:root{--ink:#172c32;--muted:#66777c;--teal:#096a62;--line:#dfe7e6;--bg:#f5f8f8}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.7 system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif}button,a{-webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}button:focus-visible,a:focus-visible{outline:3px solid #d79026;outline-offset:4px}aside{width:234px;position:fixed;inset:0 auto 0 0;background:#fff;border-right:1px solid var(--line);padding:35px 22px;display:flex;flex-direction:column}.brand{display:flex;gap:12px;color:var(--ink);text-decoration:none;align-items:center;padding:0 9px}.logo{background:var(--teal);color:white;width:43px;height:43px;border-radius:13px;display:grid;place-items:center;font-family:serif;font-size:25px}.brand b{font-size:24px;line-height:1.1}.brand b span{display:block;font-size:10px;letter-spacing:2px;margin-top:7px}.navlabel{font-size:12px;color:#81908f;margin:52px 15px 13px}nav{display:grid;gap:8px}nav button{border:0;border-radius:8px;text-align:left;background:transparent;padding:13px 15px;color:#6a797d;display:flex;gap:13px;font-size:17px}nav button span{font-size:15px}nav button.active{background:#e8f4f1;color:var(--teal);font-weight:650}.sidefoot{margin-top:auto;padding:20px 15px;font-size:15px;color:#7c8a8d;line-height:1.9}.sidefoot small{display:block;font-size:9px;letter-spacing:1px;margin-top:15px}.tinyline{display:block;width:28px;height:3px;background:#b9d3cc;margin-bottom:18px}.main{margin-left:234px}header{height:80px;border-bottom:1px solid var(--line);background:#fff;display:flex;justify-content:space-between;align-items:center;padding:0 46px;font-size:14px;color:#7a878a}header b{color:#384e53;font-weight:500}.slash{margin:0 16px;color:#bdc8c8}.headerbadge{border:1px solid var(--line);padding:5px 12px;border-radius:6px;font-size:12px}main{max-width:1400px;margin:auto;padding:37px 46px 45px}.topline{display:flex;justify-content:space-between;align-items:center}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--teal);font-weight:700}.edition{font-size:12px;color:#879594}h1{font-size:31px;letter-spacing:-.7px;margin:9px 0 7px;font-weight:650}.intro{color:var(--muted);font-size:15px;margin:0 0 27px}.feature{background:#123e40;color:#fff;border-radius:13px;display:grid;grid-template-columns:1fr 1fr;overflow:hidden;padding:30px 34px;gap:20px}.pill{font-size:12px;color:#c5e9dc;border:1px solid #54736e;border-radius:4px;padding:5px 9px}.feature h2{font-size:28px;line-height:1.5;letter-spacing:.3px;margin:18px 0 10px}.feature p{font-size:14px;line-height:1.8;color:#b7cccc;margin:0 0 20px}.primary{border:0;background:#096a62;color:#fff;border-radius:6px;padding:10px 19px;font-size:14px;font-weight:550}.feature .primary{background:#d5efb4;color:#163e34;min-width:146px;display:flex;justify-content:space-between;gap:24px}.alcoa{align-self:center;border-left:1px solid #426062;padding:25px 0 25px 35px}.alcoa>span{font-size:13px;color:#aac7c5}.alcoa>div{display:flex;gap:8px;margin:18px 0 12px}.alcoa b{font:40px Georgia,serif;color:#d7efbb;border-bottom:1px solid #638577;padding:0 9px 12px}.alcoa p{font-size:13px;margin:0 0 12px}.alcoa small{font-size:8px;letter-spacing:.3px;color:#7fa6a5;display:block;max-width:320px}.sectionhead{display:flex;justify-content:space-between;align-items:center;margin:27px 0 17px;gap:12px}.sectionhead h2{font-size:19px;margin:0}.sectionhead h2 span{font:12px system-ui;margin-left:9px;color:#869592}.sectionhead p{font-size:12px;color:#879391;margin:0}.