:root{color-scheme:light;--ink:#18343f;--muted:#526972;--accent:#096f70;--line:#d3dfdf;--paper:#f5f8f8;font-family:"Microsoft YaHei","PingFang SC",system-ui,sans-serif;color:var(--ink);background:var(--paper)}
*{box-sizing:border-box}body{margin:0}a{color:inherit;text-decoration:none}a:focus-visible{outline:3px solid #a04c14;outline-offset:5px}a:active{background:#e5f1ee}.skip{position:fixed;top:-100px;left:16px;padding:12px;background:white;z-index:5}.skip:focus{top:12px}.wrap{max-width:1160px;margin:auto;padding-inline:28px}.top{border-bottom:1px solid var(--line);background:#fff}.top .wrap{min-height:88px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:inline-flex;align-items:center;gap:13px;min-height:44px;font-size:22px;font-weight:700}.mark{display:grid;place-items:center;width:44px;height:44px;border-radius:12px;background:var(--accent);color:white;font-size:25px}.top-note{font-size:14px;color:var(--muted)}main{padding-block:30px 44px;min-height:calc(100vh - 190px)}.crumbs{display:flex;flex-wrap:wrap;align-items:center;gap:5px 12px;min-height:44px;color:var(--muted);font-size:15px}.crumbs a{display:inline-flex;align-items:center;min-height:44px;color:var(--accent)}.hero{padding:32px 0 36px}.eyebrow{font-size:14px;color:var(--accent);letter-spacing:.09em;margin:0 0 13px}.hero h1{font-size:clamp(30px,4.4vw,46px);line-height:1.3;letter-spacing:-.025em;margin:0 0 18px;text-wrap:balance}.intro{font-size:18px;line-height:1.8;color:var(--muted);max-width:760px;margin:0}.section-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin:8px 0 18px}.section-head h2{font-size:20px;margin:0}.section-head span{font-size:14px;color:var(--muted)}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.card{display:flex;flex-direction:column;padding:28px;background:white;border:1px solid var(--line);border-radius:16px;min-width:0;transition:background .16s,border-color .16s}.card:hover{border-color:var(--accent);background:#f0f8f6}.card .icon{width:52px;height:52px;background:#edf5f3;border-radius:13px;display:grid;place-items:center;color:var(--accent);margin-bottom:25px}.icon svg{width:30px;height:30px}.card h2{font-size:29px;margin:0 0 12px;line-height:1.4}.card p{font-size:16px;line-height:1.8;color:var(--muted);margin:0 0 24px}.card-bottom{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-top:auto;padding-top:20px;border-top:1px solid var(--line);font-size:15px;color:var(--accent)}.status{display:inline-block;color:var(--muted);font-size:14px}.arrow{font-size:24px;line-height:1}.lesson-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.chapter h2{font-size:24px;margin-top:14px}.chapter .chapter-no{font-size:14px;color:var(--accent)}.empty{padding:40px 28px;border:1px dashed #9fb9b6;border-radius:16px;background:#fff}.empty h2{font-size:24px;margin:0 0 14px}.empty p{font-size:17px;line-height:1.8;color:var(--muted);margin:0;max-width:660px}.notice{font-size:15px;line-height:1.8;color:var(--muted);margin:26px 0 0}.footer{border-top:1px solid var(--line);font-size:14px;line-height:1.8;color:var(--muted);padding-block:22px}.footer .wrap{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
@media(max-width:800px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}.top-note{display:none}.wrap{padding-inline:22px}.hero{padding-top:22px}}@media(max-width:540px){.wrap{padding-inline:18px}.top .wrap{min-height:76px}.brand{font-size:20px}.grid{grid-template-columns:1fr;gap:16px}.hero{padding-bottom:28px}.hero h1{font-size:31px}.intro{font-size:17px}.card{padding:24px}.card h2{font-size:26px}.chapter h2{font-size:23px}.card .icon{margin-bottom:18px}.section-head{align-items:baseline}.section-head span{font-size:13px}.empty{padding:30px 24px}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}