/* ============================================================
   LANDING PAGE — Home (/index.html)
   Cyberpunk-LITE: dark theme + brand accent + Three.js particle bg.
   No GSAP, no Lenis, no bloom. ~150KB total weight (Three.js only).
   ============================================================ */

/* ---------- BG CANVAS (particle network) ---------- */
#bg-canvas {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-bg);
    display: block;
    pointer-events: none;
    opacity: 0.85;
}

/* ---------- SCROLL PROGRESS BAR ---------- */
.scroll-progress {
    position: fixed;
    top: 0; left: 0;
    height: 2px;
    width: 0%;
    background: linear-gradient(90deg, transparent, var(--accent) 30%, var(--accent-bright));
    z-index: 9998;
    pointer-events: none;
    box-shadow: 0 0 10px var(--accent), 0 0 20px var(--accent-glow);
    transition: width 0.05s linear;
}

/* ---------- CHAR-SPLIT REVEAL ---------- */
/* `.word` keeps every character of a word together — without it, inline-block
   chars let the line-breaker split inside a word (e.g. "phẩm" → "phẩ\nm"). */
.section-title .word {
    display: inline-block;
    white-space: nowrap;
}
.section-title .char {
    display: inline-block;
    opacity: 0;
    transform: translateY(80%) rotateX(-90deg);
    transform-origin: 50% 100%;
    will-change: transform, opacity;
}
.section-title .char.is-shown {
    animation: char-rise 0.7s var(--ease-back) forwards;
}
.section-title .gradient-text .char {
    /* Inline-block children break parent background-clip:text — apply per char */
    background: var(--grad-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}
@keyframes char-rise {
    to { opacity: 1; transform: translateY(0) rotateX(0); }
}

/* ---------- TOP NAV ---------- */
.top-nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: var(--z-nav);
    padding: 0.875rem clamp(1rem, 3vw, 2rem);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-s);
    background: rgba(8, 9, 13, 0.6);
    backdrop-filter: blur(14px) saturate(160%);
    -webkit-backdrop-filter: blur(14px) saturate(160%);
    border-bottom: 1px solid transparent;
    transition: background var(--dur-base), border-color var(--dur-base);
}
.top-nav.scrolled {
    background: rgba(8, 9, 13, 0.85);
    border-bottom-color: var(--border-soft);
}
.nav-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: var(--fs-sm);
    color: var(--accent);
    letter-spacing: -0.01em;
    text-decoration: none;
}
.nav-brand-logo {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    background: linear-gradient(135deg, var(--accent-bright), var(--accent-dark));
    display: grid;
    place-items: center;
    color: var(--bg);
    font-weight: 800;
    font-size: 13px;
    letter-spacing: -0.02em;
}
.nav-links {
    display: flex;
    gap: 0.25rem;
}
.nav-links a {
    padding: 8px 14px;
    font-size: var(--fs-sm);
    color: var(--text-muted);
    border-radius: var(--radius-sm);
    transition: color var(--dur-fast), background var(--dur-fast);
}
.nav-links a:hover { color: var(--text); background: rgba(255,255,255,0.04); }
.nav-cta-group { display: inline-flex; gap: 0.5rem; align-items: center; }

/* DEV-only quick link to design reference (shajon_style). */
.dev-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--info);
    background: rgba(34, 211, 238, 0.06);
    border: 1px dashed rgba(34, 211, 238, 0.4);
    border-radius: 100px;
    text-decoration: none;
    transition: all var(--dur-fast);
}
.dev-link:hover {
    background: rgba(34, 211, 238, 0.12);
    border-color: var(--info);
    color: var(--info);
}
@media (max-width: 880px) {
    .dev-link { display: none; }    /* hide on mobile to save space */
}

.nav-burger {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 8px;
    background: none;
    border: 0;
    cursor: pointer;
}
.nav-burger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: 0.2s;
}
@media (max-width: 880px) {
    .nav-links { display: none; }
    .nav-cta-group .btn-ghost { display: none; }
    .nav-burger { display: flex; }
    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 16px; right: 16px;
        background: var(--surface);
        margin-top: 8px;
        padding: 0.5rem;
        border: 1px solid var(--border-soft);
        border-radius: var(--radius);
        gap: 2px;
    }
    .nav-links.open a { padding: 10px 14px; }
}


