:root{--bg:#0e1116;--bg2:#161b23;--card:#1a212b;--card2:#202936;--line:#2a3442;--text:#e7ecf3;--muted:#8b97a8;--accent:#5b8cff;--accent-soft:rgba(91,140,255,0.16);--good:#37c99a;--good-soft:rgba(55,201,154,0.16);--warn:#f0b14d;--warn-soft:rgba(240,177,77,0.16);--bad:#f0656b;--radius:14px;--touch:48px;--font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:var(--font);-webkit-font-smoothing:antialiased;text-size-adjust:100%;-webkit-text-size-adjust:100%}body{background:radial-gradient(1000px 500px at 50% -10%,rgba(91,140,255,.12),transparent 60%),var(--bg);min-height:100vh;overflow-wrap:break-word}.wrap{max-width:1000px;margin:0 auto;padding:20px 16px 56px}header.hero{margin-bottom:20px}header.hero h1{font-size:22px;margin:0 0 6px;letter-spacing:-.02em;line-height:1.2}header.hero p{color:var(--muted);margin:0;font-size:14.5px;line-height:1.55}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px}.label{display:block;font-size:13px;color:var(--muted);margin-bottom:8px;font-weight:600}.url-row{display:flex;flex-direction:column;gap:10px}.url-row input{width:100%;background:var(--bg2);border:1px solid var(--line);color:var(--text);border-radius:10px;padding:14px;font-size:16px;outline:none}.url-row input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}.url-row input:disabled{opacity:.6}.btn{background:var(--accent);color:#fff;border:none;border-radius:12px;padding:0 18px;min-height:var(--touch);font-size:15px;font-weight:600;cursor:pointer;white-space:nowrap;display:inline-flex;align-items:center;justify-content:center;gap:8px;transition:transform .05s ease,filter .15s ease}.btn:hover:not(:disabled){filter:brightness(1.08)}.btn:active:not(:disabled){transform:translateY(1px)}.btn:disabled{opacity:.5;cursor:not-allowed}.status{color:var(--muted);display:flex;align-items:center;gap:8px}.error,.status{margin-top:12px;font-size:13.5px}.error{color:var(--bad);line-height:1.45}.spinner{width:15px;height:15px;border:2px solid rgba(255,255,255,.3);border-top-color:#fff;border-radius:50%;display:inline-block;animation:spin .7s linear infinite;flex-shrink:0}@keyframes spin{to{transform:rotate(1turn)}}.progress-card{margin:16px 0 14px}.progress-top{display:flex;justify-content:space-between;align-items:baseline;gap:8px;margin-bottom:8px;font-size:13.5px;color:var(--muted);flex-wrap:wrap}.progress-top b{color:var(--text)}.bar{height:8px;background:var(--card2);overflow:hidden}.bar,.bar-fill{border-radius:99px}.bar-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--good));transition:width .35s ease}.lesson-grid{display:grid;grid-template-columns:1fr;grid-gap:14px;gap:14px;align-items:start}.lesson-area{order:-1;min-width:0}.tree{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}.tree summary{cursor:pointer;list-style:none;font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);padding:14px 16px;-webkit-user-select:none;-moz-user-select:none;user-select:none;display:flex;align-items:center;justify-content:space-between;gap:8px}.tree summary::-webkit-details-marker{display:none}.tree summary:after{content:"▾";font-size:12px;transition:transform .15s ease}.tree:not([open]) summary:after{transform:rotate(-90deg)}.tree-list{padding:0 6px 10px}.tree-row{display:flex;align-items:center;gap:10px;min-height:42px;padding:8px 12px;border-radius:9px;font-size:13.5px;border-left:3px solid var(--line);margin-bottom:2px;transition:background .2s ease}.tree-row .dot{width:9px;height:9px;border-radius:50%;background:var(--line);flex-shrink:0}.tree-row.done{border-left-color:var(--good);background:var(--good-soft);box-shadow:0 0 0 1px rgba(55,201,154,.25)}.tree-row.done .dot{background:var(--good)}.tree-row.current{border-left-color:var(--accent);background:var(--accent-soft);box-shadow:0 0 0 1px rgba(91,140,255,.3)}.tree-row.current .dot{background:var(--accent);box-shadow:0 0 8px var(--accent)}.tree-row.pending{opacity:.55}.tree-row .term{overflow-wrap:anywhere;min-width:0}.tree-row .check{margin-left:auto;color:var(--good);font-weight:700;font-size:12px;flex-shrink:0}.concept{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px}.concept .step{color:var(--muted);font-size:13px;font-weight:600;margin-bottom:6px}.concept h2.term{font-size:24px;margin:0 0 12px;letter-spacing:-.01em;line-height:1.2;overflow-wrap:anywhere}.concept .summary{font-size:16px;line-height:1.6;color:var(--text);background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:16px;overflow-wrap:anywhere}.expl{margin-top:12px;border:1px solid var(--line);border-left:3px solid var(--warn);border-radius:10px;padding:13px 15px;background:var(--warn-soft)}.expl .strat{display:inline-block;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--warn);margin-bottom:6px}.expl p{margin:0;font-size:15px;line-height:1.55;overflow-wrap:anywhere}.actions{display:flex;flex-direction:column;gap:10px;margin-top:20px}.actions .btn{width:100%;min-height:52px;font-size:16px}.btn.not{background:transparent;color:var(--warn);border:1.5px solid