/* =========================================================
   DERIVATIVES PRACTICE
   Mirrors Limits Practice styling
   ========================================================= */

:root
{
    --derp-navy: #0f172a;
    --derp-slate: #475569;
    --derp-muted: #64748b;

    --derp-border: #d7e2ec;

    --derp-white: #ffffff;
    --derp-surface: #f8fafc;

    --derp-teal: #0f766e;
    --derp-teal-bright: #159e9c;
    --derp-teal-soft: #ecfdf5;

    --derp-blue: #2563eb;
    --derp-blue-soft: #eff6ff;

    --derp-gold: #d97706;
    --derp-gold-soft: #fff7ed;

    --derp-green: #15803d;
    --derp-green-soft: #f0fdf4;

    --derp-shadow:
        0 1rem 2.5rem
        rgba(
            15,
            23,
            42,
            0.08
        );

    --derp-shadow-small:
        0 0.75rem 2rem
        rgba(
            15,
            23,
            42,
            0.06
        );
}


/* =========================================================
   BASE
   ========================================================= */

#derivatives-practice
{
    scroll-margin-top: 5rem;
}

#derivatives-practice,
.derp-intro-card,
.derp-problem-card,
.derp-final-review,
.derp-related-section
{
    color: var(--derp-slate);

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

#derivatives-practice h2,
#derivatives-practice h3
{
    color: var(--derp-navy);

    font-weight: 800;

    letter-spacing: -0.02em;
}

#derivatives-practice .lead
{
    color: var(--derp-slate);

    line-height: 1.75;
}


/* =========================================================
   INTRO / ESSENTIALS
   ========================================================= */

.derp-intro-card
{
    padding:
        clamp(
            1.4rem,
            4vw,
            2rem
        );

    background:
        linear-gradient(
            135deg,
            var(--derp-teal-soft),
            var(--derp-blue-soft)
        );

    border:
        1px solid
        rgba(
            13,
            148,
            136,
            0.22
        );

    border-radius: 1.2rem;
}

.derp-card-eyebrow
{
    margin:
        0
        0
        0.45rem;

    color: var(--derp-teal);

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

    letter-spacing: 0.1em;

    line-height: 1.3;

    text-transform: uppercase;
}

.derp-essentials-grid
{
    display: grid;

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

    gap: 1rem;
}

.derp-essentials-grid article
{
    min-width: 0;

    padding: 1rem;

    background:
        rgba(
            255,
            255,
            255,
            0.88
        );

    border:
        1px solid
        rgba(
            148,
            163,
            184,
            0.28
        );

    border-radius: 1rem;
}

.derp-essentials-grid h3
{
    margin-bottom: 0.65rem;

    text-align: center;
}

.derp-essentials-grid article > p
{
    color: var(--derp-slate);

    font-size: 0.9rem;

    line-height: 1.6;

    text-align: center;
}

.derp-mini-formula
{
    display: grid;

    min-width: 0;
    min-height: 5rem;

    margin-bottom: 0.7rem;

    padding: 0.65rem;

    place-items: center;

    color: var(--derp-teal);

    background: var(--derp-white);

    border:
        1px solid
        var(--derp-border);

    border-radius: 0.8rem;
}


/* =========================================================
   RESOURCE ACTIONS
   ========================================================= */

.derp-resource-actions
{
    display: flex;

    flex-wrap: wrap;

    gap: 0.75rem;
}


/* =========================================================
   LEVEL HEADINGS
   ========================================================= */

.derp-level-heading
{
    margin:
        clamp(
            3.5rem,
            7vw,
            5rem
        )
        0
        1.5rem;

    padding:
        1.3rem
        1.4rem;

    background: var(--derp-navy);

    border-radius: 1rem;

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

.derp-level-heading:first-of-type
{
    margin-top: 0;
}

.derp-level-label
{
    margin:
        0
        0
        0.35rem;

    color: #5eead4;

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

    letter-spacing: 0.1em;

    text-transform: uppercase;
}

.derp-level-heading h2
{
    color: var(--derp-white) !important;

    font-size:
        clamp(
            1.45rem,
            3vw,
            2rem
        );
}

.derp-level-heading p
{
    color: #cbd5e1;

    line-height: 1.65;
}


/* =========================================================
   PROBLEM CARDS
   ========================================================= */

.derp-problem-card
{
    overflow: hidden;

    background: var(--derp-white);

    border:
        1px solid
        var(--derp-border);

    border-radius: 1.15rem;

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

.derp-problem-body
{
    padding:
        clamp(
            1.2rem,
            4vw,
            1.7rem
        );
}

.derp-problem-heading
{
    display: flex;

    gap: 0.75rem;

    align-items: center;
    justify-content: space-between;

    flex-wrap: wrap;

    margin-bottom: 1rem;
}

.derp-problem-number
{
    margin: 0;

    color: var(--derp-teal);