/* ---------- HERO ---------- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(96px, 13vh, 150px) var(--pad-inline) var(--space-xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}
/* Subtle grid pattern — adds cyberpunk depth on top of particle network */
.hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(172, 205, 255, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(172, 205, 255, 0.04) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}
/* Hero parallax tilt wrapper — JS sets --tx --ty via mousemove */
.hero-tilt {
    position: relative;
    z-index: 2;
    transform-style: preserve-3d;
    transform:
        perspective(1200px)
        rotateX(var(--ty, 0deg))
        rotateY(var(--tx, 0deg));
    transition: transform 0.18s ease-out;
    will-change: transform;
}
.hero-inner {
    position: relative;
    z-index: 1;
    max-width: 900px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-s);
}

/* Floating tech tags — abs-positioned around hero, hidden on tablet/phone */
.hero-floats {
    position: absolute;
    inset: 0;
    pointer-events: none;
    perspective: 800px;
    transform-style: preserve-3d;
    z-index: 1;
}
.float-tag {
    position: absolute;
    left: calc(var(--x, 50) * 1%);
    top:  calc(var(--y, 50) * 1%);
    transform: translate(-50%, -50%) translateZ(var(--z, 0px));
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    font-weight: 500;
    padding: 5px 12px;
    background: rgba(172, 205, 255, 0.04);
    border: 1px solid var(--border);
    border-radius: 100px;
    color: var(--accent);
    opacity: 0.55;
    white-space: nowrap;
    animation: float-bob var(--dur, 6s) ease-in-out infinite;
    animation-delay: var(--delay, 0s);
}
.float-tag::before {
    content: "//";
    color: var(--text-faint);
    margin-right: 6px;
    font-weight: 700;
}
@keyframes float-bob {
    0%, 100% { transform: translate(-50%, -50%) translateZ(var(--z, 0px)) translateY(0); }
    50%      { transform: translate(-50%, -50%) translateZ(var(--z, 0px)) translateY(-10px); }
}
@media (max-width: 1100px) {
    .hero-floats { display: none; }
}

.hero-title {
    font-size: var(--fs-display);
    font-weight: 800;
    line-height: var(--lh-tight);
    letter-spacing: -0.04em;
    overflow-wrap: break-word;   /* break only as last resort, never mid-phrase */
    max-width: 100%;
}
/* Hero title shimmer — subtle moving gradient on the highlighted word */
.hero-title .gradient-text {
    background: linear-gradient(
        110deg,
        var(--accent-soft)   0%,
        var(--accent)       25%,
        var(--accent-bright) 50%,
        var(--accent)       75%,
        var(--accent-soft) 100%
    );
    background-size: 220% 100%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    animation: hero-shimmer 5s ease-in-out infinite;
    will-change: background-position;
}
@keyframes hero-shimmer {
    0%, 100% { background-position: 0% 50%; }
    50%      { background-position: 100% 50%; }
}
.hero-sub {
    max-width: 640px;
    font-size: var(--fs-base);
    color: var(--text-muted);
    line-height: var(--lh-loose);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
}
.hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2xs);
    justify-content: center;
    margin-top: var(--space-2xs);
}
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--text-faint);
    letter-spacing: 0.25em;
    text-transform: uppercase;
    text-decoration: none;
}
.scroll-indicator::after {
    content: "";
    display: block;
    width: 1px;
    height: 40px;
    margin: 8px auto 0;
    background: linear-gradient(to bottom, var(--accent), transparent);
    animation: scroll-line 2s ease-in-out infinite;
}
@keyframes scroll-line {
    0%, 100% { opacity: 1; transform: scaleY(1); }
    50%      { opacity: 0.4; transform: scaleY(0.5); }
}


/* ---------- SECTION COMMON ---------- */
.section {
    max-width: var(--container);
    margin: 0 auto;
    padding-block: var(--space-2xl);
    padding-inline: var(--pad-inline);
    position: relative;
}
.section-head {
    text-align: center;
    margin-bottom: var(--space-l);
    max-width: 720px;
    margin-inline: auto;
}
.section-head .section-title {
    font-size: var(--fs-h2);
    margin-top: var(--space-2xs);
}
.section-head p {
    margin-top: var(--space-s);
    color: var(--text-muted);
    font-size: var(--fs-md);
}


