/* =============================================================================
   Homepage — Immersive Services Explorer
   -----------------------------------------------------------------------------
   Uses the canonical design system tokens. Matches the surface specification
   from Design System/ui_kits/website/styles.css (faithful recreation of the
   prototype, with the PRD additions wired in).
   ============================================================================= */

html, body { height: 100%; }

body.home {
    overflow: hidden;
    height: 100vh;
}

.visual-container {
    position: fixed;
    inset: 0;
    z-index: 0;
}
.bg-image {
    position: absolute;
    inset: 0;
    width: 100%; height: 100%;
    object-fit: cover;
    /* Anchor cropping to the top of the photo — lake shorelines and
       horizon lines read best with the top edge preserved. */
    object-position: center top;
    opacity: 0;
    transition: opacity var(--duration-image) var(--ease-standard);
    z-index: 1;
}
/* Show the entire image (letterboxed) — used for landscape photos that
   the user wants framed in full rather than cropped. */
.bg-image--contain { object-fit: contain; object-position: center; }
.bg-image.active { opacity: 1; z-index: 2; }

.vignette {
    position: absolute; inset: 0;
    background: var(--vignette);
    z-index: 3;
    pointer-events: none;
}
.sidebar-gradient {
    position: absolute;
    top: 0; left: 0;
    width: 50%; height: 100%;
    background: var(--sidebar-gradient);
    z-index: 4;
    pointer-events: none;
}

.ui-container {
    position: relative;
    z-index: 10;
    height: 100vh;
    display: grid;
    grid-template-columns: 480px 1fr;
    padding: calc(var(--nav-h) + 1rem) 32px 32px;  /* top clears the fixed nav */
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--s-2);
    padding-right: var(--s-6);
    overflow-y: auto;
    -ms-overflow-style: none;
    scrollbar-width: none;
    max-height: calc(100vh - var(--nav-h) - 2rem);
}
.sidebar::-webkit-scrollbar { display: none; }

.section-header {
    font-size: var(--h2-size);
    font-weight: var(--h2-weight);
    text-align: center;
    color: var(--fg-1);
    margin: 0 0 0.75rem;
    letter-spacing: var(--h2-tracking);
    text-shadow: var(--shadow-text);
}

.division-toggle {
    display: flex;
    background: var(--overlay-medium);
    border-radius: var(--radius-sm);
    padding: 4px;
    margin-bottom: 0.75rem;
    position: sticky; top: 0;
    z-index: 20;
    backdrop-filter: var(--blur-glass);
    -webkit-backdrop-filter: var(--blur-glass);
}
.toggle-btn {
    flex: 1;
    text-align: center;
    padding: 10px 8px;
    font-size: var(--body-xs-size);
    font-weight: 600;
    border-radius: var(--radius-xs);
    transition: all var(--duration-base) var(--ease-standard);
    color: var(--fg-4);
    background: transparent;
    border: none;
    white-space: nowrap;
}
.toggle-btn.active {
    background: var(--brand-blue);
    color: var(--fg-1);
    box-shadow: 0 4px 12px var(--brand-blue-glow);
}

/* Chemistry Expertise Banner (Geo only) — two-tier per PRD §5.1 */
.expertise-banner {
    background: var(--overlay-weak);
    border: 1px solid var(--overlay-border-weak);
    border-radius: var(--radius-sm);
    padding: 0.65rem 1rem;
    margin-bottom: 0.75rem;
    display: none;
    text-align: center;
}
.expertise-banner.visible { display: block; }
.expertise-tier + .expertise-tier { margin-top: 0.6rem; }
.expertise-label {
    font-size: var(--label-xs-size);
    font-weight: 600;
    color: var(--fg-5);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.3rem;
}
.expertise-list {
    font-size: 0.78rem;
    color: var(--fg-3);
    line-height: 1.5;
}

