:root {
    --void: #0A0A0F;
    --signal: #0066FF;
    --signal-hover: #0052CC;
    --purple: #7B2FBE;
    --white: #F5F5F7;
    --steel: #8A8A9A;
    --steel-dark: #7a7a8a;
    --glass-bg: rgba(255,255,255,0.03);
    --glass-border: rgba(255,255,255,0.08);
    --glass-hover-bg: rgba(255,255,255,0.05);
    --glass-hover-border: rgba(255,255,255,0.14);
    --font-primary: 'Hanken Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Space Grotesk', 'Hanken Grotesk', sans-serif;
}
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; scroll-padding-top: 100px; }
body {
    font-family: var(--font-primary);
    background: var(--void);
    color: var(--steel);
    overflow-x: clip;
    line-height: 1.75;
    min-height: 100vh;
    position: relative;
}
body::before {
    content: '';
    position: fixed; inset: 0;
    background-image: radial-gradient(circle at 1px 1px, rgba(255,255,255,0.06) 1px, transparent 0);
    background-size: 28px 28px;
    pointer-events: none; z-index: 0;
}
body::after {
    content: '';
    position: fixed; inset: 0;
    background:
        radial-gradient(ellipse at 30% 0%, rgba(0,102,255,0.08) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 100%, rgba(123,47,190,0.06) 0%, transparent 60%);
    pointer-events: none; z-index: 0;
}
h1, h2, h3 { font-family: var(--font-display); color: var(--white); line-height: 1.2; letter-spacing: -0.025em; }
h1 { font-size: clamp(1.9rem, 4vw, 2.8rem); font-weight: 700; margin-bottom: 0.5rem; }
h2 { font-size: clamp(1.3rem, 2.2vw, 1.7rem); font-weight: 700; margin-top: 2rem; margin-bottom: 0.6rem; }
h3 { font-size: clamp(1.05rem, 1.5vw, 1.2rem); font-weight: 700; margin-bottom: 0.4rem; }
a { color: var(--signal); text-decoration: none; }
a:hover { color: var(--white); }
p { margin-bottom: 0.95rem; color: var(--steel); font-size: 1.02rem; }
strong { color: var(--white); font-weight: 600; }
ul, ol { margin: 0.5rem 0 1rem 1.3rem; color: var(--steel); }
li { margin-bottom: 0.35rem; }

/* HEADER */
header {
    position: fixed; top: 12px; left: 50%; transform: translateX(-50%);
    display: flex; align-items: center; gap: 2rem; padding: 12px 22px;
    background: rgba(10,10,15,0.72); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border); border-radius: 100px;
    z-index: 100; max-width: calc(100vw - 32px);
}
.logo {
    display: inline-flex; align-items: center; gap: 0.55rem;
    font-family: var(--font-display); font-weight: 700; font-size: 1rem;
    color: var(--white); white-space: nowrap; letter-spacing: -0.02em;
}
.logo-mark { height: 26px; width: auto; display: block; }
.logo span { background: linear-gradient(135deg, var(--signal), var(--purple)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
nav { display: flex; gap: 1.5rem; align-items: center; }
nav a { color: var(--steel); font-size: 0.95rem; font-weight: 500; transition: color 0.2s ease; }
nav a:hover, nav a.active { color: var(--white); }
.nav-cta { background: var(--signal); color: var(--void) !important; padding: 8px 18px; border-radius: 100px; font-weight: 700; }
.nav-cta:hover { background: var(--signal-hover); }
@media (max-width: 720px) { nav { display: none; } }

/* MAIN */
main { position: relative; z-index: 1; padding: 130px 22px 80px; }
.container { max-width: 740px; margin: 0 auto; }

/* BREADCRUMB */
.breadcrumb {
    font-size: 0.85rem; color: var(--steel-dark);
    margin-bottom: 1.5rem; font-family: var(--font-display);
    letter-spacing: 0.04em;
}
.breadcrumb a { color: var(--steel); }

