:root{
  --bg:#f4f7fb;--surface:#fff;--surface-2:#f8fafc;--line:#e7edf5;--text:#17243b;
  --muted:#73819a;--primary:#315efb;--primary-2:#eaf0ff;--teal:#13a89e;--teal-bg:#e7f8f6;
  --orange:#f59e0b;--orange-bg:#fff5df;--red:#e05260;--red-bg:#fff0f1;--green:#159b70;--green-bg:#e9f8f1;
  --shadow:0 10px 30px rgba(32,54,92,.06);--radius:18px;
}
*{box-sizing:border-box}
html,body{margin:0;min-height:100%;font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text)}
button,input,textarea,select{font:inherit}
button{cursor:pointer}
button:disabled{opacity:.45;cursor:not-allowed}
.app{min-height:100vh;display:flex}
.sidebar{width:250px;flex-shrink:0;background:#101c35;color:#dbe5ff;padding:22px 15px;display:flex;flex-direction:column;gap:22px}
.brand{display:flex;align-items:center;gap:11px;padding:2px 10px 17px;border-bottom:1px solid rgba(255,255,255,.1)}
.brand-mark{width:42px;height:42px;border-radius:14px;display:grid;place-items:center;background:linear-gradient(135deg,#6385ff,#20c5b8);color:white;font-size:22px;font-weight:800;box-shadow:0 8px 20px #1b4b9b55}
.brand strong{display:block;font-size:15px;color:white;letter-spacing:.3px}
.brand small{display:block;font-size:11px;color:#92a4cb;margin-top:4px}
.nav-label{font-size:10px;color:#7f92ba;letter-spacing:1.5px;padding:0 12px;margin-bottom:5px}
.nav{display:grid;gap:5px}
.nav button{border:0;color:#aebddd;background:transparent;display:flex;align-items:center;gap:12px;text-align:left;padding:12px 13px;border-radius:12px;font-size:13px;transition:.18s}
.nav button:hover{background:#1b2a4a;color:white}
.nav button.active{background:linear-gradient(100deg,#315efb,#426fff);color:#fff;box-shadow:0 7px 18px #315efb40}
.nav-icon{font-size:17px;width:22px;text-align:center}
.sidebar-bottom{margin-top:auto;background:#192747;border:1px solid #2a3b5f;padding:14px;border-radius:15px}
.sidebar-bottom strong{font-size:12px;color:#fff;display:block}
.sidebar-bottom p{font-size:11px;line-height:1.7;color:#9dafd3;margin:7px 0 12px}
.side-status{display:flex;align-items:center;gap:7px;font-size:11px;color:#a9f0dc}
.dot{width:7px;height:7px;border-radius:50%;background:#20c997;display:inline-block}
.main{flex:1;min-width:0}
.topbar{height:76px;background:rgba(255,255,255,.92);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 32px;position:sticky;top:0;z-index:5}
.top-left{display:flex;align-items:center;gap:14px;min-width:0}
.crumb{font-size:12px;color:var(--muted)}
.top-title{font-size:17px;font-weight:750;white-space:nowrap}
.role-switch{display:flex;background:#eef2f8;border:1px solid #e1e7f0;padding:4px;border-radius:13px;gap:3px}
.role-switch button{border:0;border-radius:9px;background:transparent;color:#6e7b92;padding:9px 13px;font-size:12px;font-weight:650}
.role-switch button.active{background:#fff;color:var(--primary);box-shadow:0 2px 7px #142d5715}
.user-chip{display:flex;align-items:center;gap:10px;margin-left:12px}
.avatar{width:34px;height:34px;border-radius:12px;display:grid;place-items:center;background:#e9edff;color:#315efb;font-weight:800;font-size:12px}
.user-chip strong{display:block;font-size:12px}
.user-chip small{display:block;color:var(--muted);font-size:10px;margin-top:3px}
.content{max-width:1600px;padding:28px 32px 42px;margin:auto}
.page-head{display:flex;justify-content:space-between;align-items:flex-start;gap:18px;margin-bottom:23px}
.eyebrow{font-size:11px;letter-spacing:1.5px;color:var(--primary);font-weight:800;text-transform:uppercase}
h1{font-size:26px;letter-spacing:-.6px;margin:7px 0 8px}
.subtitle{font-size:13px;color:var(--muted);line-height:1.7;margin:0;max-width:760px}
.actions{display:flex;align-items:center;gap:9px;flex-wrap:wrap}
