/* ============================================================
   PICKLEBALL UNIVERSITY — Navigation / Hub prototype
   Scoped to pku3-* classes to avoid legacy TWU conflicts.
   ============================================================ */

:root {
    --pku3-navy: #073e70;
    --pku3-navy-deep: #042d52;
    --pku3-orange: #d94300;
    --pku3-orange-dark: #ad3500;
    --pku3-ink: #17324a;
    --pku3-muted: #66798b;
    --pku3-line: #dbe4eb;
    --pku3-soft: #f4f7f9;
    --pku3-warm: #fff7f3;
    --pku3-white: #ffffff;
    --pku3-shell: 1120px;
    --pku3-shadow: 0 14px 38px rgba(7, 62, 112, 0.10);
}

.pku3-site-header,
.pku3-site-header *,
.pku3-page,
.pku3-page *,
.pku3-site-footer,
.pku3-site-footer * {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body.pku3-prototype-page {
    margin: 0;
    color: var(--pku3-ink);
    background: var(--pku3-white);
    font-family: Arial, Helvetica, sans-serif;
    line-height: 1.55;
}


.pku3-site-header a,
.pku3-site-header button,
.pku3-page a,
.pku3-page button {
    touch-action: manipulation;
}

body.pku3-menu-open {
    overflow: hidden;
}

.pku3-shell,
.pku3-footer-shell {
    width: min(calc(100% - 40px), var(--pku3-shell));
    margin-inline: auto;
}

.pku3-site-header {
    display: contents;
    font-family: Arial, Helvetica, sans-serif;
}

.pku3-brandbar {
    background: #fff;
    border-bottom: 4px solid var(--pku3-navy-deep);
}

.pku3-brandbar__inner {
    min-height: 78px;
    display: flex;
    align-items: center;
    gap: 18px;
}

.pku3-brand,
.pku3-brand:link,
.pku3-brand:visited {
    display: inline-flex;
    align-items: center;
    gap: 13px;
    min-width: 0;
    color: var(--pku3-navy-deep);
    text-decoration: none;
}

.pku3-brand__mark {
    width: 52px;
    height: 52px;
    flex: 0 0 52px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--pku3-navy-deep);
    color: #fff;
    border: 3px solid #e7edf2;
    box-shadow: inset 0 0 0 2px rgba(255,255,255,.16);
    font-size: 0.84rem;
    font-weight: 900;
    letter-spacing: .04em;
}

.pku3-brand__copy {
    display: grid;
    gap: 2px;
    min-width: 0;
}

.pku3-brand__copy strong {
    font-size: clamp(1.05rem, 1.8vw, 1.34rem);
    font-weight: 800;
    line-height: 1.15;
    white-space: nowrap;
}

.pku3-brand__copy small {
    color: var(--pku3-muted);
    font-size: .78rem;
    font-weight: 600;
}

.pku3-prototype-badge {
    margin-left: 6px;
    padding: 4px 8px;
    border-radius: 999px;
    background: var(--pku3-warm);
    color: var(--pku3-orange-dark);
    font-size: .68rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: .04em;
}

.pku3-utility {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 3px;
}

.pku3-utility a,
.pku3-utility a:link,
.pku3-utility a:visited {
    padding: 8px 9px;
    color: var(--pku3-navy);
    text-decoration: none;
    font-size: .78rem;
    font-weight: 700;
    border-radius: 6px;
}

.pku3-utility a:hover,
.pku3-utility a:focus-visible {
    background: var(--pku3-soft);
    color: var(--pku3-navy-deep);
}

.pku3-nav-shell {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--pku3-navy-deep);
    box-shadow: 0 5px 18px rgba(4, 45, 82, .12);
}

.pku3-primary__list {
    min-height: 50px;
    display: flex;
    align-items: stretch;
    margin: 0;
    padding: 0;
    list-style: none;
}

.pku3-primary__item {
    display: flex;
}

.pku3-primary__button,
.pku3-primary__link {
    position: relative;
    min-height: 50px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 0 20px;
    border: 0;
    background: transparent;
    color: #fff;
    font: inherit;
    font-size: .88rem;
    font-weight: 800;
    text-decoration: none;
    cursor: pointer;
}

.pku3-primary__button::after,
.pku3-primary__link::after {
    content: "";
    position: absolute;
    right: 13px;
    bottom: 0;
    left: 13px;
    height: 3px;
    border-radius: 3px 3px 0 0;
    background: var(--pku3-orange);
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 150ms ease;
}


