@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&display=swap');
:root{font-family:'DM Sans','Microsoft YaHei',sans-serif;color:#183258;background:#f4f6fa;font-size:16px;line-height:1.65;--navy:#183258;--green:#c5f46b;--muted:#62728a;--line:#dce3ed}*{box-sizing:border-box}body{margin:0}button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #377bef;outline-offset:4px}header{min-height:94px;display:flex;align-items:center;justify-content:space-between;max-width:1392px;margin:auto;padding:16px 48px;border-bottom:1px solid var(--line)}.brand{display:flex;gap:12px;align-items:center;text-decoration:none;color:var(--navy);font-size:21px;font-weight:700;line-height:1.2}.brand small{display:block;font-size:12px;letter-spacing:2px;margin-top:7px;font-weight:500}.mark{display:grid;place-items:center;width:42px;height:46px;background:var(--navy);color:var(--green);border-radius:12px;font-size:28px}.level{font-size:14px;color:var(--muted)}main{max-width:1392px;margin:auto;display:grid;grid-template-columns:305px minmax(0,1fr);gap:64px;padding:38px 48px 54px}aside{border-right:1px solid var(--line);padding-right:32px}.eyebrow{font-size:12px;letter-spacing:2px;color:var(--muted);font-weight:700;margin:0 0 10px}h1{font-size:32px;line-height:1.45;letter-spacing:-1px;margin:0 0 12px}h2{font-size:32px;line-height:1.35;margin:0 0 12px}h3{line-height:1.4}.intro{font-size:14px;color:var(--muted);margin-bottom:28px}nav{display:grid;gap:7px}.lesson-link{display:flex;align-items:center;gap:13px;border:0;background:transparent;color:var(--muted);width:100%;padding:11px 13px;border-radius:9px;text-align:left;font-size:14px}.lesson-link.active{background:var(--navy);color:#fff}.lesson-num{font-size:12px;opacity:.75}.lesson-link .done{margin-left:auto;color:#529d14}.tip{font-size:14px;margin-top:28px;border-top:1px solid var(--line);padding-top:22px;color:var(--muted)}.tip strong{color:var(--navy);display:block;font-size:14px;margin-top:4px}.tip p{font-size:12px}#workspace{min-width:0}.lesson-heading{padding:4px 0 26px}.lesson-heading p:last-child{color:var(--muted);margin:0}.study-card{background:white;border:1px solid var(--line);border-radius:18px;padding:34px;box-shadow:0 8px 32px #18325805}.study-card h3{font-size:32px;letter-spacing:-.7px;margin:25px 0 10px}.tag{display:inline-block;border-radius:5px;padding:4px 9px;background:#eaf3df;color:#3f681a;font-size:12px;font-weight:700}.primary,.secondary{border-radius:8px;padding:10px 18px;font-size:14px;font-weight:600;border:1px solid transparent}.primary{background:var(--navy);color:white}.primary:hover{background:#2c4b77}.secondary{background:white;color:var(--navy);border-color:var(--line)}.secondary:hover{background:#eef2f8}footer{max-width:1296px;margin:auto;padding:18px 0;border-top:1px solid var(--line);font-size:12px;color:var(--muted)}.tabs{display:flex;gap:7px;border-bottom:1px solid var(--line);margin-bottom:24px;flex-wrap:wrap}.tab{border:0;border-bottom:3px solid transparent;padding:11px 17px;background:transparent;color:var(--muted);font-size:14px}.tab.active{border-color:var(--navy);color:var(--navy);font-weight:700}.card-top,.actions{display:flex;gap:10px;align-items:center;justify-content:space-between;flex-wrap:wrap}.actions{justify-content:flex-start}.muted{color:var(--muted)}.translation{font-size:18px}.explain{margin-top:25px;background:#f4f6fa;padding:18px 20px;border-left:3px solid #badb87;border-radius:0 9px 9px 0;font-size:14px}.explain p{margin:4px 0}.pager{margin-top:24px;display:flex;justify-content:space-between;align-items:center;gap:10px;font-size:14px}.words{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:20px}.word{border:1px solid var(--line);border-radius:10px;padding:15px;background:white}.word strong{display:block;font-size:16px}.word span{font-size:14px;color:var(--muted)}.section-label{font-size:16px;margin:25px 0 10px}.hint{font-size:14px;color:var(--muted)}.bubble{background:#eff3f9;padding:18px 22px;border-radius:12px 12px 12px 0;margin:15px 0 24px}.bubble p{margin:5px 0}.choices{display:grid;gap:10px}.choice{background:white;border:1px solid var(--line);text-align:left;padding:14px 18px;border-radius:9px;color:var(--navy);font-size:16px}.choice:hover{border-color:var(--navy)}.choice.correct{background:#eff9e5;border-color:#70a63f}.choice.incorrect{background:#fff0ef;border-color:#cc6c60}.feedback{margin-top:16px;padding:14px 18px;border-radius:8px;background:#edf4ff;font-size:14px}.feedback.good{background:#eff9e5}.email{line-height:2.4;font-size:16px;white-space:pre-wrap}.email input{width:155px;max-width:100%;border:0;border-bottom:2px solid #8ea4c4;background:#f1f5fa;padding:3px 8px;border-radius:4px 4px 0 0;color:var(--navy)}.email input[aria-invalid=true]{border-color:#c04838}.email-head{font-size:14px;padding:12px 0;border-bottom:1px solid var(--line);margin-bottom:20px}.note{padding:15px 20px;border-radius:10px;background:#eaf0f9;margin-top:20px;font-size:14px}.complete{background:var(--green);color:#274819;padding:5px 10px;border-radius:30px;font-size:12px}.listen-settings{display:flex;gap:10px;align-items:center;font-size:14px}.listen-settings select{border:1px solid var(--line);border-radius:6px;padding:5px;background:white;color:var(--navy)}.practice-line{font-size:24px;line-height:1.5;padding:24px 0}.progress-row{font-size:12px;color:var(--muted);margin-top:20px}.small-btn{font-size:12px;padding:4px 8px;border:0;background:transparent;color:var(--muted);text-decoration:underline}button:disabled{opacity:.4;cursor:default}.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}
@media(min-width:1450px){main{padding-top:48px}}@media(max-width:1000px){main{gap:28px;padding:28px;grid-template-columns:230px minmax(0,1fr)}header{padding:16px 28px}aside{padding-right:22px}h1{font-size:26px}.study-card{padding:24px}.study-card h3{font-size:27px}footer{margin:0 28px}.words{grid-template-columns:1fr}}@media(max-width:700px){header{padding:15px 20px;min-height:80px}.brand{font-size:18px}.level{font-size:12px}main{display:block;padding:24px 20px}aside{border:0;padding:0}aside>.eyebrow,aside>h1,aside>.intro,.tip{display:none}nav{display:flex;overflow-x:auto;padding-bottom:13px;margin-bottom:20px;gap:8px}.lesson-link{width:auto;flex-shrink:0;white-space:nowrap;background:#e9edf4}.lesson-heading{padding-bottom:16px}h2{font-size:26px}.lesson-heading p:last-child{font-size:14px}.study-card{padding:22px 18px}.study-card h3{font-size:27px}.tabs{gap:0}.tab{flex:1;padding:10px 5px}.words{grid-template-columns:1fr}.word{display:flex;align-items:center;justify-content:space-between}.pager{flex-wrap:wrap}.primary,.secondary{min-height:44px}.email input{width:125px}footer{margin:0 20px}.progress-row{margin:0 0 18px}}