/* LESSON META */
.lesson-meta {
    display: flex; gap: 0.75rem; align-items: center;
    margin-bottom: 1rem; font-family: var(--font-display);
    font-size: 0.78rem; letter-spacing: 0.12em; text-transform: uppercase;
}
.lesson-num { color: var(--signal); font-weight: 500; }
.lesson-time {
    color: var(--steel-dark);
    padding-left: 0.75rem; border-left: 1px solid var(--glass-border);
}

/* OUTCOME */
.outcome {
    margin: 1rem 0 1.5rem;
    padding: 14px 18px;
    background: rgba(0,102,255,0.08);
    border-left: 3px solid var(--signal);
    border-radius: 4px;
    font-size: 0.97rem;
}
.outcome strong { color: var(--signal); display: block; font-size: 0.78rem; letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 0.25rem; }

/* VIDEO PLACEHOLDER */
.video-ph {
    aspect-ratio: 16 / 9;
    background: linear-gradient(135deg, rgba(0,102,255,0.08), rgba(123,47,190,0.06));
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    gap: 0.75rem;
    margin: 1.5rem 0 2rem;
    text-align: center;
}
.play-icon {
    width: 56px; height: 56px; border-radius: 50%;
    background: var(--signal); display: flex; align-items: center; justify-content: center;
    box-shadow: 0 0 0 12px rgba(0,102,255,0.12);
}
.play-icon::before {
    content: ''; display: block;
    width: 0; height: 0;
    border-left: 14px solid var(--void);
    border-top: 9px solid transparent;
    border-bottom: 9px solid transparent;
    margin-left: 4px;
}
.video-ph .video-label {
    font-size: 0.85rem; color: var(--steel); font-family: var(--font-display);
    letter-spacing: 0.05em;
}

/* BODY CONTENT */
.lesson-body p:first-of-type { color: var(--white); font-size: 1.08rem; line-height: 1.7; }
.lesson-body code {
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    background: rgba(255,255,255,0.06); padding: 1px 6px;
    border-radius: 4px; font-size: 0.92em; color: var(--white);
}
.lesson-body blockquote {
    margin: 1.25rem 0; padding: 12px 18px;
    background: var(--glass-bg);
    border-left: 3px solid var(--purple);
    border-radius: 4px;
    color: var(--steel); font-size: 0.97rem;
}

/* EXERCISE */
.exercise {
    margin: 2rem 0 1.5rem;
    padding: 22px 24px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
}
.exercise h3 {
    color: var(--signal); font-size: 0.78rem;
    letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 0.6rem;
    font-family: var(--font-display);
}
.exercise p { color: var(--white); margin-bottom: 0.5rem; }
.exercise ol { color: var(--steel); }

/* NEXT/PREV NAV */
.lesson-nav {
    display: flex; justify-content: space-between; align-items: center;
    gap: 1rem; margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--glass-border);
}
.lesson-nav a {
    display: inline-flex; align-items: center; gap: 0.5rem;
    padding: 12px 20px; border-radius: 100px;
    font-weight: 600; font-size: 0.95rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--white);
    transition: background 0.2s ease, border-color 0.2s ease;
}
.lesson-nav a:hover { background: var(--glass-hover-bg); border-color: var(--glass-hover-border); }
.lesson-nav .next { background: var(--signal); color: var(--void); border-color: var(--signal); }
.lesson-nav .next:hover { background: var(--signal-hover); border-color: var(--signal-hover); color: var(--void); }
.lesson-nav .placeholder { opacity: 0.4; pointer-events: none; }

