:root{color:#182022;background:#f3f5f2;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility}*{box-sizing:border-box}body{margin:0;min-width:320px}button,input{font:inherit}button{cursor:pointer}.login-shell{min-height:100vh;display:grid;place-items:center;padding:32px;background:linear-gradient(#13272abd,#13272abd),url(https://images.unsplash.com/photo-1522202176988-66273c2fd55f?auto=format&fit=crop&w=1800&q=80) center / cover}.login-panel{width:min(440px,100%);border-radius:8px;padding:32px;background:#fffffff5;box-shadow:0 24px 80px #00000042}.brand-mark{width:48px;height:48px;display:grid;place-items:center;color:#fff;background:#1f6f68;border-radius:8px;margin-bottom:24px}.eyebrow{margin:0 0 6px;color:#607070;font-size:12px;font-weight:700;letter-spacing:0;text-transform:uppercase}h1,h2,p{margin-top:0}.login-panel h1{margin-bottom:8px;font-size:34px;line-height:1.05}.login-copy{color:#5b6567;margin-bottom:28px}.login-form,.login-form label{display:grid;gap:10px}.login-form{gap:18px}.login-form label{color:#344244;font-weight:700;font-size:14px}.login-form input{width:100%;border:1px solid #c8d1cd;border-radius:8px;padding:13px 14px;background:#fff;color:#182022}.primary-button,.ghost-button,.recording-action,.waiting-tool button,.chat-input button,.icon-button{border:0;border-radius:8px;display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:40px;padding:0 14px;font-weight:800}.primary-button{margin-top:6px;background:#1f6f68;color:#fff}.classroom-shell{height:100vh;display:grid;grid-template-rows:auto minmax(0,1fr) 32px;gap:6px;padding:8px 12px;overflow:hidden;background:#eef2ef}.classroom-shell.has-warning{grid-template-rows:auto auto minmax(0,1fr) 32px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:8px 16px;background:#fff;border:1px solid #d9e1dd;border-radius:8px}.topbar h1{margin:0;font-size:18px;line-height:1.2}.status-strip{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:flex-end}.status-pill{height:32px;display:inline-flex;align-items:center;gap:7px;border-radius:8px;padding:0 12px;color:#3a4546;background:#f4f6f4;border:1px solid #dce4df;font-size:13px;white-space:nowrap}.status-pill.strong{color:#12312f;background:#dcefeb;border-color:#a7cec6;font-weight:800}.status-pill.recording{color:#7a2020;background:#fff1ee;border-color:#f0c5bc;font-weight:800}.record-dot,.recording-tool svg{color:#c93b2d;fill:currentColor}.ghost-button{color:#344244;background:#fff;border:1px solid #cfd9d4}.fullscreen-button,.fullscreen-tip{display:none}.warning-bar{min-height:32px;display:flex;align-items:center;gap:8px;padding:0 14px;color:#6f3d00;background:#fff4da;border:1px solid #ead094;border-radius:8px;font-weight:800}.classroom-grid{min-height:0;display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:8px}.lesson-area{min-width:0;min-height:0;display:grid;grid-template-rows:minmax(0,1fr) auto;gap:6px}.classroom-side{min-width:0;min-height:0;width:340px;display:grid;grid-template-rows:auto minmax(0,1fr);gap:8px}.video-stack{display:grid;gap:8px}.video-tile{min-width:0;display:block;background:#fff;border:1px solid #d9e1dd;border-radius:8px;overflow:hidden}.video-placeholder{position:relative;aspect-ratio:16 / 9;width:100%;display:grid;place-items:center;color:#fff;background:#274348;order:2}.video-placeholder video{width:100%;height:100%;object-fit:contain}.video-placeholder video.mirrored{transform:scaleX(-1)}.video-placeholder.camera-off{background:#1f292b}.camera-off-label{width:36px;height:36px;display:grid;place-items:center;border-radius:50%;background:#db8c4b;font-weight:900}.video-placeholder.camera-off .camera-off-label{width:auto;height:auto;min-height:32px;padding:0 12px;border-radius:8px;background:#374548;color:#d7e1dd;font-size:13px}.video-meta{position:absolute;inset:0 0 auto;z-index:2;min-width:0;display:flex;align-items:center;justify-content:space-between;gap:8px;min-height:32px;padding:6px 