(--cp-purple);

    background: var(--cp-purple);
}


.cp-legend-point-student
{
    border-color: var(--cp-teal);

    background: var(--cp-teal);
}


/* =========================================================
   GRAPH STATUS CARDS
   ========================================================= */

.cp-graph-status-row
{
    display: grid;

    grid-template-columns:
        repeat(2, minmax(0, 1fr));

    gap: 0.8rem;

    margin-top: 0.9rem;
}


.cp-graph-status-card
{
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;

    min-height: 76px;

    padding: 0.75rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.8rem;

    background: var(--cp-lighter);

    text-align: center;
}


.cp-graph-status-card span
{
    display: block;

    margin-bottom: 0.25rem;

    color: var(--cp-muted);

    font-size: 0.68rem;
    font-weight: 800;

    letter-spacing: 0.05em;

    text-transform: uppercase;
}


.cp-graph-status-card strong
{
    color: var(--cp-navy-dark);

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


/* =========================================================
   TEXT ANSWER FORM
   ========================================================= */

.cp-answer-form
{
    margin-top: 1.3rem;
}


.cp-answer-form[hidden]
{
    display: none !important;
}


.cp-input-label
{
    display: block;

    margin-bottom: 0.6rem;

    color: var(--cp-navy);

    font-size: 0.9rem;
    font-weight: 800;
}


.cp-input-row
{
    display: grid;

    grid-template-columns:
        minmax(0, 1fr) auto;

    gap: 0.8rem;
}


.cp-step-input
{
    width: 100%;
    min-height: 56px;

    padding: 0.85rem 1rem;

    border: 2px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-white);
    color: var(--cp-navy-dark);

    font-size: 1.05rem;
    font-weight: 650;

    outline: none;

    transition:
        border-color 0.2s ease,
        box-shadow 0.2s ease,
        background-color 0.2s ease;
}


.cp-step-input::placeholder
{
    color: #9aabba;

    font-weight: 500;
}


.cp-step-input:hover
{
    border-color: #b9cad8;
}


.cp-step-input:focus
{
    border-color: var(--cp-teal);

    box-shadow:
        0 0 0 4px rgba(21, 154, 156, 0.13);
}


.cp-step-input.is-correct
{
    border-color: var(--cp-green);

    background:
        rgba(25, 135, 84, 0.045);
}


.cp-step-input.is-incorrect
{
    border-color: var(--cp-red);

    background:
        rgba(192, 57, 43, 0.045);
}


/* =========================================================
   MULTIPLE CHOICE
   ========================================================= */

.cp-choice-answer-area
{
    margin-top: 1.3rem;
}


.cp-choice-answer-area[hidden]
{
    display: none !important;
}


.cp-choice-grid
{
    display: grid;

    grid-template-columns:
        repeat(2, minmax(0, 1fr));

    gap: 0.8rem;
}


.cp-choice-button
{
    min-height: 58px;

    padding: 0.8rem 1rem;

    border: 2px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-white);
    color: var(--cp-navy);

    font-size: 0.92rem;
    font-weight: 800;

    text-align: center;

    transition:
        transform 0.18s ease,
        border-color 0.18s ease,
        background-color 0.18s ease,
        color 0.18s ease,
        box-shadow 0.18s ease;
}


.cp-choice-button:hover
{
    transform: translateY(-1px);

    border-color:
        rgba(21, 154, 156, 0.55);

    background:
        rgba(21, 154, 156, 0.055);

    color: var(--cp-teal-dark);
}


.cp-choice-button.is-selected
{
    border-color: var(--cp-teal);

    background:
        rgba(21, 154, 156, 0.1);

    color: var(--cp-teal-dark);

    box-shadow:
        0 0 0 3px
        rgba(21, 154, 156, 0.08);
}


.cp-choice-button.is-correct
{
    border-color: var(--cp-green);

    background:
        rgba(25, 135, 84, 0.075);

    color: var(--cp-green-dark);
}


.cp-choice-button.is-incorrect
{
    border-color: var(--cp-red);

    background:
        rgba(192, 57, 43, 0.065);

    color: #8f2e24;
}


/* =========================================================
   GRAPH CHECK AREA
   ========================================================= */

.cp-graph-check-area
{
    display: flex;
    justify-content: center;

    margin-top: 1.15rem;
}


.cp-graph-check-area[hidden]
{
    display: none !important;
}


/* =========================================================
   FEEDBACK
   ========================================================= */

