:root{--ink:#16324a;--muted:#52697b;--navy:#103d5a;--blue:#175ea0;--accent:#efb437;--line:#dce5ec;--bg:#f3f6f9;--white:#fff;color:var(--ink);background:var(--bg);font-family:Arial,Helvetica,sans-serif}*{box-sizing:border-box}body{margin:0;font-size:16px;line-height:1.55}button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button,.button{background:var(--blue);color:#fff;cursor:pointer;border:1px solid #0000;border-radius:9px;justify-content:center;align-items:center;gap:8px;padding:11px 17px;font-size:.9rem;font-weight:600;text-decoration:none;display:inline-flex}button:hover,.button:hover{filter:brightness(.95)}button:disabled{opacity:.55;cursor:wait}a{color:var(--blue);text-underline-offset:3px}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid var(--accent);outline-offset:3px}h1,h2,h3,p{margin-top:0}h1{letter-spacing:-.035em;margin-bottom:10px;font-size:2rem;line-height:1.22}h2{margin-bottom:18px;font-size:1.22rem;line-height:1.35}h3{margin-bottom:9px;font-size:1.06rem;line-height:1.4}p{margin-bottom:16px}small{font-size:.85rem}svg{vertical-align:middle;flex-shrink:0;display:inline-block}.app-shell{min-height:100vh;display:flex}.sidebar{background:var(--navy);color:#fff;z-index:30;flex-direction:column;width:252px;padding:33px 18px;display:flex;position:fixed;inset:0 auto 0 0}.brand{color:#fff;letter-spacing:.05em;align-items:center;gap:12px;margin:0 9px 46px;font-size:.92rem;font-weight:700;text-decoration:none;display:flex}.brand small{letter-spacing:.02em;color:#b9d3e5;margin-top:3px;font-size:.78rem;font-weight:400;display:block}.brand-mark{background:var(--accent);width:40px;height:40px;color:var(--navy);border-radius:11px;flex-shrink:0;justify-content:center;align-items:center;font-size:1.4rem;font-weight:800;display:flex}.nav-label{color:#adc3d3;letter-spacing:.1em;padding:0 14px 17px;font-size:.73rem}.nav-item{color:#d6e2ed;text-align:left;background:0 0;border:0;justify-content:flex-start;gap:11px;width:100%;margin:0 0 7px;padding:14px 13px;font-size:.87rem}.nav-item.active{color:#fff;box-shadow:inset 3px 0 var(--accent);background:#245570}.nav-count{color:var(--navy);background:#fff;border-radius:20px;margin-left:auto;padding:0 7px;font-size:.75rem}.sidebar-bottom{margin-top:auto;padding:38px 10px 0}.private-note{color:#e0ebf3;gap:11px;margin-bottom:23px;font-size:.82rem;display:flex}.private-note small{color:#aec8db;margin-top:6px;font-size:.75rem;display:block}.sidebar-bottom>a{color:#c5d9e8;margin-bottom:11px;font-size:.84rem;display:block}.workspace{width:calc(100% - 252px);margin-left:252px}.topbar{border-bottom:1px solid var(--line);background:#fff;justify-content:space-between;align-items:center;gap:18px;height:87px;padding:0 40px;display:flex}.topbar-title{color:var(--muted);align-items:center;gap:10px;font-size:.84rem;display:flex}.topbar-title b{color:var(--ink);font-weight:500}.account{align-items:center;gap:12px;display:flex}.avatar{background:#e3edf5;border-radius:50%;justify-content:center;align-items:center;width:36px;height:36px;font-weight:700;display:flex}.account-name{font-size:.85rem;font-weight:600}.account-name small{color:var(--muted);font-size:.73rem;font-weight:400;display:block}.language{border:1px solid var(--line);color:var(--ink);background:#fff;padding:5px 7px;font-size:.8rem}.ghost{color:var(--muted);background:0 0;border:0;border-radius:6px;justify-content:center;align-items:center;padding:6px;display:inline-flex}.mobile-menu,.mobile-close{display:none}main{max-width:1440px;margin:auto;padding:37px 40px 0}.page-heading{justify-content:space-between;align-items:center;gap:20px;margin-bottom:27px;display:flex}.eyebrow{letter-spacing:.1em;color:var(--blue);margin-bottom:12px;font-size:.7rem;font-weight:700;display:block}.page-heading p{color:var(--muted);margin:0;font-size:.95rem}.teacher-badge{white-space:nowrap;background:#eaf1f7;border:1px solid #cfdeea;border-radius:30px;align-items:center;gap:7px;padding:7px 11px;font-size:.78rem;display:inline-flex}.overview{grid-template-columns:1fr 1fr 1fr 1.85fr;gap:13px;margin-bottom:35px;display:grid}.stat{border:1px solid var(--line);background:#fff;border-radius:12px;align-items:center;gap:13px;padding:20px;display:flex}.stat>svg{color:var(--blue);width:23px}.stat strong{letter-spacing:-.03em;font-size:1.7rem;line-height:1.2;display:block}.stat span{color:var(--muted);font-size:.75rem}.class-card{background:var(--navy);color:#fff;border-radius:12px;align-items:center;gap:12px;padding:20px;display:flex}.class-card