*{margin:0;padding:0;box-sizing:border-box}body{font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;min-height:100vh;padding:20px}.container{border-radius:20px;box-shadow:0 20px 40px rgba(0,0,0,0.1);padding:40px;max-width:600px;width:100%;text-align:center;margin:0 auto}@media (min-width: 1200px){.container{max-width:1000px;padding:50px}}@media (min-width: 1400px){.container{max-width:1200px;padding:60px}}@media (min-width: 1600px){.container{max-width:1400px;padding:70px}}@media (min-width: 1920px){.container{max-width:1600px;padding:80px}}.btn{background:linear-gradient(45deg, #667eea, #764ba2);color:white;border:none;padding:15px 30px;border-radius:25px;cursor:pointer;text-decoration:none;font-size:1rem;font-weight:500;transition:all 0.3s ease;display:inline-block}.btn:hover{box-shadow:0 10px 20px rgba(102,126,234,0.3)}.btn-secondary{background:#6c757d}.btn-secondary:hover{background:#5a6268}.alert{background:#f8d7da;color:#721c24;padding:15px;border-radius:10px;margin-bottom:20px;border:1px solid #f5c6cb}@media (max-width: 768px){.container{padding:20px}}body{display:flex;align-items:center;justify-content:center;min-height:100vh;background:linear-gradient(135deg, #667eea 0%, #764ba2 100%)}.container{max-width:1200px;width:100%;padding:2rem;background:white;border-radius:20px;box-shadow:0 20px 40px rgba(0,0,0,0.1);margin:2rem auto}.logo{font-size:3rem;font-weight:bold;background:linear-gradient(45deg, #667eea, #764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-bottom:20px;text-align:center}.title{font-size:2.5rem;color:#333;margin-bottom:20px;font-weight:300;text-align:center}.subtitle{font-size:1.2rem;color:#666;margin-bottom:40px;line-height:1.6;text-align:center}.info-sections{display:flex;flex-direction:column;gap:2rem}.info-section{background:#f8f9fa;border-radius:15px;padding:2rem;border-left:5px solid #667eea}.info-section h2{color:#333;margin-bottom:1.5rem;font-size:1.5rem;display:flex;align-items:center;gap:0.5rem}.info-content{line-height:1.6;color:#555}.mode-selection{display:grid;grid-template-columns:1fr 1fr;gap:2rem;margin:3rem 0;max-width:100%;margin-left:auto;margin-right:auto}@media (max-width: 768px){.mode-selection{grid-template-columns:1fr;gap:1.5rem}}.mode-option{background:linear-gradient(135deg, #667eea 0%, #764ba2 100%);border-radius:20px;padding:2.5rem;text-align:center;cursor:pointer;transition:all 0.3s ease;position:relative;overflow:hidden;box-shadow:0 10px 30px rgba(102,126,234,0.3)}.mode-option::before{content:'';position:absolute;top:0;left:0;right:0;bottom:0;background:linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);opacity:0;transition:opacity 0.3s ease}.mode-option:hover{transform:translateY(-10px) scale(1.02);box-shadow:0 20px 40px rgba(102,126,234,0.4)}.mode-option:hover::before{opacity:1}.mode-option:hover .mode-button{background:rgba(255,255,255,0.2);transform:scale(1.05)}.mode-option.game-master-option{background:linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);box-shadow:0 10px 30px rgba(255,107,107,0.3)}.mode-option.game-master-option:hover{box-shadow:0 20px 40px rgba(255,107,107,0.4)}.mode-icon{font-size:4rem;margin-bottom:1.5rem;display:block;filter:drop-shadow(0 4px 8px rgba(0,0,0,0.2))}.mode-option h2{color:white;font-size:2rem;margin-bottom:1rem;font-weight:700;text-shadow:0 2px 4px rgba(0,0,0,0.3)}.mode-description{color:rgba(255,255,255,0.9);font-size:1.1rem;margin-bottom:2rem;line-height:1.6;text-shadow:0 1px 2px rgba(0,0,0,0.3)}.mode-features{margin-bottom:2rem;text-align:left}.feature-item{color:rgba(255,255,255,0.9);font-size:1rem;margin-bottom:0.8rem;padding-left:1rem;position:relative;text-shadow:0 1px 2px rgba(0,0,0,0.3)}.feature-item::before{content:'';position:absolute;left:0;top:50%;transform:translateY(-50%);width:6px;height:6px;background:rgba(255,255,255,0.8);border-radius:50%}.mode-button{background:rgba(255,255,255,0.15);color:white;padding:1rem 2rem;border-radius:50px;font-size:1.1rem;font-weight:600;border:2px solid rgba(255,255,255,0.3);transition:all 0.3s ease;text-shadow:0 1px 2px rgba(0,0,0,0.3);backdrop-filter:blur(10px)}.back-section{text-align:center;margin-top:3rem}.back-button{display:inline-block;padding:1rem 2rem;background:linear-gradient(135deg, #6c757d 0%, #495057 100%);color:white;text-decoration:none;border-radius:50px;font-size:1.1rem;font-weight:600;transition:all 0.3s ease;box-shadow:0 5px 15px rgba(108,117,125,0.3)}.back-button:hover{transform:translateY(-2px);box-shadow:0 8px 25px rgba(108,117,125,0.4);color:white;text-decoration:none}@media (max-width: 768px){.container{margin:1rem auto;padding:1.5rem}.title{font-size:2rem}.subtitle{font-size:1rem}.info-section{padding:1.5rem}.mode-option{padding:2rem 1.5rem}.mode-icon{font-size:3rem}.mode-option h2{font-size:1.5rem}.mode-description{font-size:1rem}.mode-button{padding:0.8rem 1.5rem;font-size:1rem}}@keyframes fadeInUp{from{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.mode-option{animation:fadeInUp 0.6s ease forwards}