/* ============================================================
   Ambience.Systems — Design System
   Sibling of Ambience.House: shared DNA (Geist, #333366),
   distinct voice: clean, typographic, research-forward.
   ============================================================ */

/* --- Tokens ------------------------------------------------ */
:root {
    --navy:    #333366;
    --teal:    #33cccc;
    --warm-bg: #f7f6f3;
    --paper:   #ffffff;
    --ink:     #3a3830;
    --ink-mid: #6b6557;
    --ink-faint:#a09890;
    --max-w:   720px;
    --max-w-wide: 960px;
}

/* --- Reset / Base ------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; scroll-padding-top: 72px; /* keep #anchor targets (e.g. /#participate) clear of the fixed nav */ }

body {
    font-family: 'Geist', 'Inter', sans-serif;
    font-weight: 300;
    background: var(--warm-bg);
    color: var(--ink);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* --- Typography -------------------------------------------- */
h1 {
    font-size: clamp(1.6rem, 4vw, 2.4rem);
    font-weight: 500;
    color: var(--navy);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(1.1rem, 2.5vw, 1.4rem);
    font-weight: 500;
    color: var(--navy);
    line-height: 1.3;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--navy);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

p {
    font-size: 0.95rem;
    color: var(--ink-mid);
    margin-bottom: 1rem;
    max-width: 62ch;
}

p:last-child { margin-bottom: 0; }

a {
    color: var(--teal);
    text-decoration: none;
}
a:hover { text-decoration: underline; }

/* --- Layout ------------------------------------------------ */
.container {
    width: 100%;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 1.5rem;
}
.container--wide {
    max-width: var(--max-w-wide);
}

/* --- Nav --------------------------------------------------- */
.site-nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(51, 51, 102, 0.08);
}

.site-nav__inner {
    max-width: var(--max-w-wide);
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-nav__brand {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    text-decoration: none;
}

.site-nav__logo {
    height: 36px;
    width: auto;
    display: block;
}

.site-nav__brand-text {
    font-size: 0.95rem;
    font-weight: 200;
    color: var(--navy);
    letter-spacing: 0.01em;
}

.site-nav__dot { color: var(--navy); }

.site-nav__links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.site-nav__links a {
    font-size: 0.82rem;
    font-weight: 400;
    color: var(--ink-mid);
    letter-spacing: 0.02em;
}
.site-nav__links a:hover { color: var(--navy); text-decoration: none; }
.site-nav__links a.active { color: var(--navy); font-weight: 500; }

/* --- Main -------------------------------------------------- */
main {
    flex: 1;
    padding-top: 56px; /* nav height */
}

/* --- Section base ----------------------------------------- */
.section {
    padding: 5rem 0;
}
.section--alt {
    background: var(--paper);
}
.section--tight {
    padding: 3rem 0;
}

/* --- Divider ---------------------------------------------- */
.divider {
    width: 2.5rem;
    height: 2px;
    background: var(--teal);
    margin: 1.25rem 0 1.5rem;
}

/* --- Hero -------------------------------------------------- */
.hero {
    padding: 6rem 0 4rem;
}

.hero__eyebrow {
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--teal);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 1rem;
}

.hero__title {
    margin-bottom: 1.5rem;
}

.hero__lead {
    font-size: 1.05rem;
    font-weight: 300;
    color: var(--ink-mid);
    max-width: 52ch;
    line-height: 1.75;
    margin-bottom: 0;
}

/* --- Credential strip ------------------------------------- */
.cred-strip {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;
    margin-top: 1.25rem;
    margin-bottom: 1.5rem;
}

.cred-item {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--ink-faint);
    letter-spacing: 0.03em;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}
.cred-item::before {
    content: '';
    display: inline-block;
    width: 5px; height: 5px;
    border-radius: 50%;
    background: var(--teal);
    opacity: 0.6;
    flex-shrink: 0;
}

/* --- Research card ---------------------------------------- */
.research-card {
    background: var(--paper);
    border-radius: 0.75rem;
    padding: 2rem 2.5rem;
    border-left: 3px solid var(--teal);
    margin-top: 1.5rem;
}

.research-card__status {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--teal);
    background: rgba(51, 204, 204, 0.1);
    border-radius: 2rem;
    padding: 0.2rem 0.75rem;
    margin-bottom: 0.75rem;
}

.research-card__title {
    font-size: 1rem;
    font-weight: 500;
    color: var(--navy);
    line-height: 1.4;
    margin-bottom: 0.75rem;
}

.research-card__meta {
    font-size: 0.78rem;
    color: var(--ink-faint);
    margin-bottom: 1rem;
}

/* --- Participate brief grid ------------------------------- */
.participate-brief {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 2.5rem;
    row-gap: 1.25rem;
    margin: 1.5rem 0 2rem;
}

.brief-item {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

.brief-label {
    font-size: 0.68rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--teal);
}

.brief-text {
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.82);
    line-height: 1.5;
}

.participate-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    align-items: center;
    margin-top: 0.5rem;
}