.category-btn {
    text-align: left;
    padding: 0.9rem 1rem;
    border-radius: var(--radius-sm);
    background: var(--overlay-weak);
    border: 1px solid var(--overlay-border-medium);
    color: var(--fg-2);
    transition: all 0.25s var(--ease-standard);
    font-size: var(--body-sm-size);
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: space-between;
    line-height: 1.3;
    width: 100%;
}
.category-btn:hover {
    background: var(--overlay-medium);
    border-color: var(--overlay-border-strong);
    transform: translateX(4px);
}
.category-btn.expanded {
    background: var(--brand-blue-tint);
    border-color: var(--brand-blue-light);
    color: var(--fg-1);
}
.category-btn .arrow {
    transition: transform var(--duration-base) var(--ease-standard);
    font-size: 0.85rem;
    margin-left: 1rem;
    flex-shrink: 0;
}
.category-btn.expanded .arrow { transform: rotate(90deg); }

.subtopic-container {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s var(--ease-standard),
                opacity var(--duration-base) var(--ease-standard);
    opacity: 0;
    margin-left: 0.5rem;
    border-left: 2px solid var(--brand-blue-rule);
    padding-left: 0.75rem;
}
.subtopic-container.expanded {
    max-height: 600px;
    opacity: 1;
    margin-top: 0.25rem;
    margin-bottom: 0.5rem;
}

.subtopic-btn {
    text-align: left;
    padding: 0.55rem 0.85rem;
    margin: 0.15rem 0;
    border-radius: var(--radius-xs);
    background: transparent;
    border: 1px solid transparent;
    color: var(--fg-4);
    transition: all var(--duration-fast) var(--ease-standard);
    font-size: var(--body-xs-size);
    font-weight: 500;
    width: 100%;
    display: block;
    line-height: 1.3;
}
.subtopic-btn:hover {
    background: var(--overlay-weak);
    border-color: var(--overlay-border-medium);
    color: var(--fg-1);
    padding-left: 1rem;
}
.subtopic-btn.active {
    background: var(--brand-blue);
    border-color: var(--brand-blue-light);
    color: var(--fg-1);
    padding-left: 1.1rem;
}

/* -------- Center stage ---------------------------------------------------- */
.center-stage-container {
    position: relative;
    display: flex;
    flex-direction: column;
    height: 100%;
    padding: 0 2rem 1rem;
}

.hero-pitch {
    margin-top: 4rem;
    max-width: 640px;
    transition: opacity 0.25s var(--ease-standard);
}
.hero-pitch--fading { opacity: 0; }
.hero-pitch__eyebrow {
    display: block;
    color: var(--fg-5);
    font-size: var(--label-size);
    font-weight: var(--label-weight);
    text-transform: var(--label-transform);
    letter-spacing: var(--label-tracking);
    margin-bottom: 0.5rem;
}
.hero-pitch__title {
    font-size: var(--display-2-size);
    font-weight: var(--display-2-weight);
    line-height: var(--display-2-lh);
    letter-spacing: var(--display-2-tracking);
    color: var(--fg-1);
    text-shadow: var(--shadow-text-hero);
    margin: 0 0 1rem;
    max-width: 640px;
}
.hero-pitch__audience {
    display: block;
    font-style: italic;
    color: var(--fg-4);
    font-size: 0.85rem;
    line-height: 1.5;
    max-width: 560px;
}

.cwh-attribution {
    position: absolute;
    bottom: 1.5rem;
    right: 0;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 0.4rem;
    text-decoration: none;
    transition: opacity var(--duration-fast) var(--ease-standard);
}
.cwh-attribution:hover { opacity: 0.85; }
.cwh-attribution__label {
    font-size: 0.8rem;
    font-weight: 700;
    color: #ffffff;
    letter-spacing: 0.02em;
    text-shadow: var(--shadow-text);
    white-space: nowrap;
}
.cwh-attribution__logo {
    height: 54px;
    width: auto;
    display: block;
}

.bottom-cta-container {
    margin-top: auto;
    margin-bottom: 2rem;
    display: flex;
    justify-content: center;
}
/* The consult button — gradient + pill — the brand's one piece of jewelry. */
.consult-btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: linear-gradient(135deg, var(--brand-blue), var(--brand-blue-deep));
    color: var(--fg-1);
    font-weight: 600;
    font-size: 1rem;
    border-radius: var(--radius-pill);
    box-shadow: var(--shadow-cta);
    transition: transform var(--duration-base) var(--ease-standard),
                box-shadow var(--duration-base) var(--ease-standard);
}
.consult-btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-cta-hover);
    color: var(--fg-1);
}