.btn{border:1px solid var(--line);background:white;color:#35435b;border-radius:11px;padding:10px 14px;font-size:12px;font-weight:700;display:inline-flex;align-items:center;gap:7px;box-shadow:0 2px 5px #1c34540a}
.btn:hover{border-color:#cbd6e8;background:#fbfcff}
.btn.primary{background:var(--primary);border-color:var(--primary);color:white;box-shadow:0 6px 14px #315efb30}
.btn.dark{background:#17243b;border-color:#17243b;color:#fff}
.btn.danger{background:var(--red-bg);color:var(--red);border-color:#ffd8dc}
.btn.success{background:var(--green-bg);color:var(--green);border-color:#c9efdf}
.btn.small{padding:7px 10px;border-radius:9px;font-size:11px}
.grid{display:grid;gap:16px}
.stats{grid-template-columns:repeat(4,minmax(0,1fr));margin-bottom:18px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow);min-width:0}
.card-head{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:16px}
.card-head h3{font-size:14px;margin:0}
.card-head p{font-size:11px;color:var(--muted);margin:5px 0 0}
.stat-card{padding:19px 20px;position:relative;overflow:hidden}
.stat-top{display:flex;justify-content:space-between;align-items:center}
.stat-label{font-size:12px;color:var(--muted)}
.stat-icon{width:36px;height:36px;border-radius:12px;display:grid;place-items:center;font-size:17px}
.stat-value{font-size:29px;font-weight:800;letter-spacing:-1px;margin:15px 0 6px}
.stat-foot{font-size:11px;color:var(--muted)}
.stat-foot b{color:var(--green)}
.two-col{grid-template-columns:minmax(0,1.25fr) minmax(300px,.75fr)}
.three-col{grid-template-columns:repeat(3,minmax(0,1fr))}
.panel-list{display:grid;gap:10px}
.list-row{display:flex;align-items:center;gap:12px;padding:12px;border:1px solid #edf1f7;border-radius:13px}
.list-row:hover{background:#fbfcff}
.row-main{flex:1;min-width:0}
.row-main strong{font-size:12px;display:block;line-height:1.5}
.row-main small{font-size:11px;color:var(--muted);display:block;margin-top:4px;line-height:1.5}
.badge{display:inline-flex;align-items:center;gap:5px;border-radius:7px;padding:5px 8px;font-size:10px;font-weight:750;white-space:nowrap}
.badge.blue{color:#315efb;background:#edf1ff}
.badge.green{color:#168a65;background:#e9f8f1}
.badge.orange{color:#a86b00;background:#fff4db}
.badge.red{color:#d74354;background:#fff0f1}
.badge.gray{color:#65738a;background:#eef2f7}
.phase-list{display:grid;gap:9px}
.phase{display:flex;gap:12px;align-items:center;padding:13px;border:1px solid var(--line);border-radius:13px;background:white}
.phase.current{border-color:#aebfff;background:#f5f7ff}
.phase-index{width:31px;height:31px;display:grid;place-items:center;border-radius:10px;background:#eef2f8;color:#52617b;font-size:12px;font-weight:800;flex-shrink:0}
.phase.current .phase-index{background:var(--primary);color:#fff}
.phase-info{flex:1;min-width:0}
.phase-info strong{font-size:12px;display:block}
.phase-info small{font-size:10px;color:var(--muted);display:block;margin-top:4px}
.phase-actions{display:flex;gap:5px}
.icon-btn{width:28px;height:28px;display:grid;place-items:center;border:1px solid var(--line);border-radius:8px;background:#fff;color:#697890;font-size:12px}
.icon-btn:hover{background:#edf1ff;color:var(--primary)}
.progress{height:7px;background:#edf1f7;border-radius:99px;overflow:hidden}
.progress span{height:100%;display:block;background:linear-gradient(90deg,#315efb,#23b7b0);border-radius:99px}
.task-type-icon{width:39px;height:39px;border-radius:13px;display:grid;place-items:center;background:#edf1ff;color:#315efb;font-size:18px;flex-shrink:0}
.task-row{display:flex;align-items:center;gap:13px;padding:14px;border:1px solid var(--line);border-radius:14px;margin-bottom:10px}
.task-row:last-child{margin-bottom:0}
