@charset "UTF-8";
:root{font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#172944;background:#f0f3f8;font-size:16px;--navy:#152745;--blue:#255cf5;--muted:#60718c;--line:#dce4ef;--white:#fff;--orange:#ed7138;--radius:14px;--shadow:0 16px 45px #1527450a;color-scheme:light}
*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:wait;opacity:.6}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #91b3ff;outline-offset:3px}button{min-height:42px;padding:10px 16px;border:1px solid var(--line);border-radius:9px;background:white;color:var(--navy);font-weight:600;font-size:.875rem;transition:background .15s,transform .15s}button:hover{background:#eef3ff}button.primary{color:white;background:var(--blue);border-color:var(--blue)}button.primary:hover{background:#1746cf}button.quiet{border-color:transparent;background:transparent}button.danger{color:#b82b3e}button.icon-button{width:44px;padding:9px;display:inline-grid;place-items:center}button svg{width:20px;height:20px}a{color:var(--blue)}h1,h2,h3,p{margin-top:0}h1{font-size:1.9rem;letter-spacing:-.05em;line-height:1.2;margin-bottom:8px}h2{font-size:1.35rem;letter-spacing:-.03em}h3{font-size:1rem;line-height:1.4}p{line-height:1.65}small,.meta{font-size:.875rem;color:var(--muted);line-height:1.5}.muted{color:var(--muted)}.eyebrow{font-size:.75rem;letter-spacing:.12em;text-transform:uppercase;font-weight:700;color:var(--muted)}.row{display:flex;align-items:center;gap:12px}.between{justify-content:space-between}.wrap{flex-wrap:wrap}.stack{display:grid;gap:16px}.grow{flex:1;min-width:0}.hidden,[hidden]{display:none!important}.boot{padding:15vh 8vw;font-size:1.25rem}.badge{display:inline-flex;align-items:center;border-radius:7px;padding:5px 9px;font-size:.875rem;background:#edf2fa;color:#526683;white-space:nowrap}.badge.review{background:#fff0e6;color:#9c481c}.badge.done{background:#e5f5ef;color:#197150}.badge.late{background:#ffebef;color:#ad314b}.avatar{width:40px;height:40px;flex-shrink:0;border-radius:12px;background:#e6edff;color:#255cf5;display:grid;place-items:center;font-weight:750}.empty{background:white;border:1px dashed #c8d6e8;border-radius:14px;padding:48px 28px;text-align:center}.empty p{max-width:460px;margin:12px auto 24px;color:var(--muted)}
.layout{display:grid;grid-template-columns:236px minmax(0,1fr);min-height:100vh}.sidebar{background:var(--navy);color:white;padding:30px 18px;display:flex;flex-direction:column;position:sticky;top:0;height:100dvh}.brand{display:flex;align-items:center;gap:11px;font-weight:750;font-size:1.12rem;letter-spacing:-.03em;padding:0 10px}.brand img{width:36px;height:36px}.sidebar .eyebrow{color:#98abc9;margin:43px 12px 14px}.nav{display:grid;gap:7px}.nav button{display:flex;align-items:center;gap:12px;text-align:left;border:0;color:#b9c7de;background:transparent;padding:13px 15px;font-size:.9375rem;min-height:48px}.nav button:hover{background:#20395e;color:#fff}.nav button.active{background:#2a4267;color:#fff}.nav svg{width:21px}.sidebar-foot{margin-top:auto;border-top:1px solid #314460;padding:24px 12px 0;font-size:.875rem;line-height:1.7;color:#aabbd4}.sidebar-foot strong{display:block;color:white;font-weight:550}.main{min-width:0}.topbar{min-height:84px;display:flex;align-items:center;justify-content:space-between;padding:18px 36px;border-bottom:1px solid var(--line);background:white;gap:16px}.topbar .subject{font-size:.875rem;color:var(--muted)}.topbar .user{display:flex;align-items:center;gap:12px}.user strong{display:block;font-size:.875rem}.user small{font-size:.8125rem}.content{padding:32px 36px 40px;max-width:1680px;margin:auto}.page-head{display:flex;align-items:flex-start;justify-content:space-between;gap:24px;margin-bottom:27px}.page-head p{color:var(--muted);margin:0;font-size:.9375rem}.section-head{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:18px}.section-head h2{margin:0}.divider{height:1px;background:var(--line);margin:24px 0}