small{color:#c5d8e6;margin-top:5px;font-size:.75rem;display:block}.class-card strong{font-size:.9rem}.class-card>a{margin-left:auto}.light{color:var(--navy);background:#fff;padding:7px 10px}.section-row{justify-content:space-between;align-items:center;gap:15px;margin-bottom:18px;display:flex}.section-row h2,.section-row h3{margin:0}.section-row select{width:auto;max-width:250px;font-size:.85rem}.learning-layout{grid-template-columns:minmax(260px,.8fr) minmax(360px,1.35fr);align-items:start;gap:23px;display:grid}.lesson-card{text-align:left;width:100%;color:var(--ink);border:1px solid var(--line);background:#fff;border-radius:12px;justify-content:flex-start;align-items:flex-start;gap:14px;margin-bottom:13px;padding:22px 18px;font-weight:400;display:flex}.lesson-card.chosen{border-color:var(--blue);box-shadow:0 0 0 1px var(--blue);background:#f9fcff}.lesson-number{width:34px;height:34px;color:var(--blue);background:#e9f0f7;border-radius:9px;flex-shrink:0;justify-content:center;align-items:center;font-size:.84rem;font-weight:600;display:flex}.chosen .lesson-number{background:var(--blue);color:#fff}.course-label{text-transform:uppercase;letter-spacing:.075em;color:var(--blue);margin-bottom:8px;font-size:.7rem;font-weight:700;display:block}.lesson-card h3{margin-bottom:7px;font-size:1.02rem}.lesson-card p{color:var(--muted);margin-bottom:14px;font-size:.8rem}.lesson-card small{color:var(--muted);flex-wrap:wrap;align-items:center;gap:6px;font-size:.75rem;display:flex}.submitted{color:#237054;align-items:center;gap:4px;margin-left:8px;display:inline-flex}.lesson-detail{border:1px solid var(--line);background:#fff;border-radius:14px;overflow:hidden}.detail-head{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;padding:25px 29px;display:flex}.detail-head h2{letter-spacing:-.02em;margin:0 0 7px;font-size:1.55rem}.detail-head p{color:var(--muted);margin:0;font-size:.86rem}.download{background:#eef3f7;padding:10px}.study-content{padding:25px 29px}.study-content section{margin-bottom:23px}.study-content section:last-child{margin:0}.study-content h3{letter-spacing:.075em;color:var(--blue);margin-bottom:9px;font-size:.74rem}.study-content p{white-space:pre-wrap;margin:0;font-size:.96rem;line-height:1.85}.homework-box{background:#eaf2fa;border-radius:11px;margin:0 20px 20px;padding:24px}.homework-box p{font-size:.9rem;line-height:1.7}.homework-box .eyebrow{font-size:.67rem}.homework-box h3{font-size:1.15rem}.resources{padding:0 29px 22px}.file-link{border:1px solid var(--line);overflow-wrap:anywhere;border-radius:8px;align-items:center;gap:10px;margin:8px 0;padding:12px;font-size:.88rem;text-decoration:none;display:flex}.file-link>svg:last-child{margin-left:auto}.panel{border:1px solid var(--line);background:#fff;border-radius:13px;margin-bottom:20px;padding:26px}.two-columns,.manage-grid{grid-template-columns:1fr 1fr;align-items:start;gap:26px;display:grid}.muted{color:var(--muted);font-size:.88rem}.panel form{margin-top:16px}form label{margin-bottom:17px;font-size:.87rem;font-weight:600;display:block}input,textarea,select{width:100%;color:var(--ink);background:#fff;border:1px solid #cbd7e1;border-radius:8px;min-height:43px;margin-top:7px;padding:10px 11px;font-size:.95rem;display:block}textarea{resize:vertical;min-height:90px;font-weight:400;line-height:1.6}.large-textarea{min-height:165px}input[type=file]{font-size:.8rem;font-weight:400}input::file-selector-button{color:var(--navy);cursor:pointer;background:#e9f0f6;border:0;border-radius:5px;margin-right:9px;padding:6px 9px}.secondary{color:var(--navy);background:#edf3f8;margin-top:14px;font-size:.82rem}.task-mini{border-left:3px solid var(--accent);background:#f0f5fa;margin:18px 0;padding:16px;font-size:.88rem;line-height:1.65}.empty{text-align:center;color:var(--muted);background:#fff;border:1px dashed #becdd9;border-radius:13px;padding:38px 25px}.empty>svg{color:#8099ab;width:30px;height:30px;margin-bottom:17px}.empty h3{color:var(--ink)}.empty p{margin:0;font-size:.88rem}.submission .section-row small{color:var(--muted);font-size:.72rem}.submission h3{margin-top:20px}.answer{white-space:pre-wrap;font-size:.93rem}.pill{color:#755617;background:#fff4dc;border-radius:20px;padding:5px 9px;font-size:.7rem;font-weight:600;display:inline-block}.pill.reviewed{color:#276749;background:#e4f3ee}.teacher-feedback{background:#edf6f1;border-radius:8px;margin:18px 0;padding:16px;font-size:.88rem}.teacher-feedback p{white-space:pre-wrap;margin:8px 