: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{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}.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)}.text-cyan{color:var(--brand-cyan) !important}.hero-orb{position:absolute;border-radius:50%;filter:blur(80px);opacity:0.35;pointer-events:none;animation:orb-pulse 6s ease-in-out infinite alternate}.hero-orb-violet{width:420px;height:420px;background:var(--brand-violet);top:-120px;left:-80px}.hero-orb-cyan{width:320px;height:320px;background:var(--brand-cyan);bottom:-80px;right:-60px;animation-delay:-3s}@keyframes orb-pulse{from{transform:scale(1) translate(0, 0)}to{transform:scale(1.12) translate(12px, -8px)}}.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)}.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)}.feature-box{padding:1.3rem;border-radius:var(--radius-lg);border:1px solid rgba(148,163,184,0.25);background:#fff;box-shadow:var(--shadow-soft);height:100%;transition:transform 0.25s ease, box-shadow 0.25s ease}.feature-box:hover{transform:translateY(-3px);box-shadow:0 16px 36px rgba(8,20,41,0.1)}.feature-icon{font-size:1.5rem;margin-bottom:0.75rem;display:inline-block;color:var(--brand-violet)}.callout-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);padding:1.25rem 1.5rem;margin:1.5rem 0}.callout-card .callout-label{font-size:0.72rem;font-weight:700;letter-spacing:0.09em;text-transform:uppercase;color:var(--brand-cyan);display:block;margin-bottom:0.6rem}.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)}.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 1.25rem;text-align:center}.metric-value{font-size:clamp(1.6rem, 3.5vw, 2.2rem);font-weight:800;color:var(--brand-indigo);display:block;line-height:1.1}.metric-label{font-size:0.8rem;color:var(--brand-muted);margin-top:0.2rem}.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}.lesson-content{line-height:1.8;color:#1e293b;font-size:1.02rem}.lesson-content h1{display:none}.lesson-content h2{font-size:1.25rem;font-weight:700;color:var(--brand-indigo);margin-top:2rem;padding-bottom:0.4rem;border-bottom:2px solid rgba(95,55,214,0.12)}.lesson-content h3{font-size:1.05rem;font-weight:700;color:var(--brand-ink);margin-top:1.5rem}.lesson-content table{width:100%;margin:1.25rem 0;border-collapse:collapse;font-size:0.93rem}.lesson-content table th{background:rgba(95,55,214,0.07);color:var(--brand-indigo);font-weight:700;padding:0.6rem 0.75rem;border:1px solid rgba(148,163,184,0.35)}.lesson-content table td{padding:0.55rem 0.75rem;border:1px solid rgba(148,163,184,0.3);vertical-align:top}.lesson-content table tr:nth-child(even) td{background:rgba(242,246,251,0.6)}.lesson-content blockquote{border-left:4px solid var(--brand-cyan);padding:0.85rem 1.1rem;background:#f8fbff;border-radius:0 var(--radius-lg) var(--radius-lg) 0;margin:1rem 0;color:#334155}.lesson-content code{background:rgba(95,55,214,0.08);color:var(--brand-violet);padding:0.15em 0.4em;border-radius:4px;font-size:0.9em}.lesson-content pre{background:var(--brand-navy);color:#e2e8f0;border-radius:var(--radius-lg);padding:1.25rem;overflow-x:auto}.lesson-content pre code{background:transparent;color:inherit;padding:0}.lesson-content ul,.lesson-content ol{padding-left:1.4rem}.lesson-content li{margin-bottom:0.35rem}.lesson-content strong{color:var(--brand-indigo)}.sidebar-nav{position:sticky;top:80px;max-height:calc(100vh - 100px);overflow-y:auto}.sidebar-nav::-webkit-scrollbar{width:4px}.sidebar-nav::-webkit-scrollbar-thumb{background:rgba(148,163,184,0.4);border-radius:2px}.sidebar-section-btn{font-size:0.82rem;font-weight:700;text-transform:uppercase;letter-spacing:0.05em;color:var(--brand-indigo);background:none;border:none;width:100%;text-align:left;padding:0.55rem 0.75rem;border-radius:6px}.sidebar-section-btn:hover{background:rgba(95,55,214,0.06)}.sidebar-section-btn.accordion-button::after{filter:none}.sidebar-section-btn.accordion-button:not(.collapsed){box-shadow:none}.sidebar-lesson-link{display:flex;align-items:center;gap:0.5rem;font-size:0.85rem;color:#475569;padding:0.35rem 0.75rem;border-radius:6px;border-left:3px solid transparent;transition:all 0.18s ease}.sidebar-lesson-link:hover{color:var(--brand-violet);background:rgba(95,55,214,0.06)}.sidebar-lesson-link.active{color:var(--brand-violet);background:rgba(95,55,214,0.08);border-left-color:var(--brand-violet);font-weight:600}.sidebar-check{font-size:0.75rem;color:#cbd5e1;flex-shrink:0}.sidebar-check.done{color:var(--brand-cyan)}#reading-progress{position:fixed;top:0;left:0;height:3px;width:0%;background:linear-gradient(90deg, var(--brand-violet), var(--brand-cyan));z-index:9999;transition:width 0.1s linear}.sidebar-progress-wrap{padding:0.75rem}.sidebar-progress-label{font-size:0.75rem;font-weight:600;color:var(--brand-muted);display:flex;justify-content:space-between;margin-bottom:0.3rem}.progress-bar-brand{background-color:var(--brand-violet) !important}.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)}.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)}.section-space{scroll-margin-top:100px}.site-footer{background:rgba(255,255,255,0.88)}.fw-700{font-weight:700}.fw-800{font-weight:800}.sidebar-nav .accordion-button{background:transparent;padding:0.55rem 0.75rem}.sidebar-nav .accordion-button:focus{box-shadow:none}.sidebar-nav .accordion-item{background:transparent}@media (max-width: 991px){.lesson-shell{padding:1.25rem}.hero-orb{display:none}}