/* ==========================================================================
   HERO.CSS — Ooi Solutions (v18.1 — Optimized Scroll Sequence Layout)
   Canvas-based drone frame scroll sequence with 3 chapters, smart text 
   positioning, directional vignettes, and expanded 2-line heading layouts.
   Uses EXACT Ooi Solutions brand design system from variables.css.
   ========================================================================== */

/* ── Scroll Container ── */
.scroll-spacer {
    position: relative;
    width: 100%;
    height: 400vh;
    z-index: 2;
}

/* ── Sticky Viewport ── */
.sticky-viewport {
    position: sticky;
    top: 0;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    overflow: hidden;
    background: var(--bg-dark);
}

/* ── Canvas ── */
#sequence-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: block;
}

/* ── Vignette System ── */
.vignette {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 3;
    -webkit-mask-image: linear-gradient(to bottom, transparent 0%, transparent 90px, black 180px);
    mask-image: linear-gradient(to bottom, transparent 0%, transparent 90px, black 180px);
}

.vignette-left {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    width: 55%;
    background: linear-gradient(
        to right,
        var(--bg-dark) 0%,
        color-mix(in srgb, var(--bg-dark) 90%, transparent) 20%,
        color-mix(in srgb, var(--bg-dark) 62%, transparent) 42%,
        color-mix(in srgb, var(--bg-dark) 25%, transparent) 70%,
        transparent 100%
    );
    opacity: 0;
    transition: opacity var(--duration-slow) var(--ease-out);
}

.vignette-right {
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    width: 55%;
    background: linear-gradient(
        to left,
        var(--bg-dark) 0%,
        color-mix(in srgb, var(--bg-dark) 90%, transparent) 20%,
        color-mix(in srgb, var(--bg-dark) 62%, transparent) 42%,
        color-mix(in srgb, var(--bg-dark) 25%, transparent) 70%,
        transparent 100%
    );
    opacity: 0;
    transition: opacity var(--duration-slow) var(--ease-out);
}

/* Top vignette — extended to prevent cropping of text at top */
.vignette-top {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 15%;
    background: linear-gradient(
        to bottom,
        color-mix(in srgb, var(--bg-dark) 30%, transparent) 0%,
        transparent 100%
    );
}

.vignette-bottom {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 28%;
    background: linear-gradient(
        to top,
        var(--bg-dark) 0%,
        color-mix(in srgb, var(--bg-dark) 65%, transparent) 40%,
        transparent 100%
    );
}

.vignette-left.active { opacity: 1; }
.vignette-right.active { opacity: 1; }

/* ── Content Layer ── */
.content-layer {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 5;
    pointer-events: none;
}

/* ── Chapter Content ──
   UPDATED: Max-width increased to 55vw to give headings breathing room
   and force a beautiful 2-line layout that fills horizontal space. */
.chapter {
    position: absolute;
    top: 82%;
    max-width: min(720px, 55vw);
    padding: 0 clamp(2.5rem, 5vw, 4.5rem);
    opacity: 0;
    will-change: opacity, transform;
    transform: translateY(calc(-36% + 20px));
    transition: transform var(--duration-slow) var(--ease-out), opacity var(--duration-slow) var(--ease-out);
}

.chapter.is-visible {
    transform: translateY(-36%);
}

/* Text alignment per chapter position */
.chapter-left {
    left: 0;
    text-align: left;
    align-items: center;
}

.chapter-right {
    right: 0;
    text-align: right;
}

.chapter-center-left {
    left: 0;
    text-align: left;
}

.chapter-center-right {
    right: 0;
    text-align: right;
}

/* ── Chapter Tag (small label above heading) ── */
.chapter-tag {
    display: inline-block;
    font-family: var(--font-primary);
    font-size: var(--heading-label);
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
    padding: 3px 0;
    border-bottom: 1px solid var(--accent);
}

/* ── Chapter Heading ──
   UPDATED: Better clamp scaling and line-height for a punchy 2-line layout. */
.chapter-heading {
    font-family: var(--font-primary);
    font-size: clamp(3.2rem, 5.5vw, 5.8rem);
    font-weight: var(--font-weight-black);
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--fg);
    margin-bottom: 16px;
    white-space: pre-line;
    width: 100%;
}

/* Accent word uses Ooi brand accent color */
.chapter-heading .accent-word {
    background: linear-gradient(135deg, var(--accent), var(--accent-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

/* ── Chapter Paragraph ── */
.chapter-paragraph {
    font-family: var(--font-primary);
    font-size: clamp(1.05rem, 1.35vw, 1.35rem);
    font-weight: var(--font-weight-body);
    line-height: 1.55;
    color: var(--muted);
    max-width: 460px;
}

