 :root{--ink:#203b35;--muted:#68776e;--paper:#f7f8f3;--line:#dce3d9;--accent:#17634f}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:"PingFang SC","Microsoft YaHei",sans-serif;line-height:1.65}a{color:inherit;text-decoration:none}a:focus-visible{outline:3px solid #b26725;outline-offset:6px}header{height:100px;max-width:1280px;padding:0 50px;margin:auto;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line)}.brand{font-size:23px;font-weight:650;letter-spacing:1px}.brand span{display:block;font:8px/1.5 monospace;letter-spacing:2px;color:var(--muted);margin-top:4px}.header-note{font-size:12px;color:var(--muted)}main{max-width:1180px;margin:0 auto;padding:62px 0 24px}.intro{padding:8px 0 56px}.eyebrow{font:11px monospace;letter-spacing:2px;color:var(--muted);margin:0 0 15px}h1{font-family:"STSong","Songti SC","SimSun",serif;font-size:58px;line-height:1.25;font-weight:500;letter-spacing:-1px;margin:0}.intro>p:last-child{font-size:15px;color:var(--muted);margin:17px 0 0}.list-heading{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--ink);padding-bottom:16px}.list-heading h2{font-size:13px;font-weight:500;margin:0}.list-heading>span{font-size:11px;color:var(--muted)}.lesson-link{display:grid;grid-template-columns:100px 1fr auto;gap:28px;align-items:center;padding:35px 18px 35px 0;border-bottom:1px solid var(--line);transition:background .18s,padding .18s}.lesson-link:hover{background:#edf3e8;padding-left:16px}.lesson-number{font:62px/1 "STSong","Songti SC",serif;color:var(--accent)}h3{font:500 27px/1.4 "STSong","Songti SC","SimSun",serif;margin:0 0 10px}.lesson-link p{font-size:13px;color:var(--muted);margin:0 0 12px}.duration{font-size:11px;color:var(--muted)}.enter{font-size:13px;color:var(--accent);display:flex;gap:28px;align-items:center}.enter>span{font-size:22px}footer{display:flex;justify-content:space-between;gap:30px;padding:35px 0;font-size:11px;color:var(--muted)}footer p{margin:0}footer span{font-size:10px}@media(max-width:1280px){header{margin:0 35px;padding:0 15px}main{margin:0 50px}}@media(max-width:680px){header{height:86px;margin:0 22px;padding:0}.brand{font-size:20px}.header-note{font-size:10px;max-width:82px;text-align:right}main{padding-top:36px;margin:0 22px}.intro{padding-bottom:36px}h1{font-size:40px}.intro>p:last-child{font-size:13px}.lesson-link{grid-template-columns:52px 1fr;gap:14px;padding:26px 0}.lesson-number{font-size:40px;align-self:start;padding-top:4px}h3{font-size:23px}.lesson-link p{font-size:12px;line-height:1.9}.enter{grid-column:2;justify-content:space-between}.duration{font-size:10px}footer{flex-direction:column;gap:8px;padding:27px 0}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}
