/*---------------------------------------------------------------------------------------------------------------------
 * Project: Decay Function Web App
 * Version: 1.0.0
 * Date:    2025
 * Author:  Rohin Gosling
 *
 * Description:
 *
 *   Provides the completed Fluent-inspired visual system, appearance themes, and responsive explorer layout.
 *
 * TODO:
 *
 *   1. None.
 *
 *-------------------------------------------------------------------------------------------------------------------*/

/* Theme tokens and appearance modes. */

.application-shell
{
    --page-background: #f5f5f5;
    --card-background: #ffffff;
    --panel-background: #fafafa;
    --control-background: #ffffff;
    --text-primary: #242424;
    --text-secondary: #616161;
    --scenario-label-color: #737373;
    --border-color: #d1d1d1;
    --accent-color: #0f6cbd;
    --accent-contrast: #ffffff;
    --error-color: #c50f1f;
    --focus-color: #0f6cbd;
    color: var(--text-primary);
    background: var(--page-background);
    color-scheme: light;
}

.application-shell[data-appearance="dark"]
{
    --page-background: #1b1a19;
    --card-background: #292827;
    --panel-background: #323130;
    --control-background: #1f1f1f;
    --text-primary: #ffffff;
    --text-secondary: #d2d0ce;
    --scenario-label-color: #a19f9d;
    --border-color: #605e5c;
    --accent-color: #62abf5;
    --accent-contrast: #111111;
    --error-color: #ff99a4;
    --focus-color: #62abf5;
    color-scheme: dark;
}

@media (prefers-color-scheme: dark)
{
    .application-shell[data-appearance="system"]
    {
        --page-background: #1b1a19;
        --card-background: #292827;
        --panel-background: #323130;
        --control-background: #1f1f1f;
        --text-primary: #ffffff;
        --text-secondary: #d2d0ce;
        --scenario-label-color: #a19f9d;
        --border-color: #605e5c;
        --accent-color: #62abf5;
        --accent-contrast: #111111;
        --error-color: #ff99a4;
        --focus-color: #62abf5;
        color-scheme: dark;
    }
}

/* Primary card structure and appearance controls. */

.explorer-card
{
    width: min(100%, 64rem);
    padding: clamp(1.25rem, 4vw, 2.5rem);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    background: var(--card-background);
    box-shadow: 0 0.25rem 1rem rgb(0 0 0 / 10%);
}

.card-header
{
    display: block;
}

.card-header h1
{
    width: 100%;
    margin: 0;
    font-size: clamp(1.45rem, 2.6vw, 2rem);
    line-height: 1.08;
}

.introduction
{
    width: 100%;
    max-width: none;
    margin: 1rem 0 0;
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.control-group
{
    min-width: 0;
    margin: 0;
    padding: 0;
    border: 0;
}

.appearance-selector
{
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 0.65rem;
    margin-top: 0.75rem;
    font-size: 0.75rem;
}

.appearance-label
{
    font-weight: 650;
    white-space: nowrap;
}

.control-group legend
{
    padding: 0;
    font-weight: 650;
}

.appearance-options
{
    display: flex;
    flex-wrap: nowrap;
    gap: 0.3rem;
    margin: 0;
}

.appearance-options label
{
    position: relative;
}

.appearance-options input
{
    position: absolute;
    opacity: 0;
}

.appearance-options span
{
    display: flex;
    min-height: 1.75rem;
    padding: 0.25rem 0.55rem;
    align-items: center;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    background: var(--control-background);
    cursor: pointer;
}

.appearance-options input:checked+span
{
    border-color: var(--accent-color);
    color: var(--accent-contrast);
    background: var(--accent-color);
}

.appearance-options input:focus-visible+span
{
    outline: 0.15rem solid var(--focus-color);
    outline-offset: 0.15rem;
}

