*,*:before,*:after{box-sizing:border-box}:root{--bg: #121212;--card: #1e1e1e;--muted: #bfc4c8;--accent: #06bb97;--accent-2: #00ffcc;--danger: #ff5252;--success: #4caf50;--btn-bg: #333;--btn-hover: #444}body{background-color:var(--bg);color:#fff;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;margin:0;padding:0;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;min-height:100vh}.start-hero{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:28px;background:linear-gradient(180deg,#0f0f0f 0%,#121212 100%)}.start-card{background:linear-gradient(180deg,rgba(255,255,255,.02),rgba(255,255,255,.01));border:1px solid rgba(255,255,255,.04);padding:32px;border-radius:14px;width:100%;max-width:720px;text-align:center;box-shadow:0 10px 30px #0009}.start-title{margin:0 0 10px;font-size:2.1rem;line-height:1.02;color:var(--accent-2, #00ffcc);font-weight:700}.start-subtitle{color:var(--muted, #bfc4c8);font-size:1rem;max-width:64ch;margin:0 auto 20px}.start-actions{display:flex;gap:16px;justify-content:center;margin-top:8px;margin-bottom:8px}.start-link,.learn-link{text-decoration:none}.start-button{background-color:var(--accent, #06bb97);color:#061715;padding:12px 22px;border:none;border-radius:10px;font-size:1rem;font-weight:700;cursor:pointer;box-shadow:0 6px 18px #06bb971f;transition:transform .12s ease,background .12s ease;min-width:160px}.learn-button{background:transparent;color:var(--muted, #bfc4c8);border:1px solid rgba(255,255,255,.06);padding:12px 18px;border-radius:10px;cursor:pointer;min-width:120px}.start-button:hover{transform:translateY(-3px);background-color:#05a67e}.learn-button:hover{background:rgba(255,255,255,.02);transform:translateY(-2px)}.small-note{margin-top:12px;font-size:.9rem;color:#9aa3a6}@media (max-width: 1024px){.start-card{padding:26px;max-width:640px}.start-title{font-size:1.9rem}.start-subtitle{font-size:.98rem}.start-actions{gap:12px}.start-button{min-width:140px}}@media (max-width: 600px){.start-card{padding:20px;border-radius:12px;width:100%}.start-title{font-size:1.5rem}.start-subtitle{font-size:.95rem;padding:0 6px}.start-actions{flex-direction:column;gap:12px;align-items:stretch}.start-button,.learn-button{width:100%;min-width:unset;padding:14px;font-size:1rem}.small-note{font-size:.88rem;margin-top:14px}}.start-button:focus-visible,.learn-button:focus-visible{outline:3px solid rgba(0,255,204,.12);outline-offset:3px}.about-container{max-width:800px;margin:0 auto;padding:2rem;text-align:center}.about-title{font-size:2rem;margin-bottom:1.5rem;color:#0fc}.about-text{font-size:1.2rem;margin-bottom:1.5rem;line-height:1.6;color:#fff}.about-card{background:#f9f9f9;color:#000;border-radius:12px;padding:1.5rem;margin:1.5rem 0;box-shadow:0 4px 12px #0000001a}.about-card h2{margin-bottom:1rem;font-size:1.5rem}.about-card ul{list-style:none;padding:0;margin:0;text-align:center}.about-card li{margin:.5rem 0;font-size:1rem}.about-button{background-color:#0fc;color:#fff;border:none;padding:12px 24px;border-radius:8px;margin-right:30px;font-size:1.2rem;cursor:pointer;transition:.3s}.about-button:hover{background-color:#1b5e20;transform:scale(1.05)}@media (max-width: 600px){.about-title{font-size:1.5rem}.about-text{font-size:1rem}.about-card h2{font-size:1.2rem}}.quiz-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;padding:28px;gap:18px}.quiz-title{font-size:2.25rem;margin:0;color:var(--accent-2);text-align:center;line-height:1.05}.score{font-size:1.2rem;font-weight:600;color:gold;margin:0}.question-box{background-color:var(--card);padding:28px;border-radius:12px;width:100%;max-width:720px;text-align:center;box-shadow:0 