:root{--color-bg: #0D1117;--color-surface: #161B22;--color-surface-2: #21262D;--color-border: #30363D;--color-gold: #D4A843;--color-gold-light: #F0C96B;--color-green: #2EA043;--color-green-light: #3FB950;--color-text: #E6EDF3;--color-text-muted: #8B949E;--color-danger: #F85149;--color-warning: #E3B341;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 20px;--radius-xl: 28px;--transition: .2s cubic-bezier(.4, 0, .2, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--color-bg);color:var(--color-text);font-family:Inter,Noto Sans,sans-serif;min-height:100vh;-webkit-font-smoothing:antialiased}.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:1rem}.btn-primary{background:var(--color-gold);color:#000;border:none;border-radius:var(--radius-md);padding:.75rem 1.5rem;font-weight:600;cursor:pointer;transition:var(--transition);width:100%}.btn-primary:active{transform:scale(.98);background:var(--color-gold-light)}.btn-secondary{background:var(--color-surface-2);color:var(--color-text);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:.75rem 1.5rem;font-weight:600;cursor:pointer;transition:var(--transition)}.btn-danger{background:var(--color-danger);color:#fff;border:none;border-radius:var(--radius-md);padding:.75rem 1.5rem;font-weight:600;cursor:pointer}.badge{padding:.25rem .5rem;border-radius:var(--radius-sm);font-size:.75rem;font-weight:600}.badge-success{background:#2ea04333;color:var(--color-green-light);border:1px solid var(--color-green)}.badge-warning{background:#e3b34133;color:var(--color-warning);border:1px solid var(--color-warning)}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{transform:translateY(20px);opacity:0}to{transform:translateY(0);opacity:1}}.fade-in{animation:fadeIn .3s ease-in-out}.slide-up{animation:slideUp .4s ease-out}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:var(--color-bg)}::-webkit-scrollbar-thumb{background:var(--color-border);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}.bottom-nav{position:fixed;bottom:0;left:0;right:0;height:65px;background:#161b22eb;backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-top:1px solid var(--color-border);display:flex;justify-content:space-around;align-items:center;z-index:1000}.bottom-nav a{text-decoration:none;text-align:center;font-size:.72rem;color:var(--color-text-muted);display:flex;flex-direction:column;align-items:center;gap:3px;transition:var(--transition);padding:6px 16px;border-radius:var(--radius-sm)}.bottom-nav a.active{color:var(--color-gold)}.bottom-nav a:active{transform:scale(.92)}.bottom-nav .nav-icon{font-size:1.4rem}.lesson-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:1rem;cursor:pointer;transition:var(--transition);position:relative;overflow:hidden}.lesson-card:active{transform:scale(.97)}.lesson-card:hover{border-color:var(--color-gold)}.lesson-card.done{border-color:var(--color-green);background:#2ea0430f}.lesson-card.in-progress{border-color:var(--color-warning);background:#e3b3410f}.lesson-card.locked{opacity:.5;cursor:default}.lesson-card.done:hover{border-color:var(--color-green-light)}.progress-ring-container{display:flex;flex-direction:column;align-items:center;justify-content:center;position:relative}.progress-ring-label{position:absolute;display:flex;flex-direction:column;align-items:center;justify-content:center}.progress-ring-label .count{font-size:2rem;font-weight:800;color:var(--color-gold)}.progress-ring-label .total{font-size:.85rem;color:var(--color-text-muted)}.stat-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:1rem 1.25rem;flex:1;min-width:0}.stat-card .stat-value{font-size:1.6rem;font-weight:800;color:var(--color-gold)}.stat-card .stat-label{font-size:.78rem;color:var(--color-text-muted);margin-top:2px}.tab-bar{display:flex;border-bottom:1px solid var(--color-border);background:var(--color-surface);position:sticky;top:0;z-index:10}.tab-btn{flex:1;padding:.9rem .5rem;background:none;border:none;border-bottom:2px solid transparent;color:var(--color-text-muted);font-size:.85rem;font-weight:600;cursor:pointer;transition:var(--transition)}.tab-btn.active{color:var(--color-gold);border-bottom-color:var(--color-gold)}.tab-btn:active{background:var(--color-surface-2)}.page-header{padding:1.25rem 1.25rem .75rem;background:var(--color-surface);border-bottom:1px solid var(--color-border)}.page-header h1{font-size:1.3rem;font-weight:700}.page-header .subtitle{font-size:.82rem;color:var(--color-text-muted);margin-top:2px}.grade-A{color:#4ade80}.grade-B{color:#60a5fa}.grade-C{color:var(--color-warning)}.grade-D{color:#fb923c}.grade-F{color:var(--color-danger)}.quiz-option{width:100%;padding:.9rem 1rem;margin-bottom:.6rem;background:var(--color-surface-2);border:1.5px solid var(--color-border);border-radius:var(--radius-md);color:var(--color-text);font-size:.95rem;text-align:left;cursor:pointer;transition:var(--transition)}.quiz-option:active{transform:scale(.98)}.quiz-option:hover:not(:disabled){border-color:var(--color-gold)}.quiz-option.correct{border-color:var(--color-green);background:#2ea04326;color:var(--color-green-light)}.quiz-option.wrong{border-color:var(--color-danger);background:#f851491f;color:var(--color-danger)}.glass-hero{background:#161b22b3;backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border:1px solid rgba(212,168,67,.3);border-radius:var(--radius-xl);padding:1.5rem;position:relative;overflow:hidden}.glass-hero:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle at 50% 50%,rgba(212,168,67,.06),transparent 60%);pointer-events:none}@keyframes pulse-gold{0%,to{box-shadow:0 0 #d4a84366}50%{box-shadow:0 0 0 8px #d4a84300}}.pulse-gold{animation:pulse-gold 2s infinite}@keyframes stagger-in{0%{opacity:0;transform:translateY(16px)}to{opacity:1;transform:translateY(0)}}.stagger-in{animation:stagger-in .4s ease-out both}.stagger-1{animation-delay:.05s}.stagger-2{animation-delay:.1s}.stagger-3{animation-delay:.15s}.stagger-4{animation-delay:.2s}.stagger-5{animation-delay:.25s}