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

    letter-spacing: 0.08em;

    text-transform: uppercase;
}

.derp-problem-skill
{
    display: inline-flex;

    align-items: center;

    padding:
        0.35rem
        0.65rem;

    color: var(--derp-muted);

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

    letter-spacing: 0.06em;

    text-transform: uppercase;

    background: var(--derp-surface);

    border:
        1px solid
        var(--derp-border);

    border-radius: 999px;
}

.derp-problem-card h3
{
    margin-bottom: 1.25rem;

    line-height: 1.55;
}


/* =========================================================
   CHOICES
   ========================================================= */

.derp-choice-grid,
.derp-equation-choice-grid
{
    display: grid;

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

    gap: 0.8rem;

    margin:
        1rem
        0
        1.25rem;
}

.derp-choice,
.derp-equation-choice
{
    display: grid;

    min-width: 0;
    min-height: 4.2rem;

    padding: 0.8rem;

    place-items: center;

    color: var(--derp-navy);

    font-weight: 700;

    text-align: center;

    background: var(--derp-surface);

    border:
        1px solid
        var(--derp-border);

    border-radius: 0.8rem;
}

.derp-equation-choice
{
    color: var(--derp-teal);
}


/* =========================================================
   SOLUTIONS
   ========================================================= */

.derp-solution
{
    margin-top: 1rem;

    padding:
        1.15rem
        1.2rem;

    background:
        linear-gradient(
            135deg,
            var(--derp-teal-soft),
            var(--derp-blue-soft)
        );

    border:
        1px solid
        rgba(
            13,
            148,
            136,
            0.22
        );

    border-radius: 1rem;
}

.derp-solution-label
{
    margin:
        0
        0
        0.7rem;

    color: var(--derp-teal);

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

    letter-spacing: 0.09em;

    text-transform: uppercase;
}

.derp-solution p
{
    color: var(--derp-slate);

    line-height: 1.7;
}

.derp-solution-math
{
    display: grid;

    min-width: 0;

    margin:
        0.8rem
        0;

    padding: 0.8rem;

    place-items: center;

    color: var(--derp-teal);

    background:
        rgba(
            255,
            255,
            255,
            0.82
        );

    border:
        1px solid
        rgba(
            148,
            163,
            184,
            0.24
        );

    border-radius: 0.8rem;
}

.derp-final-answer
{
    display: flex;

    gap: 0.8rem;

    align-items: center;

    flex-wrap: wrap;

    min-width: 0;

    margin-top: 1rem;

    padding:
        0.9rem
        1rem;

    color: var(--derp-green);

    background: var(--derp-green-soft);

    border:
        1px solid
        rgba(
            21,
            128,
            61,
            0.22
        );

    border-radius: 0.8rem;
}

.derp-final-answer strong
{
    color: var(--derp-navy);
}

.derp-final-answer span
{
    color: var(--derp-slate);

    font-weight: 700;
}


/* =========================================================
   PROCESS LIST
   ========================================================= */

.derp-process-list
{
    display: grid;

    gap: 0.65rem;

    padding-left: 1.35rem;
}

.derp-process-list li
{
    padding-left: 0.2rem;

    color: var(--derp-slate);

    line-height: 1.65;
}

.derp-process-list li::marker
{
    color: var(--derp-teal);

    font-weight: 800;
}


/* =========================================================
   FINAL REVIEW
   ========================================================= */

.derp-final-review
{
    padding:
        clamp(
            1.4rem,
            4vw,
            2rem
        );

    background:
        linear-gradient(
            135deg,
            var(--derp-teal-soft),
            var(--derp-blue-soft)
        );

    border:
        1px solid
        rgba(
            13,
            148,
            136,
            0.22
        );

    border-radius: 1.2rem;
}


/* =========================================================
   RELATED RESOURCES
   ========================================================= */

.derp-related-section h2
{
    color: var(--derp-navy);

    font-weight: 800;
}

.derp-related-section > p
{
    color: var(--derp-slate);

    line-height: 1.7;
}

.derp-related-grid
{
    display: grid;

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

    gap: 1rem;
}

.derp-related-card
{
    display: flex;

    flex-direction: column;

    min-width: 0;
    min-height: 100%;

    padding: 1.15rem;

    color: var(--derp-navy);

    text-decoration: none;

    background: var(--derp-white);

    border:
        1px solid
        var(--derp-border);

    border-radius: 1rem;

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

    transition:
        transform 180ms ease,
        border-color 180ms ease,
        box-shadow 180ms ease;
}

.derp-related-card:hover
{
    color: var(--derp-navy);

    text-decoration: none;

    border-color:
        rgba(
            13,
            148,
            136,
            0.5
        );

    box-shadow: var(--derp-shadow);

    transform:
        translateY(-3px);
}

.derp-related-icon
{
    display: grid;

    width: 2.7rem;
    height: 2.7rem;

    margin-bottom: 0.8rem;

    place-items: center;

    color: var(--derp-teal);

    background: var(--derp-teal-soft);

    border-radius: 0.8rem;
}

.derp-related-card h3
{
    margin-bottom: 0.45rem;

    color: inherit;