/* -------- Popup modal ----------------------------------------------------- */
.popup-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--s-5);
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-base) var(--ease-standard);
}
.popup-overlay.active {
    opacity: 1;
    visibility: visible;
}
.popup-card {
    background: linear-gradient(145deg, rgba(15, 23, 42, 0.98), rgba(30, 41, 59, 0.98));
    border: 1px solid var(--brand-blue-rule);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    max-width: 520px;
    width: 90%;
    position: relative;
    box-shadow: var(--shadow-popup);
    transform: translateY(20px) scale(0.95);
    transition: transform var(--duration-base) var(--ease-standard);
}
.popup-overlay.active .popup-card { transform: translateY(0) scale(1); }
.popup-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 32px; height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--overlay-medium);
    border: none;
    border-radius: 50%;
    color: var(--fg-4);
    font-size: 1.2rem;
    transition: all var(--duration-fast) var(--ease-standard);
}
.popup-close:hover { background: var(--overlay-strong); color: var(--fg-1); }
.popup-title {
    font-size: var(--h3-size);
    font-weight: 700;
    margin: 0 0 1rem;
    color: var(--fg-1);
    letter-spacing: var(--h3-tracking);
    line-height: 1.3;
    padding-right: 2rem;
}
.popup-description {
    color: var(--fg-3);
    line-height: 1.7;
    margin: 0 0 2rem;
    font-size: var(--body-size);
}
.popup-cta-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.popup-cta-primary {
    padding: 1rem 1.5rem;
    background: linear-gradient(135deg, var(--brand-blue), var(--brand-blue-hover));
    color: var(--fg-1);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-align: center;
    box-shadow: 0 4px 15px var(--brand-blue-glow);
    transition: all var(--duration-base) var(--ease-standard);
}
.popup-cta-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.50);
    background: linear-gradient(135deg, var(--brand-blue-light), var(--brand-blue));
    color: var(--fg-1);
}
.popup-cta-secondary {
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: var(--fg-4);
    border: 1px solid rgba(148, 163, 184, 0.30);
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.9rem;
    text-align: center;
    transition: all var(--duration-fast) var(--ease-standard);
}
.popup-cta-secondary:hover {
    background: var(--overlay-weak);
    border-color: rgba(148, 163, 184, 0.5);
    color: var(--fg-1);
}

/* -------- Tablet landscape / small laptop (two-column preserved) ---------- */
@media (max-width: 1100px) and (min-width: 901px) {
    .ui-container { grid-template-columns: 400px 1fr; padding-left: var(--s-5); padding-right: var(--s-5); }
    .center-stage-container { padding: 0 1rem 1rem; }
    .hero-pitch { margin-top: 2.5rem; }
    .hero-pitch__title { font-size: 1.9rem; }
}

/* -------- Tablet portrait & mobile (stacked) ----------------------------- */
@media (max-width: 900px) {
    body.home { overflow: auto; height: auto; }
    .visual-container { position: fixed; height: 100vh; }
    .ui-container {
        grid-template-columns: 1fr;
        height: auto;
        min-height: 100vh;
        padding: calc(var(--nav-h) + var(--s-4)) var(--s-4) var(--s-6);
    }
    .sidebar {
        max-height: none;
        padding-right: 0;
        order: 2;
    }
    .center-stage-container { order: 1; padding: 0; min-height: 42vh; }
    .hero-pitch { margin-top: 1.5rem; }
    .hero-pitch__title { font-size: 1.6rem; }
    .cwh-attribution { position: static; align-items: flex-start; margin-top: var(--s-5); }
    .bottom-cta-container { margin-top: var(--s-5); margin-bottom: 0; justify-content: stretch; }
    .consult-btn { width: 100%; text-align: center; }
    .popup-card { padding: 1.75rem; }
    .popup-title { font-size: 1.25rem; }
}

/* -------- Small phones --------------------------------------------------- */
@media (max-width: 420px) {
    .ui-container { padding-left: var(--s-3); padding-right: var(--s-3); }
    .hero-pitch__title { font-size: 1.4rem; }
    .section-header { font-size: 1.3rem; }
    .toggle-btn { font-size: 0.72rem; padding: 9px 6px; }
    .popup-card { padding: 1.5rem; }
}

.hero-pitch__cred {
    display: block;
    margin-top: 0.85rem;
    color: var(--fg-3);
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.01em;
    text-shadow: var(--shadow-text);
}