8px;color:#fff;background:linear-gradient(#0d181ab8,#0d181a00);pointer-events:none}.video-meta strong,.video-meta span{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.video-meta span{color:#ffffffd1;font-size:12px}.mini-icons{display:flex;gap:6px;pointer-events:auto}.audio-activity{width:34px;height:22px;display:inline-flex;align-items:center;justify-content:center;gap:3px;flex:0 0 auto}.audio-activity span{width:4px;min-height:4px;border-radius:999px;background:#cbd7d1;transition:height 90ms ease-out,background-color .14s ease-out}.audio-activity.active span{background:#1f6f68}.media-toggle{width:28px;height:28px;display:inline-flex;align-items:center;justify-content:center;border:1px solid #cbd7d1;border-radius:8px;background:#fff}.media-toggle.on{color:#1f6f68}.media-toggle.off{color:#8d2f28;background:#fff1ee;border-color:#e9bcb4}.media-toggle:disabled{opacity:.48;cursor:not-allowed}.lesson-viewer{position:relative;min-height:0;overflow:hidden;display:grid;place-items:center;container-type:size;padding:6px;background:#f7f9f7;border:1px solid #d9e1dd;border-radius:8px}.lesson-nav{position:absolute;top:50%;z-index:5;width:50px;height:64px;display:inline-flex;align-items:center;justify-content:center;border:1px solid rgba(31,111,104,.24);border-radius:8px;color:#1f6f68;background:#ffffffeb;box-shadow:0 12px 28px #17262629;transform:translateY(-50%)}.lesson-nav-left{left:18px}.lesson-nav-right{right:18px}.lesson-nav:disabled{opacity:.42;cursor:not-allowed}.lesson-card{width:min(100cqw,177.78cqh);max-width:100%;max-height:100%;aspect-ratio:16 / 9;position:relative;display:grid;align-content:center;padding:clamp(16px,3.5cqh,30px);background:#fffdf8;border:1px solid #e2d7bf;border-radius:8px;box-shadow:0 14px 32px #282e2a1a;z-index:1;overflow:hidden}.lesson-page{color:#1f6f68;font-weight:900;margin-bottom:clamp(6px,1.3cqh,10px);position:relative;z-index:2}.lesson-card h2{margin-bottom:clamp(6px,1.2cqh,10px);font-size:clamp(30px,4.6cqw,50px);line-height:1.02;position:relative;z-index:2}.lesson-card.has-material{align-content:stretch;padding:clamp(12px,2.3cqh,22px)}.lesson-material-shell{position:relative;z-index:2;min-height:0;display:grid;grid-template-rows:minmax(0,1fr)}.lesson-prompt{color:#435052;font-size:clamp(15px,1.55cqw,19px);position:relative;z-index:2}.lesson-pending{position:relative;z-index:2;display:grid;place-items:center;gap:clamp(10px,2cqh,18px);text-align:center;color:#1f6f68;min-height:100%}.lesson-pending h2{max-width:15ch;margin:0}.lesson-board{display:grid;gap:clamp(6px,1.2cqh,10px);margin-top:clamp(8px,1.8cqh,14px);position:relative;z-index:2}.lesson-material-frame{position:relative;z-index:2;width:100%;height:100%;min-height:0;border:1px solid #d8ded9;border-radius:8px;background:#fff}.lesson-material-image{position:relative;z-index:2;width:100%;height:100%;min-height:0;object-fit:contain;border:1px solid #d8ded9;border-radius:8px;background:#fff}.sentence-card{display:flex;align-items:center;gap:12px;min-height:clamp(34px,6.3cqh,48px);padding:clamp(6px,1.1cqh,9px) 14px;color:#233033;background:#fff;border:1px solid #d8ded9;border-radius:8px;font-size:clamp(15px,1.6cqw,19px);font-weight:800}.sentence-card svg{color:#1f6f68;flex:0 0 auto}.watermark{position:absolute;inset:-120px;display:grid;grid-template-columns:repeat(3,1fr);gap:42px;transform:rotate(-24deg);color:#1f6f6847;font-size:18px;font-weight:900;pointer-events:none;-webkit-user-select:none;user-select:none;z-index:4}.watermark-banner{position:absolute;top:clamp(12px,3cqh,24px);left:50%;z-index:6;transform:translate(-50%);padding:8px 18px;border:2px solid