.pku3-primary__button:hover,
.pku3-primary__button:focus-visible,
.pku3-primary__link:hover,
.pku3-primary__link:focus-visible,
.pku3-primary__button[aria-expanded="true"] {
    background: rgba(255,255,255,.10);
}

.pku3-chevron {
    width: 8px;
    height: 8px;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg) translateY(-2px);
    transition: transform .18s ease;
}

.pku3-primary__button[aria-expanded="true"] .pku3-chevron {
    transform: rotate(225deg) translate(-1px, -1px);
}

.pku3-panel {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    background: #fff;
    border-bottom: 1px solid var(--pku3-line);
    box-shadow: var(--pku3-shadow);
}

.pku3-panel[hidden] {
    display: none;
}

.pku3-panel__inner {
    display: grid;
    grid-template-columns: minmax(220px, .75fr) minmax(0, 2fr);
    gap: 40px;
    padding-block: 28px 32px;
}

.pku3-panel__intro {
    padding-right: 28px;
    border-right: 1px solid var(--pku3-line);
}

.pku3-panel__eyebrow,
.pku3-eyebrow,
.pku3-panel-kicker,
.pku3-card__label {
    margin: 0 0 7px;
    color: var(--pku3-orange-dark);
    font-size: .72rem;
    font-weight: 900;
    line-height: 1.2;
    text-transform: uppercase;
    letter-spacing: .085em;
}

.pku3-panel__intro h2 {
    margin: 0 0 8px;
    color: var(--pku3-navy-deep);
    font-size: 1.22rem;
    line-height: 1.25;
}

.pku3-panel__intro p:last-child {
    margin: 0;
    color: var(--pku3-muted);
    font-size: .86rem;
}

.pku3-panel__links {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 10px;
    align-content: start;
}

.pku3-panel__links--two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.pku3-panel__links--three {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.pku3-panel__links > a,
.pku3-panel__links > a:link,
.pku3-panel__links > a:visited {
    min-width: 0;
    padding: 12px 13px;
    border: 1px solid var(--pku3-line);
    border-radius: 10px;
    display: grid;
    gap: 3px;
    color: var(--pku3-ink);
    text-decoration: none;
    background: #fff;
}

.pku3-panel__links > a:focus-visible {
    border-color: rgba(217,67,0,.35);
    background: var(--pku3-warm);
}

@media (hover: hover) and (pointer: fine) {
    .pku3-panel__links > a:hover {
        border-color: rgba(217,67,0,.35);
        background: var(--pku3-warm);
        transform: translateY(-1px);
    }
}

.pku3-panel__links strong {
    color: var(--pku3-navy-deep);
    font-size: .88rem;
}

.pku3-panel__links span {
    color: var(--pku3-muted);
    font-size: .76rem;
    line-height: 1.35;
}

.pku3-menu-toggle,
.pku3-mobile-utility,
.pku3-backdrop {
    display: none;
}

.pku3-site-header :focus-visible,
.pku3-page :focus-visible,
.pku3-site-footer :focus-visible {
    outline: 3px solid #ffb38e;
    outline-offset: 2px;
}

/* ---------------- Hub ---------------- */

.pku3-page {
    display: block;
}

.pku3-hero {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 82% 24%, rgba(217,67,0,.10), transparent 28%),
        linear-gradient(180deg, #f8fbfd 0%, #fff 100%);
    border-bottom: 1px solid var(--pku3-line);
}

.pku3-hero::after {
    content: "";
    position: absolute;
    width: 360px;
    height: 360px;
    right: -150px;
    bottom: -235px;
    border: 34px solid rgba(7,62,112,.045);
    border-radius: 50%;
}

.pku3-hero__grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: minmax(0, 1.35fr) minmax(300px, .65fr);
    gap: 54px;
    align-items: center;
    padding-block: clamp(58px, 8vw, 104px);
}

.pku3-hero__copy h1 {
    max-width: 760px;
    margin: 0;
    color: var(--pku3-navy-deep);
    font-size: clamp(2.55rem, 5.4vw, 4.8rem);
    line-height: .98;
    letter-spacing: -.04em;
}

.pku3-hero__lead {
    max-width: 760px;
    margin: 24px 0 0;
    color: var(--pku3-ink);
    font-size: clamp(1.12rem, 2.1vw, 1.38rem);
    line-height: 1.5;
    font-weight: 650;
}

.pku3-hero__intro {
    max-width: 760px;
    margin: 18px 0 0;
    color: var(--pku3-muted);
    font-size: 1rem;
    line-height: 1.7;
}

