/* Learn (/learn/, learn.py + learn.js), rendered inside the app shell (appshell.py / app.css).
   Site tokens from style.css, so light/dark follow the theme. Versioned by MEMBERS_V in learn.py (immutable cache). */
.ln [hidden]{display:none!important}
.ln button{font:inherit}
.ln .btn{border:0;cursor:pointer}
.ln .btn:disabled{opacity:.6;cursor:wait}
.ln-kicker{color:var(--brand);font-weight:700;font-size:.82rem;letter-spacing:.02em;margin:0 0 6px}
/* course page */
.ln-course{padding:10px 0 28px}
.ln-hero{display:grid;grid-template-columns:1.5fr 1fr;gap:28px;align-items:center;margin:6px 0 26px}
.ln-hero h1{font-size:2.2rem;line-height:1.15;margin:0 0 12px;letter-spacing:-.01em}
.ln-hero .bl-lede a{color:var(--brand);text-decoration:none}
.ln-progress{margin:0}
.ln-pl{margin:0 0 10px;font-size:1.05rem}
.ln-pl b{font-size:1.5rem}
.ln-bar{height:10px;border-radius:999px;background:var(--line);overflow:hidden;margin:0 0 14px}
.ln-bar span{display:block;height:100%;width:0;background:var(--brand);border-radius:999px;transition:width .3s}
.ln-next{margin:10px 0 0;font-size:.9rem;color:var(--mute)}
.ln-next a{color:var(--ink)}
.ln-reset{border:0;background:none;color:var(--mute);text-decoration:underline;cursor:pointer;padding:0;margin-top:8px;font-size:.84rem}
.ln-mods{display:grid;gap:16px}
.ln-mod.card{padding:18px 18px 8px}
.ln-modhead{display:flex;gap:14px;align-items:flex-start}
.ln-modhead h2{font-size:1.2rem;margin:2px 0 4px}
.ln-modhead p{margin:0;color:var(--mute);font-size:.92rem}
.ln-modhead>div{flex:1}
.ln-num{flex:none;width:34px;height:34px;border-radius:10px;display:grid;place-items:center;font-weight:800;color:#fff;background:linear-gradient(135deg,#16a34a,#0ea5e9)}
.ln-modprog{flex:none;color:var(--mute);font-size:.82rem;font-weight:600;white-space:nowrap}
.ln-mod ol{list-style:none;margin:12px 0 0;padding:0}
.ln-mod li a{display:flex;align-items:center;gap:12px;padding:10px 4px;border-top:1px solid var(--line);text-decoration:none}
.ln-mod li a:hover .ln-t{color:var(--brand)}
.ln-t{flex:1;font-weight:600}
.ln-m{color:var(--mute);font-size:.82rem;white-space:nowrap}
.ln-q{font-style:normal;margin-left:8px;padding:1px 7px;border-radius:6px;background:#16a34a22;color:var(--up);font-weight:700}
.ln-tick{flex:none;width:20px;height:20px;border-radius:50%;border:2px solid var(--line);position:relative}
li.done .ln-tick{background:var(--brand);border-color:var(--brand)}
li.done .ln-tick::after{content:"";position:absolute;left:5px;top:1px;width:5px;height:10px;border:solid #fff;border-width:0 2px 2px 0;transform:rotate(45deg)}
li.seen:not(.done) .ln-tick{border-color:var(--brand)}
/* lesson page */
.ln-lesson{padding:6px 0 28px}
.ln-grid{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:36px;align-items:start;margin-top:10px}
.ln-main{max-width:760px}
.ln-main h1{font-size:2.1rem;line-height:1.18;margin:4px 0 12px}
.ln-side{position:sticky;top:16px;max-height:calc(100vh - 32px);overflow:auto;border:1px solid var(--line);border-radius:12px;background:var(--card);padding:12px 12px 4px;font-size:.88rem}
.ln-sidehead{display:flex;justify-content:space-between;gap:8px;margin:0 0 6px;font-weight:700}
.ln-sidehead a{text-decoration:none}
.ln-sidehead span{color:var(--mute);font-weight:600}
.ln-side .ln-mod h3{font-size:.8rem;margin:12px 0 4px;color:var(--mute);text-transform:uppercase;letter-spacing:.04em}
.ln-side .ln-mod h3 span{display:block;font-size:.7rem;color:var(--brand)}
.ln-side .ln-mod ol{margin:0}
.ln-side .ln-mod li a{padding:6px 2px;gap:8px;border:0}
.ln-side .ln-t{font-weight:500}
.ln-side .ln-m{display:none}
.ln-side .ln-tick{width:16px;height:16px}
.ln-side li.done .ln-tick::after{left:3px;top:0;width:4px;height:8px}
.ln-side li.cur .ln-t{color:var(--brand);font-weight:700}
.ln-quiz{margin:30px 0 18px;padding:18px 20px}
.ln-quiz h2{font-size:1.3rem;margin:0 0 4px}
.ln-qq{border:0;padding:0;margin:18px 0 0}
.ln-qq legend{font-weight:600;margin-bottom:8px;padding:0}
.ln-opt{display:flex;gap:10px;align-items:flex-start;padding:9px 12px;border:1px solid var(--line);border-radius:10px;margin:6px 0;cursor:pointer}
.ln-opt:hover{border-color:var(--mute)}
.ln-opt input{margin-top:4px;accent-color:var(--brand)}
.ln-opt.right{border-color:var(--up);background:#16a34a14}
.ln-opt.wrong{border-color:var(--dn);background:#dc262612}
.ln-why{margin:8px 0 0;padding:8px 12px;border-left:3px solid var(--brand);color:var(--mute);font-size:.92rem}
.ln-quiz .msg{min-height:1.2em;font-weight:600;margin:14px 0 10px}
.ln-quiz .msg.err{color:var(--dn)}
.ln-done{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin:6px 0 20px}
.ln-done .btn{padding:9px 16px}
.ln-done .btn.ghostbtn{background:transparent;color:var(--ink);border:1px solid var(--line)}
.ln-done .btn.ok{background:#16a34a22;color:var(--up);border-color:transparent;cursor:default}
.ln-status{color:var(--mute);font-size:.9rem}
.ln-pn{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:10px 0}
.ln-pn a{display:block;padding:12px 14px;border:1px solid var(--line);border-radius:12px;background:var(--card);text-decoration:none;font-weight:600}
.ln-pn a:hover{border-color:var(--brand)}
.ln-pn small{display:block;color:var(--mute);font-weight:500;font-size:.78rem}
.ln-nextl{text-align:right}
.ln-sync{margin:14px 0}
.ln-sync a{color:var(--brand)}
@media (max-width:900px){.ln-hero{grid-template-columns:1fr}.ln-grid{grid-template-columns:1fr}.ln-side{position:static;max-height:none;order:2}}
@media (max-width:560px){.ln-hero h1{font-size:1.7rem}.ln-main h1{font-size:1.6rem}.ln-pn{grid-template-columns:1fr}.ln-nextl{text-align:left}}