@import "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;700&display=swap";
:root{--bg-color:#111;--card-bg:#1e1e1e;--text-main:#fff;--text-muted:#a0a0a0;--btc-orange:#f7931a;--success:#00d1b2;--line-color:#333}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-main);font-family:Inter,sans-serif;line-height:1.6}a{color:inherit;text-decoration:none}.container{max-width:800px;margin:0 auto;padding:20px}header{text-align:center;padding:60px 0}h1{margin-bottom:10px;font-size:2.5rem;font-weight:700}.subtitle{color:var(--text-muted);font-size:1.1rem}.timeline{padding:20px 0;position:relative}.timeline:before{content:"";background:var(--line-color);z-index:0;width:2px;position:absolute;top:0;bottom:0;left:20px}.level-card{background:var(--card-bg);border:1px solid #0000;border-radius:12px;margin-bottom:20px;margin-left:60px;padding:20px;transition:transform .2s,box-shadow .2s;position:relative}.level-card:hover{border-color:#333;transform:translateY(-3px);box-shadow:0 5px 15px #00000080}.level-status{background:var(--card-bg);border:2px solid var(--line-color);z-index:1;border-radius:50%;justify-content:center;align-items:center;width:40px;height:40px;font-weight:700;display:flex;position:absolute;top:50%;left:-50px;transform:translateY(-50%)}.locked{opacity:.5;pointer-events:none;filter:grayscale()}.active .level-status{border-color:var(--btc-orange);color:var(--btc-orange);box-shadow:0 0 10px #f7931a4d}.completed .level-status{background:var(--success);border-color:var(--success);color:#000}.lesson-content{background:var(--card-bg);border-radius:16px;margin-top:20px;padding:40px}.lesson-content h2{color:var(--btc-orange);margin-top:30px;margin-bottom:15px}.lesson-content p{color:#ddd;margin-bottom:20px;font-size:1.1rem}.lesson-content ul{color:#ddd;margin-bottom:20px;margin-left:20px}.lesson-content li{margin-bottom:10px}.quote{border-left:4px solid var(--btc-orange);color:var(--text-muted);margin:30px 0;padding-left:20px;font-style:italic}.btn-next{background:var(--btc-orange);color:#fff;text-align:center;cursor:pointer;border-radius:8px;width:100%;margin-top:40px;padding:15px;font-size:1.1rem;font-weight:700;transition:background .2s;display:block}.btn-next:hover{background:#d67b0e}