.pku3-button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 28px;
}

.pku3-button,
.pku3-button:link,
.pku3-button:visited {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 16px;
    border: 2px solid var(--pku3-navy);
    border-radius: 999px;
    color: var(--pku3-navy);
    background: #fff;
    text-decoration: none;
    font-size: .86rem;
    font-weight: 800;
    transition: transform .15s ease, background .15s ease, color .15s ease;
}

.pku3-button--primary,
.pku3-button--primary:link,
.pku3-button--primary:visited {
    background: var(--pku3-navy);
    color: #fff;
}

.pku3-button:hover,
.pku3-button:focus-visible {
    transform: translateY(-1px);
    background: var(--pku3-navy-deep);
    border-color: var(--pku3-navy-deep);
    color: #fff;
}

.pku3-hero__panel {
    padding: 26px;
    border: 1px solid rgba(7,62,112,.15);
    border-radius: 18px;
    background: rgba(255,255,255,.88);
    box-shadow: var(--pku3-shadow);
    backdrop-filter: blur(8px);
}

.pku3-metric {
    display: grid;
    grid-template-columns: 36px 1fr;
    gap: 12px;
    padding: 15px 0;
    border-top: 1px solid var(--pku3-line);
}

.pku3-metric:first-of-type {
    border-top: 0;
}

.pku3-metric > span {
    color: var(--pku3-orange);
    font-size: .72rem;
    font-weight: 900;
}

.pku3-metric strong {
    display: block;
    color: var(--pku3-navy-deep);
    font-size: .94rem;
}

.pku3-metric p {
    margin: 4px 0 0;
    color: var(--pku3-muted);
    font-size: .82rem;
    line-height: 1.45;
}

.pku3-section {
    padding-block: clamp(60px, 7vw, 92px);
}

.pku3-section--tools {
    background: #fff;
}

.pku3-section-head {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(260px, .85fr);
    gap: 40px;
    align-items: end;
    margin-bottom: 32px;
}

.pku3-section-head h2,
.pku3-method-grid h2 {
    margin: 0;
    color: var(--pku3-navy-deep);
    font-size: clamp(1.85rem, 3.6vw, 3rem);
    line-height: 1.08;
    letter-spacing: -.025em;
}

.pku3-section-head > p {
    margin: 0;
    color: var(--pku3-muted);
    font-size: .96rem;
    line-height: 1.65;
}

.pku3-card-grid {
    display: grid;
    gap: 14px;
}

.pku3-card-grid--tools {
    grid-template-columns: repeat(6, minmax(0, 1fr));
}

.pku3-card-grid--tools .pku3-card {
    grid-column: span 2;
}

.pku3-card-grid--tools .pku3-card--featured {
    grid-column: span 3;
}

.pku3-card-grid--articles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.pku3-card {
    min-width: 0;
    padding: 22px;
    border: 1px solid var(--pku3-line);
    border-radius: 14px;
    background: #fff;
    box-shadow: 0 6px 20px rgba(7,62,112,.045);
}

.pku3-card--featured {
    border-top: 4px solid var(--pku3-orange);
}

.pku3-card--article {
    background: linear-gradient(180deg, #fff 0%, #fbfcfd 100%);
}

.pku3-card h3 {
    margin: 0;
    font-size: 1.12rem;
    line-height: 1.28;
}

.pku3-card h3 a,
.pku3-card h3 a:link,
.pku3-card h3 a:visited {
    color: var(--pku3-navy-deep);
    text-decoration: none;
}

.pku3-card h3 a:hover,
.pku3-card h3 a:focus-visible {
    color: var(--pku3-orange-dark);
}

.pku3-card > p:not(.pku3-card__label) {
    color: var(--pku3-muted);
    font-size: .9rem;
    line-height: 1.6;
}

.pku3-text-link,
.pku3-text-link:link,
.pku3-text-link:visited {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    color: var(--pku3-orange-dark);
    font-size: .82rem;
    font-weight: 800;
    text-decoration: none;
}

.pku3-text-link:hover,
.pku3-text-link:focus-visible {
    text-decoration: underline;
    text-underline-offset: 3px;
}

.pku3-section--research {
    background: var(--pku3-navy-deep);
    color: #fff;
}

.pku3-section-head--light h2,
.pku3-section-head--light > p {
    color: #fff;
}

.pku3-section-head--light > p {
    color: rgba(255,255,255,.72);
}

.pku3-section--research .pku3-eyebrow,
.pku3-section--research .pku3-card__label {
    color: #ffae87;
}

.pku3-research-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
}

.pku3-research-card {
    display: grid;
    grid-template-columns: 52px 1fr;
    gap: 16px;
    padding: 26px;
    border: 1px solid rgba(255,255,255,.18);
    border-radius: 14px;
    background: rgba(255,255,255,.055);
}