.cp-feedback
{
    margin-top: 1.35rem;

    padding: 1rem 1.1rem;

    border: 1px solid var(--cp-border);
    border-left-width: 4px;
    border-radius: 0.8rem;

    font-size: 0.9rem;
    font-weight: 650;
    line-height: 1.6;
}


.cp-feedback-neutral
{
    border-left-color: var(--cp-blue);

    background:
        rgba(31, 111, 139, 0.05);

    color: var(--cp-text);
}


.cp-feedback-correct
{
    border-color:
        rgba(25, 135, 84, 0.25);

    border-left-color:
        var(--cp-green);

    background:
        rgba(25, 135, 84, 0.065);

    color: #12663f;
}


.cp-feedback-incorrect
{
    border-color:
        rgba(192, 57, 43, 0.22);

    border-left-color:
        var(--cp-red);

    background:
        rgba(192, 57, 43, 0.055);

    color: #8f2e24;
}


/* =========================================================
   PRIMARY BUTTONS
   ========================================================= */

.cp-submit-button,
.cp-next-button
{
    display: inline-flex;
    align-items: center;
    justify-content: center;

    gap: 0.45rem;

    min-height: 56px;

    padding: 0.85rem 1.4rem;

    border: 0;
    border-radius: 0.85rem;

    color: var(--cp-white);

    font-size: 0.92rem;
    font-weight: 800;

    white-space: nowrap;

    transition:
        transform 0.2s ease,
        box-shadow 0.2s ease,
        filter 0.2s ease;
}


.cp-submit-button
{
    background:
        linear-gradient(
            135deg,
            var(--cp-teal),
            var(--cp-blue)
        );

    box-shadow:
        0 8px 20px rgba(21, 154, 156, 0.22);
}


.cp-next-button
{
    background:
        linear-gradient(
            135deg,
            var(--cp-green),
            var(--cp-green-dark)
        );

    box-shadow:
        0 8px 20px rgba(25, 135, 84, 0.22);
}


.cp-submit-button:hover,
.cp-next-button:hover
{
    transform: translateY(-2px);

    filter: brightness(1.04);
}


.cp-submit-button:active,
.cp-next-button:active
{
    transform: translateY(0);
}


.cp-submit-button:disabled
{
    cursor: not-allowed;

    opacity: 0.58;

    transform: none;

    box-shadow: none;
}


/* =========================================================
   ACTION ROW
   ========================================================= */

.cp-action-row
{
    display: flex;
    flex-wrap: wrap;

    gap: 0.7rem;

    margin-top: 1.25rem;
}


.cp-secondary-button
{
    display: inline-flex;
    align-items: center;
    justify-content: center;

    gap: 0.45rem;

    min-height: 42px;

    padding: 0.6rem 0.9rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.7rem;

    background: var(--cp-white);
    color: var(--cp-navy);

    font-size: 0.82rem;
    font-weight: 750;

    transition:
        border-color 0.2s ease,
        background-color 0.2s ease,
        color 0.2s ease,
        transform 0.2s ease;
}


.cp-secondary-button:hover
{
    transform: translateY(-1px);

    border-color:
        rgba(21, 154, 156, 0.5);

    background:
        rgba(21, 154, 156, 0.055);

    color: var(--cp-teal-dark);
}


/* =========================================================
   HELP PANEL
   ========================================================= */

.cp-help-panel
{
    display: grid;

    grid-template-columns:
        auto minmax(0, 1fr);

    gap: 1rem;

    margin-top: 1.25rem;

    padding: 1.1rem;

    border:
        1px solid rgba(217, 119, 6, 0.24);

    border-radius: 0.9rem;

    background:
        rgba(217, 119, 6, 0.055);
}


.cp-help-panel[hidden]
{
    display: none !important;
}


.cp-help-panel-icon
{
    display: flex;
    align-items: center;
    justify-content: center;

    width: 42px;
    height: 42px;

    border-radius: 50%;

    background:
        rgba(217, 119, 6, 0.12);

    color: var(--cp-orange);

    font-size: 1rem;
}


.cp-help-panel strong
{
    display: block;

    margin-bottom: 0.25rem;

    color: var(--cp-navy);

    font-size: 0.9rem;
}


.cp-help-panel p
{
    margin: 0;

    color: var(--cp-text);

    font-size: 0.86rem;
    line-height: 1.6;
}


/* =========================================================
   REFERENCE PANEL
   ========================================================= */