rgba(127,29,29,.5);border-radius:8px;color:#7f1d1deb;background:#ffffffc7;font-size:clamp(16px,2.2cqw,28px);font-weight:950;letter-spacing:0;white-space:nowrap;pointer-events:none;-webkit-user-select:none;user-select:none}.annotation-layer{position:absolute;inset:0;z-index:3;width:100%;height:100%;pointer-events:none;touch-action:none}.annotation-layer.active{pointer-events:auto}.annotation-layer.pen,.annotation-layer.shape{cursor:crosshair}.annotation-layer.erase{cursor:cell}.annotation-layer.laser{cursor:none}.laser-dot{fill:#ef1d1d;filter:drop-shadow(0 0 7px rgba(239,29,29,.95));pointer-events:none}.toolkit{min-height:48px;display:flex;align-items:center;gap:6px;padding:6px;overflow:hidden;background:#fff;border:1px solid #d9e1dd;border-radius:8px}.tool-button,.icon-button{width:34px;height:34px;flex:0 0 34px;padding:0;border:1px solid #d2ddd7;background:#f8faf8;color:#2d3a3c}.tool-button.active{color:#fff;border-color:#1f6f68;background:#1f6f68}.tool-button:disabled,.waiting-tool button:disabled{opacity:.45;cursor:not-allowed}.tool-divider{width:1px;height:30px;background:#dce4df;margin:0 2px}.segmented{display:flex;align-items:center;gap:4px;padding:4px;background:#f0f4f2;border-radius:8px}.shape-control{display:inline-flex;align-items:center;gap:4px}.shape-control select{height:34px;max-width:112px;border:1px solid #d2ddd7;border-radius:8px;background:#fff;color:#2d3a3c;font-size:12px;font-weight:800;padding:0 8px}.tool-spacer{flex:1 1 auto}.waiting-tool,.timer-tool,.recording-tool{min-height:34px;display:inline-flex;align-items:center;gap:8px;flex:0 0 auto;padding:0 8px;border-radius:8px;background:#f8faf8;border:1px solid #dce4df;font-weight:800;font-size:12px}.waiting-tool button{min-height:28px;color:#fff;background:#1f6f68;padding:0 8px}.recording-tool{color:#7a2020}.recording-action{color:#fff;background:#1f6f68;flex:0 0 auto;min-height:34px;padding:0 10px}.recording-action.active{background:#a13d34}.recording-action svg{fill:currentColor}.chat-panel{position:relative;min-height:0;width:100%;display:grid;grid-template-rows:auto minmax(0,1fr) auto auto;background:#fff;border:1px solid #d9e1dd;border-radius:8px;overflow:hidden}.chat-panel.drag-active{outline:3px solid rgba(31,111,104,.35);outline-offset:-4px}.chat-header{display:flex;align-items:center;justify-content:space-between;min-height:74px;padding:14px;border-bottom:1px solid #e0e7e3}.chat-header h2{margin:0;font-size:18px}.messages{min-height:0;overflow-y:auto;padding:14px;display:flex;flex-direction:column;gap:10px}.message{padding:10px 12px;border-radius:8px;background:#f2f5f3}.message.teacher{background:#e9f3f0}.message>div{display:flex;justify-content:space-between;gap:10px;color:#526061;font-size:12px}.message p{margin:6px 0 0;color:#1f292b;line-height:1.35}.chat-image{width:100%;display:grid;gap:6px;margin-top:8px;padding:0;border:0;background:transparent;color:#344244;text-align:left}.chat-image img{width:100%;max-height:180px;object-fit:contain;border-radius:8px;border:1px solid #cfd9d4;background:#fff}.chat-image span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:12px;font-weight:800}.latest-button{position:absolute;right:14px;bottom:70px;min-height:32px;display:inline-flex;align-items:center;gap:6px;padding:0 10px;border:1px solid #b7cbc5;border-radius:8px;color:#1f6f68;background:#fff;font-weight:800}.chat-input{display:grid;grid-template-columns:42px minmax(0,1fr) 42px;gap:8px;padding:12px;border-top:1px solid #e0e7e3}.chat-input input:not(.file-input){min-width:0;border:1px solid #cfd9d4;border-radius:8px;padding:0 12px}.chat-input button{width:42px;padding:0;color:#fff;background:#1f6f68}.attach-button{color:#1f6f68!important;background:#eef6f3!important;border:1px solid #c6d8d2!important}.file-input{display:none}.chat-error{padding:0 12px 10px;color:#8d2f28;font-size:12px;font-weight:800}.image-preview-backdrop{position:fixed;inset:0;z-index:10;display:grid;place-items:center;padding:32px;background:#11181ab8}.image-preview-backdrop img{max-width:min(1080px,94vw);max-height:88vh;object-fit:contain;border-radius:8px;background:#fff;box-shadow:0 24px 90px #00000057}.preview-close{position:absolute;top:18px;right:18px;width:40px;height:40px;display:inline-flex;align-items:center;justify-content:center;border:0;border-radius:8px;color:#fff;background:#0000007a}.modal-backdrop{position:fixed;inset:0;z-index:12;display:grid;place-items:center;padding:24px;background:#11181a8a}.confirm-modal{width:min(420px,100%);padding:22px;border:1px solid #d9e1dd;border-radius:8px;background:#fff;box-shadow:0 24px 80px #00000042}.confirm-modal h2{margin:0 0 8px;color:#182022;font-size:20px;line-height:1.2}.confirm-modal p{margin:0;color:#526061;line-height:1.45}.confirm-modal-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:22px}.modal-cancel-button,.modal-danger-button{min-height:38px;padding:0 14px;border-radius:8px;font-weight:800}.modal-cancel-button{color:#344244;background:#fff;border:1px solid #cfd9d4}.modal-danger-button{color:#fff;background:#a13d34;border:1px solid #8d332c}.recording-footer{height:32px;min-height:32px;display:flex;align-items:center;gap:10px;padding:0 10px;background:#fff;border:1px solid #d9e1dd;border-radius:8px;color:#4c5a5b;overflow:hidden;font-size:13px}.recording-footer span{font-weight:800}.recording-footer code{min-width:0;flex:1 1 auto;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:#1f6f68}.recording-footer .icon-button{width:30px;height:30px;flex-basis:30px}@media(max-width:980px){.classroom-shell{min-height:900px;overflow:auto}.topbar,.classroom-grid{grid-template-columns:1fr}.topbar,.classroom-grid{display:grid}.classroom-side{width:100%}.video-stack{grid-template-columns:repeat(2,minmax(0,1fr))}.chat-panel{width:100%;min-height:360px}}@media(max-width:680px){.login-shell{padding:18px}.login-panel{padding:24px}.classroom-shell{padding:10px}.video-stack{grid-template-columns:1fr}.video-placeholder{min-height:96px}.lesson-card{width:calc(100% - 24px);padding:24px}.sentence-card{font-size:16px}}.mobile-rotate-notice{display:none}@media(hover:none)and (pointer:coarse)and (max-width:940px)and (orientation:portrait){body{overflow:hidden}.mobile-rotate-notice{min-height:100dvh;display:grid;place-content:center;justify-items:center;gap:14px;padding:max(24px,env(safe-area-inset-top)) max(20px,env(safe-area-inset-right)) max(24px,env(safe-area-inset-bottom)) max(20px,env(safe-area-inset-left));color:#152224;text-align:center;background:#eef2ef}.rotate-phone-mark{width:48px;height:78px;border:4px solid #1f6f68;border-radius:8px;position:relative;transform:rotate(90deg);background:#fff;box-shadow:0 18px 40px #17262629}.rotate-phone-mark:after{content:"";position:absolute;left:50%;bottom:7px;width:9px;height:9px;border-radius:50%;background:#1f6f68;transform:translate(-50%)}.mobile-rotate-notice h1{margin:0;font-size:28px;line-height:1.08}.mobile-rotate-notice p{max-width:280px;margin:0;color:#526061;line-height:1.45}.classroom-shell{display:none}}@media(hover:none)and (pointer:coarse)and (max-width:940px)and (orientation:landscape){html,body,#root{width:100%;height:100%;overflow:hidden}.mobile-rotate-notice{display:none}.classroom-shell,.classroom-shell.has-warning{height:100dvh;min-height:0;display:grid;grid-template-rows:38px minmax(0,1fr) 28px;gap:0;padding:0;overflow:hidden}.classroom-shell.has-warning,.classroom-shell.has-fullscreen-tip{grid-template-rows:38px 28px minmax(0,1fr) 28px}.classroom-shell.viewer-student{grid-template-rows:38px minmax(0,1fr)}.classroom-shell.viewer-student.has-warning,.classroom-shell.viewer-student.has-fullscreen-tip{grid-template-rows:38px 28px minmax(0,1fr)}.topbar{min-height:0;display:flex;gap:8px;padding:4px 8px;overflow:hidden;border-radius:0}.topbar .eyebrow{display:none}.topbar h1{max-width:40vw;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px;line-height:1.1}.status-strip{min-width:0;flex-wrap:nowrap;gap:4px}.status-pill{height:28px;max-width:24vw;gap:4px;padding:0 7px;font-size:11px}.status-pill