/* HUB-SPECIFIC */
.hero-learn { padding: 24px 0 48px; max-width: 880px; }
.hero-label {
    display: inline-block;
    font-family: var(--font-display); font-size: 0.78rem; font-weight: 500;
    text-transform: uppercase; letter-spacing: 0.18em;
    color: var(--signal); margin-bottom: 1.5rem;
}
.hero-tag {
    font-family: var(--font-display); font-size: clamp(1.05rem, 1.5vw, 1.3rem);
    color: var(--signal); margin-bottom: 1.5rem; font-weight: 500;
}
.hero-sub {
    font-size: clamp(1rem, 1.2vw, 1.08rem); color: var(--steel);
    max-width: 680px; line-height: 1.7; margin-bottom: 2rem;
}
.btn-primary {
    display: inline-flex; align-items: center; gap: 0.5rem;
    font-family: var(--font-primary); font-size: 1rem; font-weight: 600;
    color: var(--void); background: var(--signal);
    padding: 14px 28px; border-radius: 100px; text-decoration: none;
    transition: background 0.25s ease, transform 0.15s ease, box-shadow 0.25s ease;
}
.btn-primary:hover { background: var(--signal-hover); color: var(--void); transform: translateY(-1px); box-shadow: 0 8px 24px rgba(0,102,255,0.35); }

.section-head { margin: 48px 0 18px; padding-top: 18px; border-top: 1px solid var(--glass-border); }
.section-head h2 { margin-top: 0; margin-bottom: 0.3rem; }
.section-head p { color: var(--steel-dark); font-size: 0.95rem; }

.lessons-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.7rem; }
@media (max-width: 720px) { .lessons-list { grid-template-columns: 1fr; } }
.lesson-card {
    display: flex; align-items: center; gap: 0.85rem;
    padding: 14px 16px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
    text-decoration: none; color: inherit;
}
.lesson-card:hover { background: var(--glass-hover-bg); border-color: var(--glass-hover-border); transform: translateX(2px); color: inherit; }
.lc-num { font-family: var(--font-display); font-size: 1.1rem; font-weight: 700; color: var(--signal); min-width: 32px; }
.lc-body { flex: 1; }
.lc-title { font-family: var(--font-display); font-weight: 600; color: var(--white); font-size: 0.98rem; margin-bottom: 0.05rem; }
.lc-meta { font-size: 0.82rem; color: var(--steel-dark); }
.lc-arrow { color: var(--steel); transition: color 0.2s, transform 0.2s; }
.lesson-card:hover .lc-arrow { color: var(--signal); transform: translateX(2px); }

/* FOOTER */
footer {
    position: relative; z-index: 1;
    padding: 32px 22px; text-align: center;
    color: var(--steel-dark); font-size: 0.85rem;
    border-top: 1px solid var(--glass-border);
}
footer a { color: var(--steel); }

/* WHATSAPP FLOAT */
.whatsapp-float {
    position: fixed; bottom: 20px; right: 20px;
    width: 56px; height: 56px; border-radius: 50%;
    background: #25D366; display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 16px rgba(0,0,0,0.4);
    z-index: 99; transition: transform 0.2s ease;
}
.whatsapp-float:hover { transform: scale(1.06); }
.whatsapp-float svg { width: 28px; height: 28px; fill: white; }

/* SKIP LINK */
.skip-link {
    position: absolute; left: -9999px; top: 0;
    background: var(--signal); color: var(--void);
    padding: 12px 18px; border-radius: 8px; font-weight: 700;
}
.skip-link:focus { left: 12px; top: 12px; z-index: 1000; }

/* HUB CONTINUE BANNER */
.continue-banner {
    margin-bottom: 1.5rem; padding: 16px 20px;
    background: rgba(0,102,255,0.10);
    border: 1px solid rgba(0,102,255,0.25);
    border-radius: 12px;
    display: flex; align-items: center; justify-content: space-between; gap: 1rem;
    flex-wrap: wrap;
}
.continue-banner .cb-text { color: var(--white); font-size: 0.95rem; }
.continue-banner .cb-text strong { color: var(--signal); }
.continue-banner a {
    padding: 8px 16px; background: var(--signal); color: var(--void) !important;
    border-radius: 100px; font-weight: 600; font-size: 0.9rem;
}