@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Syne:wght@700;800&display=swap');

:root {
    --bg:       #03091a;
    --sky:      #0ea5e9;
    --cyan:     #38bdf8;
    --indigo:   #6366f1;
    --muted:    #7fa8c4;
    --surface:  rgba(14, 165, 233, 0.06);
    --border:   rgba(14, 165, 233, 0.16);
    --white:    #e8f4ff;
}

* { box-sizing: border-box; }

body, html {
    margin: 0; padding: 0;
    font-family: 'Space Grotesk', sans-serif;
    background-color: var(--bg);
    color: var(--white);
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    min-height: 100vh;
}

/* ── Canvas ─────────────────────────────────────────────────────── */

#star-canvas {
    position: fixed; top: 0; left: 0;
    width: 100%; height: 100%;
    z-index: 0; pointer-events: none;
}

/* ── Nav ─────────────────────────────────────────────────────────── */

nav {
    display: flex; justify-content: space-between; align-items: center;
    padding: 20px 8%;
    background: rgba(3, 9, 26, 0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    position: sticky; top: 0; z-index: 100;
}

.logo {
    font-family: 'Syne', sans-serif;
    font-size: 1.55rem; font-weight: 800;
    letter-spacing: 2px; text-transform: uppercase;
}

.logo-ye   { color: var(--cyan); }
.logo-bius { color: var(--white); opacity: 0.9; }

.nav-link {
    font-weight: 600; font-size: 0.82rem;
    text-decoration: none;
    color: var(--white);
    border: 1.5px solid var(--sky);
    padding: 10px 22px; border-radius: 5px;
    letter-spacing: 1px; text-transform: uppercase;
    transition: background 0.2s, transform 0.2s;
    white-space: nowrap;
}

.nav-link:hover {
    background: var(--sky);
    color: var(--bg);
    transform: translateY(-1px);
}

@media (max-width: 650px) {
    nav { padding: 14px 5%; }
    .logo { font-size: 1.2rem; }
    .nav-link { padding: 8px 14px; font-size: 0.72rem; }
}

/* ── Hero ────────────────────────────────────────────────────────── */

.hero {
    max-width: 1100px; margin: 0 auto;
    padding: 14vh 24px 6vh;
    text-align: center;
    position: relative; z-index: 1;
}

.hero-eyebrow {
    display: inline-block;
    font-size: 0.76rem; font-weight: 600;
    letter-spacing: 3px; text-transform: uppercase;
    color: var(--cyan);
    border: 1px solid rgba(56, 189, 248, 0.28);
    padding: 6px 18px; border-radius: 20px;
    margin-bottom: 32px;
}

.brand-h1 {
    font-family: 'Syne', sans-serif;
    font-size: clamp(2.4rem, 10vw, 11rem);
    font-weight: 800; line-height: 0.95;
    margin: 0 0 28px;
    letter-spacing: -2px;
    background: linear-gradient(135deg, var(--cyan) 0%, var(--sky) 45%, var(--indigo) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 0 48px rgba(14, 165, 233, 0.28));
}

.hero-sub {
    font-size: clamp(1rem, 2.2vw, 1.35rem);
    font-weight: 600;
    color: var(--white); opacity: 0.75;
    margin: 0 0 20px;
    letter-spacing: 0.3px;
}

.hero-tagline {
    max-width: 660px; margin: 0 auto 64px;
    color: var(--muted);
    font-size: 1.06rem; line-height: 1.78;
}

@media (max-width: 480px) {
    .brand-h1 { letter-spacing: -1px; }
    .hero-tagline { font-size: 0.95rem; }
}

/* ── Cards ───────────────────────────────────────────────────────── */

.grid {
    max-width: 1100px; margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    position: relative; z-index: 1;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 34px 28px;
    border-radius: 10px;
    text-align: left;
    transition: transform 0.28s, box-shadow 0.28s, border-color 0.28s;
    position: relative; overflow: hidden;
}

.card::before {
    content: '';
    position: absolute; top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--sky), var(--indigo));
    opacity: 0; transition: opacity 0.3s;
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 40px rgba(14, 165, 233, 0.14);
    border-color: rgba(14, 165, 233, 0.34);
}

.card:hover::before { opacity: 1; }

.card-icon {
    font-size: 1.5rem; margin-bottom: 14px; display: block;
}

.card-label {
    font-size: 0.7rem; font-weight: 700;
    letter-spacing: 2.5px; text-transform: uppercase;
    color: var(--cyan); margin-bottom: 14px; display: block;
}

.card h3 {
    font-family: 'Syne', sans-serif;
    font-size: 1.05rem; font-weight: 700;
    margin: 0 0 12px; color: var(--white);
}

.card p {
    font-size: 0.92rem; line-height: 1.72;
    color: var(--muted); margin: 0;
}

/* ── Use cases ───────────────────────────────────────────────────── */

.use-cases {
    max-width: 1100px; margin: 70px auto 0;
    padding: 0 24px;
    text-align: center;
    position: relative; z-index: 1;
}

.use-cases-title {
    font-size: 0.74rem; font-weight: 600;
    letter-spacing: 2.5px; text-transform: uppercase;
    color: var(--muted); margin-bottom: 20px;
}

.pills {
    display: flex; flex-wrap: wrap;
    gap: 10px; justify-content: center;
}

.pill {
    font-size: 0.83rem; font-weight: 500;
    color: var(--cyan);
    background: rgba(56, 189, 248, 0.07);
    border: 1px solid rgba(56, 189, 248, 0.2);
    padding: 7px 18px; border-radius: 999px;
}

/* ── CTA ─────────────────────────────────────────────────────────── */

.signal-line {
    padding: 90px 20px 100px;
    text-align: center;
    position: relative; z-index: 1;
}

.signal-inner { max-width: 520px; margin: 0 auto; }

.signal-status {
    font-size: 0.74rem; font-weight: 600;
    letter-spacing: 3px; text-transform: uppercase;
    color: var(--cyan); margin-bottom: 28px;
}

.signal-cta {
    display: inline-block;
    font-weight: 700; font-size: 0.88rem;
    text-decoration: none;
    background: linear-gradient(135deg, var(--sky), var(--indigo));
    color: var(--white);
    padding: 16px 44px; border-radius: 6px;
    letter-spacing: 1px; text-transform: uppercase;
    transition: opacity 0.2s, transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 0 32px rgba(14, 165, 233, 0.3);
}

.signal-cta:hover {
    opacity: 0.88;
    transform: translateY(-2px);
    box-shadow: 0 0 54px rgba(14, 165, 233, 0.5);
}

.signal-sub {
    margin-top: 20px;
    font-size: 0.85rem;
    color: var(--muted);
}