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:17px}.card{background:#fff;border:1px solid var(--line);border-radius:10px;padding:22px;display:flex;flex-direction:column;min-height:228px}.cardtop{display:flex;align-items:center;justify-content:space-between}.icon{width:38px;height:38px;border:1px solid #dbe9e3;background:#eff7f3;color:#317a6a;border-radius:9px;display:grid;place-items:center;font-size:20px}.category{color:#879391;font-size:12px}.card h3{font-size:18px;margin:17px 0 6px}.card p{font-size:14px;color:var(--muted);margin:0 0 20px;line-height:1.8}.cardbottom{margin-top:auto;border-top:1px solid #edf0ee;padding-top:15px;display:flex;justify-content:space-between;align-items:center}.cardbottom span{font-size:12px;color:#89958e}.cardbottom button{border:0;color:var(--teal);background:none;font-size:14px;padding:0}.note{font-size:12px;color:#84918f;margin-top:26px;line-height:1.8}footer{border-top:1px solid var(--line);padding:22px 46px;font-size:12px;display:flex;justify-content:space-between;color:#95a09f}footer b{font-weight:500}dialog{border:0;border-radius:14px;padding:38px;width:min(720px,92vw);max-height:88vh;color:var(--ink);box-shadow:0 25px 100px #163e3433}dialog::backdrop{background:#122d3899;backdrop-filter:blur(3px)}dialog h2{font-size:26px;margin:12px 0 25px}.close{float:right;border:0;background:#eef3f1;border-radius:50%;width:34px;height:34px;font-size:24px;line-height:1}.point{border-top:1px solid var(--line);padding:16px 0}.point h3{font-size:16px;margin:0 0 6px}.point p{font-size:15px;color:#5e7276;margin:0}.lessonfooter{margin-top:22px}.practicebox,.resource{background:white;border:1px solid var(--line);border-radius:12px;padding:30px;margin:15px 0}.practicebox{max-width:850px}.practicebox h2,.resource h2{font-size:23px}.practicebox p{line-height:1.9}#answers{display:grid;gap:12px;margin:24px 0}#answers button{background:#f8faf9;border:1px solid var(--line);border-radius:7px;text-align:left;padding:14px 18px;color:var(--ink)}#answers button:disabled{cursor:default;opacity:1}#answers button.correct{background:#edf7ec;border-color:#7dae82}#answers button.wrong{background:#fff0ec;border-color:#d69580}#feedback{padding:0 0 18px;color:var(--teal)}.muted{font-size:14px;color:var(--muted)}.record{background:white;padding:20px 25px;border:1px solid var(--line);border-radius:8px;margin:10px 0;display:flex;justify-content:space-between;gap:20px}.record span{color:var(--teal);font-size:14px}.resource>span{color:#7c918d;font-size:12px}.resource p{color:var(--muted);font-size:15px}.resource a{color:var(--teal);font-size:14px}[hidden]{display:none!important}@media(min-width:1450px){main{padding-top:48px}.feature{padding:38px}.card{min-height:244px}}@media(max-width:1100px){aside{width:190px;padding:28px 14px}.main{margin-left:190px}main{padding:30px 25px}header{padding:0 25px}.cards{grid-template-columns:repeat(2,1fr)}.alcoa{padding-left:20px}.alcoa b{padding:0 5px 10px;font-size:32px}}@media(max-width:760px){aside{position:static;width:auto;padding:18px;border-right:0;border-bottom:1px solid var(--line)}.brand b{font-size:20px}.navlabel,.sidefoot{display:none}nav{display:flex;margin-top:18px;gap:4px;overflow:auto}nav button{flex-shrink:0;padding:8px 10px;font-size:14px;gap:6px}nav button span{font-size:13px}.main{margin:0}header{height:54px;padding:0 20px}.headerbadge{display:none}main{padding:25px 20px}h1{font-size:25px}.edition{display:none}.feature{grid-template-columns:1fr;padding:26px}.feature h2{font-size:26px}.alcoa{display:none}.cards{grid-template-columns:1fr}.sectionhead p{display:none}.card{min-height:215px}footer{padding:20px;gap:15px;font-size:11px}dialog{padding:25px}.record{flex-direction:column;gap:5px}.resource,.practicebox{padding:23px}}