:root{--bg-primary: #ffffff;--bg-secondary: #f8f9fa;--bg-tertiary: #f0f1f2;--text-primary: #1a1a2e;--text-secondary: #4a4a5a;--text-muted: #8a8a9a;--accent: #6366f1;--accent-light: #818cf8;--accent-dark: #4f46e5;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .1), 0 4px 6px -4px rgb(0 0 0 / .1);--radius-sm: 8px;--radius: 12px;--radius-lg: 16px;--radius-xl: 24px;--transition: all .3s cubic-bezier(.4, 0, .2, 1)}*{margin:0;padding:0;box-sizing:border-box}html{scroll-behavior:smooth}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:var(--bg-primary);color:var(--text-primary);line-height:1.6;-webkit-font-smoothing:antialiased;min-height:100vh}.app{min-height:100vh;display:flex;flex-direction:column}.nav{position:fixed;top:0;left:0;right:0;z-index:1000;background:#ffffffe6;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-bottom:1px solid rgba(0,0,0,.05)}.nav-inner{max-width:1400px;margin:0 auto;padding:1rem 2rem;display:flex;justify-content:space-between;align-items:center}.nav-logo{font-size:1.5rem;font-weight:700;background:linear-gradient(135deg,var(--text-primary),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;letter-spacing:-.5px}.nav-links{display:flex;gap:2rem}.nav-link{color:var(--text-secondary);text-decoration:none;font-weight:500;font-size:.95rem;transition:var(--transition);cursor:pointer}.nav-link:hover{color:var(--accent)}.hero{min-height:100vh;display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center;padding:8rem 2rem 4rem;background:linear-gradient(180deg,var(--bg-secondary) 0%,var(--bg-primary) 100%)}.hero-title{font-size:clamp(3rem,6vw,5rem);font-weight:800;margin-bottom:1.5rem;letter-spacing:-.03em;color:var(--text-primary)}.hero-subtitle{font-size:clamp(1rem,1.5vw,1.25rem);color:var(--text-secondary);max-width:600px;margin-bottom:2.5rem;line-height:1.7}.hero-cta{padding:1rem 2.5rem;background:var(--text-primary);color:#fff;border:none;border-radius:50px;font-size:1rem;font-weight:600;cursor:pointer;transition:var(--transition);box-shadow:var(--shadow)}.hero-cta:hover{background:var(--accent);transform:translateY(-2px);box-shadow:var(--shadow-lg)}.section{padding:6rem 2rem;width:100%}.section-alt{background:var(--bg-secondary)}.section-inner{max-width:1200px;margin:0 auto}.section-header{text-align:center;margin-bottom:4rem}.section-title{font-size:clamp(2rem,4vw,2.5rem);font-weight:700;color:var(--text-primary);margin-bottom:.75rem}.section-desc{color:var(--text-muted);font-size:1.1rem}.content-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(350px,1fr));gap:2rem}.content-card{background:var(--bg-primary);border-radius:var(--radius-xl);padding:2rem;box-shadow:var(--shadow);transition:var(--transition)}.content-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}.card-header{display:flex;align-items:center;gap:1rem;margin-bottom:1.5rem}.card-icon{width:48px;height:48px;background:linear-gradient(135deg,var(--accent-light),var(--accent));border-radius:var(--radius);display:flex;align-items:center;justify-content:center;font-size:1.5rem}.card-title{font-size:1.25rem;font-weight:600;color:var(--text-primary)}.footer{background:var(--text-primary);color:#ffffffb3;text-align:center;padding:3rem 2rem;margin-top:auto}@media(max-width:768px){.nav-links{gap:1rem}.nav-link{font-size:.85rem}.section{padding:4rem 1.5rem}.content-grid{grid-template-columns:1fr}}.back-btn{display:inline-flex;align-items:center;gap:.5rem;padding:.75rem 1.5rem;background:var(--bg-secondary);color:var(--text-secondary);border:none;border-radius:var(--radius);font-size:.95rem;font-weight:500;cursor:pointer;transition:var(--transition);margin-bottom:2rem}.back-btn:hover{background:var(--bg-tertiary);color:var(--text-primary)}.active-app-container{width:100%;max-width:100%;margin:0;padding:0}.calculator{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:1.5rem;box-shadow:var(--shadow-lg)}.calc-display{background:var(--bg-primary);color:var(--text-primary);font-size:2.5rem;font-weight:600;padding:1.5rem;text-align:right;border-radius:var(--radius);margin-bottom:1rem;min-height:80px}.calc-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:.75rem}.calc-btn{padding:1.25rem;font-size:1.25rem;font-weight:600;border:none;border-radius:var(--radius);cursor:pointer;transition:var(--transition)}.calc-num{background:var(--bg-primary);color:var(--text-primary)}.calc-num:hover{background:var(--bg-tertiary)}.calc-op{background:var(--accent);color:#fff}.calc-op:hover{background:var(--accent-dark)}.calc-clear{background:#ef4444;color:#fff}.calc-clear:hover{background:#dc2626}.pomodoro{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:2.5rem;text-align:center;box-shadow:var(--shadow-lg)}.pomodoro-modes{display:flex;gap:1rem;justify-content:center;margin-bottom:2rem}.mode-btn{padding:.75rem 1.5rem;background:transparent;border:2px solid