.cp-reference-panel
{
    margin-top: 1.25rem;

    padding: 1.25rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background: var(--cp-white);

    box-shadow: var(--cp-shadow-small);
}


.cp-reference-panel[hidden]
{
    display: none !important;
}


.cp-reference-panel-heading
{
    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 1rem;

    margin-bottom: 1rem;
}


.cp-reference-panel-heading h3
{
    margin: 0;

    color: var(--cp-navy);

    font-size: 1.15rem;
    font-weight: 800;
}


.cp-close-button
{
    display: inline-flex;
    align-items: center;
    justify-content: center;

    flex: 0 0 auto;

    width: 38px;
    height: 38px;

    padding: 0;

    border: 1px solid var(--cp-border);
    border-radius: 50%;

    background: var(--cp-white);
    color: var(--cp-muted);
}


.cp-close-button:hover
{
    border-color:
        rgba(21, 154, 156, 0.5);

    color: var(--cp-teal-dark);
}


.cp-reference-hero
{
    padding: 1.2rem;

    border-radius: 0.9rem;

    background:
        linear-gradient(
            135deg,
            rgba(21, 154, 156, 0.09),
            rgba(31, 111, 139, 0.045)
        );

    text-align: center;
}


.cp-reference-main-equation
{
    display: block;

    margin-bottom: 0.5rem;

    color: var(--cp-navy-dark);

    font-size:
        clamp(1.7rem, 5vw, 2.4rem);

    font-weight: 800;
}


.cp-reference-hero p
{
    margin: 0;

    color: var(--cp-muted);

    line-height: 1.6;
}


.cp-reference-grid
{
    display: grid;

    grid-template-columns:
        repeat(2, minmax(0, 1fr));

    gap: 1rem;

    margin-top: 1rem;
}


.cp-reference-item
{
    padding: 1rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-lighter);
}


.cp-reference-item strong
{
    display: block;

    margin-bottom: 0.4rem;

    color: var(--cp-navy);

    font-size: 0.9rem;
}


.cp-reference-equation
{
    display: block;

    margin-bottom: 0.45rem;

    color: var(--cp-teal-dark);

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


.cp-reference-item p
{
    margin: 0;

    color: var(--cp-muted);

    font-size: 0.82rem;
    line-height: 1.55;
}


.cp-reference-note
{
    margin: 1rem 0 0;

    padding: 0.9rem 1rem;

    border-left:
        4px solid var(--cp-orange);

    border-radius: 0.65rem;

    background:
        rgba(217, 119, 6, 0.055);

    color: var(--cp-text);

    font-size: 0.84rem;
    line-height: 1.6;
}


/* =========================================================
   PROBLEM COMPLETE
   ========================================================= */

.cp-problem-complete
{
    display: grid;

    grid-template-columns:
        auto minmax(0, 1fr) auto;

    align-items: center;

    gap: 1rem;

    margin-top: 1.4rem;

    padding: 1.2rem;

    border:
        1px solid rgba(25, 135, 84, 0.25);

    border-radius: 1rem;

    background:
        rgba(25, 135, 84, 0.06);
}


.cp-problem-complete[hidden]
{
    display: none !important;
}


.cp-problem-complete-icon
{
    color: var(--cp-green);

    font-size: 1.8rem;
}


.cp-problem-complete-label
{
    margin: 0 0 0.2rem;

    color: var(--cp-green);

    font-size: 0.72rem;
    font-weight: 800;

    letter-spacing: 0.08em;

    text-transform: uppercase;
}


.cp-problem-complete h3
{
    margin: 0 0 0.2rem;

    color: var(--cp-navy);

    font-size: 1.15rem;
    font-weight: 800;
}


.cp-problem-complete p:last-child
{
    margin: 0;

    color: var(--cp-muted);

    font-size: 0.86rem;
    line-height: 1.55;
}


/* =========================================================
   STATS
   ========================================================= */

.cp-stats
{
    display: grid;

    grid-template-columns:
        repeat(4, minmax(0, 1fr));

    gap: 1rem;

    margin-top: 1.25rem;
}


.cp-stat
{
    padding: 1rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.9rem;

    background: var(--cp-white);

    text-align: center;

    box-shadow: var(--cp-shadow-small);
}


.cp-stat span
{
    display: block;

    margin-bottom: 0.3rem;

    color: var(--cp-muted);

    font-size: 0.72rem;
    font-weight: 800;
}


.cp-stat strong
{
    color: var(--cp-navy-dark);

    font-size: 1.45rem;
    font-weight: 800;
}


/* =========================================================
   RESULTS SCREEN
   ========================================================= */

