*{margin:0;padding:0;box-sizing:border-box}:root{--primary: #2563eb;--primary-dark: #1d4ed8;--success: #22c55e;--success-light: #dcfce7;--error: #ef4444;--error-light: #fee2e2;--gray-50: #f9fafb;--gray-100: #f3f4f6;--gray-200: #e5e7eb;--gray-300: #d1d5db;--gray-600: #4b5563;--gray-700: #374151;--gray-800: #1f2937;--gray-900: #111827}body{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;background:linear-gradient(135deg,#84fab0,#8fd3f4);min-height:100vh;color:var(--gray-800)}.app{max-width:900px;margin:0 auto;padding:80px 20px 20px;min-height:100vh}.header{text-align:center;color:#fff;margin-bottom:30px}.header h1{font-size:2.5rem;margin-bottom:10px;text-shadow:2px 2px 4px rgba(0,0,0,.2)}.header p{font-size:1.1rem;opacity:.9}.streak-display{background:#fff;border-radius:12px;padding:15px 25px;display:flex;align-items:center;justify-content:center;gap:10px;box-shadow:0 4px 15px #0000001a;margin-bottom:20px}.streak-display .label{font-size:1rem;color:var(--gray-600)}.streak-display .value{font-size:2rem;font-weight:700;color:var(--primary)}.file-selector{background:#fff;border-radius:12px;padding:20px;margin-bottom:20px;box-shadow:0 4px 15px #0000001a}.file-selector h3{margin-bottom:15px;color:var(--gray-700)}.file-buttons{display:flex;flex-wrap:wrap;gap:10px}.file-btn{padding:8px 16px;border:2px solid var(--gray-200);border-radius:8px;background:#fff;cursor:pointer;font-size:.95rem;transition:all .2s}.file-btn:hover{border-color:var(--primary);color:var(--primary)}.file-btn.selected{background:var(--primary);border-color:var(--primary);color:#fff}.file-btn.all-btn{background:var(--gray-100);font-weight:600}.file-btn.all-btn.selected{background:var(--primary);color:#fff}.quiz-card{background:#fff;border-radius:16px;padding:30px;box-shadow:0 10px 40px #00000026;margin-bottom:20px}.question-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;padding-bottom:15px;border-bottom:2px solid var(--gray-100)}.question-number{font-size:.9rem;color:var(--gray-600);background:var(--gray-100);padding:5px 12px;border-radius:20px}.source-file{font-size:.85rem;color:var(--gray-600)}.question-text{font-size:1.3rem;line-height:1.6;color:var(--gray-900);margin-bottom:25px}.answers{display:flex;flex-direction:column;gap:12px}.answer-btn{display:flex;align-items:flex-start;gap:15px;padding:18px 20px;border:2px solid var(--gray-200);border-radius:12px;background:#fff;cursor:pointer;text-align:left;font-size:1.05rem;transition:all .2s}.answer-btn:hover:not(:disabled){border-color:var(--primary);background:var(--gray-50)}.answer-btn:disabled{cursor:default}.answer-btn .letter{font-weight:700;color:var(--gray-600);min-width:30px}.answer-btn .text{flex:1;color:var(--gray-800)}.answer-btn.correct{border-color:var(--success);background:var(--success-light)}.answer-btn.correct .letter,.answer-btn.correct .text{color:#166534}.answer-btn.incorrect{border-color:var(--error);background:var(--error-light)}.answer-btn.incorrect .letter,.answer-btn.incorrect .text{color:#991b1b}.next-btn{width:100%;padding:15px;margin-top:20px;background:var(--primary);color:#fff;border:none;border-radius:10px;font-size:1.1rem;font-weight:600;cursor:pointer;transition:background .2s}.next-btn:hover{background:var(--primary-dark)}.action-buttons{display:flex;justify-content:center;gap:15px;margin-top:20px}.report-btn,.leaderboard-btn,.contact-btn{padding:10px 20px;border:none;border-radius:8px;font-size:.9rem;cursor:pointer;transition:all .2s;text-decoration:none;display:inline-block}.contact-btn{background:#e0f2fe;color:#0369a1}.contact-btn:hover{background:#bae6fd}.report-btn{background:var(--gray-200);color:var(--gray-700)}.report-btn:hover{background:var(--gray-300)}.leaderboard-btn{background:#fbbf24;color:#78350f}.leaderboard-btn:hover{background:#f59e0b}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:#00000080;display:flex;align-items:center;justify-content:center;z-index:1000}.modal{background:#fff;border-radius:16px;padding:30px;max-width:500px;width:90%;max-height:80vh;overflow-y:auto}.modal h2{margin-bottom:20px;color:var(--gray-800)}.modal p{margin-bottom:15px;line-height:1.6;color:var(--gray-700)}.modal input{width:100%;padding:12px 15px;border:2px solid var(--gray-200);border-radius:8px;font-size:1rem;margin-bottom:15px}.modal