.participate-box__details {
    display: inline-block;
    padding: 0.7rem 1.75rem;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 2rem;
    color: rgba(255, 255, 255, 0.85);
    font-family: 'Geist', 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: 0.02em;
    cursor: pointer;
    vertical-align: middle;
    transition: border-color 0.2s, color 0.2s;
    -webkit-appearance: none;
    appearance: none;
}
.participate-box__details:hover {
    border-color: rgba(255, 255, 255, 0.7);
    color: #fff;
}

.participate-box__ghost {
    display: inline-block;
    padding: 0.7rem 1.75rem;
    background: transparent;
    border: 1px solid transparent;
    color: rgba(255, 255, 255, 0.55);
    font-family: 'Geist', 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    text-decoration: none;
    border-radius: 2rem;
    transition: color 0.2s;
    cursor: pointer;
}
.participate-box__ghost:hover {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
}

/* --- Modal ------------------------------------------------ */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 500;
    background: rgba(20, 20, 40, 0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
}
.modal-overlay.is-open {
    display: flex;
}

.modal-dialog {
    background: var(--navy);
    border-radius: 1rem;
    padding: 2.5rem;
    max-width: 560px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    color: rgba(255, 255, 255, 0.85);
}

.modal-close {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    background: none;
    border: none;
    color: rgba(255, 255, 255, 0.5);
    font-size: 1.4rem;
    cursor: pointer;
    line-height: 1;
    padding: 0.25rem 0.5rem;
    transition: color 0.15s;
}
.modal-close:hover { color: #fff; }

.modal-eyebrow {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--teal);
    margin-bottom: 0.5rem;
}

.modal-title {
    font-size: clamp(1.1rem, 2.5vw, 1.4rem);
    font-weight: 500;
    color: #fff;
    line-height: 1.3;
    letter-spacing: -0.01em;
    margin-bottom: 0;
}

.modal-intro {
    color: rgba(255, 255, 255, 0.72);
    font-size: 0.92rem;
    line-height: 1.7;
    max-width: none;
    margin-bottom: 1.25rem;
}

.modal-body {
    color: rgba(255, 255, 255, 0.72);
    font-size: 0.88rem;
    line-height: 1.65;
    max-width: none;
    margin-bottom: 1rem;
}

.modal-body a {
    color: var(--teal);
    text-decoration: none;
}
.modal-body a:hover { text-decoration: underline; }

.modal-dialog .divider { opacity: 0.5; margin-bottom: 1.25rem; }

.modal-list {
    list-style: none;
    margin: 0.5rem 0 1.25rem;
}
.modal-list li {
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.78);
    padding: 0.3rem 0 0.3rem 1.25rem;
    position: relative;
    line-height: 1.55;
}
.modal-list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--teal);
    font-size: 0.8rem;
}

.modal-actions {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.modal-btn {
    display: inline-block;
    padding: 0.65rem 1.4rem;
    border-radius: 2rem;
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    text-decoration: none;
    transition: opacity 0.2s;
}
.modal-btn--primary {
    background: var(--teal);
    color: var(--navy);
}
.modal-btn--outline {
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: rgba(255, 255, 255, 0.85);
}
.modal-btn:hover { opacity: 0.85; text-decoration: none; }

/* --- Page teaser grid (main page) -------------------------- */
.page-teaser {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
    margin-top: 1.5rem;
}

.page-teaser__item {
    text-decoration: none;
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(51,51,102,0.08);
    transition: transform 0.2s, box-shadow 0.2s;
    background: var(--paper);
}
.page-teaser__item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(51,51,102,0.14);
    text-decoration: none;
}
.page-teaser__item img {
    width: 100%;
    display: block;
}
.page-teaser__cap {
    display: block;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--ink-mid);
    text-align: center;
    padding: 0.6rem 0.5rem;
    letter-spacing: 0.03em;
}

@media (max-width: 640px) {
    .page-teaser { grid-template-columns: 1fr; }
}

/* --- Teaser carousel ---------------------------------------- */
.teaser {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin: 1.25rem 0 0.5rem;
    overflow: hidden;
}
.teaser__slide {
    flex-shrink: 0;
    width: 52%;
    text-decoration: none;
    transition: transform 0.35s, opacity 0.35s;
    border-radius: 0.5rem;
    overflow: hidden;
    opacity: 0.5;
    transform: scale(0.88);
}
.teaser__slide.is-center {
    opacity: 1;
    transform: scale(1);
    z-index: 1;
}
.teaser__slide img {
    width: 100%;
    display: block;
    border-radius: 0.5rem;
}
.teaser__cap {
    display: block;
    font-size: 0.72rem;
    color: rgba(255,255,255,0.6);
    text-align: center;
    padding: 0.35rem 0 0;
    letter-spacing: 0.03em;
}
.teaser__nav {
    background: none;
    border: 1px solid rgba(255,255,255,0.25);
    border-radius: 50%;
    color: rgba(255,255,255,0.7);
    width: 30px; height: 30px;
    font-size: 1.1rem;
    cursor: pointer;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.2s;
    z-index: 2;
}
.teaser__nav:hover { border-color: rgba(255,255,255,0.6); color: #fff; }
.teaser__dots {
    display: flex;
    justify-content: center;
    gap: 0.4rem;
    margin-bottom: 0.5rem;
}
.teaser__dot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: rgba(255,255,255,0.3);
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}
.teaser__dot.is-active { background: var(--teal); }

