*{box-sizing:border-box}body{margin:0;font-family:Inter,ui-rounded,system-ui,-apple-system,sans-serif;background:#f8fbff;color:#17233c}main{max-width:1180px;margin:auto;padding:0 24px}header{height:86px;justify-content:space-between}.brand,header{display:flex;align-items:center}.brand{gap:10px}.owl{background:#1557c9;border-radius:15px;padding:9px;font-size:25px}.brand b{font-size:27px;color:#1453bc}.brand span{display:block;font-size:12px;color:#71809c}.grade{background:#edf5ff;color:#1557c9;padding:10px 16px;border-radius:20px;font-weight:700}.hero{min-height:430px;border-radius:34px;background:linear-gradient(120deg,#eaf5ff,#fff8e5);padding:50px 55px;display:grid;grid-template-columns:1.1fr .9fr;align-items:center;overflow:hidden}.hero h1{font-size:50px;line-height:1.05;margin:15px 0}.hero em{font-style:normal;color:#ff9c16}.hero p{font-size:19px;line-height:1.55;max-width:580px;color:#53627d}.hero img{width:100%;max-height:360px;object-fit:cover;object-position:left;border-radius:28px}.pill{display:inline-block;background:white;padding:8px 13px;border-radius:18px;color:#1453bc;font-weight:700}.composer button,.hero button{border:0;background:#1557c9;color:white;font-weight:800;padding:14px 20px;border-radius:15px;font-size:16px;cursor:pointer}section{margin:48px 0}h2{font-size:28px}.cards{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.cards article{background:white;border:1px solid #e7edf7;border-radius:22px;padding:22px;box-shadow:0 8px 30px #1d4d8c0b}.cards i{font-style:normal;font-size:31px}.cards h3{margin-bottom:8px}.cards p{color:#66738a;line-height:1.45}.subjects{display:flex;flex-wrap:wrap;gap:10px}.subjects button{border:1px solid #dce6f5;background:white;border-radius:14px;padding:12px 17px;font-weight:700;color:#53627d;cursor:pointer}.subjects button.active{background:#1557c9;color:white;border-color:#1557c9}.chat{background:white;border:1px solid #e1e9f5;border-radius:25px;overflow:hidden;box-shadow:0 12px 40px #1d4d8c10}.chatHead{padding:18px 22px;border-bottom:1px solid #edf1f7;display:flex;align-items:center;gap:12px}.chatHead .avatar{font-size:27px;background:#eaf3ff;padding:8px;border-radius:13px}.chatHead small{display:block;color:#71809c}.chatHead span{margin-left:auto;color:#21a66a;font-size:13px}.messages{min-height:220px;padding:25px;background:#fbfdff}.msg,.welcome{max-width:70%;padding:13px 16px;border-radius:17px;background:#edf5ff;line-height:1.45}.msg{margin:8px 0}.msg.ti{margin-left:auto;background:#1557c9;color:white}.composer{display:flex;gap:10px;padding:15px;border-top:1px solid #edf1f7}.composer input{flex:1 1;border:1px solid #dce5f2;border-radius:14px;padding:14px;font-size:16px;outline:none}.note{color:#8a95a7;font-size:11px;padding:0 15px 14px}.note,footer{text-align:center}footer{color:#8b97a9;padding:25px}@media (max-width:800px){.hero{grid-template-columns:1fr;padding:35px 25px}.hero h1{font-size:39px}.hero img{margin-top:25px}.cards{grid-template-columns:1fr 1fr}}@media (max-width:520px){main{padding:0 14px}.cards{grid-template-columns:1fr}.hero img{display:none}.grade{font-size:13px}.msg,.welcome{max-width:88%}}.voiceToggle{margin-left:auto;font-size:12px;color:#53627d;display:flex;align-items:center;gap:5px}.chatHead>span{margin-left:12px}.msgText{white-space:pre-wrap}.speakBtn{margin-top:8px;border:0;background:transparent;color:#1557c9;font-weight:700;cursor:pointer;padding:2px}.quick{display:flex;gap:8px;padding:10px 15px 0;border-top:1px solid #edf1f7}.quick button{border:1px solid #dce6f5;background:#f8fbff;color:#1557c9;border-radius:12px;padding:9px 12px;font-weight:700;cursor:pointer}.mic{width:50px;border:1px solid #dce5f2!important;background:#f3f7fd!important;color:#17233c!important;font-size:20px!important;padding:8px!important}.mic.recording{background:#ffe9e9!important;animation:pulse 1s infinite}@keyframes pulse{50%{transform:scale(1.06)}}@media (max-width:700px){.chatHead{flex-wrap:wrap}.voiceToggle{order:3;margin-left:52px}.chatHead>span{margin-left:auto}.quick{flex-wrap:wrap}.quick button{flex:1 1;min-width:180px}}.photoPreview{margin:12px 18px;padding:12px;border:1px solid #dce5f5;border-radius:16px;display:flex;gap:12px;align-items:center;background:#f8fbff}.photoPreview img{width:92px;height:92px;object-fit:cover;border-radius:12px}.photoPreview div{display:flex;flex-direction:column;gap:5px}.photoPreview span{font-size:13px;color:#667085}.photoPreview button{width:max-content;border:0;background:transparent;color:#c0392b;cursor:pointer;padding:0}.quick,nav{flex-wrap:wrap}nav{max-width:1180px;margin:12px auto 0;padding:0 24px;display:flex;gap:10px}nav a{padding:10px 