/* =====================================================
   1807-chain — robotics.css (v1.1)
   Page styles for robotics.html
   - Hero with video banner overlay
   - Cards grid + chips
   - Architecture grid
   - Gallery strip
   - Docs & Diagrams (PDF viewer)
   - CTA section
   - Responsive tiers
   ===================================================== */

:root {
    --rbx-gap: clamp(12px, 2.2vw, 20px);
    --rbx-radius: var(--radius-lg, 16px);
    --rbx-card-bg: color-mix(in srgb, var(--surface-2, #151a1f) 84%, transparent);
    --rbx-card-bg-active: color-mix(in srgb, var(--surface-2, #151a1f) 92%, transparent);
    --rbx-blur: 6px;
    --rbx-blur-strong: 10px;
}

/* ------------------------------ HERO ------------------------------ */
.page-hero {
    position: relative;
    padding: clamp(16px, 3vw, 28px) 0;
    overflow: hidden;
}

.page-hero__media {
    position: relative;
    max-width: min(1100px, 94vw);
    margin: 0 auto;
}

.page-hero .scrolly-video {
    position: sticky;
    top: clamp(56px, 8vh, 96px);
    z-index: 0;
    border-radius: var(--rbx-radius);
}

.page-hero .scrolly-banner {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 1;
    transition: opacity .6s ease;
    pointer-events: none;
    border-radius: var(--rbx-radius);
}

.page-hero .hero-video {
    display: block;
    width: 100%;
    height: clamp(340px, 60vh, 720px);
    object-fit: cover;
    border-radius: var(--rbx-radius);
    border: 1px solid var(--border);
    filter: grayscale(18%) contrast(1.05);
}

/* content on top */
.page-hero__content {
    position: relative;
    z-index: 2;
    max-width: 980px;
    margin: clamp(10px, 2.4vw, 18px) auto 0;
    text-align: center;
}

.page-title {
    margin: 0 0 .35em 0;
    font-size: clamp(1.75rem, 2.6vw, 2.6rem);
    line-height: 1.15;
    font-weight: 800;
    background: linear-gradient(180deg, var(--text) 0%, var(--blue-400) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    -webkit-text-fill-color: transparent;
}

.page-subtitle {
    color: var(--accent-2);
    max-width: 72ch;
    margin: 0 auto;
}

/* ------------------------------ STATS ------------------------------ */
.section {
    padding: clamp(28px, 5vw, 56px) 0;
}

.container {
    max-width: min(1100px, 92vw);
    margin: 0 auto;
    padding: 0 clamp(12px, 2.6vw, 20px);
}

.section--stats .stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--rbx-gap);
}

.stat {
    background: var(--rbx-card-bg);
    border: 1px solid var(--border);
    border-radius: var(--rbx-radius);
    padding: clamp(14px, 2vw, 18px);
    text-align: center;
}

.stat__num {
    font-size: clamp(1.25rem, 3.2vw, 2rem);
    font-weight: 800;
    color: var(--text);
}

.stat__label {
    color: var(--muted);
}

/* ------------------------------ PROJECT CARDS ------------------------------ */
.section-title {
    font-size: clamp(1.4rem, 2.2vw, 2rem);
    margin: 0 0 .75rem 0;
}

.cards-grid--projects {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--rbx-gap);
}

.card {
    position: relative;
    display: grid;
    grid-template-rows: auto 1fr;
    border-radius: var(--rbx-radius);
    overflow: clip;
    border: 1px solid var(--border);
    background: var(--rbx-card-bg);
}

.card__media {
    aspect-ratio: 16/9;
    overflow: hidden;
}

.card__media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    filter: saturate(1.05) contrast(1.02);
}

.card__body {
    padding: clamp(12px, 2vw, 18px);
    display: grid;
    gap: .5rem;
}

.card__title {
    font-size: clamp(1.05rem, 1.6vw, 1.25rem);
    margin: 0;
}

.card__desc {
    color: var(--accent-2);
    margin: 0;
}

/* chips */
.chipset {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: .25rem 0 0 0;
}

