:root{--bg: #0b1220;--card: #131c2e;--card-2: #182338;--line: #23304a;--text: #e8eef8;--muted: #9fb0c9;--accent: #4da3ff;--green: #4ade80;--amber: #fbbf24;--teal: #2dd4bf;--red: #f87171;--radius: 14px}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;background:var(--bg);color:var(--text);font:17px/1.65 -apple-system,BlinkMacSystemFont,Segoe UI,system-ui,sans-serif;-webkit-font-smoothing:antialiased}.wrap{max-width:760px;margin:0 auto;padding:20px 18px 96px}h1{font-size:26px;margin:0 0 4px;letter-spacing:-.02em}h2{font-size:20px;margin:26px 0 10px;letter-spacing:-.01em}h3{font-size:16px;margin:0 0 6px}p{margin:0 0 12px}.muted{color:var(--muted);font-size:14px}.small{font-size:13px}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:14px}button{font:inherit;border-radius:10px;border:1px solid var(--line);background:var(--card-2);color:var(--text);padding:10px 14px;cursor:pointer;transition:filter .12s ease}button:hover:not(:disabled){filter:brightness(1.15)}button:disabled{opacity:.45;cursor:not-allowed}button.primary{background:var(--accent);border-color:var(--accent);color:#04121f;font-weight:640}button.ghost{background:transparent}button.link{background:none;border:none;color:var(--accent);padding:6px 0}button.link.teal{color:var(--teal)}button.wide{width:100%;padding:14px;font-size:17px}input[type=text]{font:inherit;background:var(--card-2);border:1px solid var(--line);color:var(--text);border-radius:10px;padding:11px 13px;width:100%}.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.row.tight{gap:6px}.spread{display:flex;justify-content:space-between;align-items:center;gap:12px}.stack{display:flex;flex-direction:column;gap:10px}.chips{display:flex;gap:6px;overflow-x:auto;padding-bottom:4px;scrollbar-width:none}.chips::-webkit-scrollbar{display:none}.chip{white-space:nowrap;border-radius:999px;padding:7px 13px;font-size:14px;background:var(--card-2);border:1px solid var(--line);color:var(--text)}.chip.on{background:#4da3ff2e;border-color:var(--accent);color:var(--accent)}.chip.done{background:#4ade8024;border-color:#4ade8066;color:var(--green)}.chip.locked{opacity:.5}.bar{height:8px;background:var(--card-2);border-radius:999px;overflow:hidden}.bar>i{display:block;height:100%;background:var(--accent);border-radius:999px}.article h3{margin-top:18px;color:var(--accent);font-size:15px;text-transform:none;letter-spacing:.01em}.article p{font-size:17px}.qa{background:var(--card-2);border-radius:12px;padding:14px;margin-bottom:12px}.qa .q{font-weight:640;margin-bottom:6px}.plain{background:#2dd4bf1a;border-radius:10px;padding:12px;margin-top:10px}.plain .label{color:var(--teal);font-size:13px;font-weight:640;margin-bottom:6px}.choice{display:block;width:100%;text-align:left;margin-bottom:8px;padding:12px 14px;line-height:1.45}.choice.right{border-color:var(--green);background:#4ade8024}.choice.wrong{border-color:var(--red);background:#f871711f}.topbar{position:sticky;top:0;z-index:20;background:#0b1220eb;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}.topbar .inner{max-width:760px;margin:0 auto;padding:10px 18px;display:flex;gap:8px;align-items:center}.tab{background:none;border:none;color:var(--muted);padding:8px 10px;border-radius:8px}.tab.on{color:var(--text);background:var(--card-2)}.spinner{width:16px;height:16px;border-radius:50%;border:2px solid var(--line);border-top-color:var(--accent);animation:spin .8s linear infinite;display:inline-block;vertical-align:-3px}@keyframes spin{to{transform:rotate(360deg)}}.banner{border-radius:10px;padding:10px 12px;margin-bottom:12px;font-size:14px}.banner.error{background:#f8717124;color:var(--red)}.banner.info{background:#4da3ff1f;color:var(--accent)}.center{min-height:70vh;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:14px}@media (max-width: 480px){body{font-size:16px}.wrap{padding:16px 14px 90px}h1{font-size:22px}}