.scenario-panel
{
    display: grid;
    gap: 1rem;
    margin-top: 2rem;
}

/* Chart surface, equation overlay, and accessible labels. */

.bias-chart
{
    --chart-panel-border-width: 1px;
    --equation-panel-right-inset: 30px;
    --equation-panel-top-inset: 31px;

    position: relative;
    height: 330px;
    min-width: 0;
    margin: 0;
    padding: 1rem;
    border: var(--chart-panel-border-width) solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--panel-background);
}

.bias-chart-canvas
{
    position: relative;
    width: 100%;
    height: 100%;
    min-height: 0;
}

.method-equation
{
    position: absolute;
    top: calc(var(--equation-panel-top-inset) - var(--chart-panel-border-width));
    right: calc(var(--equation-panel-right-inset) - var(--chart-panel-border-width));
    z-index: 2;
    max-width: calc(100% - 3.5rem);
    padding: 0.25rem 0.4rem;
    overflow-x: auto;
    overflow-y: hidden;
    border: 1px solid var(--border-color);
    border-radius: 0.25rem;
    color: var(--text-primary);
    background: var(--panel-background);
    box-shadow: 0 0.1rem 0.3rem rgb(0 0 0 / 8%);
    font-family: "Cambria Math", "STIX Two Math", "Times New Roman", serif;
    line-height: 1;
}

.method-equation math
{
    margin: 0;
    font-size: 0.85rem;
    white-space: nowrap;
}

.method-equation[data-method="extended"] math
{
    font-size: clamp(0.58rem, 1.15vw, 0.75rem);
}

.vertical-axis-label
{
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0.25rem;
    display: flex;
    align-items: center;
    z-index: 1;
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-weight: 600;
    writing-mode: horizontal-tb;
    line-height: 1;
    pointer-events: none;
    transform: none;
}

.visually-hidden
{
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Current-scenario readout. */

.scenario-readout
{
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--panel-background);
}

.scenario-readout h2,
.controls-section h2
{
    margin: 0;
    font-size: 1.15rem;
}

.scenario-readout dl
{
    display: grid;
    gap: 0.6rem;
    margin: 1rem 0 0;
}

.scenario-readout dl div
{
    min-width: 0;
    display: grid;
    grid-template-columns: minmax(10rem, 1.2fr) minmax(0, 1fr);
    gap: 1rem;
    align-items: baseline;
}

.scenario-readout dt,
.scenario-readout dd
{
    font-family: inherit;
    font-size: 0.9rem;
    line-height: 1.4;
}

.scenario-readout dt
{
    color: var(--scenario-label-color);
    font-weight: 700;
}

.scenario-readout dt var
{
    font-style: italic;
    color: var(--accent-color);
}

.scenario-readout dd
{
    margin: 0;
    text-align: left;
    font-weight: 400;
    font-variant-numeric: tabular-nums;
    overflow-wrap: anywhere;
}

/* Model controls and validation feedback. */

.controls-section
{
    margin-top: 2rem;
}

.control-list
{
    display: grid;
    gap: 1rem;
    margin-top: 1rem;
}

.control-group
{
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--panel-background);
}

.control-symbol
{
    margin-left: 0.5rem;
    color: var(--accent-color);
    font-family: Cambria, Georgia, serif;
    font-style: italic;
}

.control-description
{
    margin: 0.4rem 0 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.45;
}

.numeric-inputs
{
    display: grid;
    grid-template-columns: minmax(0, 1fr) 7rem;
    gap: 1rem;
    align-items: end;
    margin-top: 0.85rem;
}

.numeric-inputs-single
{
    grid-template-columns: minmax(0, 1fr);
}

.range-field,
.value-field,
.select-field
{
    display: grid;
    gap: 0.35rem;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
}