span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.ghost-button{min-height:28px;padding:0 9px;flex:0 0 auto}.fullscreen-button{position:fixed;left:42%;bottom:max(12px,env(safe-area-inset-bottom));z-index:20;min-height:28px;display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:0 12px;border:1px solid #a7cec6;border-radius:8px;color:#12312f;background:#dcefeb;box-shadow:0 10px 28px #1726262e;font-weight:800;font-size:11px;transform:translate(-50%)}.fullscreen-tip{min-height:28px;display:flex;align-items:center;padding:0 8px;overflow:hidden;color:#12312f;background:#dcefeb;border:1px solid #a7cec6;font-size:12px;font-weight:800}.warning-bar{min-height:28px;padding:0 8px;overflow:hidden;font-size:12px}.classroom-grid{min-height:0;display:grid;grid-template-columns:minmax(0,1fr) clamp(168px,29vw,240px);gap:0}.lesson-area{min-height:0;grid-template-rows:minmax(0,1fr) auto;gap:4px}.classroom-side{width:auto;min-height:0;grid-template-rows:auto minmax(0,1fr);gap:4px}.video-stack{grid-template-columns:repeat(2,minmax(0,1fr));gap:4px}.video-tile{border-radius:6px}.video-placeholder{min-height:0}.video-meta{min-height:24px;gap:4px;padding:3px 5px;font-size:11px}.video-meta span{display:none}.mini-icons{gap:3px}.audio-activity{width:24px;height:20px}.media-toggle{width:24px;height:24px;border-radius:6px}.camera-off-label,.video-placeholder.camera-off .camera-off-label{min-height:24px;padding:0 8px;font-size:11px}.lesson-viewer{padding:3px;border-radius:0}.lesson-card{width:min(100cqw,177.78cqh);padding:clamp(8px,2.2cqh,16px);border-radius:6px}.lesson-card.has-material{padding:clamp(6px,1.5cqh,12px)}.lesson-page{margin-bottom:clamp(3px,.9cqh,6px);font-size:clamp(10px,1.4cqw,13px)}.lesson-card h2{margin-bottom:clamp(4px,1cqh,7px);font-size:clamp(18px,3.3cqw,30px)}.lesson-prompt{font-size:clamp(11px,1.45cqw,15px);line-height:1.25}.lesson-board{gap:clamp(3px,.9cqh,6px);margin-top:clamp(4px,1.2cqh,8px)}.lesson-material-frame{min-height:0;height:100%}.sentence-card{min-height:clamp(24px,5.4cqh,34px);gap:6px;padding:clamp(3px,.8cqh,6px) 8px;font-size:clamp(11px,1.45cqw,15px);line-height:1.2}.lesson-nav{width:34px;height:44px;border-radius:6px}.lesson-nav-left{left:6px}.lesson-nav-right{right:6px}.toolkit{min-height:40px;gap:4px;padding:3px;overflow-x:auto;overflow-y:hidden;border-radius:0;-webkit-overflow-scrolling:touch}.tool-button,.icon-button{width:30px;height:30px;flex-basis:30px;border-radius:6px}.segmented{gap:2px;padding:2px;border-radius:6px}.shape-control select{height:30px;max-width:92px;font-size:11px}.tool-divider{height:24px}.waiting-tool,.timer-tool,.recording-tool{min-height:30px;gap:5px;padding:0 6px;border-radius:6px;font-size:11px}.waiting-tool span{display:none}.waiting-tool button,.recording-action{width:30px;flex:0 0 30px;min-height:28px;gap:0;padding:0;border-radius:6px;font-size:0}.recording-tool{display:none}.chat-panel{min-height:0;border-radius:0;grid-template-rows:34px minmax(0,1fr) 38px auto}.chat-header{min-height:34px;padding:5px 8px}.chat-header .eyebrow,.chat-header svg{display:none}.chat-header h2{max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}.messages{gap:5px;padding:6px}.message{padding:6px 7px;border-radius:6px}.message>div{gap:4px;font-size:10px}.message p{margin-top:3px;font-size:11px;line-height:1.25}.chat-image{gap:4px;margin-top:5px}.chat-image img{max-height:82px;border-radius:6px}.latest-button{right:6px;bottom:44px;min-height:26px;padding:0 7px;font-size:11px}.chat-input{grid-template-columns:32px minmax(0,1fr) 32px;gap:4px;padding:4px}.chat-input input:not(.file-input){min-height:30px;padding:0 8px;font-size:12px}.chat-input button{width:32px;min-height:30px;border-radius:6px}.chat-error{padding:0 6px 5px;font-size:10px}.recording-footer{height:28px;min-height:28px;gap:6px;padding:0 7px;border-radius:0;font-size:11px}.recording-footer .icon-button{width:24px;height:24px;flex-basis:24px}}