@media (max-width: 640px) {
    .participate-brief { grid-template-columns: 1fr; }
    .modal-dialog { padding: 1.75rem; }

    /* Participate box: center everything on mobile */
    .participate-box { text-align: center; }
    .participate-box .divider { margin-left: auto; margin-right: auto; }
    .brief-item { align-items: center; }
    .participate-actions { justify-content: center; }
}

/* --- Participate section ---------------------------------- */
.participate-box {
    background: var(--navy);
    border-radius: 1rem;
    padding: 2.5rem;
    color: rgba(255,255,255,0.85);
}

.participate-box h2 {
    color: #fff;
    margin-bottom: 0.5rem;
}

.participate-box .divider {
    background: var(--teal);
    opacity: 0.7;
}

.participate-box p {
    color: rgba(255,255,255,0.72);
}

.participate-box__list {
    list-style: none;
    margin: 1.25rem 0;
}

.participate-box__list li {
    font-size: 0.88rem;
    color: rgba(255,255,255,0.78);
    padding: 0.35rem 0;
    padding-left: 1.25rem;
    position: relative;
}
.participate-box__list li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--teal);
    font-size: 0.8rem;
}

.participate-box__cta {
    display: inline-block;
    padding: 0.7rem 1.75rem;
    background: var(--teal);
    color: var(--navy);
    font-size: 0.85rem;
    font-weight: 600;
    line-height: 1.2;
    border-radius: 2rem;
    letter-spacing: 0.02em;
    transition: opacity 0.2s;
    text-decoration: none;
    vertical-align: middle;
}
.participate-box__cta:hover {
    opacity: 0.88;
    text-decoration: none;
}

/* --- Footer ----------------------------------------------- */
.site-footer {
    background: var(--paper);
    border-top: 1px solid rgba(51,51,102,0.08);
    padding: 2.5rem 0;
    margin-top: auto;
}

.site-footer__inner {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    justify-content: space-between;
}

.site-footer p {
    font-size: 0.78rem;
    color: var(--ink-faint);
    margin: 0;
}

.site-footer a {
    font-size: 0.78rem;
    color: var(--teal);
}

/* --- About layout ----------------------------------------- */
.about-layout {
    display: flex;
    gap: 3rem;
    align-items: flex-start;
}

.about-body {
    flex: 1;
    min-width: 0;
}

.about-photo-wrap {
    flex-shrink: 0;
}

.about-photo {
    width: 160px;
    height: 200px;
    object-fit: cover;
    object-position: 42% top;
    border-radius: 0.5rem;
    filter: grayscale(100%);
    display: block;
}

@media (max-width: 640px) {
    .about-layout {
        flex-direction: column-reverse;
        gap: 1.5rem;
    }
    .about-photo {
        width: 120px;
        height: 150px;
    }
}

/* --- About links + contact -------------------------------- */
.about-links {
    display: flex;
    gap: 1.5rem;
    margin-top: 1.75rem;
    margin-bottom: 0.5rem;
}

.about-links a {
    font-size: 0.82rem;
    font-weight: 400;
    color: var(--teal);
    letter-spacing: 0.02em;
}

.about-contact {
    font-size: 0.82rem;
    color: var(--ink-faint);
    margin-top: 1rem;
}

/* --- Hamburger -------------------------------------------- */
.site-nav__burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 36px;
    height: 36px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.site-nav__burger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--navy);
    border-radius: 2px;
    transition: transform 0.2s, opacity 0.2s;
}

.site-nav__burger[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.site-nav__burger[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}
.site-nav__burger[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* --- Mobile menu ------------------------------------------ */
.site-nav__mobile {
    display: none;
    background: rgba(255, 255, 255, 0.98);
    border-top: 1px solid rgba(51, 51, 102, 0.08);
    padding: 0.5rem 1.5rem 1rem;
}

.site-nav__mobile ul {
    list-style: none;
}

.site-nav__mobile li {
    border-bottom: 1px solid rgba(51, 51, 102, 0.06);
}

.site-nav__mobile a {
    display: block;
    padding: 0.75rem 0;
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--ink-mid);
    letter-spacing: 0.02em;
}

.site-nav__mobile a:hover {
    color: var(--navy);
    text-decoration: none;
}

/* --- Mobile ----------------------------------------------- */
@media (max-width: 640px) {
    .site-nav__links { display: none; }
    .site-nav__burger { display: flex; }
    .site-nav__mobile.is-open { display: block; }
    .hero { padding: 4rem 0 3rem; }
    .section { padding: 3.5rem 0; }
    .participate-box { padding: 1.75rem; }
    .research-card { padding: 1.5rem; }
}