.pku3-research-card__number {
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: rgba(255,255,255,.10);
    color: #ffae87;
    font-size: .76rem;
    font-weight: 900;
}

.pku3-research-card h3 {
    margin: 0;
    font-size: 1.25rem;
    line-height: 1.25;
}

.pku3-research-card h3 a,
.pku3-research-card h3 a:link,
.pku3-research-card h3 a:visited {
    color: #fff;
    text-decoration: none;
}

.pku3-research-card p:not(.pku3-card__label) {
    color: rgba(255,255,255,.73);
    font-size: .9rem;
    line-height: 1.6;
}

.pku3-text-link--light,
.pku3-text-link--light:link,
.pku3-text-link--light:visited {
    color: #ffd0ba;
}

.pku3-section--method {
    background: var(--pku3-soft);
    border-top: 1px solid var(--pku3-line);
}

.pku3-method-grid {
    display: grid;
    grid-template-columns: .9fr 1.1fr;
    gap: 60px;
}

.pku3-method-list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 10px;
}

.pku3-method-list li {
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 13px;
    padding: 15px;
    border: 1px solid var(--pku3-line);
    border-radius: 12px;
    background: #fff;
}

.pku3-method-list li > span {
    width: 32px;
    height: 32px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--pku3-warm);
    color: var(--pku3-orange-dark);
    font-size: .75rem;
    font-weight: 900;
}

.pku3-method-list strong {
    color: var(--pku3-navy-deep);
}

.pku3-method-list p {
    margin: 3px 0 0;
    color: var(--pku3-muted);
    font-size: .86rem;
}

/* ---------------- Footer ---------------- */

.pku3-site-footer {
    clear: both;
    width: 100%;
    background: #031f38;
    color: #fff;
}

.pku3-footer-shell {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 32px;
    align-items: center;
    padding-block: 30px;
}

.pku3-footer-brand {
    display: grid;
    gap: 3px;
}

.pku3-footer-brand strong {
    font-size: .95rem;
}

.pku3-footer-brand span {
    color: rgba(255,255,255,.66);
    font-size: .78rem;
}

.pku3-footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 4px 16px;
}

.pku3-footer-links a,
.pku3-footer-links a:link,
.pku3-footer-links a:visited {
    color: rgba(255,255,255,.82);
    text-decoration: none;
    font-size: .78rem;
    font-weight: 700;
}

.pku3-footer-links a:hover,
.pku3-footer-links a:focus-visible {
    color: #fff;
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* ---------------- Responsive navigation ---------------- */

@media (max-width: 860px) {
    .pku3-brandbar {
        position: sticky;
        top: 0;
        z-index: 1000;
    }

    .pku3-brandbar,
    .pku3-brandbar__inner {
        min-height: 64px;
    }

    .pku3-brand__mark {
        width: 42px;
        height: 42px;
        flex-basis: 42px;
        font-size: .72rem;
    }

    .pku3-brand__copy strong {
        font-size: .96rem;
    }

    .pku3-brand__copy small,
    .pku3-prototype-badge,
    .pku3-utility {
        display: none;
    }

    .pku3-menu-toggle {
        margin-left: auto;
        display: inline-flex;
        align-items: center;
        gap: 8px;
        padding: 8px 10px;
        border: 1px solid #cfdbe4;
        border-radius: 8px;
        background: #fff;
        color: var(--pku3-navy);
        font: inherit;
        font-size: .8rem;
        font-weight: 800;
        cursor: pointer;
    }

    .pku3-menu-toggle__icon {
        width: 20px;
        display: grid;
        gap: 4px;
    }

    .pku3-menu-toggle__icon i {
        display: block;
        width: 20px;
        height: 2px;
        border-radius: 999px;
        background: var(--pku3-navy);
        transition: transform .18s ease, opacity .18s ease;
    }

    .pku3-site-header[data-mobile-open="true"] .pku3-menu-toggle__icon i:nth-child(1) {
        transform: translateY(6px) rotate(45deg);
    }

    .pku3-site-header[data-mobile-open="true"] .pku3-menu-toggle__icon i:nth-child(2) {
        opacity: 0;
    }

    .pku3-site-header[data-mobile-open="true"] .pku3-menu-toggle__icon i:nth-child(3) {
        transform: translateY(-6px) rotate(-45deg);
    }

    .pku3-nav-shell {
        display: none;
        position: fixed;
        top: 64px;
        right: 0;
        bottom: 0;
        width: min(88vw, 390px);
        overflow-y: auto;
        background: #fff;
        box-shadow: -12px 0 34px rgba(4,45,82,.18);
    }