/* ---------- ABOUT (value cards + timeline) ---------- */
.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
    gap: var(--space-s);
    margin-bottom: var(--space-l);
}
.value-card {
    background: var(--surface);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius-md);
    padding: var(--space-m);
    position: relative;
    overflow: hidden;
    transition: border-color var(--dur-base), transform var(--dur-base) var(--ease);
}
.value-card:hover { border-color: var(--border-strong); transform: translateY(-3px); }
.value-card::before {
    content: "";
    position: absolute;
    top: 0; left: 0;
    width: 3px; height: 0;
    background: linear-gradient(180deg, var(--accent-bright), var(--accent-dark));
    transition: height var(--dur-base) var(--ease);
}
.value-card:hover::before { height: 100%; }
.value-num {
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--accent);
    letter-spacing: 0.2em;
    margin-bottom: var(--space-2xs);
    opacity: 0.7;
}
.value-card h3 {
    font-size: var(--fs-md);
    font-weight: 700;
    margin-bottom: var(--space-3xs);
}
.value-card p {
    font-size: var(--fs-sm);
    color: var(--text-muted);
    line-height: var(--lh-base);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 32px;
    border-left: 2px solid var(--border-soft);
    display: flex;
    flex-direction: column;
    gap: var(--space-m);
    max-width: 720px;
    margin-inline: auto;
}
.timeline-item {
    position: relative;
    padding-left: var(--space-s);
}
.timeline-item::before {
    content: "";
    position: absolute;
    left: -41px;
    top: 6px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--bg);
    border: 2px solid var(--border);
    transition: all var(--dur-base);
}
.timeline-item.is-current::before {
    background: var(--accent);
    border-color: var(--accent-bright);
    box-shadow: 0 0 0 4px rgba(172, 205, 255, 0.18), 0 0 12px var(--accent-glow);
    animation: timeline-pulse 2s ease-in-out infinite;
}
@keyframes timeline-pulse {
    0%, 100% { box-shadow: 0 0 0 4px rgba(172,205,255,0.18), 0 0 12px var(--accent-glow); }
    50%      { box-shadow: 0 0 0 8px rgba(172,205,255,0.10), 0 0 20px var(--accent-glow); }
}
.timeline-year {
    font-family: var(--font-mono);
    font-size: var(--fs-md);
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 4px;
    letter-spacing: 0.05em;
}
.timeline-event {
    font-size: var(--fs-sm);
    color: var(--text-muted);
    line-height: var(--lh-base);
}


/* ---------- FEATURES (4 cards) ---------- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(240px, 100%), 1fr));
    gap: var(--space-s);
}
.feature-card {
    background: var(--surface);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius-md);
    padding: var(--space-m);
    transition: all var(--dur-base) var(--ease);
    position: relative;
    overflow: hidden;
}
.feature-card::before {
    content: "";
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
    opacity: 0;
    transition: opacity var(--dur-base);
}
.feature-card:hover {
    border-color: var(--border-strong);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}
.feature-card:hover::before { opacity: 1; }
.feature-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius);
    background: rgba(172, 205, 255, 0.08);
    border: 1px solid var(--border);
    display: grid;
    place-items: center;
    color: var(--accent);
    margin-bottom: var(--space-s);
}
.feature-icon svg { width: 22px; height: 22px; }
.feature-card h3 {
    font-size: var(--fs-md);
    margin-bottom: var(--space-3xs);
}
.feature-card p {
    font-size: var(--fs-sm);
    line-height: var(--lh-base);
}


/* ---------- SOFTWARE SHOWCASE (4 software) ---------- */
.software-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
    gap: var(--space-s);
}
.software-card {
    background: var(--surface);
    border: 1px solid var(--border-soft);
    border-radius: var(--radius-md);
    padding: var(--space-m);
    display: flex;
    flex-direction: column;
    gap: var(--space-2xs);
    transition: border-color var(--dur-base) var(--ease), transform var(--dur-base) var(--ease);
}
.software-card:hover {
    border-color: var(--border-strong);
    transform: translateY(-3px);
}
.software-icon {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, var(--accent-bright) 0%, var(--accent-dark) 100%);
    border-radius: var(--radius);
    display: grid;
    place-items: center;
    margin-bottom: var(--space-2xs);
    box-shadow: 0 6px 16px -8px var(--accent-glow), inset 0 1px 0 rgba(255,255,255,0.25);
    color: var(--bg);
    transition: transform var(--dur-base) var(--ease), box-shadow var(--dur-base);
}
.software-icon svg {
    width: 26px;
    height: 26px;
    stroke: currentColor;
    stroke-width: 2;
    fill: none;
}
.software-card:hover .software-icon {
    transform: rotate(-4deg) scale(1.05);
    box-shadow: 0 10px 22px -6px var(--accent-glow), inset 0 1px 0 rgba(255,255,255,0.35);
}
.software-card h4 {
    font-size: var(--fs-md);
    margin-bottom: var(--space-3xs);
}
.software-card .software-desc {
    font-size: var(--fs-sm);
    color: var(--text-muted);
    flex-grow: 1;
}
.software-card .software-link {
    margin-top: var(--space-2xs);
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--accent);
    align-self: flex-start;
    text-decoration: none;
    transition: gap var(--dur-fast), color var(--dur-fast);
    display: inline-flex;
    gap: 4px;
}
.software-card .software-link:hover { gap: 10px; color: var(--accent-bright); }

