.platform-nav{display:flex;gap:8px;align-items:center}.platform-nav button.active{color:#216dcc;background:#eaf3ff;border-color:#a9cdfa}.course-library{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin-top:22px}.course-item{border:1px solid var(--line);border-radius:8px;background:white;overflow:hidden;display:flex;flex-direction:column}.course-art{height:190px;display:grid;place-items:center;background:#eaf5ff;border-bottom:1px solid var(--line)}.course-art .iso{height:170px;width:180px}.course-art .fraction-preview{width:180px;height:130px}.course-item:nth-child(2) .course-art{background:#edf7f5}.course-body{padding:20px;display:flex;flex-direction:column;gap:12px;flex:1}.course-body p{line-height:1.7;color:var(--muted);font-size:14px}.course-body .actions{margin-top:auto;padding-top:8px}.platform-toolbar{display:flex;justify-content:space-between;gap:15px;align-items:center;flex-wrap:wrap;margin:0 0 22px}.platform-toolbar select{min-width:140px}.tenant-tag{font-size:13px;color:#2673c5;background:#eaf3ff;border-radius:4px;padding:5px 8px}.login-panel details{margin:12px 0;font-size:13px;color:var(--muted)}.login-panel summary{cursor:pointer}.login-panel .field{margin:17px 0}.login-logo{display:grid;place-items:center;margin-bottom:20px}.login-logo svg{width:52px;height:52px;color:#2878ed}.admin-form{display:grid;grid-template-columns:1fr 1fr;gap:0 18px}.admin-form .span-all{grid-column:1/-1}.assignment-options{display:flex;gap:12px;flex-wrap:wrap;margin:12px 0 18px}.assignment-options label{display:flex;align-items:center;gap:7px;border:1px solid var(--line);padding:10px 13px;border-radius:6px}.assignment-options input{min-height:0}.admin-table{width:100%;border-collapse:collapse;background:white}.admin-table th,.admin-table td{text-align:left;padding:17px 15px;border-bottom:1px solid var(--line);font-size:14px}.admin-table th{font-size:12px;color:var(--muted);background:#edf3fa}.admin-table .badge{margin:0}.table-scroll{overflow:auto;border:1px solid var(--line);border-radius:8px}.admin-table .actions{flex-wrap:nowrap}.course-count{color:#75869a;font-size:13px}.fraction-stage{background:#f5faf9;border:1px solid #cfe5e0;border-radius:8px;min-height:490px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:25px;padding:25px}.fraction-target{display:flex;align-items:center;gap:20px;font-size:17px;color:#4b726d}.fraction-number{display:flex;flex-direction:column;min-width:40px;text-align:center;font-size:30px;color:#207f76}.fraction-number b:first-child{border-bottom:2px solid #207f76;padding-bottom:4px}.fraction-number b:last-child{padding-top:4px}.fraction-board{display:grid;grid-template-columns:repeat(var(--cols),minmax(0,1fr));gap:8px;width:min(600px,100%)}.fraction-cell{aspect-ratio:1.3;min-height:0;width:100%;padding:0;border:2px solid #a8ccc6;background:#fff;border-radius:5px}.fraction-cell:hover{background:#e4f3f0;border-color:#54a79c}.fraction-cell.filled{background:#39a99e;border-color:#218b81}.fraction-cell:disabled{opacity:1}.fraction-summary{font-size:15px;color:#547e77}.fraction-preview{width:110px;height:92px;flex-shrink:0}.editor-host .workspace{min-height:490px}.editor-host .scene-wrap{height:510px}.editor-host [data-tool].active{background:#e8f3ff;color:#2673c5;border-color:#96c0f2}.editor-host [data-tool]{width:42px;padding:9px}.editor-host .hint{min-height:35px}.work-card>div{min-width:0}.dialog-work .editor-host{min-height:0}.dialog-work .scene-wrap{height:420px}.dialog-work .workspace{min-height:420px}.dialog-work .fraction-stage{min-height:400px}.status-screen{padding:100px 25px;text-align:center}.status-screen p{margin:20px 0;color:var(--muted)}.error-banner{background:#fff1f3;border:1px solid #f1c7cf;border-radius:6px;color:#b9455c;padding:14px;margin-bottom:18px}.sync-state{font-size:12px;color:#6e849c;display:inline-flex;align-items:center;gap:6px}.sync-state:before{content:"";width:7px;height:7px;background:#24a777;border-radius:50%}.sync-state.offline:before{background:#e9a634}.login-tiles{width:250px;margin:auto;display:grid;grid-template-columns:repeat(3,1fr);gap:10px;transform:rotate(-7deg);padding:20px}.login-tile{height:68px;border:1px solid #8fc5ec;border-radius:6px;background:#a5d6f5}.login-tile:nth-child(3n){background:#83c8bc;border-color:#6cb6a9}.login-tile:nth-child(4n){background:#f4d18b;border-color:#e2b861}.login-tiles .lift{transform:translateY(-12px)}.lesson-top{margin-bottom:20px}.lesson-top h2{margin-bottom:8px}.lesson-top p{color:var(--muted);line-height:1.7}.teacher-note{font-size:13px;color:var(--muted);margin-top:7px}.library-title{margin-top:10px}.badge.good{background:#e5f6ef;color:#228760}@media(max-width:1100px){.course-library{grid-template-columns:repeat(2,minmax(0,1fr))}.admin-table th,.admin-table td{padding:13px 10px}.header{gap:14px}}@media(max-width:760px){.course-library{grid-template-columns:1fr}.course-art{height:150px}.course-art .iso{height:145px}.platform-nav{width:100%}.platform-nav button{flex:1}.fraction-stage{padding:20px 14px;min-height:420px}.fraction-board{gap:6px}.fraction-cell{aspect-ratio:1}.fraction-preview{width:75px}.admin-form{grid-template-columns:1fr}.admin-form .span-all{grid-column:1}.editor-host .scene-wrap{height:420px}.platform-toolbar .actions{width:100%}.platform-toolbar select{flex:1;min-width:0}.work-card{padding:12px 9px}.header .actions{gap:6px}.tenant-tag{font-size:12px}.admin-table{min-width:720px}}