:root{--brand-navy: #081429;--brand-indigo: #1c2d7a;--brand-violet: #5f37d6;--brand-cyan: #1fd3ff;--brand-ink: #0f172a;--brand-muted: #64748b;--brand-bg: #f2f6fb;--shadow-soft: 0 16px 40px rgba(8, 20, 41, 0.08);--radius-lg: 1.1rem}html.auth-locked #site-shell{display:none}html.auth-ok #auth-gate{display:none}#auth-gate{position:fixed;inset:0;z-index:9999;display:grid;place-items:center;padding:1rem}.auth-gate-backdrop{position:absolute;inset:0;background:linear-gradient(140deg, rgba(8,20,41,0.95), rgba(28,45,122,0.9))}.auth-gate-card{position:relative;width:min(100%, 420px);border-radius:var(--radius-lg);border:1px solid rgba(148,163,184,0.35);background:#fff;box-shadow:0 24px 60px rgba(8,20,41,0.35);padding:1.25rem}.auth-gate-error{min-height:1rem;color:#b91c1c}html{scroll-behavior:smooth}body{font-family:"Manrope", "Segoe UI", sans-serif;color:var(--brand-ink);background:radial-gradient(circle at 10% -10%, rgba(95,55,214,0.28), transparent 32%),radial-gradient(circle at 95% 10%, rgba(31,211,255,0.2), transparent 36%),linear-gradient(180deg, #fff 0%, var(--brand-bg) 70%, #fff 100%)}a{color:var(--brand-indigo);text-decoration:none}a:hover{color:var(--brand-violet)}.navbar-glass{backdrop-filter:blur(8px);background:rgba(255,255,255,0.94)}.navbar .nav-link.active{color:var(--brand-indigo);font-weight:700}.nav-cta-group{min-width:240px}@media (max-width: 1199px){.nav-cta-group{min-width:100%}}.brand-logo{width:auto;height:34px}.hero-wrap{color:#fff;background:linear-gradient(112deg, rgba(8,20,41,0.97), rgba(28,45,122,0.93) 52%, rgba(31,211,255,0.55)),url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='64' height='64' viewBox='0 0 64 64'%3E%3Cg fill='none' stroke='rgba(255,255,255,0.08)' stroke-width='1'%3E%3Cpath d='M1 32h62M32 1v62'/%3E%3C/g%3E%3C/svg%3E")}.hero-small{padding-top:2.5rem;padding-bottom:2.5rem}.text-white-75{color:rgba(255,255,255,0.78)}.glass-panel{border:1px solid rgba(255,255,255,0.25);border-radius:var(--radius-lg);background:rgba(255,255,255,0.08);box-shadow:var(--shadow-soft)}.section-space{scroll-margin-top:100px}.bg-soft{background:rgba(255,255,255,0.75);border-top:1px solid rgba(148,163,184,0.25);border-bottom:1px solid rgba(148,163,184,0.25)}.card-soft{border:1px solid rgba(148,163,184,0.25);border-radius:var(--radius-lg);box-shadow:var(--shadow-soft);background:#fff;transition:transform 0.25s ease, box-shadow 0.25s ease}.card-soft:hover{transform:translateY(-4px);box-shadow:0 20px 40px rgba(8,20,41,0.12)}.acronym-card{border:1px solid rgba(31,211,255,0.35);border-radius:var(--radius-lg);box-shadow:var(--shadow-soft);background:linear-gradient(160deg, #fff, #effbff)}.badge-soft{background:rgba(95,55,214,0.12);color:var(--brand-indigo);border:1px solid rgba(95,55,214,0.2)}.badge-brand{background:rgba(31,211,255,0.2);color:#fff;border:1px solid rgba(31,211,255,0.45)}.feature-box{position:relative;padding:1.3rem;border-radius:var(--radius-lg);border:1px solid rgba(148,163,184,0.25);background:#fff;box-shadow:var(--shadow-soft)}.feature-icon{font-size:1.5rem;margin-bottom:0.75rem;display:inline-block;color:var(--brand-violet)}.text-cyan{color:var(--brand-cyan) !important}.metric-card{border-radius:var(--radius-lg);border:1px solid rgba(148,163,184,0.2);box-shadow:var(--shadow-soft);background:#fff;padding:1rem}.metric-value{font-size:clamp(1.6rem, 3.5vw, 2.2rem);font-weight:800;color:var(--brand-indigo)}.lesson-shell{border:1px solid rgba(148,163,184,0.25);border-radius:var(--radius-lg);background:#fff;box-shadow:var(--shadow-soft);padding:2rem}.acronym-lesson{background:linear-gradient(180deg, #fff, #f1fcff);border-color:rgba(31,211,255,0.35)}.lesson-content{line-height:1.75;color:#1e293b}.lesson-content h2,.lesson-content h3{margin-top:1.8rem}.lesson-content table{width:100%;margin:1rem 0;border-collapse:collapse;font-size:0.95rem}.lesson-content table th,.lesson-content table td{border:1px solid rgba(148,163,184,0.4);padding:0.6rem}.lesson-content blockquote{border-left:4px solid var(--brand-cyan);padding:0.8rem 1rem;background:#f8fbff}.btn-brand{--bs-btn-bg: var(--brand-violet);--bs-btn-border-color: var(--brand-violet);--bs-btn-hover-bg: #4f2cc4;--bs-btn-hover-border-color: #4f2cc4;--bs-btn-active-bg: #4224a9;--bs-btn-active-border-color: #4224a9;--bs-btn-color: #fff}.btn-outline-brand{--bs-btn-color: var(--brand-indigo);--bs-btn-border-color: rgba(28, 45, 122, 0.45);--bs-btn-hover-bg: var(--brand-indigo);--bs-btn-hover-border-color: var(--brand-indigo);--bs-btn-hover-color: #fff}.reveal-up{opacity:0;transform:translateY(14px);transition:opacity 0.55s ease, transform 0.55s ease}.reveal-up.is-visible{opacity:1;transform:translateY(0)}.site-footer{background:rgba(255,255,255,0.88)}@media (max-width: 991px){.lesson-shell{padding:1.25rem}}