:root{--et-blue:#0b4fa8;--et-blue2:#072f69;--et-bg:#f5f8fc;--et-border:#dbe5f2;--et-text:#12233f}
.et-app,.et-auth,.et-admin{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--et-text)}
.et-head{display:flex;justify-content:space-between;gap:20px;align-items:center;background:linear-gradient(135deg,var(--et-blue),var(--et-blue2));color:#fff;padding:22px 26px;border-radius:18px}.et-head h1{margin:6px 0;color:#fff}.et-head p{margin:0;opacity:.9}.et-badge{background:#fff;color:var(--et-blue);font-weight:900;padding:4px 9px;border-radius:999px}.et-user{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.et-user span{background:#ffffff18;padding:8px 12px;border-radius:10px}
.et-tabs{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0}.et-tabs button{border:0;background:#eaf1fb;padding:10px 14px;border-radius:10px;font-weight:800;cursor:pointer}.et-tabs button.active{background:var(--et-blue);color:#fff}.et-tab{display:none}.et-tab.active{display:block}.et-layout{display:grid;grid-template-columns:275px 1fr;gap:14px}.et-side,.et-chat,.et-card,.et-plan,.et-board,.et-avatar{background:#fff;border:1px solid var(--et-border);border-radius:16px;box-shadow:0 4px 18px #163b6810}.et-side{padding:16px}.et-side label{display:block;font-weight:800;margin:0 0 6px}.et-side select,.et-side input,.et-row input,.et-row select,.et-auth input,.et-admin-form input,.et-admin-form select,.et-admin-form textarea,.et-settings-grid input{width:100%;box-sizing:border-box;margin:0 0 12px;min-height:40px}.et-upload{margin-top:15px;border:1px dashed #a8bfdc;border-radius:12px;padding:12px}.et-upload small{display:block;color:#64748b;margin-top:8px}.et-upload span{display:block;background:#eef5ff;padding:5px 8px;border-radius:7px;margin-top:5px}.et-chat{overflow:hidden}.et-chat #et-messages{height:560px;overflow:auto;background:#f8fbff;padding:18px}.et-welcome{text-align:center;padding:100px 20px}.et-msg{max-width:88%;padding:12px 14px;border-radius:14px;margin-bottom:14px}.et-msg.user{margin-left:auto;background:var(--et-blue);color:#fff}.et-msg.assistant{background:#fff;border:1px solid var(--et-border)}.et-msg b{display:block;font-size:11px;text-transform:uppercase;margin-bottom:6px}.et-msg small{display:block;margin-top:8px;opacity:.65}.et-msg pre{white-space:pre-wrap;background:#0b1725;color:#eaf2ff;padding:12px;border-radius:9px}.et-compose{padding:13px;border-top:1px solid var(--et-border)}.et-compose textarea{width:100%;box-sizing:border-box;border-radius:10px}.et-compose>div{display:flex;gap:8px;justify-content:flex-end;margin-top:8px}
.et-card{padding:20px;margin:14px 0}.et-row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}.et-row>*{flex:1;min-width:140px}.et-q{padding:14px 0;border-bottom:1px solid #e5edf6}.et-q small{display:block;color:#60728b;margin:4px 0}.et-q label{display:block;padding:5px 0}.et-analysis{margin-top:15px;background:#eef6ff;border-left:4px solid var(--et-blue);padding:14px;border-radius:8px}
.et-teacher-wrap{display:grid;grid-template-columns:210px 1fr;gap:16px}.et-avatar{text-align:center;padding:22px;background:linear-gradient(180deg,#fff,#eef5ff)}.et-face{width:120px;height:140px;margin:0 auto 12px;border-radius:50% 50% 45% 45%;background:#f4c7a1;position:relative;border:5px solid #163b68;box-shadow:inset 0 -8px 0 #e5ae82}.et-eyes{position:absolute;top:48px;left:0;right:0;font-size:24px;letter-spacing:23px;padding-left:18px}.et-mouth{position:absolute;bottom:33px;left:48px;width:25px;height:8px;border-bottom:3px solid #7d2c2c;border-radius:50%}.et-mouth.talking{animation:talk .22s infinite alternate}@keyframes talk{to{height:18px;border:3px solid #7d2c2c;background:#421717}}.et-avatar strong,.et-avatar span{display:block}.et-avatar span{color:#64748b;font-size:12px}.et-board{background:#173b2f;color:#fff;min-height:520px;padding:20px;border:10px solid #8a6038;box-shadow:inset 0 0 20px #0005}.et-board-top{display:flex;gap:8px;flex-wrap:wrap}.et-board-top>*{min-height:38px}.et-board-top input{flex:1;min-width:180px}.et-board-text{font-family:"Comic Sans MS",cursive;font-size:24px;line-height:1.55;white-space:pre-wrap;padding:35px 20px;min-height:200px}.et-ask{background:#fff;color:var(--et-text);padding:14px;border-radius:12px}.et-ask .button{margin:8px 6px 0 0}.et-feedback{margin-top:10px}.et-teacher-controls{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}.et-done{margin-top:25px;background:#ffffff1a;padding:10px;border-radius:8px}
.et-plan-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.et-plan{text-align:center;padding:22px}.et-price{font-size:34px;font-weight:900;color:var(--et-blue)}
.et-auth{max-width:900px;margin:40px auto}.et-brand{text-align:center;background:linear-gradient(135deg,var(--et-blue),var(--et-blue2));color:#fff;padding:30px;border-radius:18px}.et-brand h1{color:#fff}.et-logo{width:58px;height:58px;border-radius:16px;background:#fff;color:var(--et-blue);display:grid;place-items:center;font-size:36px;font-weight:900;margin:auto}.et-authgrid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:14px}.et-auth .et-card{padding:24px}.et-auth small{display:block;margin-top:8px;color:#64748b}
.et-admin{max-width:1500px}.et-admin-tabs{display:flex;gap:10px;flex-wrap:wrap}.et-admin-tabs a{background:#eaf1fb;padding:8px 12px;border-radius:8px;text-decoration:none;font-weight:800}.et-settings-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.et-settings-grid label{font-weight:800}.et-admin-form{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.et-admin-form textarea{grid-column:1/-1;min-height:100px}.et-admin-form button{grid-column:1/-1;width:max-content}#et-toast{position:fixed;right:20px;bottom:20px;background:#10233f;color:#fff;padding:12px 16px;border-radius:10px;z-index:999999;box-shadow:0 8px 26px #0004}
@media(max-width:900px){.et-layout,.et-teacher-wrap{grid-template-columns:1fr}.et-plan-grid{grid-template-columns:1fr}.et-authgrid{grid-template-columns:1fr}.et-settings-grid,.et-admin-form{grid-template-columns:1fr}.et-admin-form textarea,.et-admin-form button{grid-column:auto}.et-chat #et-messages{height:480px}.et-head{flex-direction:column;align-items:flex-start}}@media(max-width:520px){.et-chat #et-messages{height:430px}.et-msg{max-width:97%}.et-board-text{font-size:20px;padding:25px 8px}.et-teacher-controls{flex-direction:column}}
.et-ref-card{max-width:950px}.et-ref-code{display:flex;gap:18px;align-items:center;justify-content:space-between;background:#f3f8ff;border:1px solid #cfe1ff;padding:16px 18px;border-radius:12px;margin:14px 0}.et-ref-code strong{font-size:22px;letter-spacing:1px;color:#104f9f}.et-ref-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}.et-ref-stats>div{background:#fff;border:1px solid #e1e7ef;border-radius:12px;padding:16px;text-align:center}.et-ref-stats b{display:block;font-size:24px;color:#104f9f}.et-ref-stats span{display:block;font-size:12px;color:#65758b;margin-top:4px}#et-ref-link{min-width:320px;flex:1}@media(max-width:700px){.et-ref-stats{grid-template-columns:1fr}.et-ref-code{align-items:flex-start;flex-direction:column}#et-ref-link{min-width:0;width:100%}}