input:focus{outline:none;border-color:var(--primary)}.modal-buttons{display:flex;gap:10px;justify-content:flex-end}.modal-btn{padding:10px 20px;border:none;border-radius:8px;font-size:1rem;cursor:pointer}.modal-btn.primary{background:var(--primary);color:#fff}.modal-btn.secondary{background:var(--gray-200);color:var(--gray-700)}.contact-email{text-align:center;font-size:1.2rem;margin:20px 0}.contact-email a{color:var(--primary);text-decoration:none;font-weight:600}.contact-email a:hover{text-decoration:underline}.leaderboard-list{list-style:none}.leaderboard-item{display:flex;align-items:center;padding:12px 0;border-bottom:1px solid var(--gray-100)}.leaderboard-item:last-child{border-bottom:none}.leaderboard-rank{width:40px;font-weight:700;color:var(--gray-600)}.leaderboard-rank.gold{color:#ca8a04}.leaderboard-rank.silver{color:#6b7280}.leaderboard-rank.bronze{color:#b45309}.leaderboard-name{flex:1;color:var(--gray-800)}.leaderboard-score{font-weight:700;color:var(--primary)}.loading{text-align:center;padding:40px;color:#fff;font-size:1.2rem}.no-questions{text-align:center;padding:40px;background:#fff;border-radius:16px;color:var(--gray-600)}.welcome-card{background:#fff;border-radius:16px;padding:30px;box-shadow:0 10px 40px #00000026;text-align:center}.welcome-image{max-width:500px;width:100%;height:auto;margin-bottom:25px;border-radius:12px}.welcome-text{text-align:left;margin-bottom:25px}.welcome-text p{margin-bottom:15px;line-height:1.7;color:var(--gray-700)}.welcome-text .warning{background:#fef3c7;border-left:4px solid #f59e0b;padding:15px;border-radius:0 8px 8px 0;color:#92400e;font-size:1.1rem}.welcome-text .disclaimer{background:var(--gray-100);border-left:4px solid var(--gray-400);padding:15px;border-radius:0 8px 8px 0;color:var(--gray-600);font-size:1rem}.welcome-text .center-text{text-align:center;font-size:1rem}.welcome-text .contact{text-align:center;font-size:1rem;margin-top:20px}.welcome-text a{color:var(--primary);text-decoration:none;font-weight:500}.welcome-text a:hover{text-decoration:underline}.start-btn{padding:15px 40px;background:var(--primary);color:#fff;border:none;border-radius:10px;font-size:1.2rem;font-weight:600;cursor:pointer;transition:background .2s}.start-btn:hover{background:var(--primary-dark)}@media (max-width: 600px){.header h1{font-size:1.8rem}.quiz-card{padding:20px}.question-text{font-size:1.1rem}.answer-btn{padding:15px;font-size:1rem}.welcome-card{padding:20px}.welcome-image{max-width:150px}}.top-bar{position:fixed;top:0;left:0;right:0;height:60px;background:#fffffff2;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:0 2px 10px #0000001a;display:flex;align-items:center;justify-content:flex-end;padding:0 20px;z-index:1000}.hamburger{width:45px;height:45px;background:transparent;border:none;cursor:pointer;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:5px;transition:all .3s}.hamburger:hover{transform:scale(1.05)}.hamburger-line{width:24px;height:3px;background:var(--gray-700);border-radius:2px;transition:all .3s}.hamburger.open .hamburger-line:nth-child(1){transform:rotate(45deg) translate(5px,6px)}.hamburger.open .hamburger-line:nth-child(2){opacity:0}.hamburger.open .hamburger-line:nth-child(3){transform:rotate(-45deg) translate(5px,-6px)}.nav-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:#00000080;opacity:0;visibility:hidden;transition:all .3s;z-index:1001}.nav-overlay.visible{opacity:1;visibility:visible}.nav-panel{position:fixed;top:0;right:0;bottom:0;width:280px;max-width:80vw;background:#fff;box-shadow:-5px 0 30px #0003;transform:translate(100%);transition:transform .3s ease-out;z-index:1002;display:flex;flex-direction:column}.nav-panel.open{transform:translate(0)}.nav-panel-header{display:flex;justify-content:space-between;align-items:center;padding:20px;border-bottom:1px solid var(--gray-100)}.nav-panel-header h2{margin:0;font-size:1.3rem;color:var(--gray-800)}.nav-close{width:40px;height:40px;background:none;border:none;font-size:2rem;color:var(--gray-500);cursor:pointer;display:flex;align-items:center;justify-content:center;transition:color .2s}.nav-close:hover{color:var(--gray-800)}.nav-items{flex:1;padding:10px 0}.nav-item{display:block;width:100%;padding:18px 25px;border:none;background:none;text-align:left;font-size:1.1rem;color:var(--gray-700);cursor:pointer;transition:all .2s}.nav-item:hover{background:var(--gray-50);color:var(--primary);padding-left:30px}.nav-item.active{background:linear-gradient(90deg,var(--primary) 0%,#3b82f6 100%);color:#fff}.nav-item.active:hover{padding-left:30px}.summaries-page{max-width:900px;margin:0 auto;padding:80px 20px 20px;min-height:100vh}.summaries-page .header{margin-bottom:20px}.summaries-page .subtitle{color:#ffffffe6;font-size:1.1rem;margin-top:5px}.expand-controls{display:flex;gap:10px;margin-bottom:20px;justify-content:center}.expand-btn{padding:10px 20px;background:#fff;border:2px solid var(--gray-200);border-radius:8px;font-size:.95rem;cursor:pointer;transition:all .2s;color:var(--gray-700)}.expand-btn:hover{border-color:var(--primary);color:var(--primary)}.topics-container{display:flex;flex-direction:column;gap:10px}.topic-card{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 4px 15px #0000001a;margin-bottom:10px}.topic-header.level1{width:100%;padding:18px 20px;border:none;background:var(--primary);display:flex;justify-content:space-between;align-items:center;cursor:pointer;text-align:left;transition:all .2s}.topic-header.level1:hover{background:var(--primary-dark)}.topic-header.level1 .topic-title{font-size:1.2rem;font-weight:700;color:#fff}.topic-header.level1 .topic-icon{font-size:1.5rem;font-weight:300;color:#fffc}.topic-header.level1.open .topic-icon{color:#fff}.topic-content{padding:0}.level2-item{border-bottom:1px solid var(--gray-100)}.level2-item:last-child{border-bottom:none}.level2-header{width:100%;padding:16px 20px;border:none;background:none;display:flex;justify-content:space-between;align-items:flex-start;gap:15px;cursor:pointer;text-align:left;transition:all .2s}.level2-header:hover{background:#f0fdf4}.level2-title{flex:1;font-size:1rem;font-weight:600;color:#16a34a;line-height:1.5}.level2-icon{font-size:1.3rem;font-weight:300;color:#86efac;flex-shrink:0}.level2-header.open .level2-icon{color:#16a34a}.level2-content{padding:0 20px 20px;background:#fafafa}.level3-item{padding:15px 0;border-bottom:1px solid var(--gray-200)}.level3-item:last-child{border-bottom:none;padding-bottom:0}.level3-title{font-size:.95rem;font-weight:600;color:var(--gray-800);margin:0 0 8px}.level3-content{font-size:.9rem;line-height:1.7;color:var(--gray-700);margin:0}.error-message{text-align:center;padding:40px;background:var(--error-light);border-radius:16px;color:var(--error);font-size:1.1rem}.back-btn{display:block;margin:20px auto;padding:12px 30px;background:var(--primary);color:#fff;border:none;border-radius:8px;font-size:1rem;cursor:pointer;transition:background .2s}.back-btn:hover{background:var(--primary-dark)}@media (max-width: 600px){.app{padding-top:70px}.top-bar{height:50px;padding:0 15px}.hamburger{width:40px;height:40px}.nav-panel{width:100%;max-width:100%}.summaries-page{padding:70px 15px 15px}.topic-header{font-size:1rem;padding:15px}.section-title{font-size:.95rem}.expand-controls{flex-direction:column}.expand-btn{width:100%}}.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}.login-card{background:#fff;border-radius:16px;padding:40px;width:100%;max-width:400px;box-shadow:0 10px 40px #00000026}.login-card h1{text-align:center;color:var(--gray-800);margin-bottom:10px}.login-subtitle{text-align:center;color:var(--gray-600);margin-bottom:30px;font-size:.95rem}.form-group{margin-bottom:20px}.form-group label{display:block;margin-bottom:8px;color:var(--gray-700);font-weight:500}.form-group input{width:100%;padding:12px 15px;border:2px solid var(--gray-200);border-radius:8px;font-size:1rem;transition:border-color .2s}.form-group input:focus{outline:none;border-color:var(--primary)}.login-error{background:var(--error-light);color:var(--error);padding:12px 15px;border-radius:8px;margin-bottom:20px;font-size:.95rem;text-align:center}.login-btn{width:100%;padding:15px;background:var(--primary);color:#fff;border:none;border-radius:10px;font-size:1.1rem;font-weight:600;cursor:pointer;transition:background .2s}.login-btn:hover:not(:disabled){background:var(--primary-dark)}.login-btn:disabled{opacity:.7;cursor:not-allowed}.nav-logout{margin-top:auto;border-top:1px solid var(--gray-200);color:var(--error)!important}.nav-logout:hover{background:var(--error-light)!important;color:var(--error)!important}