.select-field
{
    width: 100%;
    margin-top: 0.85rem;
}

input[type="text"],
input[type="number"],
select
{
    width: 100%;
    min-height: 2.5rem;
    padding: 0.5rem 0.65rem;
    border: 1px solid var(--border-color);
    border-radius: 0.3rem;
    color: var(--text-primary);
    background: var(--control-background);
    font: inherit;
    font-variant-numeric: tabular-nums;
}

input[type="range"]
{
    width: 100%;
    min-height: 2.5rem;
    accent-color: var(--accent-color);
}

input[aria-invalid="true"]
{
    border-color: var(--error-color);
}

input:focus-visible,
select:focus-visible
{
    outline: 0.15rem solid var(--focus-color);
    outline-offset: 0.1rem;
}

.control-error
{
    margin: 0.65rem 0 0;
    color: var(--error-color);
    font-size: 0.85rem;
    font-weight: 600;
}

/* Supporting context and reset action. */

.supporting-note
{
    margin: 1.25rem 0 0;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
}

.card-actions
{
    display: flex;
    justify-content: flex-end;
    margin-top: 1.25rem;
}

.reset-button
{
    min-width: 5.5rem;
    min-height: 2.5rem;
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.3rem;
    color: var(--text-primary);
    background: var(--control-background);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
}

.reset-button:hover
{
    border-color: var(--accent-color);
    color: var(--accent-color);
}

.reset-button:active
{
    background: var(--panel-background);
}

.reset-button:focus-visible
{
    outline: 0.15rem solid var(--focus-color);
    outline-offset: 0.1rem;
}

/* Responsive layout adjustments. */

@media (min-width: 48rem)
{
    .scenario-panel
    {
        grid-template-columns: minmax(0, 1.8fr) minmax(14rem, 1fr);
    }

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

@media (max-width: 32rem)
{
    .application-shell
    {
        padding: 0.75rem;
        place-items: start center;
    }

    .numeric-inputs
    {
        grid-template-columns: 1fr;
    }

    .numeric-inputs-single
    {
        grid-template-columns: 1fr;
    }

    .bias-chart
    {
        padding: 0.75rem;
    }

    .method-equation
    {
        max-width: calc(100% - 2.5rem);
    }

    .method-equation[data-method="extended"] math
    {
        font-size: 0.58rem;
    }
}

/*---------------------------------------------------------------------------------------------------------------------
 * Project: Decay Function Web App
 * Version: 0.1.0
 * Date:    2026
 * Author:  Rohin Gosling
 *
 * Description:
 *
 *   Establishes the document baseline and full-page application mount layout.
 *
 * TODO:
 *
 *   1. None.
 *
 *-------------------------------------------------------------------------------------------------------------------*/

/* Document baseline. */

:root
{
    color: #242424;
    background: #f5f5f5;
    font-family: "Segoe UI", system-ui, sans-serif;
    font-synthesis: none;
    text-rendering: optimizeLegibility;
}

*
{
    box-sizing: border-box;
}

body
{
    min-width: 20rem;
    min-height: 100vh;
    margin: 0;
}

/* Full-page React mount. */

.application-shell
{
    display: grid;
    min-height: 100vh;
    padding: 1.5rem;
    place-items: center;
}

/* Legacy foundation-shell styles retained for the development scaffold. */

.foundation-card
{
    width: min(100%, 46rem);
    padding: clamp(1.5rem, 5vw, 3rem);
    border: 1px solid #d1d1d1;
    border-radius: 0.75rem;
    background: #ffffff;
    box-shadow: 0 0.25rem 1rem rgb(0 0 0 / 8%);
}

.foundation-card h1
{
    max-width: 18ch;
    margin: 0;
    font-size: clamp(2rem, 7vw, 3.5rem);
    line-height: 1.05;
}

.foundation-card p:last-child
{
    max-width: 60ch;
    margin: 1.5rem 0 0;
    color: #616161;
    font-size: 1.05rem;
    line-height: 1.6;
}

.eyebrow
{
    margin: 0 0 0.75rem;
    color: #0f6cbd;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}