    .pku3-site-header[data-mobile-open="true"] .pku3-nav-shell {
        display: block;
    }

    .pku3-primary {
        background: #fff;
    }

    .pku3-primary > .pku3-shell {
        width: 100%;
    }

    .pku3-primary__list {
        min-height: 0;
        display: block;
        padding: 10px 14px 4px;
    }

    .pku3-primary__item {
        display: block;
        border-bottom: 1px solid var(--pku3-line);
    }

    .pku3-primary__button,
    .pku3-primary__link {
        width: 100%;
        min-height: 50px;
        justify-content: space-between;
        padding: 0 6px;
        color: var(--pku3-navy-deep);
    }

    .pku3-primary__button:hover,
    .pku3-primary__button:focus-visible,
    .pku3-primary__link:hover,
    .pku3-primary__link:focus-visible,
    .pku3-primary__button[aria-expanded="true"] {
        background: var(--pku3-soft);
    }

    .pku3-panel {
        position: static;
        box-shadow: none;
        border: 0;
        background: var(--pku3-soft);
        margin: 0 -14px;
    }

    .pku3-panel__inner {
        width: 100%;
        display: block;
        padding: 18px 18px 20px;
    }

    .pku3-panel__intro {
        padding: 0 0 14px;
        border: 0;
    }

    .pku3-panel__intro h2 {
        font-size: 1rem;
    }

    .pku3-panel__links,
    .pku3-panel__links--two,
    .pku3-panel__links--three {
        grid-template-columns: 1fr;
        gap: 7px;
    }

    .pku3-mobile-utility {
        display: grid;
        gap: 4px;
        padding: 12px 20px 24px;
    }

    .pku3-mobile-utility a {
        padding: 8px 0;
        color: var(--pku3-navy);
        font-size: .8rem;
        font-weight: 800;
        text-decoration: none;
    }

    .pku3-backdrop {
        position: fixed;
        inset: 64px 0 0 0;
        border: 0;
        background: rgba(3,31,56,.36);
    }

    .pku3-site-header[data-mobile-open="true"] .pku3-backdrop {
        display: block;
    }

    .pku3-hero__grid,
    .pku3-section-head,
    .pku3-method-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .pku3-card-grid--tools,
    .pku3-card-grid--articles,
    .pku3-research-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .pku3-card-grid--tools .pku3-card,
    .pku3-card-grid--tools .pku3-card--featured {
        grid-column: auto;
    }

    .pku3-card-grid--articles .pku3-card:last-child,
    .pku3-card-grid--tools .pku3-card:last-child {
        grid-column: 1 / -1;
    }

    .pku3-footer-shell {
        grid-template-columns: 1fr;
    }

    .pku3-footer-links {
        justify-content: flex-start;
    }
}

@media (max-width: 560px) {
    .pku3-shell,
    .pku3-footer-shell {
        width: min(calc(100% - 28px), var(--pku3-shell));
    }

    .pku3-menu-toggle__label {
        position: absolute;
        width: 1px;
        height: 1px;
        margin: -1px;
        overflow: hidden;
        clip: rect(0 0 0 0);
        clip-path: inset(50%);
        white-space: nowrap;
    }

    .pku3-hero__grid {
        padding-block: 46px 54px;
    }

    .pku3-hero__copy h1 {
        font-size: clamp(2rem, 8vw, 2.55rem);
    }

    .pku3-button-row {
        display: grid;
        grid-template-columns: 1fr;
    }

    .pku3-button {
        width: 100%;
    }

    .pku3-card-grid--tools,
    .pku3-card-grid--articles,
    .pku3-research-grid {
        grid-template-columns: 1fr;
    }

    .pku3-card-grid--articles .pku3-card:last-child,
    .pku3-card-grid--tools .pku3-card:last-child {
        grid-column: auto;
    }

    .pku3-research-card {
        grid-template-columns: 1fr;
    }

    .pku3-footer-links {
        display: grid;
        gap: 10px;
    }

}

/* Strong desktop hover/open/current indicator */
@media (min-width: 861px) {

    .pku3-primary__button:hover,
    .pku3-primary__button:focus-visible,
    .pku3-primary__button:active,
    .pku3-primary__button[aria-expanded="true"],
    .pku3-primary__link:hover,
    .pku3-primary__link:focus-visible,
    .pku3-primary__link:active,
    .pku3-primary__link[aria-current="page"] {
        background: rgba(255,255,255,.10);
        box-shadow: inset 0 -4px 0 var(--pku3-orange);
    }
}