0 0}.notice{background:#e8f1fa;border:1px solid #c1d8ed;border-radius:9px;justify-content:space-between;align-items:center;gap:16px;margin-bottom:24px;padding:13px 16px;font-size:.9rem;display:flex}.notice button{color:var(--ink);background:0 0;padding:3px}.video-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;display:grid}.video-card{padding:0 0 22px;overflow:hidden}.video-card .course-label,.video-card h3,.video-card p,.video-card>a{margin-left:24px;margin-right:24px}.video-card .course-label{margin-top:22px}.video-card p{color:var(--muted);font-size:.9rem}.video-card>a{font-size:.86rem}.video-screen{aspect-ratio:16/9;background:#173e59;justify-content:center;align-items:center;display:flex}.video-screen button{background:#173e59;border-radius:0;flex-direction:column;gap:17px;width:100%;height:100%;font-size:.88rem;font-weight:400}.play-icon{width:64px;height:64px;color:var(--accent);border:1px solid #6d8da4;border-radius:50%;justify-content:center;align-items:center;display:flex}.video-screen iframe{border:0;width:100%;height:100%}.video-admin{border-top:1px solid var(--line);justify-content:space-between;align-items:center;margin-top:16px;padding-top:12px;font-size:.83rem;display:flex}details{font-size:.87rem}summary{cursor:pointer;color:var(--blue);font-weight:600}footer{color:var(--muted);border-top:1px solid var(--line);justify-content:space-between;gap:20px;margin-top:23px;padding:31px 0;font-size:.76rem;display:flex}.loading{text-align:center;flex-direction:column;justify-content:center;align-items:center;gap:18px;min-height:100vh;padding:30px;display:flex}.loading p{max-width:570px}.spin{animation:1s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}@media (width>=1500px){main{padding-top:44px}}@media (width<=1200px){.sidebar{width:223px}.workspace{width:calc(100% - 223px);margin-left:223px}main{padding:30px 25px 0}.topbar{padding:0 25px}.overview{grid-template-columns:repeat(3,1fr)}.class-card{grid-column:1/-1}.learning-layout{grid-template-columns:minmax(230px,.8fr) minmax(310px,1.2fr)}.teacher-badge{display:none}}@media (width<=850px){.sidebar{transition:transform .2s;transform:translate(-100%)}.sidebar.visible{transform:translate(0)}.workspace{width:100%;margin-left:0}.mobile-menu,.mobile-close{display:inline-flex}.mobile-close{color:#fff;position:absolute;top:12px;right:12px}.scrim{z-index:25;background:#1238;position:fixed;inset:0}.topbar{height:74px}.topbar-title>span{display:none}.two-columns,.manage-grid,.video-grid{grid-template-columns:1fr}.account-name small{display:none}}@media (width<=600px){main{padding:26px 17px 0}.topbar{padding:0 17px}.account{gap:8px}.account-name{text-overflow:ellipsis;white-space:nowrap;max-width:120px;font-size:.8rem;overflow:hidden}.page-heading{margin-bottom:22px}h1{font-size:1.7rem}.eyebrow{font-size:.65rem}.overview{gap:8px;margin-bottom:27px}.stat{gap:7px;padding:13px 9px}.stat>svg{width:16px}.stat strong{font-size:1.35rem}.stat span{font-size:.65rem}.learning-layout{grid-template-columns:1fr}.lesson-list{grid-template-columns:1fr;display:grid}.lesson-card{padding:17px}.detail-head,.study-content{padding:23px}.section-row{flex-wrap:wrap}.section-row select{width:100%;max-width:100%}.panel{padding:22px}.class-card{padding:17px}.homework-box{margin:0 14px 14px;padding:20px}footer{flex-direction:column;gap:6px}.notice{overflow-wrap:anywhere}}@media (prefers-reduced-motion:reduce){.spin{animation:none}.sidebar{transition:none}}.auth-page{background:#eff5f1;place-items:center;min-height:100dvh;padding:24px;display:grid}.auth-card{background:#fff;border:1px solid #dbe5dd;border-radius:24px;width:100%;max-width:480px;padding:clamp(24px,6vw,42px);box-shadow:0 16px 60px #18463112}.auth-card .brand{margin-bottom:36px}.auth-card h1{margin:12px 0;font-size:32px}.auth-card p{line-height:1.65}.auth-card form{margin:24px 0}.auth-card form button{width:100%;margin-top:10px}.auth-card label{margin-top:16px}.auth-error{color:#922d25;background:#fff1ee;border-radius:12px;padding:12px}.auth-private{color:#5b7064;margin-top:24px;line-height:1.6;display:block}.password-control{z-index:3;font-size:12px;position:fixed;bottom:12px;right:16px;box-shadow:0 4px 20px #1232}.file-link{text-align:left;justify-content:flex-start;width:100%}@media (width<=520px){.password-control{margin:8px 16px;position:static}.auth-page{padding:16px}.auth-card h1{font-size:28px}}.auth-card .brand{color:var(--navy)}.auth-card .brand small{color:var(--muted)}