.board-layout{display:grid;grid-template-columns:225px minmax(0,1fr);gap:20px;align-items:start}.board-list{display:grid;gap:8px}.board-card{text-align:left;display:block;width:100%;padding:15px 16px;background:white;border-radius:12px;border-color:transparent;box-shadow:var(--shadow)}.board-card.active{border-color:#95b3ff;background:#f5f8ff;box-shadow:inset 3px 0 0 var(--blue)}.board-card strong{display:block;font-size:.9375rem;margin:8px 0}.board-card small{display:block;font-weight:400}.board-card .eyebrow{font-size:.6875rem}.canvas-shell{background:white;border:1px solid var(--line);border-radius:16px;overflow:hidden;min-width:0;box-shadow:var(--shadow)}.canvas-top{padding:17px 21px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center;gap:14px}.canvas-top h2{font-size:1rem;margin:0 0 3px}.toolbar{padding:12px 16px;display:flex;align-items:center;gap:7px;flex-wrap:wrap;border-bottom:1px solid var(--line);background:#fbfcfe}.toolbar button{padding:8px;min-width:39px;min-height:39px;display:inline-flex;align-items:center;justify-content:center}.toolbar button.active{color:var(--blue);background:#e9efff;border-color:#9fb8fb}.toolbar .separator{height:24px;width:1px;background:var(--line);margin:0 5px}.toolbar .color{width:28px;height:28px;min-width:28px;min-height:28px;border-radius:50%;padding:0;border:3px solid white;box-shadow:0 0 0 1px #c3cede}.toolbar .color.active{box-shadow:0 0 0 2px var(--blue)}.color[data-color="#172944"]{background:#172944}.color[data-color="#255cf5"]{background:#255cf5}.color[data-color="#ed7138"]{background:#ed7138}.color[data-color="#1b865e"]{background:#1b865e}.toolbar select{width:auto;padding:5px;min-height:36px;font-size:.875rem}.canvas-view{padding:0;position:relative;background:#fff;overflow:hidden}.board-svg{width:100%;height:auto;aspect-ratio:8/5;display:block;touch-action:none;cursor:crosshair;background:#fff}.board-svg text{font-family:"Segoe UI",sans-serif;font-size:26px;user-select:none}.board-svg .shape{pointer-events:stroke}.board-svg.erase .shape{cursor:pointer}.canvas-foot{padding:11px 18px;display:flex;justify-content:space-between;gap:12px;border-top:1px solid var(--line);font-size:.8125rem;color:var(--muted)}.save-status.error{color:#bd3347}.no-board{padding:80px 25px;text-align:center;color:var(--muted)}
.filters{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:24px}.filters button{background:transparent;border-color:transparent;color:var(--muted)}.filters button.active{background:#fff;color:var(--navy);box-shadow:0 2px 8px #1729440a;border-color:var(--line)}.filters select{max-width:260px;margin-left:auto}.task-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.task-card{background:white;border:1px solid var(--line);border-radius:14px;display:flex;flex-direction:column;overflow:hidden;box-shadow:var(--shadow)}.task-body{padding:23px;flex:1}.task-card h3{font-size:1.125rem;margin:17px 0 9px}.task-excerpt{color:var(--muted);font-size:.9375rem;line-height:1.65;white-space:pre-wrap;overflow-wrap:anywhere}.task-foot{border-top:1px solid #edf1f7;padding:13px 23px;display:flex;justify-content:space-between;align-items:center;gap:14px;font-size:.875rem}.task-foot strong{font-weight:600}.task-body .meta{margin-top:20px}.stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin-bottom:28px}.stat{background:white;border:1px solid var(--line);border-radius:14px;padding:24px}.stat strong{display:block;font-size:2.15rem;font-weight:700;letter-spacing:-.05em;margin-top:12px}.stat small{display:block;margin-top:8px}.table-wrap{border:1px solid var(--line);border-radius:14px;background:white;overflow:auto}.table-wrap table{border-collapse:collapse;width:100%;text-align:left;min-width:600px}.table-wrap th{font-size:.875rem;color:var(--muted);font-weight:550;background:#fafbfd}.table-wrap th,.table-wrap td{padding:18px 23px;border-bottom:1px solid #edf1f7}.table-wrap tr:last-child td{border-bottom:0}.table-wrap td{font-size:.9375rem}.progress{display:flex;align-items:center;gap:14px}.progress progress{width:120px;height:7px;accent-color:var(--blue)}.student-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.student-card{background:white;border:1px solid var(--line);border-radius:14px;padding:23px}.student-card h3{margin:16px 0 3px;font-size:1.1rem}.student-card button{width:100%;margin-top:20px}
.auth{min-height:100dvh;display:grid;grid-template-columns:minmax(0,.95fr) minmax(400px,1.05fr)}.auth-aside{background:var(--navy);color:white;padding:50px;display:flex;flex-direction:column;position:relative;overflow:hidden}.auth-aside .brand{padding:0}.auth-aside h1{font-size:clamp(2.4rem,4.2vw,4.5rem);line-height:1.12;letter-spacing:-.06em;max-width:550px;margin:70px 0 26px}.auth-aside h1 span{color:#97b6ff}.auth-aside p{color:#afc1de;max-width:400px;font-size:1.05rem}.auth-aside footer{margin-top:auto;padding-top:55px;color:#9aafce;font-size:.875rem}.auth-graph{max-width:370px;margin:25px 0 0}.auth-form-wrap{display:flex;align-items:center;justify-content:center;padding:50px 35px;background:white}.auth-card{width:100%;max-width:380px}.auth-card h2{font-size:1.8rem;margin-bottom:12px}.auth-card .muted{margin-bottom:30px}.auth-card button.primary{width:100%;margin-top:8px;min-height:48px}.auth-card .auth-note{font-size:.875rem;margin-top:24px;line-height:1.6;color:var(--muted)}label{display:grid;gap:8px;font-size:.875rem;font-weight:600}input,textarea,select{width:100%;min-height:45px;padding:11px 13px;border:1px solid #cbd7e5;background:white;border-radius:8px;color:var(--navy);font-weight:400;font-size:1rem}textarea{resize:vertical;line-height:1.55;min-height:120px}input[type="color"]{padding:0}.form-error{color:#b32d45;font-size:.875rem;min-height:20px;line-height:1.5}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:16px}.form-actions{display:flex;justify-content:flex-end;gap:9px;margin-top:8px}.full-width{width:100%}dialog{border:0;border-radius:18px;padding:0;width:min(620px,calc(100% - 32px));max-height:calc(100dvh - 48px);color:var(--navy);box-shadow:0 30px 100px #0c193f40}dialog::backdrop{background:#0c193f77;backdrop-filter:blur(3px)}.dialog-head{padding:24px 26px 17px;display:flex;justify-content:space-between;align-items:center;gap:16px;border-bottom:1px solid var(--line)}.dialog-head h2{margin:0;font-size:1.25rem}.dialog-body{padding:24px 26px 28px}.dialog-body pre{font:inherit;white-space:pre-wrap;line-height:1.65;overflow-wrap:anywhere}.answer-block{background:#f2f5fa;border-radius:10px;padding:18px;margin:20px 0}.answer-block h3{color:var(--muted);font-size:.875rem}.answer-block p{margin:0;white-space:pre-wrap;overflow-wrap:anywhere}.invite-url{font-size:.875rem;word-break:break-all;min-height:85px}.help{font-size:.875rem;color:var(--muted);font-weight:400;line-height:1.5}#notice{position:fixed;bottom:24px;left:50%;transform:translateX(-50%);z-index:30;max-width:calc(100% - 32px);padding:14px 20px;background:var(--navy);color:white;border-radius:10px;box-shadow:0 8px 25px #101b3040;font-size:.9375rem;line-height:1.5}#notice.error{background:#9b2940}
