:root{--bg-primary:#0a1628;--bg-secondary:#1a1a2e;--bg-tertiary:#16213e;--bg-accent:#0f3460;--gold-primary:#e8b931;--gold-light:#f7d560;--gold-subtle:#e8b93126;--gold-border:#e8b9314d;--gold-border-hover:#e8b93180;--text-primary:#e8e8e8;--text-muted:#8b9dc3;--card-bg:#ffffff0a;--card-border:#ffffff14;--section-border:#ffffff0f;--shadow-gold-sm:0 2px 12px #e8b93114;--shadow-gold-md:0 8px 32px #e8b9311f;--shadow-gold-lg:0 0 24px #e8b9312e;--radius-sm:.5rem;--radius-md:.75rem;--radius-lg:1rem;--radius-xl:1.25rem}body{background:linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 30%, var(--bg-tertiary) 60%, var(--bg-accent) 100%);color:var(--text-primary);-webkit-font-smoothing:antialiased;background-attachment:fixed;flex-direction:column;min-height:100vh;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;display:flex}.text-gold-gradient{background:linear-gradient(135deg, var(--gold-primary), var(--gold-light));-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text}.text-gold{color:var(--gold-primary)!important}.text-gold-light{color:var(--gold-light)!important}.text-muted-custom{color:var(--text-muted)!important}.hero-title{letter-spacing:-.02em;font-size:clamp(1.75rem,5vw,3rem);font-weight:800;line-height:1.1}.hero-subtitle{letter-spacing:.01em;font-size:clamp(1rem,2.5vw,1.25rem)}.card-dark{background:var(--card-bg);border:1px solid var(--card-border);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);transition:all .25s}.card-dark:hover{border-color:var(--gold-border-hover);box-shadow:var(--shadow-gold-md);transform:translateY(-3px)}.btn-gold{background:linear-gradient(135deg, var(--gold-primary), var(--gold-light));color:#0a1628;border:none;font-weight:600;transition:all .25s}.btn-gold:hover{background:linear-gradient(135deg, var(--gold-light), var(--gold-primary));color:#0a1628;transform:translateY(-1px);box-shadow:0 4px 20px #e8b93159}.btn-outline-gold{border:1px solid var(--gold-primary);color:var(--gold-primary);background:0 0;font-weight:500;transition:all .25s}.btn-outline-gold:hover{background:var(--gold-primary);color:#0a1628;box-shadow:var(--shadow-gold-sm)}.btn-outline-gold:disabled,.btn-outline-gold.disabled{opacity:.35;pointer-events:none}.badge-gold{background:var(--gold-subtle);color:var(--gold-light);font-size:.75rem;font-weight:500}.badge-lesson-id{color:var(--text-muted);background:#ffffff14;font-size:.75rem;font-weight:500}.nav-pills .nav-link.active{font-weight:600;background:linear-gradient(135deg, var(--gold-primary), var(--gold-light))!important;color:#0a1628!important}.nav-pills .nav-link{color:var(--text-muted);border:1px solid #0000;transition:all .25s}.nav-pills .nav-link:hover:not(.active){color:var(--gold-light);background:var(--gold-subtle);border-color:var(--gold-border)}.progress{border-radius:var(--radius-sm);background:#ffffff14}.progress-bar-gold{background:linear-gradient(90deg, var(--gold-primary), var(--gold-light));border-radius:var(--radius-sm)}.border-gold{border-color:var(--gold-primary)!important}.border-gold-subtle{border-color:var(--gold-border)!important}.section-divider{border-color:var(--section-border)}.glow-gold{box-shadow:var(--shadow-gold-lg)}.alert-gold{border:1px solid var(--gold-border);color:var(--text-primary);background:#e8b93114}.video-overlay{background:linear-gradient(#0000,#000000d9);padding:48px 24px 24px}.lesson-container{max-width:800px;margin:0 auto}.content-section{border:1px solid var(--card-border);background:var(--card-bg);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}.content-section-title{letter-spacing:.02em;font-size:1rem;font-weight:600}.example-divider{border-color:var(--section-border)!important}.check-gold{color:var(--gold-primary);font-size:1.1rem;line-height:1}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:0 0}::-webkit-scrollbar-thumb{background:#ffffff26;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--gold-primary)}*{scrollbar-width:thin;scrollbar-color:#ffffff26 transparent}@media (max-width:576px){.hero-title{font-size:1.75rem}}