.cp-results
{
    margin-top: 1.5rem;

    padding: 2rem;

    border: 1px solid var(--cp-border);
    border-radius: 1.2rem;

    background: var(--cp-white);

    text-align: center;

    box-shadow: var(--cp-shadow);
}


.cp-results[hidden]
{
    display: none !important;
}


.cp-results-label
{
    margin-bottom: 0.4rem;

    color: var(--cp-teal-dark);

    font-size: 0.75rem;
    font-weight: 800;

    letter-spacing: 0.09em;

    text-transform: uppercase;
}


.cp-results h2
{
    color: var(--cp-navy);

    font-weight: 800;
}


.cp-results-grid
{
    display: grid;

    grid-template-columns:
        repeat(4, minmax(0, 1fr));

    gap: 1rem;

    margin: 1.5rem 0;
}


.cp-result-item
{
    padding: 1rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-lighter);
}


.cp-result-item span
{
    display: block;

    margin-bottom: 0.35rem;

    color: var(--cp-muted);

    font-size: 0.72rem;
    font-weight: 800;
}


.cp-result-item strong
{
    color: var(--cp-navy);

    font-size: 1.45rem;
    font-weight: 800;
}


.cp-result-accuracy strong
{
    color: var(--cp-teal-dark);
}


/* =========================================================
   INFO CARDS
   ========================================================= */

.cp-info
{
    display: grid;

    grid-template-columns:
        repeat(3, minmax(0, 1fr));

    gap: 1.25rem;

    padding-top: 4rem;
    padding-bottom: 4rem;
}


.cp-info article
{
    padding: 1.35rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background: var(--cp-white);

    box-shadow: var(--cp-shadow-small);
}


.cp-info-icon
{
    display: flex;
    align-items: center;
    justify-content: center;

    width: 46px;
    height: 46px;

    margin-bottom: 1rem;

    border-radius: 0.8rem;

    background:
        rgba(21, 154, 156, 0.1);

    color: var(--cp-teal-dark);
}


.cp-info h2
{
    margin-bottom: 0.5rem;

    color: var(--cp-navy);

    font-size: 1.1rem;
    font-weight: 800;
}


.cp-info p
{
    margin: 0;

    color: var(--cp-muted);

    font-size: 0.9rem;
    line-height: 1.65;
}


/* =========================================================
   EXAMPLE SECTION
   ========================================================= */

.cp-example-section
{
    padding: 4.5rem 0;

    background:
        linear-gradient(
            180deg,
            #f7fafc,
            #ffffff
        );
}


.cp-example-content
{
    width: min(100%, 900px);

    margin: 0 auto;
}


.cp-example-heading
{
    margin-bottom: 1.5rem;
}


.cp-example-heading h2
{
    color: var(--cp-navy);

    font-weight: 800;
}


.cp-example-heading p:last-child
{
    color: var(--cp-muted);

    line-height: 1.7;
}


.cp-example-equation
{
    margin-bottom: 1.5rem;

    padding: 1.3rem;

    border: 1px solid var(--cp-border);
    border-radius: 1rem;

    background: var(--cp-white);
    color: var(--cp-navy-dark);

    font-size:
        clamp(1.4rem, 4vw, 2rem);

    font-weight: 800;
    line-height: 1.5;

    text-align: center;

    box-shadow: var(--cp-shadow-small);
}


.cp-example-steps
{
    display: grid;

    gap: 0.85rem;
}


.cp-example-step
{
    display: grid;

    grid-template-columns:
        auto minmax(0, 1fr);

    align-items: center;

    gap: 1rem;

    padding: 1rem;

    border: 1px solid var(--cp-border);
    border-radius: 0.85rem;

    background: var(--cp-white);
}


.cp-example-step-number
{
    display: flex;
    align-items: center;
    justify-content: center;

    width: 38px;
    height: 38px;

    border-radius: 50%;

    background: var(--cp-teal);
    color: var(--cp-white);

    font-weight: 800;
}


.cp-example-step-label
{
    display: block;

    margin-bottom: 0.2rem;

    color: var(--cp-muted);

    font-size: 0.75rem;
    font-weight: 800;

    text-transform: uppercase;
}


.cp-example-step strong
{
    color: var(--cp-navy);
}


.cp-example-note
{
    margin-top: 1.2rem;

    padding: 1rem;

    border-left:
        4px solid var(--cp-teal);

    border-radius: 0.7rem;

    background:
        rgba(21, 154, 156, 0.06);

    color: var(--cp-text);

    line-height: 1.65;
}


/* =========================================================
   SEO SECTION
   ========================================================= */