6px 20px #0009}.question{font-size:1.5rem;margin:0 0 18px;color:#fff}.timer{font-size:1.05rem;font-weight:600;color:var(--danger);text-align:center;margin:6px 0 14px;background:rgba(255,82,82,.06);display:inline-block;padding:6px 10px;border-radius:8px}.options{display:flex;flex-direction:column;gap:14px;margin-top:6px}.option-btn{display:flex;align-items:center;justify-content:center;background-color:#2a2a2a;border:1px solid #3a3a3a;color:#fff;padding:14px 16px;border-radius:10px;font-size:1rem;cursor:pointer;transition:transform .12s ease,background .12s ease;width:100%;text-align:center}.option-btn:hover,.option-btn:focus{transform:translateY(-2px);background-color:#353535;outline:none}.option-btn.correct{background-color:var(--success);color:#081710;border-color:#0003}.option-btn.wrong{background-color:var(--danger);color:#fff;border-color:#0003}.correct{color:var(--success);font-weight:700;margin-top:10px;text-align:center}.wrong{color:var(--danger);font-weight:700;margin-top:10px;text-align:center}.nav-buttons{display:flex;justify-content:center;gap:20px;margin-top:18px;width:100%;max-width:720px}.nav-btn{padding:12px 18px;border:none;background-color:var(--accent);color:#fff;font-size:1rem;border-radius:10px;cursor:pointer;min-width:160px;transition:background .15s ease,transform .12s}.nav-btn:hover:not(:disabled){background-color:#049f7f;transform:translateY(-2px)}.nav-btn:disabled{opacity:.45;cursor:not-allowed;transform:none}.score-card{background:#181818;padding:28px;border-radius:12px;box-shadow:0 6px 18px #0009;text-align:center;width:100%;max-width:560px}.final-score{font-size:1.4rem;margin:12px 0;color:var(--success)}.res-btn{padding:12px 18px;border:none;background-color:var(--accent);color:#fff;font-size:1rem;border-radius:10px;cursor:pointer;margin-top:14px}button:disabled{opacity:.6}@media (max-width: 1024px){.quiz-title{font-size:2rem}.question{font-size:1.35rem}.question-box{padding:22px;max-width:680px}.option-btn{padding:13px 14px;font-size:1rem}.nav-btn{min-width:140px;padding:11px 14px}}@media (max-width: 600px){.quiz-container{padding:18px;min-height:100vh;justify-content:flex-start;gap:12px}.quiz-title{font-size:1.6rem;margin-top:18px}.score{font-size:1.05rem}.question-box{padding:16px;max-width:100%;border-radius:10px}.question{font-size:1.1rem;margin-bottom:12px}.timer{font-size:1rem;padding:6px 8px}.options{gap:12px}.option-btn{padding:12px;font-size:.98rem;border-radius:10px}.nav-buttons{gap:12px;flex-direction:column;align-items:stretch;width:100%;max-width:100%;margin-top:14px}.nav-btn,.res-btn{width:100%;min-width:0;padding:12px;font-size:1rem}.score-card{padding:18px}.final-score{font-size:1.15rem}}@media (max-width: 380px){.quiz-title{font-size:1.45rem}.question{font-size:1rem}.option-btn{padding:11px;font-size:.95rem}.timer{font-size:.98rem}}.option-btn:focus-visible,.nav-btn:focus-visible,.res-btn:focus-visible{outline:3px solid rgba(0,255,204,.12);outline-offset:3px}.footer{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:20px;background:var(--bg);color:var(--muted);gap:10px}.footer-links a{font-size:2rem;color:#fff;transition:color .2s ease}.footer-links a:hover{color:var(--accent-2)}@media (min-width: 600px){.footer{flex-direction:row;justify-content:space-between;padding:20px 40px;text-align:left}}