:root{--ink:#21224a;--muted:#8385a6;--purple:#6758df;--purple-dark:#5448c4;--lilac:#efedff;--cream:#fff9f3;--canvas:#f7f8fe;--line:#ebeaf5;--mint:#ddf8e9;--green:#23a979;--yellow:#ffc65c;--orange:#ff8e67;--shadow:0 14px 42px rgba(48,43,91,.065);font-family:'Trebuchet MS','Avenir Next','Segoe UI',sans-serif;color:var(--ink)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--canvas);font-size:15px}button,input,select,textarea{font:inherit}button{cursor:pointer}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #b8acff;outline-offset:3px}button:disabled{cursor:not-allowed;opacity:.55}svg{display:block}::selection{background:#dcd6ff}
.shell{display:flex;min-height:100vh}.sidebar{width:254px;flex-shrink:0;background:#fff;padding:27px 19px;position:sticky;top:0;height:100vh;border-right:1px solid var(--line);display:flex;flex-direction:column;gap:26px;z-index:4}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;padding:0 8px}.logo-mark{height:45px;width:45px;display:grid;place-items:center;border-radius:16px;background:#6a5ce7;color:#fff;font-size:27px;box-shadow:0 8px 18px #7667e44d;transform:rotate(-7deg)}.brand-copy strong{display:block;font-size:18px;letter-spacing:-.7px;line-height:1.08}.brand-copy small{display:block;color:var(--purple);font-size:10px;font-weight:800;letter-spacing:2.5px;text-transform:uppercase;margin-top:4px}.section-label{color:#abaac0;font-weight:800;font-size:10px;letter-spacing:2px;margin:8px 15px 9px}.nav-group{display:grid;gap:5px}.nav-btn{border:0;background:transparent;color:#777a9c;border-radius:14px;padding:13px 14px;display:flex;gap:14px;align-items:center;text-align:left;width:100%;font-size:14px;font-weight:800;transition:.18s}.nav-btn:hover{background:#f6f5ff;color:var(--purple)}.nav-btn.active{background:#efecff;color:var(--purple)}.nav-icon{font-size:20px;width:23px;text-align:center}.sidebar-bottom{margin-top:auto;display:grid;gap:14px}.side-note{background:#f0edff;padding:18px;border-radius:21px;position:relative;overflow:hidden}.side-note .note-emoji{font-size:35px;line-height:1;margin-bottom:9px}.side-note strong{display:block;font-size:14px}.side-note p{line-height:1.5;margin:5px 0 12px;font-size:12px;color:#77739d}.pill-btn{border:0;border-radius:999px;color:#fff;background:var(--purple);padding:10px 18px;font-weight:900;box-shadow:0 7px 18px #6758df35}.pill-btn:hover{background:var(--purple-dark)}.pill-btn.light{background:#fff;color:var(--purple);box-shadow:none}.pill-btn.outline{background:#fff;color:var(--purple);border:1px solid #dcd7fa;box-shadow:none}.pill-btn.peach{background:#ff9166}.pill-btn.small{padding:9px 13px;font-size:12px}.main{flex:1;min-width:0;padding:0 38px 70px;max-width:1700px;margin:0 auto}.topbar{height:96px;display:flex;align-items:center;gap:18px;justify-content:space-between}.mobile-brand{display:none}.top-search{height:46px;width:min(340px,35vw);border:1px solid var(--line);background:#fff;border-radius:14px;display:flex;align-items:center;gap:11px;padding:0 14px;color:var(--muted)}.top-search input{background:transparent;border:0;outline:0;flex:1;min-width:0;color:var(--ink);font-size:13px}.top-actions{display:flex;align-items:center;gap:12px}.role-control{display:flex;align-items:center;gap:7px;padding:5px;background:#fff;border:1px solid var(--line);border-radius:999px}.role-control button{border:0;background:transparent;color:#9090ae;border-radius:999px;padding:8px 13px;font-size:12px;font-weight:800}.role-control