var(--accent);color:var(--accent);border-radius:50px;font-weight:600;cursor:pointer;transition:var(--transition)}.mode-btn.active{background:var(--accent);color:#fff}.pomodoro-timer{font-size:5rem;font-weight:700;color:var(--text-primary);margin-bottom:2rem}.pomodoro-progress{width:100%;height:8px;background:var(--bg-tertiary);border-radius:4px;overflow:hidden;margin-bottom:2rem}.pomodoro-progress-bar{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent-light));border-radius:4px;transition:width 1s ease}.pomodoro-controls{display:flex;gap:1rem;justify-content:center}.pomodoro-btn{padding:1rem 2rem;border:none;border-radius:var(--radius);font-size:1rem;font-weight:600;cursor:pointer}.pomodoro-btn.primary{background:var(--accent);color:#fff}.todo{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:2rem;box-shadow:var(--shadow-lg)}.todo-stats{text-align:center;color:var(--text-muted);margin-bottom:1.5rem}.todo-input-group{display:flex;gap:.75rem;margin-bottom:1.5rem}.todo-input{flex:1;padding:1rem;border:2px solid var(--bg-tertiary);border-radius:var(--radius);font-size:1rem}.todo-add-btn{width:50px;height:50px;background:var(--accent);color:#fff;border:none;border-radius:var(--radius);font-size:1.5rem;cursor:pointer}.todo-item{display:flex;align-items:center;gap:1rem;padding:1rem;background:var(--bg-primary);border-radius:var(--radius);margin-bottom:.75rem}.todo-item.completed .todo-text{text-decoration:line-through;color:var(--text-muted)}.todo-text{flex:1}.todo-delete{width:28px;height:28px;background:transparent;border:none;color:var(--text-muted);font-size:1.25rem;cursor:pointer}.app-card,.game-card{cursor:pointer}.app-desc,.game-desc{color:var(--text-muted);text-align:center}.active-game-container{max-width:500px;margin:0 auto}.game-2048{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:2rem;box-shadow:var(--shadow-lg)}.game-2048-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem}.game-2048-score{background:var(--bg-tertiary);border-radius:var(--radius);padding:.75rem 1.5rem;text-align:center}.score-label{font-size:.8rem;color:var(--text-muted)}.score-value{font-size:1.5rem;font-weight:700;color:var(--text-primary)}.game-2048-restart{padding:.75rem 1.5rem;background:var(--accent);color:#fff;border:none;border-radius:var(--radius);font-weight:600;cursor:pointer}.game-2048-message{text-align:center;padding:1rem;background:linear-gradient(135deg,#22c55e,#16a34a);color:#fff;border-radius:var(--radius);margin-bottom:1rem;font-weight:600}.game-2048-board{background:var(--bg-tertiary);border-radius:var(--radius-lg);padding:1rem;margin-bottom:1.5rem}.game-2048-row{display:flex;gap:.75rem;margin-bottom:.75rem}.game-2048-cell{width:75px;height:75px;display:flex;align-items:center;justify-content:center;font-size:1.5rem;font-weight:700;border-radius:var(--radius);transition:all .15s ease}.game-2048-controls{display:flex;flex-direction:column;align-items:center;gap:.5rem}.game-2048-controls button{width:60px;height:60px;background:var(--bg-tertiary);border:none;border-radius:var(--radius);font-size:1.5rem;cursor:pointer;color:var(--text-secondary)}.game-2048-controls button:hover{background:var(--accent);color:#fff}.game-2048-controls-row{display:flex;gap:.5rem}.music-player{background:var(--bg-secondary);border-radius:var(--radius-xl);padding:2.5rem;box-shadow:var(--shadow-lg);max-width:500px;margin:0 auto}.music-visualizer{display:flex;justify-content:center;align-items:flex-end;gap:4px;height:80px;margin-bottom:1.5rem}.visualizer-bar{width:8px;height:20px;background:var(--bg-tertiary);border-radius:4px;transition:height .1s ease}.visualizer-bar.active{animation:visualizer .5s ease-in-out infinite alternate}@keyframes visualizer{0%{height:20px;background:var(--accent)}to{height:60px;background:var(--accent-light)}}.frequency-display{text-align:center;font-size:2rem;font-weight:700;color:var(--text-primary);margin-bottom:1.5rem}.frequency-control{margin-bottom:1.5rem}.frequency-slider{width:100%;height:8px;appearance:none;background:var(--bg-tertiary);border-radius:4px}.frequency-slider::-webkit-slider-thumb{appearance:none;width:20px;height:20px;background:var(--accent);border-radius:50%;cursor:pointer}.music-controls{display:flex;justify-content:center;gap:1rem;margin-bottom:2rem}.music-play-btn{padding:1rem 2rem;background:var(--accent);color:#fff;border:none;border-radius:var(--radius);font-size:1rem;font-weight:600;cursor:pointer}.music-play-btn:hover{background:var(--accent-dark)}.music-play-btn.playing{background:#ef4444}.piano-keys{display:flex;justify-content:center;gap:4px}.piano-key{flex:1;height:120px;background:var(--bg-primary);border:2px solid var(--bg-tertiary);border-radius:0 0 var(--radius) var(--radius);cursor:pointer;display:flex;align-items:flex-end;justify-content:center;padding-bottom:.5rem;font-size:.8rem;color:var(--text-muted)}.piano-key:hover{background:var(--accent);color:#fff}