.et-upload-label{display:flex;flex-direction:column;gap:5px;padding:12px;border:1px dashed #aac2e7;border-radius:10px;background:#f7fbff}.et-upload-label span{font-size:12px;color:#64748b}.et-source-toolbar{display:grid;grid-template-columns:minmax(150px,190px) minmax(220px,1fr) auto;gap:8px;align-items:center}.et-file-status{margin-top:8px;font-size:12px;color:#334155}.et-file-status ul,.et-source-list ul{margin:7px 0 0 18px}.et-source-list{margin-top:8px}.et-source-list li{margin:3px 0}.et-source-list small{color:#64748b}.et-library-table td{vertical-align:top}@media(max-width:900px){.et-source-toolbar{grid-template-columns:1fr}.et-source-toolbar .button{width:100%}}
/* v3.0 classroom + admin controls */
.et-key-status{display:inline-block;margin:5px 6px 0 0;font-size:12px;color:#166534;font-weight:700}
.et-teacher-stage{display:grid;grid-template-columns:280px minmax(0,1fr);gap:18px;align-items:start}
.et-teacher-panel{background:#fff;border:1px solid var(--et-border);border-radius:18px;padding:16px;box-shadow:0 4px 18px #163b6810;position:sticky;top:20px;text-align:center}
.et-photo-wrap{position:relative;width:210px;height:265px;margin:0 auto 12px;border-radius:22px;overflow:hidden;border:3px solid #e4ecf7;background:#eef4fb;box-shadow:0 8px 28px #19385b25;transform-origin:50% 85%}
.et-teacher-photo{width:100%;height:100%;object-fit:cover;object-position:center 18%;display:block}
.et-photo-wrap.speaking{animation:etTeacherTalk 1.7s ease-in-out infinite}
.et-photo-wrap.speaking:after{content:"";position:absolute;left:47%;top:34.5%;width:10%;height:4%;border-radius:50%;background:#8a1e2d44;animation:etMouthPulse .22s alternate infinite;mix-blend-mode:multiply}
.et-speaking-dot{position:absolute;right:10px;bottom:10px;width:12px;height:12px;border-radius:50%;background:#22c55e;box-shadow:0 0 0 0 #22c55e88}
.et-photo-wrap.speaking .et-speaking-dot{animation:etPulse 1s infinite}
@keyframes etTeacherTalk{0%,100%{transform:translateY(0) scale(1)}50%{transform:translateY(-2px) scale(1.008)}}
@keyframes etMouthPulse{to{height:7%;transform:scaleX(.85)}}
@keyframes etPulse{70%{box-shadow:0 0 0 10px #22c55e00}}
.et-teacher-panel strong{display:block;font-size:20px;color:#102d54}.et-teacher-panel>span{display:block;color:#64748b;margin-bottom:14px}
.et-class-options{text-align:left}.et-class-options label{display:block;font-weight:800;font-size:12px;margin:8px 0}.et-class-options select,.et-class-options input{width:100%;min-height:40px;margin-top:5px;box-sizing:border-box}
.et-teacher-controls{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:12px}.et-teacher-controls .button:last-child{grid-column:1/-1}
.et-classroom{min-width:0}.et-board{position:relative;background:radial-gradient(circle at 30% 20%,#214e3e,#12362b 70%);color:#fff;min-height:560px;padding:40px 52px 52px;border:14px solid #805a36;border-radius:8px;box-shadow:inset 0 0 28px #0007,0 7px 20px #0002;overflow:hidden}
.et-chalk-title{position:absolute;top:12px;right:18px;font-size:11px;letter-spacing:2px;opacity:.2;font-weight:900}
.et-board-text{font-family:"Comic Sans MS","Segoe Print",cursive;font-size:25px;line-height:1.65;white-space:pre-wrap;min-height:430px;padding:0;margin:0;text-shadow:0 1px 1px #0004}
.et-writing-hand{display:none;position:absolute;right:18%;bottom:28%;font-size:42px;filter:drop-shadow(0 3px 3px #0006);transform:rotate(-12deg);z-index:3}.et-writing-hand.writing{display:block;animation:etWriteHand 2.2s ease-in-out infinite}
