.navbar{position:fixed;top:0;left:0;z-index:1000;background:#000;padding:.75rem 1rem;box-sizing:border-box;border-bottom-right-radius:0}.navbar,.navbar-link{display:flex;align-items:center}.navbar-link{gap:.5rem;text-decoration:none;color:#fff;transition:opacity .2s}.navbar-link:hover{opacity:.8}.navbar-logo{flex-shrink:0;display:block;width:20px;height:20px}.navbar-text{font-size:1rem;font-weight:600;color:#fff;white-space:nowrap}@media (max-width:768px){.navbar{padding:.6rem .8rem}.navbar-text{font-size:.9rem}.navbar-logo{width:18px;height:18px}}.about-page{min-height:100vh;display:flex;flex-direction:column;background-color:#fff;font-family:Georgia,Times New Roman,Times,serif}.about-header{background:#fff;border-bottom:2px double #000;padding:1.5rem 2rem}.header-content{max-width:900px;margin:0 auto;display:flex;align-items:center;gap:2rem}.back-link{color:#000;text-decoration:none;font-size:.95rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;border:2px solid #000;padding:.5rem 1rem;transition:background-color .2s}.back-link:hover{background-color:#000;color:#fff}.about-header h1{margin:0;font-size:2.5rem;font-weight:700;letter-spacing:.02em}.about-content{flex:1 1;max-width:900px;margin:0 auto;padding:3rem 2rem}.about-content section{margin-bottom:3rem;padding-bottom:2rem;border-bottom:1px solid #d4d4d4}.about-content section:last-child{border-bottom:none}.about-content h2{font-size:2rem;margin:0 0 1rem;text-transform:uppercase;border-bottom:3px solid #000;padding-bottom:.5rem}.about-content h2,.about-content h3{font-weight:700;letter-spacing:.02em}.about-content h3{font-size:1.4rem;margin:1.5rem 0 1rem}.about-content p{font-size:1.1rem;line-height:1.8;color:#333;margin:1rem 0}.about-content ol,.about-content ul{font-size:1.05rem;line-height:1.8;color:#333;padding-left:2rem}.about-content li{margin:.75rem 0}.about-content strong{font-weight:700;color:#000}.steps-explanation{background-color:#fafafa;padding:1.5rem;border:2px solid #d4d4d4;margin-top:1.5rem}.steps-explanation ol{margin:1rem 0 0}.demo-section{background-color:#f8f8f8;padding:2rem;border:3px solid #000;margin:2rem 0}.demo-container{margin-top:2rem}.demo-board{display:inline-block;border:2px solid #d0d0d0;background-color:#f5f5f5;padding:8px;gap:1px;margin-bottom:2rem;position:relative}.demo-row{display:flex;gap:1px}.demo-cell{width:70px;height:70px;background-color:#e8e8e8;display:flex;align-items:center;justify-content:center;position:relative;transition:all .3s ease}.demo-cell.filled{background-color:#fff}.demo-cell.domino-left{background-color:#fff;border:2px solid #000;border-right:none;position:relative;z-index:2}.demo-cell.domino-left:after{content:"";position:absolute;top:20%;right:0;bottom:20%;width:1.5px;background-color:#999}.demo-cell.domino-right{border:2px solid #000;border-left:none}.demo-cell.domino-right,.demo-cell.domino-top{background-color:#fff;position:relative;z-index:2}.demo-cell.domino-top{border:2px solid #000;border-bottom:none}.demo-cell.domino-top:after{content:"";position:absolute;left:20%;right:20%;bottom:0;height:1.5px;background-color:#999}.demo-cell.domino-bottom{background-color:#fff;border:2px solid #000;border-top:none;position:relative;z-index:2}.demo-cell.highlight{box-shadow:inset 0 0 0 3px rgba(255,215,0,.6)}.demo-cell.highlight.error{box-shadow:inset 0 0 0 3px rgba(204,0,0,.6);animation:shake .5s}.demo-cell.highlight.backtrack{box-shadow:inset 0 0 0 3px rgba(255,136,0,.6)}@keyframes