*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;font-family:system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;line-height:1.8;overflow-wrap:anywhere}a{color:inherit;text-underline-offset:5px}a:focus-visible,summary:focus-visible{outline:3px solid currentColor;outline-offset:5px}h1,h2,h3,p{margin:0 0 16px}h1{font-size:clamp(1.8rem,4vw,3.3rem);line-height:1.25;letter-spacing:-.035em}h2{font-size:1.5rem;line-height:1.4}h3{font-size:1.12rem}p{max-width:70ch}main,header,footer,section,article,aside,nav,div{min-width:0}header,main,footer{width:min(1120px,calc(100% - 36px));margin-inline:auto}header{padding:24px 0;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px}nav{display:flex;flex-wrap:wrap;gap:12px 22px}nav a{font-size:.9rem}section{scroll-margin-top:24px}.eyebrow{font-size:.77rem;font-weight:750;letter-spacing:.15em;text-transform:uppercase}.lead{font-size:1.12rem}.tag{display:inline-block;padding:4px 10px;border:1px solid currentColor;border-radius:30px;font-size:.8rem}.notice{padding:20px;border:1px solid currentColor;margin:24px 0}.muted{opacity:.75}footer{padding:30px 0 40px;font-size:.85rem}ol,ul{padding-left:1.3em}li{margin-bottom:10px}.button{display:inline-block;padding:10px 18px;border:1px solid currentColor;text-decoration:none}details{padding:18px 0;border-bottom:1px solid currentColor}summary{cursor:pointer;font-weight:650}details p{margin-top:14px}.grid{display:grid;gap:24px}article{min-width:0}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{background:#eef0fb;color:#272846}.learninghead{padding:45px 0}.learninghead p:last-child{color:#5a6084}.path{padding:25px;background:#dbe0f8;border-radius:18px}.path nav a{background:#fff;padding:10px 16px;border-radius:8px;text-decoration:none}.topics{display:grid;gap:20px;margin:30px 0}.topics article{background:#fff;border:1px solid #d9dced;border-radius:18px;padding:26px}.letter{display:grid;place-items:center;width:48px;height:48px;background:#5c61a5;color:white;font-size:1.5rem;border-radius:14px;margin-bottom:25px}.topics h3{border-top:1px solid #dedff0;padding-top:20px;font-size:.9rem}.recap{padding:30px;border-left:6px solid #5c61a5;background:#e1e4f5}@media(min-width:850px){.topics{grid-template-columns:repeat(3,1fr)}.learninghead{max-width:820px}}

.expanded-reading{margin-top:36px}.expanded-reading>section{padding:26px 0;border-top:1px solid currentColor}.expanded-reading h2{font-size:clamp(1.2rem,2.6vw,1.5rem);line-height:1.5}.expanded-reading p{max-width:74ch;line-height:1.9;margin-bottom:18px}.expanded-reading p:last-child{margin-bottom:0}