@keyframes etWriteHand{0%{right:72%;bottom:38%;transform:rotate(-14deg)}35%{right:30%;bottom:38%;transform:rotate(-7deg)}50%{right:70%;bottom:31%;transform:rotate(-14deg)}85%{right:25%;bottom:31%;transform:rotate(-7deg)}100%{right:72%;bottom:24%;transform:rotate(-14deg)}}
.et-question-dock{margin-top:14px}.et-question-dock .et-ask{background:#fff;border:1px solid var(--et-border);box-shadow:0 4px 14px #17395d12;padding:16px;border-radius:14px;color:var(--et-text)}
.et-table-scroll{overflow:auto}.et-table-scroll table{min-width:1150px}.et-table-scroll input,.et-table-scroll select{min-height:34px;max-width:190px}
@media(max-width:900px){.et-teacher-stage{grid-template-columns:1fr}.et-teacher-panel{position:static}.et-photo-wrap{width:170px;height:215px}.et-board{min-height:460px;padding:30px 22px}.et-board-text{font-size:21px;min-height:360px}}

/* v3.2 real-teacher presentation mode */
.et-panel-head{display:inline-block;background:#eaf2ff;color:#0f4ca0;font-size:11px;letter-spacing:.4px;font-weight:900;padding:7px 10px;border-radius:999px;margin-bottom:10px;text-transform:uppercase}
.et-live-badge{display:inline-block;background:#f4f8ff;color:#345178;border:1px solid #d9e5f7;border-radius:999px;padding:7px 11px;font-size:12px;font-weight:700;margin-bottom:14px}
.et-real-avatar{width:230px;height:290px;border-radius:26px;box-shadow:0 12px 30px #17355b20;}.et-real-avatar .et-teacher-photo{object-position:center 12%}
.et-lesson-side{margin-top:14px;text-align:left;background:#f7fbff;border:1px solid #dbe8f8;border-radius:16px;padding:14px 14px 12px}.et-lesson-title{font-weight:900;color:#102d54;margin-bottom:6px}.et-lesson-progress{font-size:12px;font-weight:800;color:#0f4ca0;margin-bottom:8px}.et-lesson-point{font-size:13px;line-height:1.5;color:#475569}
.et-board-shell{background:#f4efe8;border-radius:14px;padding:14px;box-shadow:0 10px 24px #0000000d}.et-board{border-radius:4px;border-width:12px;min-height:590px}.et-board-text{font-size:27px;line-height:1.7}.et-writing-hand{font-size:46px}
.et-mode-real .et-teacher-panel{padding:18px 18px 16px}.et-mode-real .et-teacher-controls{grid-template-columns:1fr 1fr}.et-mode-real .et-teacher-controls .button:last-child{grid-column:1/-1}
@media(max-width:900px){.et-real-avatar{width:180px;height:230px}.et-board-shell{padding:8px}.et-board{min-height:500px}.et-board-text{font-size:22px}}
/* v3.3 clean classroom + playback safety */
.et-clean-classroom{grid-template-columns:250px minmax(0,1fr)}
.et-control-panel{padding:18px;text-align:left;position:sticky;top:20px}
.et-control-title{display:block;font-size:20px;color:#102d54;margin:2px 0 4px}
.et-control-sub{display:block;font-size:12px;color:#64748b;margin-bottom:14px}
.et-playback-controls{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:12px}
.et-playback-controls #et-teacher-skip{grid-column:1/-1}
.et-playback-controls .button,.et-teacher-controls .button{min-height:38px}
.et-clean-classroom .et-board-shell{background:#f4efe8;border-radius:14px;padding:14px;box-shadow:0 10px 24px #0000000d}
.et-clean-classroom .et-board{min-height:600px;padding:44px 54px 52px;border:14px solid #805a36;background:radial-gradient(circle at 30% 20%,#214e3e,#12362b 70%)}
.et-clean-classroom .et-board-text{font-size:27px;line-height:1.7;min-height:500px}
.et-clean-classroom .et-lesson-side{margin-top:14px}
#et-teaching-speed{font-weight:800}
@media(max-width:900px){.et-clean-classroom{grid-template-columns:1fr}.et-control-panel{position:static}.et-clean-classroom .et-board{min-height:500px;padding:30px 24px}.et-clean-classroom .et-board-text{font-size:22px;min-height:410px}}