.cp-seo-section
{
    padding: 4.5rem 0;
}


.cp-seo-content
{
    width: min(100%, 900px);

    margin: 0 auto;
}


.cp-seo-content h2
{
    margin-bottom: 1rem;

    color: var(--cp-navy);

    font-weight: 800;
}


.cp-seo-content h3
{
    margin-top: 2rem;
    margin-bottom: 0.65rem;

    color: var(--cp-navy);

    font-size: 1.25rem;
    font-weight: 800;
}


.cp-seo-content p
{
    color: var(--cp-text);

    line-height: 1.75;
}


.cp-seo-links
{
    display: flex;
    flex-wrap: wrap;
    align-items: center;

    gap: 0.8rem;

    margin-top: 2rem;
}


.cp-resource-link
{
    color: var(--cp-teal-dark);

    font-size: 0.88rem;
    font-weight: 750;

    text-decoration: none;
}


.cp-resource-link:hover
{
    text-decoration: underline;
}


/* =========================================================
   RESPONSIVE
   ========================================================= */

@media (max-width: 1050px)
{
    .cp-mode-tabs
    {
        grid-template-columns:
            repeat(3, minmax(0, 1fr));
    }
}


@media (max-width: 900px)
{
    .cp-toolbar
    {
        align-items: stretch;
        flex-direction: column;
    }


    .cp-controls
    {
        width: 100%;
    }


    .cp-control-group
    {
        width: 100%;
    }


    .cp-stats,
    .cp-results-grid
    {
        grid-template-columns:
            repeat(2, minmax(0, 1fr));
    }


    .cp-info
    {
        grid-template-columns: 1fr;
    }


    .cp-graph
    {
        height: 520px;
    }
}


@media (max-width: 767.98px)
{
    .cp-section
    {
        padding:
            3.5rem 1rem;
    }


    .cp-card
    {
        padding: 1.25rem;
    }


    .cp-card-top
    {
        flex-direction: column;
    }


    .cp-card-badges
    {
        justify-content: flex-start;
    }


    .cp-step-progress
    {
        gap: 0.25rem;
    }


    .cp-step-marker
    {
        min-width: 55px;
    }


    .cp-step-marker span
    {
        width: 34px;
        height: 34px;
    }


    .cp-input-row
    {
        grid-template-columns: 1fr;
    }


    .cp-submit-button
    {
        width: 100%;
    }


    .cp-reference-grid
    {
        grid-template-columns: 1fr;
    }


    .cp-problem-complete
    {
        grid-template-columns:
            auto minmax(0, 1fr);
    }


    .cp-problem-complete
    .cp-next-button
    {
        grid-column: 1 / -1;

        width: 100%;
    }


    .cp-graph-heading
    {
        align-items: flex-start;
        flex-direction: column;
    }


    .cp-coordinate-readout
    {
        width: 100%;

        text-align: left;
    }


    .cp-graph
    {
        height: 470px;
    }


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


@media (max-width: 575.98px)
{
    .cp-mode-heading
    {
        flex-direction: column;

        align-items: flex-start;
    }


    .cp-mode-tabs
    {
        grid-template-columns: 1fr;
    }


    .cp-mode-button
    {
        justify-content: flex-start;

        padding-left: 1rem;
    }


    .cp-step-progress
    {
        grid-template-columns:
            auto minmax(10px, 1fr)
            auto minmax(10px, 1fr)
            auto;
    }


    .cp-step-marker
    {
        min-width: 46px;
    }


    .cp-step-marker small
    {
        max-width: 62px;

        font-size: 0.61rem;
    }


    .cp-stats,
    .cp-results-grid
    {
        grid-template-columns:
            1fr 1fr;
    }


    .cp-action-row
    {
        display: grid;

        grid-template-columns: 1fr;
    }


    .cp-secondary-button
    {
        width: 100%;
    }


    .cp-graph-shell
    {
        padding: 0.75rem;
    }


    .cp-graph
    {
        height: 420px;
    }


    .cp-graph-status-row
    {
        grid-template-columns: 1fr;
    }


    .cp-graph-legend
    {
        top: 10px;
        right: 10px;

        padding: 0.5rem 0.6rem;

        font-size: 0.68rem;
    }
}


/* =========================================================
   REDUCED MOTION
   ========================================================= */

@media (prefers-reduced-motion: reduce)
{
    .cp-mode-button,
    .cp-select,
    .cp-step-marker span,
    .cp-progress-bar,
    .cp-step-input,
    .cp-choice-button,
    .cp-submit-button,
    .cp-next-button,
    .cp-secondary-button
    {
        transition: none;
    }
}