var(--warn)}.btn.not:hover:not(:disabled){background:var(--warn-soft)}.btn.got{background:var(--good)}.btn.got:hover:not(:disabled){filter:brightness(1.08)}.restart-row{display:flex;justify-content:flex-end;margin-top:12px}.done-card{text-align:center;padding:32px 18px}.done-card h2{margin:0 0 8px;font-size:24px}.done-card p{color:var(--muted);margin:0 0 6px;font-size:15px}.glossary{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:22px 0}.chip{background:var(--card2);border:1px solid var(--line);border-radius:99px;padding:8px 13px;font-size:13px;color:var(--text);overflow-wrap:anywhere}.chip.good{background:var(--good-soft);border-color:rgba(55,201,154,.35);color:var(--good)}.foot{margin-top:34px;text-align:center;color:var(--muted);font-size:12.5px;line-height:1.5}.mono{font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.auth-bar{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:12px;font-size:13.5px;flex-wrap:wrap}.auth-who{display:inline-flex;align-items:center;gap:6px;min-width:0}.muted{color:var(--muted)}.link-btn{background:none;border:none;color:var(--accent);cursor:pointer;font-size:14px;padding:8px 10px;text-decoration:underline;min-height:36px}.link-btn:hover{color:#8fb1ff}.icon-btn{background:var(--card2);border:1px solid var(--line);color:var(--muted);border-radius:8px;min-height:36px;min-width:36px;padding:0 10px;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;font-size:13px;transition:color .15s ease,border-color .15s ease}.icon-btn:hover{color:var(--accent);border-color:var(--accent)}.gate-card{margin-top:16px}.gate-card h3{margin:0 0 8px;font-size:18px}.gate-card p{color:var(--muted);margin:0 0 14px;font-size:14.5px;line-height:1.5}.gsi-btn{min-height:44px;max-width:320px}.pay-card ol.pay-steps{margin:0 0 16px;padding-left:20px;color:var(--text);font-size:14.5px;line-height:1.6}.pay-amount{font-size:22px;font-weight:700;color:var(--good);letter-spacing:-.01em;margin-bottom:8px;overflow-wrap:anywhere;line-height:1.3}.copy-btn{background:var(--card2);border:1px solid var(--line);color:var(--text);border-radius:8px;padding:8px 12px;font-size:13px;cursor:pointer;min-height:38px;flex-shrink:0}.copy-btn:hover{border-color:var(--accent);color:var(--accent)}.pay-amount-row{display:flex;align-items:flex-start;justify-content:space-between;gap:10px;flex-wrap:wrap}.pay-address-row{margin-bottom:14px}.pay-address-row .label-row{display:flex;align-items:center;justify-content:space-between;gap:10px}.pay-address{display:block;background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:12px;font-size:13px;word-break:break-all;color:var(--text);margin-top:6px;line-height:1.5}.free-banner{display:flex;align-items:center;gap:10px;background:var(--good-soft);border:1px solid rgba(55,201,154,.35);border-radius:12px;padding:12px 16px;margin-bottom:16px;font-size:14px;flex-wrap:wrap;line-height:1.5}.free-pill{background:var(--good);color:#04271c;font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.06em;padding:4px 9px;border-radius:99px;white-space:nowrap}.free-section{margin-top:36px}.free-section h2{font-size:19px;margin:0 0 4px}.free-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));grid-gap:12px;gap:12px;margin-top:16px}.free-card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px;text-decoration:none;color:var(--text);display:flex;flex-direction:column;gap:6px;transition:border-color .15s ease,transform .05s ease}.free-card:hover{border-color:var(--accent)}.free-card span{color:var(--muted);font-size:13px;line-height:1.4}.free-link{color:var(--accent)!important;font-size:12px!important;overflow-wrap:anywhere}.cta-link{color:var(--accent);text-decoration:none;font-weight:600}.cta-link:hover{text-decoration:underline}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}@media (prefers-reduced-motion:reduce){*{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}}@media (min-width:560px){.url-row{flex-direction:row}.url-row .btn{flex-shrink:0}.actions{flex-direction:row}.actions .btn{flex:1 1}}@media (min-width:860px){.wrap{padding:28px 20px 60px}header.hero h1{font-size:26px}.lesson-grid{grid-template-columns:300px 1fr;gap:16px}.lesson-area{order:0}.tree{position:-webkit-sticky;position:sticky;top:64px}.tree-list{max-height:60vh;overflow-y:auto}.concept{padding:26px}.concept h2.term{font-size:30px}.done-card h2,.pay-amount{font-size:26px}}.nav{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 0 14px;position:-webkit-sticky;position:sticky;top:0;z-index:10;background:linear-gradient(var(--bg),var(--bg) 72%,transparent)}.brand{font-weight:800;font-size:17px;color:var(--text);letter-spacing:-.01em}.brand,.nav-link{text-decoration:none}.nav-link{color:var(--accent);font-size:14px;font-weight:600}.nav-link:hover{text-decoration:underline}.lesson-head{display:flex;align-items:baseline;justify-content:space-between;gap:10px;margin:18px 0 8px;flex-wrap:wrap}.lesson-title{font-size:16px;font-weight:700;color:var(--text);overflow-wrap:anywhere;flex:1 1;min-width:0}.lesson-meta{display:flex;align-items:center;gap:14px;font-size:13.5px;color:var(--muted)}.tree-row.clickable{cursor:pointer}.tree-row.clickable:hover{background:var(--card2)}#free{scroll-margin-top:72px}