.chapter-right .chapter-paragraph,
.chapter-center-right .chapter-paragraph {
    margin-left: auto;
}

/* ── Chapter Divider ── */
.chapter-divider {
    width: 32px;
    height: 2px;
    margin-top: 16px;
    background: var(--accent);
    border-radius: var(--radius-full);
    opacity: 0.6;
}

.chapter-right .chapter-divider,
.chapter-center-right .chapter-divider {
    margin-left: auto;
}

/* ── Progress Bar ── */
.progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--border);
    z-index: 10;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent), var(--accent-gold));
    will-change: width;
}

/* ── Chapter Dots ── */
.chapter-dots {
    position: absolute;
    bottom: clamp(20px, 3.5vh, 36px);
    right: clamp(16px, 2.5vw, 32px);
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.chapter-dot {
    width: 5px;
    height: 5px;
    border-radius: var(--radius-full);
    background: color-mix(in srgb, var(--fg) 12%, transparent);
    transition: all var(--duration-mid) var(--ease-out);
    cursor: pointer;
    pointer-events: auto;
}

.chapter-dot.active {
    width: 22px;
    background: var(--accent);
}

/* ── Scroll Hint ── */
.scroll-hint {
    position: absolute;
    bottom: clamp(20px, 3.5vh, 36px);
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    opacity: 1;
    transition: opacity var(--duration-slow) ease;
}

.scroll-hint.hidden {
    opacity: 0;
    pointer-events: none;
}

.scroll-hint-text {
    font-family: var(--font-primary);
    font-size: 9px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.4em;
    text-transform: uppercase;
    color: color-mix(in srgb, var(--fg) 18%, transparent);
}

.scroll-hint-line {
    width: 1px;
    height: 28px;
    background: linear-gradient(to bottom, color-mix(in srgb, var(--fg) 30%, transparent), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; transform: scaleY(0.6); }
    50% { opacity: 1; transform: scaleY(1); }
}

/* ── Responsive: Tablet ── */
@media (max-width: 1024px) {
    .chapter {
        max-width: min(550px, 60vw);
    }

    .chapter-heading {
        font-size: clamp(2.4rem, 4.8vw, 3.8rem);
    }

    .chapter-paragraph {
        font-size: clamp(1rem, 1.6vw, 1.2rem);
    }
}

/* ── Responsive: Mobile ── */
@media (max-width: 768px) {
    .chapter {
        max-width: 85vw;
        padding: 0 clamp(1.5rem, 5vw, 3rem);
        padding-top: clamp(0px, 6vh, 60px);
    }

    .chapter-heading {
        font-size: clamp(2.2rem, 8vw, 3.4rem);
    }

    .chapter-paragraph {
        font-size: clamp(1rem, 3.4vw, 1.15rem);
        max-width: 100%;
    }

    .chapter-right,
    .chapter-center-right {
        right: 0;
        text-align: left;
    }

    .chapter-right .chapter-paragraph,
    .chapter-center-right .chapter-paragraph {
        margin-left: 0;
    }

    .chapter-right .chapter-divider,
    .chapter-center-right .chapter-divider {
        margin-left: 0;
    }

    .vignette-left,
    .vignette-right {
        width: 80%;
    }

    .vignette-left {
        background: linear-gradient(
            to right,
            var(--bg-dark) 0%,
            color-mix(in srgb, var(--bg-dark) 92%, transparent) 30%,
            color-mix(in srgb, var(--bg-dark) 55%, transparent) 60%,
            transparent 100%
        );
    }

    .vignette-right {
        background: linear-gradient(
            to left,
            var(--bg-dark) 0%,
            color-mix(in srgb, var(--bg-dark) 92%, transparent) 30%,
            color-mix(in srgb, var(--bg-dark) 55%, transparent) 60%,
            transparent 100%
        );
    }

    .chapter-dots {
        flex-direction: row;
        bottom: clamp(14px, 2.5vh, 24px);
        right: 50%;
        transform: translateX(50%);
    }
}

/* ── Responsive: Small phones ── */
@media (max-width: 480px) {
    .chapter-heading {
        line-height: 1.18;
        margin-bottom: 10px;
    }

    .chapter-paragraph {
        line-height: 1.5;
        max-width: 100%;
    }

    .chapter-tag {
        margin-bottom: 10px;
    }
}

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
    .scroll-hint-line {
        animation: none;
    }
    .vignette-left,
    .vignette-right {
        transition-duration: 0.01ms;
    }
    .chapter-dot {
        transition-duration: 0.01ms;
    }
}