@media(min-width:1600px){.board-layout{grid-template-columns:255px minmax(0,1fr)}.content{padding-top:40px}}
@media(max-width:1150px){.layout{grid-template-columns:190px minmax(0,1fr)}.sidebar{padding:26px 12px}.brand{font-size:1rem;gap:9px}.brand img{width:30px;height:30px}.content{padding:28px 24px}.topbar{padding:16px 24px}.board-layout{grid-template-columns:1fr}.board-list{display:flex;overflow:auto;padding-bottom:7px}.board-card{min-width:200px;max-width:260px}.student-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.auth-aside{padding:40px}}
@media(max-width:760px){.layout{display:block}.sidebar{position:static;height:auto;padding:17px 16px 10px}.sidebar .brand{padding:0 6px;font-size:1.1rem}.sidebar .eyebrow,.sidebar-foot{display:none}.nav{display:flex;overflow:auto;gap:2px;margin-top:15px}.nav button{flex:1;justify-content:center;white-space:nowrap;padding:10px;min-height:44px;font-size:.875rem;gap:7px}.nav button svg{width:18px}.topbar{min-height:68px;padding:13px 18px}.topbar .subject{font-size:.8125rem}.topbar .user{gap:8px}.user .avatar{display:none}.content{padding:25px 16px}.page-head{gap:15px;margin-bottom:22px}.page-head h1{font-size:1.6rem}.page-head p{font-size:.875rem}.page-head>button{font-size:.8125rem;padding:10px 12px}.task-grid,.student-grid{grid-template-columns:1fr}.stats{gap:10px}.stat{padding:16px 12px}.stat strong{font-size:1.7rem}.stat .meta{font-size:.8125rem}.stat small{font-size:.75rem}.canvas-top{padding:14px}.canvas-top>button{padding:8px}.canvas-foot{font-size:.75rem;padding:10px 12px;flex-wrap:wrap}.toolbar{gap:5px;padding:10px}.toolbar .separator{margin:0 2px}.filters select{max-width:100%;margin-left:0}.auth{display:block}.auth-aside{padding:26px 26px 24px}.auth-aside h1{font-size:2.1rem;margin:32px 0 14px}.auth-aside p,.auth-aside footer,.auth-graph{display:none}.auth-form-wrap{padding:38px 26px 50px}.auth-card{max-width:460px}.dialog-head{padding:20px}.dialog-body{padding:20px}.two-col{grid-template-columns:1fr}.board-card{min-width:185px}.task-foot{flex-wrap:wrap}}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
.files-section{margin:22px 0}.files-section h3{margin-bottom:10px;color:var(--muted);font-size:.875rem}.file-list{display:grid;gap:9px;margin:10px 0 18px}.file-card{display:flex;align-items:center;gap:11px;padding:10px 11px;border:1px solid var(--line);border-radius:10px;background:#fff}.file-thumb,.file-kind{width:48px;height:48px;flex:0 0 48px;border-radius:8px;background:#eef3fb;object-fit:cover}.file-kind{display:grid;place-items:center;font-size:.72rem;font-weight:750;color:var(--muted);letter-spacing:.04em}.file-link{min-width:0;flex:1;text-decoration:none;color:var(--navy)}.file-link strong,.file-link small{display:block}.file-link strong{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.875rem}.file-link small{margin-top:3px}.attachment-note{display:inline-block;margin-top:12px;padding:5px 8px;border-radius:7px;background:#eef3ff;color:#425f93;font-size:.78rem}.compact-form{border-top:1px solid var(--line);padding-top:18px;margin-top:18px}.credentials{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:18px 0}.credentials input{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.answer-block .file-list{margin-bottom:0}
@media(max-width:760px){.credentials{grid-template-columns:1fr}.file-card{align-items:flex-start}.file-thumb,.file-kind{width:42px;height:42px;flex-basis:42px}}