button.selected{background:var(--purple);color:white}.avatar{width:43px;height:43px;border-radius:16px;background:#fff1dc;display:grid;place-items:center;font-size:22px;border:3px solid #fff;box-shadow:0 4px 11px #e2d3b85a}.main h1{font-size:31px;line-height:1.16;letter-spacing:-1.1px;margin:0}.main h2{font-size:21px;letter-spacing:-.6px;margin:0}.main h3{font-size:16px;margin:0}.subtitle{color:var(--muted);font-size:14px;margin:7px 0 0}.eyebrow{color:var(--purple);font-size:11px;font-weight:900;letter-spacing:1.8px;text-transform:uppercase}.heading-row{display:flex;justify-content:space-between;align-items:end;gap:20px;margin:0 0 21px}.heading-actions{display:flex;gap:10px}.chip{border-radius:999px;background:#f1efff;color:var(--purple);display:inline-flex;align-items:center;gap:6px;padding:7px 11px;font-weight:900;font-size:11px}.chip.green{background:#dcf8eb;color:#199265}.chip.yellow{background:#fff4d7;color:#b37a0c}.chip.gray{background:#f0f0f6;color:#9091ac}.chip.coral{background:#ffefed;color:#cf6558}.card{border:1px solid #eeedf6;background:#fff;border-radius:23px;box-shadow:var(--shadow)}.surface{padding:23px}.card-hover{transition:transform .19s,box-shadow .19s}.card-hover:hover{transform:translateY(-3px);box-shadow:0 18px 32px #52477c19}.hero{background:linear-gradient(115deg,#6255db 0%,#8772ed 63%,#b394ff 100%);border-radius:27px;display:flex;align-items:center;min-height:249px;padding:31px 42px;position:relative;overflow:hidden;color:#fff;box-shadow:0 18px 36px #6555df30}.hero:after{content:'';position:absolute;width:310px;height:310px;border-radius:50%;background:#ffffff13;right:-50px;bottom:-180px}.hero:before{content:'';position:absolute;width:175px;height:175px;border:2px dashed #ffffff35;border-radius:50%;right:120px;top:-60px}.hero h2{font-size:33px;max-width:480px;line-height:1.17;letter-spacing:-1.3px;position:relative;z-index:2}.hero p{max-width:440px;color:#f6eeff;line-height:1.65;font-size:13px;margin:13px 0 22px;position:relative;z-index:2}.hero-art{font-size:97px;position:absolute;right:11%;bottom:13px;z-index:1;filter:drop-shadow(0 14px 8px #39308644);transform:rotate(-9deg)}.star-a,.star-b{position:absolute;color:#ffdf83;font-size:33px}.star-a{right:35%;top:35px}.star-b{right:5%;top:39px;font-size:22px}.section-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:30px 0 16px}.text-link{border:0;background:none;color:var(--purple);font-weight:900;font-size:12px}.dashboard-grid{display:grid;grid-template-columns:1.7fr 1fr;gap:19px;margin-top:20px}.mini-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.stat{padding:20px;position:relative;overflow:hidden}.stat .stat-icon{font-size:25px;background:#f5f2ff;border-radius:15px;width:43px;height:43px;display:grid;place-items:center;margin-bottom:14px}.stat strong{font-size:25px;display:block;letter-spacing:-.7px}.stat span{font-size:12px;color:var(--muted);font-weight:700}.progress-card{padding:21px}.progress-top{display:flex;justify-content:space-between;gap:14px;align-items:center}.progress-bar{height:9px;background:#f0edfc;border-radius:99px;overflow:hidden;margin:13px 0 8px}.progress-bar>span{height:100%;display:block;background:linear-gradient(90deg,#675ce8,#8c78f6);border-radius:99px}.progress-card p,.task-line p{color:var(--muted);font-size:12px;line-height:1.5}.right-illustration{background:#fff0dd;border-radius:14px;width:54px;height:54px;display:grid;place-items:center;font-size:29px}.task-list{display:grid;gap:11px;margin-top:15px}.task-line{display:flex;gap:12px;align-items:center;background:#fafaff;border:1px solid #f3f1fc;padding:11px;border-radius:14px}.task-line .task-icon{width:39px;height:39px;border-radius:12px;background:#edebff;display:grid;place-items:center;font-size:20px}.task-line strong{font-size:12px;display:block}.task-line p{margin:3px 0 0}.task-line button{margin-left:auto}.unit-grid{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:16px}.unit-card{border:1px solid #eeecf8;background:#fff;padding:18px;border-radius:20px;cursor:pointer;text-align:left;min-height:186px;transition:transform .2s,box-shadow .2s;position:relative}.unit-card:hover{transform:translateY(-3px);box-shadow:var(--shadow)}.unit-card.current{border:2px solid #afa5fb;background:#fcfbff}.unit-emoji{display:grid;place-items:center;width:56px;height:56px;background:var(--lilac);border-radius:17px;font-size:28px;margin-bottom:14px}.unit-card:nth-child(5n+2) .unit-emoji{background:#fff1db}.unit-card:nth-child(5n+3) .unit-emoji{background:#e4f9ec}.unit-card:nth-child(5n+4) .unit-emoji{background:#ffe9ed}.unit-card:nth-child(5n) .unit-emoji{background:#dff5ff}.unit-card small{color:#a3a0b6;font-size:10px;font-weight:900;letter-spacing:1px;text-transform:uppercase}.unit-card strong{font-size:15px;display:block;margin:7px 0 5px}.unit-card p{font-size:11px;color:var(--muted);margin:0;line-height:1.35}.unit-tag{position:absolute;right:12px;top:12px;font-size:10px;font-weight:900;color:var(--purple)}.book-card{display:flex;gap:22px;align-items:center;padding:22px}.book-cover{background:linear-gradient(145deg,#a28ff7,#6658df);color:#fff;width:125px;height:164px;flex-shrink:0;border-radius:12px 19px 19px 12px;display:flex;flex-direction:column;justify-content:space-between;padding:17px;box-shadow:6px 6px 0 #e5dff8,inset 5px 0 0 #ffffff38;position:relative;overflow:hidden}.book-cover:after{content:'✦';position:absolute;font-size:95px;color:#ffffff32;right:-10px;top:18px}.book-cover strong{font-size:19px;line-height:1.1;position:relative;z-index:1}.book-cover small{font-size:11px;font-weight:700;z-index:1}.book-info h3{font-size:20px;margin-bottom:8px}.book-info p{font-size:13px;color:var(--muted);line-height:1.6}.book-metrics{display:flex;gap:18px;color:#8c8baa;font-size:12px;font-weight:700;margin:16px 0}.lesson-hero{display:flex;align-items:center;gap:20px;background:#fff;border:1px solid var(--line);padding:26px;border-radius:24px;margin-bottom:22px}.lesson-hero>.illustration{font-size:66px;width:120px;height:120px;background:#edeaff;border-radius:28px;display:grid;place-items:center}.lesson-hero p{color:var(--muted);font-size:13px}.tab-list{display:flex;gap:7px;overflow-x:auto;margin:20px 0}.tab{border:0;background:#fff;color:#8686aa;padding:12px 20px;border-radius:13px;font-weight:800;white-space:nowrap}.tab.selected{background:var(--purple);color:#fff;box-shadow:0 8px 18px #6758df30}.media-list{display:grid;gap:12px}.media-row{display:flex;gap:15px;align-items:center;border:1px solid #efedf8;background:#fff;border-radius:18px;padding:15px}.media-bubble{width:44px;height:44px;border-radius:13px;background:#eeeaff;display:grid;place-items:center;font-size:23px;flex-shrink:0}.media-row .media-copy{flex:1;min-width:0}.media-row strong{font-size:13px;display:block;word-break:break-word}.media-row p{margin:5px 0 0;color:var(--muted);font-size:11px}.media-row audio{width:min(245px,37vw);height:34px}.media-row .pill-btn{flex-shrink:0}.media-preview{width:100%;max-height:320px;border-radius:17px;background:#12152d}.notice{border:1px dashed #d7d0fd;border-radius:17px;padding:16px;background:#f5f3ff;color:#7669b5;font-size:12px;line-height:1.6}.muted{color:var(--muted)}.empty-state{text-align:center;padding:43px 