14px;border-radius:12px;background:#edf5ff;color:#1557c9;text-decoration:none;font-weight:700}button,select{font:inherit;cursor:pointer}button:disabled{opacity:.55;cursor:not-allowed}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #ff9c16;outline-offset:3px}.grade select{border:0;background:transparent;color:#1557c9;font-weight:700}.panel{background:white;border:1px solid #e1e9f5;border-radius:25px;padding:28px;line-height:1.6}.narrow{max-width:720px;margin:40px auto}.chatHead button,.panel button{border:1px solid #dce6f5;background:#edf5ff;color:#1557c9;border-radius:12px;padding:10px 15px;font-weight:700}.actions{display:flex;flex-wrap:wrap;gap:10px}.notice{background:#fff5dd;color:#604518;padding:14px 18px;border-radius:12px;margin:16px;overflow-wrap:anywhere}.muted{color:#66738a;font-size:14px}.panel form label{display:block;margin:16px 0}.panel form input{display:block;width:100%;padding:12px;border:1px solid #c8d7ed;border-radius:10px;font:inherit}.panel form button{margin:5px}fieldset{border:1px solid #dce6f5;border-radius:14px;margin:20px 0;padding:18px;min-width:0}legend{font-weight:700;padding:0 8px}.option{display:flex;gap:10px;align-items:baseline;padding:10px;border-radius:10px;background:#f8fbff;margin:8px 0}.option input{flex:none}.feedback{background:#edf8f3;border-radius:12px;padding:16px;margin-top:15px}.feedback p{margin:8px 0}.tableWrap{overflow:auto}table{border-collapse:collapse;width:100%;text-align:left}td,th{padding:12px;border-bottom:1px solid #e1e9f5}.activityList{padding:0;list-style:none}.activityList li{padding:14px 0;border-bottom:1px solid #edf1f7}small{display:block;color:#67748b}.historyGrid{display:grid;grid-template-columns:minmax(200px,1fr) 2fr;gap:22px}.historyItem{padding:15px;border-bottom:1px solid #dce6f5;display:flex;flex-direction:column;align-items:start;gap:8px}.historyItem button{max-width:100%;overflow-wrap:anywhere}.danger{color:#a42c2c!important}.messagePhoto{max-width:100%;max-height:360px;object-fit:contain;border-radius:10px}.msgText{overflow-wrap:anywhere}.composer input{min-width:0}.historyGrid .msg{max-width:100%}@media (max-width:600px){.panel{padding:18px 14px}.historyGrid{grid-template-columns:1fr}.composer{gap:6px;padding:10px}.composer button{padding:12px 10px;font-size:14px}.composer .mic{width:40px;flex:none}.composer input{padding:10px;font-size:16px}header{height:auto;min-height:100px;gap:10px;flex-wrap:wrap}.grade{padding:8px}.hero img{display:block;max-height:220px;object-fit:contain}.panel .cards{grid-template-columns:1fr 1fr}.cards article{padding:12px}.cards h2{font-size:24px}nav{padding:0 14px;gap:6px}nav a{padding:9px 10px;font-size:14px}.chatHead .voiceToggle{margin-left:0}.photoPreview{margin:10px}.quick button{min-width:130px}.notice{margin:12px 0}h1{font-size:30px}}.panel select{display:block;margin-top:6px;padding:10px 12px;border:1px solid #c8d7ed;border-radius:10px;background:white;color:#17233c;max-width:100%}.accountModes button[aria-pressed=true]{background:#1557c9;color:white}.profile{margin-bottom:26px}.profile b{overflow-wrap:anywhere}.actions{align-items:center}.activityList button{margin-top:8px}.topicSection{margin:28px 0;padding:24px;background:white;border:1px solid #e1e9f5;border-radius:22px}.topicHeading{display:flex;align-items:end;justify-content:space-between;gap:16px}.topicHeading h2{margin:0 0 5px}.topicHeading p{margin:0 0 18px;color:#71809c}.topicClear{border:1px solid #dce6f5;background:#f8fbff;color:#1557c9;border-radius:10px;padding:8px 12px;font-weight:700;cursor:pointer;margin-bottom:18px}.topicGrid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}.topicCard{text-align:left;min-height:118px;border:1px solid #dce6f5;background:#f8fbff;border-radius:16px;padding:15px;color:#17233c;cursor:pointer;display:flex;flex-direction:column;gap:5px}.topicCard:hover{border-color:#8fb8f3}.topicCard.active{background:#eaf3ff;border:2px solid #1557c9;padding:14px}.topicIcon{font-size:25px}.topicCard small{color:#71809c;line-height:1.35}.topicActions{display:flex;flex-wrap:wrap;align-items:center;gap:9px;margin-top:16px;padding:13px;background:#f4f8ff;border-radius:14px}.topicActions b{margin-right:auto}.topicActions button{border:1px solid #d5e3f7;background:white;color:#1557c9;border-radius:10px;padding:9px 11px;font-weight:700;cursor:pointer}@media (max-width:900px){.topicGrid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (max-width:520px){.topicGrid{grid-template-columns:1fr}.topicActions b{width:100%}}.math-text{font-family:Georgia,Times New Roman,serif;font-size:1.04em}.math-frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;line-height:1.05;margin:0 .12em}.math-frac>span:first-child{border-bottom:1px solid;padding:0 .15em .08em}.math-frac>span:last-child{padding:.08em .15em 0}.math-text sup{font-size:.75em;vertical-align:super}