/* New richer-card sub-elements */
.software-card-head {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--space-2xs);
    margin-bottom: var(--space-2xs);
}
.software-card-head .software-icon { margin-bottom: 0; }
.software-meta {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
}
.software-version {
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--text-dim);
    letter-spacing: 0.05em;
}
.software-card .software-tagline {
    font-size: var(--fs-sm);
    color: var(--accent);
    font-weight: 500;
    margin: 0 0 var(--space-3xs);
}
.software-features {
    list-style: none;
    margin: var(--space-2xs) 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex-grow: 1;
}
.software-features li {
    font-size: var(--fs-xs);
    color: var(--text-muted);
    padding-left: 18px;
    position: relative;
    line-height: 1.5;
}
.software-features li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 7px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(172, 205, 255, 0.12);
    border: 1px solid var(--accent);
    box-shadow: inset 0 0 0 2px var(--bg);
}
.software-card .software-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: var(--space-2xs);
    padding-top: var(--space-2xs);
    border-top: 1px solid var(--border-soft);
}
.software-card .software-tags .tag {
    font-size: 10px;
    padding: 2px 8px;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.04);
    border-color: var(--border-soft);
}
.software-card:hover .software-tags .tag { color: var(--accent); border-color: var(--border); }


/* ---------- STATS STRIP ---------- */
.stats-strip {
    margin: var(--space-l) auto 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(160px, 100%), 1fr));
    gap: var(--space-s);
    background: rgba(255, 255, 255, 0.025);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-m);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
.stat-item {
    text-align: center;
    position: relative;
}
.stat-item + .stat-item::before {
    content: "";
    position: absolute;
    left: 0; top: 14%; bottom: 14%;
    width: 1px;
    background: linear-gradient(to bottom, transparent, var(--border-strong), transparent);
}
.stat-num {
    font-size: clamp(26px, 4vw, 44px);
    font-weight: 800;
    line-height: 1;
    background: var(--grad-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 4px;
}
.stat-label {
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--text-dim);
    letter-spacing: 0.1em;
    text-transform: uppercase;
}
@media (max-width: 600px) {
    .stat-item + .stat-item::before { display: none; }
}


/* ---------- CTA STRIP (bottom) ---------- */
.cta-strip {
    margin: 0 auto;
    max-width: var(--container);
    padding: var(--space-2xl) var(--pad-inline);
}
.cta-card {
    background: linear-gradient(135deg, rgba(172, 205, 255, 0.06), rgba(172, 205, 255, 0.02));
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-l) var(--space-m);
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-card::before {
    content: "";
    position: absolute;
    top: -50%; left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, var(--accent-glow), transparent 70%);
    opacity: 0.15;
    pointer-events: none;
}
.cta-card > * { position: relative; z-index: 1; }
.cta-card h2 {
    font-size: var(--fs-h2);
    margin-bottom: var(--space-2xs);
}
.cta-card p {
    color: var(--text-muted);
    margin-bottom: var(--space-m);
    max-width: 540px;
    margin-inline: auto;
}


/* ---------- FOOTER ---------- */
.footer {
    border-top: 1px solid var(--border-soft);
    padding: var(--space-l) var(--pad-inline);
    max-width: var(--container);
    margin: 0 auto;
}
.footer-inner {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: var(--space-m);
    align-items: center;
}
.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.footer-brand .nav-brand { font-size: var(--fs-md); }
.footer-brand p {
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--text-faint);
}
.footer-links {
    display: flex;
    gap: var(--space-s);
    flex-wrap: wrap;
}
.footer-links a {
    font-size: var(--fs-sm);
    color: var(--text-muted);
}
.footer-links a:hover { color: var(--accent); }
.footer-bottom {
    margin-top: var(--space-s);
    padding-top: var(--space-s);
    border-top: 1px solid var(--border-soft);
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    color: var(--text-faint);
}
@media (max-width: 600px) {
    .footer-inner { grid-template-columns: 1fr; }
}