.chip {
    font-size: .85rem;
    padding: .25rem .5rem;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: color-mix(in srgb, var(--surface-2) 78%, transparent);
}

.card:hover {
    border-color: var(--blue-400);
    box-shadow: 0 8px 22px rgba(96, 165, 250, .18);
}

.card:hover .card__media img {
    transform: scale(1.02);
    transition: transform .4s ease;
}

/* ------------------------------ ARCHITECTURE GRID ------------------------------ */
.arch-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--rbx-gap);
}

.arch-card {
    background: var(--rbx-card-bg);
    border: 1px solid var(--border);
    border-radius: var(--rbx-radius);
    padding: clamp(14px, 2vw, 18px);
    display: grid;
    gap: .35rem;
}

.arch-card__title {
    font-size: 1rem;
    margin: 0;
}

.arch-card__text {
    color: var(--accent-2);
    margin: 0;
}

/* ------------------------------ DOCS & DIAGRAMS (PDF) ------------------------------ */
.doc-card {
    background: var(--rbx-card-bg);
    border: 1px solid var(--border);
    border-radius: var(--rbx-radius);
    box-shadow: var(--shadow);
    overflow: clip;
    -webkit-backdrop-filter: blur(var(--rbx-blur));
    backdrop-filter: blur(var(--rbx-blur));
}

.doc-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: clamp(10px, 1.6vw, 14px) clamp(12px, 2vw, 18px);
    border-bottom: 1px solid var(--border);
}

.doc-title {
    margin: 0;
    font-size: clamp(1.05rem, 1.6vw, 1.25rem);
}

.doc-toolbar {
    display: inline-flex;
    gap: 8px;
    flex-wrap: wrap;
}

.doc-figure {
    padding: clamp(8px, 1.4vw, 12px);
}

.doc-viewer {
    width: 100%;
    height: clamp(420px, 70vh, 900px);
    border: 1px solid var(--border);
    border-radius: var(--rbx-radius);
    background: var(--surface);
}

/* ------------------------------ GALLERY STRIP ------------------------------ */
.section--gallery {
    background: linear-gradient(180deg, transparent, color-mix(in srgb, var(--surface-2) 45%, transparent));
    padding-top: clamp(12px, 2vw, 18px);
}

.gallery-strip {
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: minmax(220px, 1fr);
    gap: var(--rbx-gap);
    overflow-x: auto;
    padding: 6px var(--rbx-gap) 2px;
    scroll-snap-type: x mandatory;
}

.gallery-item {
    scroll-snap-align: start;
    border-radius: var(--rbx-radius);
    overflow: clip;
    border: 1px solid var(--border);
    background: var(--rbx-card-bg);
}

.gallery-item img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ------------------------------ CTA ------------------------------ */
.section--cta .lead {
    color: var(--accent-2);
    max-width: 72ch;
}

.hero-ctas {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

/* ------------------------------ TRANSPARENCY & BLUR ------------------------------ */
.card,
.stat,
.arch-card,
.gallery-item {
    -webkit-backdrop-filter: blur(var(--rbx-blur));
    backdrop-filter: blur(var(--rbx-blur));
}

.card.active,
.doc-card.active {
    background: var(--rbx-card-bg-active);
    -webkit-backdrop-filter: blur(var(--rbx-blur-strong));
    backdrop-filter: blur(var(--rbx-blur-strong));
}

/* ------------------------------ UTIL ------------------------------ */
code {
    background: color-mix(in srgb, var(--surface-2) 70%, transparent);
    padding: .1rem .35rem;
    border-radius: 6px;
    border: 1px solid var(--border);
}

/* ------------------------------ RESPONSIVE ------------------------------ */
@media (max-width: 1024px) {
    .arch-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 860px) {
    .cards-grid--projects {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .section--stats .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .page-hero .hero-video {
        height: clamp(260px, 48vh, 520px);
    }

    .doc-head {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    .doc-toolbar {
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .gallery-strip {
        grid-auto-columns: minmax(180px, 1fr);
    }
}