20px;color:#7f80a0}.empty-state .big-emoji{font-size:54px;margin-bottom:10px}.empty-state strong{display:block;color:var(--ink)}.empty-state p{font-size:13px;max-width:360px;margin:10px auto 20px;line-height:1.6}.quiz-layout{max-width:810px;margin:0 auto}.quiz-question{padding:27px}.quiz-question h2{font-size:25px;margin:16px 0 21px}.answer-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px;margin:21px 0}.answer-option{background:#fff;border:2px solid #f0edf8;border-radius:15px;padding:18px;text-align:left;font-size:15px;font-weight:800}.answer-option:hover{border-color:#d0c8fb}.answer-option.selected{border-color:var(--purple);background:#f5f3ff}.quiz-result{padding:32px;text-align:center}.quiz-result>.big-emoji{font-size:61px}.score-number{font-size:62px;color:var(--purple);font-weight:900;letter-spacing:-2px}.review-question{text-align:left;background:#f9f9fd;padding:17px;margin:13px 0;border-radius:16px}.review-question strong{font-size:13px}.review-question p{font-size:12px;color:var(--muted);line-height:1.6}.exam-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.exam-card{padding:20px}.exam-card .unit-emoji{width:48px;height:48px;margin-bottom:12px}.exam-card strong{display:block;font-size:15px;margin-bottom:8px}.exam-card p{font-size:12px;color:var(--muted);line-height:1.5}.exam-card .pill-btn{width:100%;margin-top:8px}.game-wrap{max-width:740px;margin:0 auto}.memory-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin:20px 0}.memory-card{border:2px solid #edeaf7;background:#fff;border-radius:17px;height:110px;font-size:22px;font-weight:900;color:var(--purple);display:grid;place-items:center;transition:.2s;position:relative}.memory-card.hidden-card{background:linear-gradient(145deg,#8170eb,#6154d8);color:#fff;border-color:#695bdd;font-size:35px}.memory-card.matched{background:#e6faef;border-color:#a2e9c4;color:#228864;cursor:default}.game-banner{background:#fff4de;border:1px solid #ffebbf;border-radius:20px;padding:18px 23px;display:flex;align-items:center;justify-content:space-between;gap:18px}.game-banner strong{display:block}.game-banner p{font-size:12px;color:#b38b4e;line-height:1.5}.homework-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.homework-card{padding:22px}.homework-card h3{font-size:17px;margin:14px 0 6px}.homework-card p{font-size:13px;color:var(--muted);line-height:1.6}.record-panel{background:#f9f7ff;border:1px solid #e7e3fc;border-radius:18px;padding:18px;margin:16px 0}.record-button{width:70px;height:70px;border-radius:50%;border:7px solid #fce1df;background:#ff6d78;color:#fff;font-size:27px;display:grid;place-items:center;margin:16px auto}.record-button.recording{animation:pulse 1s infinite alternate}@keyframes pulse{to{box-shadow:0 0 0 15px #ff8d8645}}.record-note{text-align:center;font-size:12px;color:var(--muted)}.teacher-tiles{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}.teacher-panel{padding:23px;margin-top:18px}.table-wrap{overflow-x:auto}.data-table{width:100%;border-collapse:collapse;font-size:13px}.data-table th{text-align:left;color:#9392ab;font-size:11px;letter-spacing:.7px;padding:13px 10px;border-bottom:1px solid var(--line)}.data-table td{padding:14px 10px;border-bottom:1px solid #f5f3fa}.data-table tr:last-child td{border:0}.form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.field{display:flex;flex-direction:column;gap:7px}.field label{font-size:12px;font-weight:900;color:#7c7a98}.field input,.field select,.field textarea{border:1px solid #e8e7f1;border-radius:12px;background:#fff;padding:12px 13px;color:var(--ink);width:100%;font-size:13px}.field textarea{min-height:92px;resize:vertical}.field.full{grid-column:1/-1}.form-actions{display:flex;justify-content:end;gap:10px;margin-top:17px}.modal-backdrop{position:fixed;inset:0;background:#17173c8c;z-index:20;display:flex;align-items:center;justify-content:center;padding:22px;overflow-y:auto}.modal{width:min(610px,100%);background:#fff;border-radius:24px;padding:29px;box-shadow:0 30px 80px #17173c59;position:relative;max-height:90vh;overflow-y:auto}.modal-close{position:absolute;right:20px;top:19px;border:0;background:#f4f3fb;border-radius:12px;height:37px;width:37px;font-size:19px}.modal h2{margin:0 0 9px}.modal p{color:var(--muted);font-size:13px;line-height:1.65}.demo-banner{margin-top:18px;padding:11px 14px;background:#fff8e9;border:1px solid #ffebc9;border-radius:13px;color:#b4863d;font-size:11px;line-height:1.5}.teacher-alert{background:#ecf9f3;border:1px solid #ccefdc;padding:11px 14px;border-radius:13px;color:#288d65;font-size:12px}.page-footer{text-align:center;color:#aaa9bd;font-size:11px;margin-top:40px}.back-link{border:0;background:none;color:var(--purple);font-weight:900;font-size:13px;padding:0;display:inline-flex;gap:7px;align-items:center;margin-bottom:18px}.loading-screen{height:100vh;display:grid;align-content:center;justify-items:center;gap:12px}.loading-screen p{color:var(--muted)}#toast{position:fixed;bottom:25px;right:25px;z-index:99;pointer-events:none}#toast.show{background:#252452;color:#fff;border-radius:13px;padding:13px 19px;box-shadow:var(--shadow)}.filter-row{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:20px 0}.filter-row select,.filter-row input{border:1px solid #e8e6f1;border-radius:12px;background:#fff;padding:11px 13px;color:var(--ink);font-size:13px}.filter-row input{flex:1;min-width:200px}.small-caps{font-size:11px;text-transform:uppercase;letter-spacing:1.4px;color:var(--muted);font-weight:900}.mobile-bar{display:none}.roadmap{display:flex;gap:15px;align-items:center;border-radius:18px;background:#f1efff;padding:18px;margin-top:12px}.roadmap .icon{font-size:33px}.roadmap p{margin:5px 0;color:#7773a5;font-size:12px;line-height:1.5}
@media(max-width:1250px){.main{padding:0 27px 65px}.unit-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.sidebar{width:225px}.hero-art{right:5%}.dashboard-grid{grid-template-columns:1.45fr 1fr}}
@media(max-width:950px){.sidebar{display:none}.main{padding:0 20px 100px}.mobile-brand{display:flex;gap:8px;align-items:center;font-weight:900}.mobile-brand .logo-mark{width:38px;height:38px;font-size:21px}.top-search{display:none}.unit-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.mobile-bar{position:fixed;left:12px;right:12px;bottom:12px;z-index:12;display:flex;justify-content:space-around;background:#fff;box-shadow:0 15px 40px #35305d30;border:1px solid #efedf7;border-radius:19px;padding:8px}.mobile-bar button{display:grid;gap:3px;justify-items:center;border:0;background:transparent;color:#9392aa;padding:6px 8px;font-weight:800;font-size:10px}.mobile-bar button.active{color:var(--purple)}.mobile-bar .nav-icon{font-size:19px}.teacher-tiles{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:690px){.topbar{height:77px}.main h1{font-size:25px}.hero{padding:26px;min-height:238px}.hero h2{font-size:28px;max-width:250px}.hero p{max-width:240px}.hero-art{font-size:66px;right:4%;bottom:42px}.star-a{right:14%;top:22px}.dashboard-grid{grid-template-columns:1fr}.mini-grid{gap:9px}.stat{padding:13px}.stat .stat-icon{width:35px;height:35px;font-size:19px}.stat strong{font-size:21px}.unit-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:11px}.unit-card{min-height:171px;padding:14px}.book-card{align-items:flex-start;gap:13px}.book-cover{width:95px;height:132px;padding:12px}.book-info h3{font-size:17px}.book-metrics{gap:10px;flex-wrap:wrap;margin:12px 0}.exam-grid,.homework-grid{grid-template-columns:1fr}.lesson-hero{padding:17px;gap:13px}.lesson-hero>.illustration{height:78px;width:78px;font-size:43px;border-radius:18px}.media-row{align-items:flex-start;flex-wrap:wrap}.media-row audio{width:100%}.heading-row{align-items:flex-start}.role-control button{padding:7px 9px}.role-control{gap:2px}.avatar{width:37px;height:37px}.memory-card{height:80px;font-size:17px}.memory-grid{gap:7px}.form-grid{grid-template-columns:1fr}.form-actions{flex-wrap:wrap}.form-actions button{flex:1}.quiz-question{padding:18px}.quiz-question h2{font-size:21px}.answer-option{padding:13px;font-size:13px}.modal{padding:23px}.teacher-tiles{grid-template-columns:repeat(2,minmax(0,1fr))}}

/* Real sign-in and registration experience. */
.auth-screen{min-height:100vh;display:grid;grid-template-columns:minmax(320px,1fr) minmax(400px,1.1fr);background:#fff}
.auth-intro{background:linear-gradient(143deg,#6758df,#8c78ee 75%,#a389f2);color:white;padding:clamp(40px,7vw,110px);display:flex;flex-direction:column;justify-content:center;position:relative;overflow:hidden}
.auth-intro::before{content:'';border:2px dashed #ffffff40;border-radius:50%;position:absolute;width:410px;height:410px;top:-165px;right:-145px}
.auth-logo{width:63px;height:63px;display:grid;place-items:center;background:#ffffff2e;border-radius:20px;font-size:40px;margin-bottom:32px}
.auth-intro .eyebrow{color:#e7dfff}.auth-intro h1{font-size:clamp(38px,4vw,59px);line-height:1.1;letter-spacing:-2px;margin:15px 0 22px;max-width:600px}
.auth-intro p{font-size:16px;line-height:1.8;max-width:500px;color:#ece6ff}.auth-art{font-size:clamp(65px,8vw,135px);letter-spacing:-15px;margin:38px 0 28px;filter:drop-shadow(0 15px 9px #3d258855)}
.auth-trust{font-size:13px;font-weight:800;color:#e7ddff}.auth-panel{display:flex;flex-direction:column;justify-content:center;max-width:720px;width:100%;margin:auto;padding:34px clamp(20px,6vw,70px)}
.auth-switch{display:flex;gap:8px;margin-bottom:18px}.auth-switch button{border:1px solid #ebe8fa;background:#f8f7ff;color:#8b84b5;border-radius:99px;padding:10px 16px;font-size:12px;font-weight:900}.auth-switch button.selected{background:var(--purple);color:#fff}
.auth-card{padding:clamp(24px,4vw,40px)}.auth-card h2{font-size:29px;margin:18px 0 5px}.auth-form{display:grid;gap:16px;margin-top:26px}.auth-form .pill-btn{padding:15px 22px;margin-top:6px}.auth-feedback{font-size:13px;min-height:20px;line-height:1.6}.auth-feedback.error{color:#c8434e}.auth-feedback.success{color:#16895f}.auth-footnote{font-size:11px;color:#9995b7;line-height:1.7;margin-top:22px}.auth-consent{display:flex;gap:10px;font-size:12px;line-height:1.7;color:#77759a}.auth-consent input{align-self:flex-start;flex:none;margin-top:5px}.auth-consent span[lang=zh]{display:block;margin-top:5px}
[hidden]{display:none!important}
@media(max-width:860px){.auth-screen{grid-template-columns:1fr}.auth-intro{padding:35px 25px}.auth-intro h1{font-size:31px;letter-spacing:-.7px;margin:11px 0}.auth-intro p{font-size:13px;margin:0}.auth-logo{margin-bottom:15px}.auth-art{display:none}.auth-trust{margin-top:15px}.auth-panel{padding:25px 18px}.auth-card{padding:23px}}