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

    line-height: 1.4;
}

.derp-related-card p
{
    margin: 0;

    color: var(--derp-slate);

    font-size: 0.88rem;

    line-height: 1.6;
}


/* =========================================================
   MATHJAX SAFETY
   ========================================================= */

.derp-mini-formula mjx-container,
.derp-equation-choice mjx-container,
.derp-solution-math mjx-container,
.derp-final-answer mjx-container,
.derp-problem-card h3 mjx-container,
.derp-choice mjx-container
{
    max-width: 100%;

    overflow-x: auto;
    overflow-y: hidden;
}


/* =========================================================
   DISPLAY MATH
   ========================================================= */

.derp-mini-formula mjx-container[display="true"],
.derp-equation-choice mjx-container[display="true"],
.derp-solution-math mjx-container[display="true"],
.derp-final-answer mjx-container[display="true"],
.derp-choice mjx-container[display="true"]
{
    margin:
        0.35rem
        auto !important;
}


/* =========================================================
   GUIDE CONTACT CTA FIX
   ========================================================= */

#guideContactCtaTitle
{
    color: #ffffff !important;
}


/* =========================================================
   ACCESSIBILITY
   ========================================================= */

.derp-related-card:focus-visible,
.derp-resource-actions a:focus-visible,
.derp-problem-card button:focus-visible
{
    outline:
        3px solid
        rgba(
            37,
            99,
            235,
            0.38
        );

    outline-offset: 4px;
}


/* =========================================================
   TABLET
   ========================================================= */

@media (max-width: 991.98px)
{

    .derp-essentials-grid
    {
        grid-template-columns: 1fr;
    }

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

}


/* =========================================================
   MOBILE
   ========================================================= */

@media (max-width: 767.98px)
{

    #derivatives-practice
    {
        overflow-x: hidden;
    }


    /* -----------------------------------------
       Intro
       ----------------------------------------- */

    .derp-intro-card,
    .derp-final-review
    {
        padding: 1.15rem;

        border-radius: 1rem;
    }


    /* -----------------------------------------
       Resource buttons
       ----------------------------------------- */

    .derp-resource-actions
    {
        display: grid;

        grid-template-columns: 1fr;
    }

    .derp-resource-actions .btn
    {
        width: 100%;
    }


    /* -----------------------------------------
       Level headings
       ----------------------------------------- */

    .derp-level-heading
    {
        margin-top: 3.5rem;

        padding: 1.1rem;

        border-radius: 1rem;
    }


    /* -----------------------------------------
       Problem cards
       ----------------------------------------- */

    .derp-problem-body
    {
        padding: 1.1rem;
    }

    .derp-problem-heading
    {
        align-items: flex-start;

        flex-direction: column;
    }


    /* -----------------------------------------
       Grids
       ----------------------------------------- */

    .derp-choice-grid,
    .derp-equation-choice-grid,
    .derp-related-grid
    {
        grid-template-columns: 1fr;
    }


    /* -----------------------------------------
       Solutions
       ----------------------------------------- */

    .derp-solution
    {
        padding: 1rem;
    }

    .derp-final-answer
    {
        align-items: flex-start;

        flex-direction: column;
    }


    /* -----------------------------------------
       Related resources
       ----------------------------------------- */

    .derp-related-card
    {
        padding: 1.05rem;
    }


    /* -----------------------------------------
       Math
       ----------------------------------------- */

    .derp-mini-formula mjx-container,
    .derp-equation-choice mjx-container,
    .derp-solution-math mjx-container,
    .derp-final-answer mjx-container,
    .derp-problem-card h3 mjx-container,
    .derp-choice mjx-container
    {
        width: 100%;
        max-width: 100%;

        overflow-x: auto;
        overflow-y: hidden;
    }

}


/* =========================================================
   SMALL MOBILE
   ========================================================= */

@media (max-width: 479.98px)
{

    .derp-problem-body,
    .derp-solution,
    .derp-intro-card,
    .derp-final-review
    {
        padding: 1rem;
    }

    .derp-problem-card h3
    {
        font-size: 1rem;
    }

    .derp-problem-skill
    {
        font-size: 0.68rem;
    }

    .derp-choice,
    .derp-equation-choice
    {
        min-height: 3.8rem;

        padding: 0.7rem;
    }

}


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

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

    .derp-related-card
    {
        transition: none;
    }

    .derp-related-card:hover
    {
        transform: none;
    }

}


/* =========================================================
   PRINT
   ========================================================= */

@media print
{

    .derp-resource-actions,
    .derp-related-section
    {
        display: none !important;
    }

    .derp-intro-card,
    .derp-level-heading,
    .derp-problem-card,
    .derp-solution,
    .derp-final-review
    {
        break-inside: avoid;

        box-shadow: none;
    }

}