:root{--bg:#07111f;--card:#0d1b2d;--line:#1d3550;--text:#eef6ff;--muted:#9fb2c8;--accent:#5ee1ff;--accent2:#8b7cff}
*{box-sizing:border-box}
body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
a{color:var(--accent);text-decoration:none}
.wrap{max-width:900px;margin:auto;padding:0 20px}
header{display:flex;align-items:center;justify-content:space-between;padding:20px 0;border-bottom:1px solid var(--line)}
.logo{font-size:20px;font-weight:800}.logo span{color:var(--accent)}
.user{color:var(--muted);font-size:14px}.user button{margin-left:12px}
button{background:var(--accent);color:#04101c;border:0;border-radius:10px;padding:9px 16px;font-weight:700;cursor:pointer}
button.ghost{background:transparent;color:var(--muted);border:1px solid var(--line)}
input{width:100%;padding:11px 13px;border-radius:10px;border:1px solid var(--line);background:#0a1727;color:var(--text);font-size:16px;margin:6px 0 14px}
.card{border:1px solid var(--line);border-radius:14px;background:var(--card);padding:20px;margin:14px 0}
.lesson-row{display:flex;gap:14px;align-items:baseline}
.lesson-row .n{color:var(--muted);min-width:34px}.lesson-row .d{margin-left:auto;color:var(--muted);font-size:13px}
.theory table{border-collapse:collapse}.theory td,.theory th{border:1px solid var(--line);padding:6px 10px}
pre{background:#050c17;border:1px solid var(--line);border-radius:10px;padding:14px;overflow-x:auto}
code{font-family:ui-monospace,Consolas,monospace;font-size:14px}
.err{color:#ff7b8a;min-height:1.4em}
.muted{color:var(--muted)}
.ok{color:#5be59a}
.badge{font-size:14px;font-weight:400;margin-left:8px}
.ed .CodeMirror{height:auto;min-height:140px;border-radius:10px;border:1px solid var(--line);font-size:15px}
button:disabled{opacity:.5;cursor:wait}
.task button{margin-top:12px}
.opt{display:block;padding:8px 12px;margin:6px 0;border:1px solid var(--line);border-radius:10px;cursor:pointer}
.opt input{width:auto;margin:0 8px 0 0}
.theory svg{display:block;margin:10px auto;max-width:100%}
.wrap.wide{max-width:1240px}
.lesson-grid{display:grid;grid-template-columns:minmax(0,1fr) 360px;gap:28px}
#side{position:sticky;top:16px;align-self:start}
#side svg{width:100%;height:auto}
.cap{color:var(--muted);font-style:italic;text-align:center;font-size:14px}
@media(max-width:1100px){.lesson-grid{display:block}#side{display:none}}