shake{0%,to{transform:translateX(0)}25%{transform:translateX(-5px)}75%{transform:translateX(5px)}}.demo-pip{width:8px;height:8px;position:absolute;border-radius:50%;background-color:#333;z-index:3}.demo-region-symbol{position:absolute;width:20px;height:20px;transform:rotate(45deg);display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:700;color:#fff;z-index:10;border-radius:3px;pointer-events:none}.demo-region-symbol span{transform:rotate(-45deg);line-height:1}.demo-dominoes{margin-top:1.5rem;padding-top:1rem;border-top:2px solid #d0d0d0;text-align:center}.demo-dominoes-label{font-size:.95rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;margin-bottom:.75rem;color:#333}.demo-domino-slots{display:flex;gap:12px;justify-content:center;align-items:center}.demo-unused-domino{display:flex;background-color:#fff;border:2px solid #000;height:35px;width:70px;transition:all .15s ease;position:relative}.demo-unused-domino.domino-used{background-color:#e8e8e8;border:1px dashed #999}.demo-unused-half{flex:1 1;position:relative;border-radius:0}.demo-unused-half:first-child{border-right:none;position:relative}.demo-unused-half:first-child:after{content:"";position:absolute;top:20%;right:0;bottom:20%;width:1.5px;background-color:#999}.domino-hole-content{width:100%;height:100%;display:flex;align-items:center;justify-content:center}.demo-info{margin:1.5rem 0;padding:1.5rem;background-color:#fff;border:2px solid #000}.demo-info h3{margin:0 0 .75rem;font-size:1.3rem;text-transform:uppercase}.step-description{font-size:1.1rem;margin:.5rem 0;color:#333}.step-message{font-style:italic;margin:1rem 0 0;padding:1rem;background-color:#f0f0f0;border-left:4px solid #000;font-size:1rem}.step-message.error{background-color:#ffebeb;border-left-color:#c00;color:#c00}.step-message.backtrack{background-color:#fff5e6;border-left-color:#f80;color:#c60}.demo-controls{display:flex;gap:1rem;justify-content:center;margin-top:1.5rem}.demo-button{padding:.75rem 1.5rem;border:2px solid #000;background-color:#fff;color:#000;font-size:.95rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;cursor:pointer;font-family:Georgia,Times New Roman,Times,serif;transition:all .2s}.demo-button:hover:not(:disabled){background-color:#f0f0f0}.demo-button.primary{background-color:#000;color:#fff}.demo-button.primary:hover:not(:disabled){background-color:#333}.demo-button:disabled{opacity:.5;cursor:not-allowed}.complexity-section p,.optimizations-section ul{font-size:1.05rem}.cta-section{text-align:center;padding:2rem;background-color:#000;color:#fff;border:none}.cta-section h2{color:#fff;border-bottom-color:#fff}.cta-section p{color:#fff;font-size:1.2rem}.cta-button{display:inline-block;margin-top:1.5rem;padding:1rem 2rem;background-color:#fff;color:#000;text-decoration:none;font-weight:700;font-size:1.1rem;text-transform:uppercase;letter-spacing:.05em;border:3px solid #fff;transition:all .2s}.cta-button:hover{background-color:#000;color:#fff}.about-footer{background:#fafafa;padding:1.5rem;text-align:center;border-top:1px solid #d4d4d4}.about-footer p{margin:.25rem 0;color:#666;font-size:.9rem;font-style:italic}.about-footer p.credit{margin-top:.5rem;font-size:.85rem}.about-footer a{color:#000;text-decoration:underline;font-weight:600}.about-footer a:hover{color:#333}@media (max-width:768px){.about-header h1{font-size:1.8rem}.header-content{flex-direction:column;align-items:flex-start;gap:1rem}.about-content{padding:2rem 1rem}.about-content h2{font-size:1.5rem}.demo-cell{width:50px;height:50px}.demo-pip{width:6px;height:6px}.demo-region-symbol{width:16px;height:16px;font-size:11px}.demo-domino-slots{flex-wrap:wrap;gap:8px}.demo-unused-domino{width:60px;height:30px}.demo-dominoes-label{font-size:.85rem}.demo-controls{flex-direction:column}.demo-button{width:100%}}