:root{--bg-primary: #F8F9FE;--bg-dark: #0F172A;--text-primary: #2D2D44;--text-secondary: #6B6B8A;--text-tertiary: #9999B3;--success: #A8E6A3;--success-dark: #90D08B;--error: #FFB3BA;--error-dark: #F0A0A8;--warning: #FFD9B3;--info: #B3D9FF;--card-bg: #FFFFFF;--card-border: rgba(0, 0, 0, .05);--card-shadow: 0px 4px 12px rgba(0, 0, 0, .06);--btn-primary-bg: #2D2D44;--btn-primary-text: #FFFFFF;--btn-radius: 16px;--btn-height-lg: 56px;--btn-height-md: 48px;--accent-indigo: #6366F1;--accent-purple: #A855F7;--accent-coral: #FF7F50;--accent-sky: #87CEEB;--radius-sm: 12px;--radius-md: 16px;--radius-lg: 20px;--radius-xl: 24px;--radius-2xl: 32px;--space-xs: 8px;--space-sm: 12px;--space-md: 16px;--space-lg: 24px;--space-xl: 32px}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}body{font-family:Poppins,system-ui,sans-serif;background-color:var(--bg-primary);margin:0;padding:0;overscroll-behavior:none;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;transition:background-color .3s ease;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}.font-emoji{font-family:"Apple Color Emoji","Segoe UI Emoji",Segoe UI Symbol,"Noto Color Emoji",sans-serif}.dark body{background-color:var(--bg-dark)}.hide-scrollbar::-webkit-scrollbar{display:none}.hide-scrollbar{-ms-overflow-style:none;scrollbar-width:none}.custom-scrollbar::-webkit-scrollbar{width:8px}.custom-scrollbar::-webkit-scrollbar-track{background:transparent;margin:8px 0}.custom-scrollbar::-webkit-scrollbar-thumb{background:#00000026;border-radius:100px;border:2px solid transparent;background-clip:padding-box}.custom-scrollbar::-webkit-scrollbar-thumb:hover{background:#00000040;border:2px solid transparent;background-clip:padding-box}.dark .custom-scrollbar::-webkit-scrollbar-thumb{background:#ffffff26;border:2px solid transparent;background-clip:padding-box}.dark .custom-scrollbar::-webkit-scrollbar-thumb:hover{background:#ffffff40;border:2px solid transparent;background-clip:padding-box}.custom-scrollbar{scrollbar-width:thin;scrollbar-color:rgba(0,0,0,.15) transparent}.dark .custom-scrollbar{scrollbar-color:rgba(255,255,255,.15) transparent}.glass-nav{background:#ffffffd9;backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-top:1px solid rgba(255,255,255,.4);transition:background .3s ease,border-color .3s ease}.dark .glass-nav{background:#0f172ae0;border-top:1px solid rgba(255,255,255,.08)}.glass-bar{background:#ffffffb3;backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}.dark .glass-bar{background:#0f172ab3}@keyframes subtle-pulse{0%,to{opacity:1}50%{opacity:.85}}.animate-subtle-pulse{animation:subtle-pulse 2s ease-in-out infinite}@keyframes gentle-float{0%,to{transform:translateY(0)}50%{transform:translateY(-6px)}}.animate-float{animation:gentle-float 3s ease-in-out infinite}@keyframes slow-spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.animate-slow-spin{animation:slow-spin 20s linear infinite}@keyframes gradient-shift{0%,to{background-position:0% 50%}50%{background-position:100% 50%}}.animate-gradient{background-size:200% 200%;animation:gradient-shift 4s ease infinite}.btn-primary{height:var(--btn-height-lg);background-color:var(--btn-primary-bg);color:var(--btn-primary-text);border-radius:var(--btn-radius);font-weight:700;font-size:18px;border:none;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:8px;transition:background-color .2s ease,opacity .2s ease;box-shadow:0 4px 14px #2d2d4440}.btn-primary:active{opacity:.9}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.dark .btn-primary{background-color:#e2e8f0;color:#0f172a}.btn-secondary{height:var(--btn-height-md);background-color:transparent;color:var(--text-secondary);border-radius:var(--btn-radius);font-weight:700;border:2px solid rgba(0,0,0,.08);cursor:pointer;display:flex;align-items:center;justify-content:center;gap:8px;transition:background-color .2s ease,border-color .2s ease}.btn-secondary:hover{background-color:#00000005}.dark .btn-secondary{border-color:#ffffff1a;color:#94a3b8}.dark .btn-secondary:hover{background-color:#ffffff0d}.card{background:var(--card-bg);border-radius:var(--radius-lg);border:1px solid var(--card-border);box-shadow:var(--card-shadow);transition:background-color .3s ease,border-color .3s ease}.dark .card{background:#1e293b;border-color:#ffffff14;box-shadow:0 4px 12px #0000004d}.option-btn{height:56px;border-radius:var(--radius-md);border:2px solid transparent;background:var(--card-bg);color:var(--text-primary);font-weight:600;font-size:15px;padding:0 12px;text-align:center;cursor:pointer;transition:background-color .2s ease,border-color .2s ease,opacity .2s ease;box-shadow:0 2px 8px #0000000a}.option-btn:hover{background-color:#f1f5f9}.dark .option-btn{background:#1e293b;color:#e2e8f0;box-shadow:0 2px 8px #0003}.dark .option-btn:hover{background-color:#334155}.option-btn.correct{background-color:var(--success);border-color:var(--success-dark);color:#166534}.option-btn.wrong{background-color:var(--error);border-color:var(--error-dark);color:#991b1b}.option-btn.disabled{opacity:.4;cursor:default;pointer-events:none}.toast-success{background-color:var(--success);color:#166534}.toast-error{background-color:var(--error);color:#991b1b}.progress-bar{height:4px;background:#00000014;overflow:hidden}.dark .progress-bar{background:#ffffff1a}.progress-fill{height:100%;background:var(--accent-sky);transition:width .4s ease}.pb-safe{padding-bottom:env(safe-area-inset-bottom,0)}.pt-safe{padding-top:env(safe-area-inset-top,0)}