@import url("https://fonts.googleapis.com/css2?family=Syne:wght@600;700;800&family=IBM+Plex+Sans:ital,wght@0,300;0,400;0,500;0,600;1,400&family=IBM+Plex+Mono:wght@400;500&display=swap");:root{--bg:#0b0f14;--sidebar:#0f141a;--card:#161d26;--card2:#1c2531;--border:#1f2c3a;--accent:#00c2ff;--accent2:#00ffb0;--gold:#f5c542;--red:#ff5252;--text:#d4e0ec;--muted:#5a7a96;--white:#fff;--sidebar-w:310px;--topbar-h:56px}*,:after,:before{box-sizing:border-box;margin:0;padding:0}html{font-size:15px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{background:var(--bg);color:var(--text);font-family:IBM Plex Sans,sans-serif;line-height:1.65}.lesson-content h2{font-family:Syne,sans-serif;font-weight:700;font-size:1.25rem;color:var(--white);margin:2rem 0 .875rem;letter-spacing:-.3px}.lesson-content h3{font-family:Syne,sans-serif;font-weight:600;font-size:1rem;color:var(--accent);margin:1.5rem 0 .625rem}.lesson-content h4{font-size:.9rem;font-weight:600;color:var(--white);margin-bottom:.25rem}.lesson-content p{color:var(--text);line-height:1.8;margin-bottom:.875rem;font-size:.95rem}.lesson-content ol,.lesson-content ul{padding-left:1.25rem;margin-bottom:1rem}.lesson-content li{color:var(--text);line-height:1.75;margin-bottom:.375rem;font-size:.93rem}.lesson-content strong{color:var(--white);font-weight:600}.lesson-content code{font-family:IBM Plex Mono,monospace;font-size:.82rem;background:rgba(0,194,255,.08);padding:1px 6px;border-radius:4px;color:var(--accent)}.lesson-content .callout{border-left:3px solid var(--accent);background:rgba(0,194,255,.05);border-radius:0 10px 10px 0;padding:1rem 1.25rem;margin:1.25rem 0}.lesson-content .callout.tip{border-color:var(--accent2);background:rgba(0,255,176,.05)}.lesson-content .callout.warn{border-color:var(--gold);background:rgba(245,197,66,.05)}.lesson-content .callout-label{font-size:.72rem;font-weight:700;letter-spacing:1px;text-transform:uppercase;color:var(--accent);margin-bottom:.375rem}.lesson-content .callout.tip .callout-label{color:var(--accent2)}.lesson-content .callout.warn .callout-label{color:var(--gold)}.lesson-content .callout p{margin:0;font-size:.88rem}.lesson-content .code-block{background:#0d1117;border:1px solid var(--border);border-radius:10px;padding:1.125rem 1.25rem;margin:1.125rem 0;overflow-x:auto}.lesson-content .code-block code{font-family:IBM Plex Mono,monospace;font-size:.82rem;color:#e6edf3;background:transparent;padding:0;line-height:1.7;white-space:pre}.lesson-content .key-points{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:1.375rem 1.5rem;margin:1.5rem 0}.lesson-content .key-points h3{font-family:Syne,sans-serif;font-weight:700;font-size:.9rem;color:var(--white);margin:0 0 .875rem}.lesson-content .kp-item{display:flex;gap:.75rem;margin-bottom:.75rem;align-items:flex-start}.lesson-content .kp-num{width:22px;height:22px;border-radius:6px;background:rgba(0,194,255,.1);border:1px solid rgba(0,194,255,.25);color:var(--accent);font-size:.68rem;font-weight:700;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:1px}.lesson-content .kp-text{font-size:.88rem;color:var(--text);line-height:1.55}.lesson-content .kp-text strong{color:var(--white)}.lesson-content .step-box{background:var(--card2);border:1px solid var(--border);border-radius:12px;padding:1.25rem 1.375rem;margin:.75rem 0;display:flex;gap:1rem;align-items:flex-start}.lesson-content .step-n{font-family:Syne,sans-serif;font-weight:800;font-size:1.4rem;color:var(--border);flex-shrink:0;line-height:1;min-width:28px}.lesson-content .step-content h4{font-size:.9rem;font-weight:600;color:var(--white);margin-bottom:.3rem}.lesson-content .step-content p{font-size:.85rem;color:var(--muted);margin:0;line-height:1.6}::-webkit-scrollbar{width:5px;height:5px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--muted)}@media (max-width:900px){.lesson-layout-main{margin-left:0!important}.lesson-content-scroll{padding:24px 20px 60px!important}.lesson-topbar{padding:0 16px!important}.lesson-content .step-box{flex-direction:column;gap:8px}.lesson-content .step-n{font-size:1rem}.lesson-content .key-points{padding:16px 18px}.lesson-content .kp-item{flex-direction:row;align-items:flex-start}.lesson-content .code-block{font-size:.76rem;padding:14px 16px}}@media (max-width:600px){.lesson-content h2{font-size:1.1rem}.lesson-content li,.lesson-content p{font-size:.9rem}}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:2px solid var(--accent);outline-offset:2px}a,button{transition-property:color,background-color,border-color,opacity,transform;transition-duration:.15s;transition-timing-function:ease}html{font-display:swap}