.task-details{flex:1;min-width:0}
.task-details strong{font-size:13px;display:block}
.task-meta{font-size:11px;color:var(--muted);margin-top:5px;display:flex;gap:9px;flex-wrap:wrap}
.task-actions{display:flex;gap:6px;flex-wrap:wrap}
.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:13px}
table{border-collapse:collapse;width:100%;min-width:600px}
th,td{padding:13px 14px;text-align:left;border-bottom:1px solid #edf1f6;font-size:12px;white-space:nowrap}
th{background:#f8fafd;color:#7b879c;font-size:10px;letter-spacing:.4px;font-weight:800}
tr:last-child td{border-bottom:0}
.student-name{display:flex;align-items:center;gap:9px}
.mini-avatar{width:28px;height:28px;border-radius:9px;background:#eaf0ff;color:#315efb;display:grid;place-items:center;font-size:10px;font-weight:800}
.status-pill{font-size:10px;font-weight:750;border-radius:7px;padding:5px 8px;display:inline-block}
.status-pill.online{background:#e9f8f1;color:#168a65}
.status-pill.offline{background:#eef2f7;color:#68768d}
.status-pill.muted{background:#fff4db;color:#9a6800}
.status-pill.disabled{background:#fff0f1;color:#d74354}
.chart{display:flex;align-items:flex-end;gap:13px;height:190px;padding:15px 8px 0;border-bottom:1px solid var(--line)}
.bar-col{height:100%;flex:1;display:flex;flex-direction:column;justify-content:flex-end;align-items:center;gap:8px;min-width:0}
.bar-count{font-size:11px;font-weight:800;color:#34425b}
.bar{width:min(42px,75%);min-height:3px;border-radius:8px 8px 2px 2px;background:linear-gradient(180deg,#6586ff,#315efb);transition:height .25s}
.bar-label{font-size:11px;color:#66748a;padding-bottom:10px}
.legend{display:flex;gap:13px;flex-wrap:wrap;font-size:10px;color:var(--muted);margin-top:12px}
.legend span{display:flex;align-items:center;gap:6px}
.legend i{width:7px;height:7px;border-radius:50%;display:inline-block}
.notice{display:flex;align-items:flex-start;gap:11px;padding:13px 14px;border:1px solid #dbe5ff;background:#f2f5ff;border-radius:13px;color:#43557d;font-size:11px;line-height:1.7;margin-bottom:18px}
.notice .notice-icon{font-size:16px}
.notice.warn{border-color:#f6e4b7;background:#fff9e9;color:#89651a}
.empty{padding:32px;text-align:center;color:var(--muted);font-size:12px}
.empty .emoji{font-size:27px;margin-bottom:9px}
.filter-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:15px}
.input,.select,.textarea{border:1px solid #dfe6f0;border-radius:10px;padding:10px 12px;background:white;color:var(--text);font-size:12px;outline:none;width:100%}
.input:focus,.select:focus,.textarea:focus{border-color:#8ea6ff;box-shadow:0 0 0 3px #315efb12}
.textarea{min-height:90px;resize:vertical;line-height:1.6}
.filter-row .input,.filter-row .select{width:auto;min-width:150px}
.field{display:grid;gap:7px;margin-bottom:14px}
.field label{font-size:11px;font-weight:750;color:#586780}
.field .hint{font-size:10px;color:var(--muted);line-height:1.5}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:0 13px}
.full{grid-column:1/-1}
.modal-backdrop{position:fixed;inset:0;background:#101c3575;display:none;align-items:center;justify-content:center;padding:18px;z-index:30}
.modal-backdrop.open{display:flex}
.modal{width:min(650px,100%);max-height:90vh;overflow:auto;background:white;border-radius:20px;box-shadow:0 25px 90px #0a193e40}
.modal-head{padding:20px 23px;border-bottom:1px solid var(--line);display:flex;justify-content:space-between;align-items:center}
.modal-head h2{font-size:17px;margin:0}
.modal-body{padding:22px 23px}
.modal-foot{padding:15px 23px;border-top:1px solid var(--line);display:flex;justify-content:flex-end;gap:8px}
.close-btn{border:0;background:#f0f3f8;border-radius:9px;width:31px;height:31px;color:#6c7890}
.choice-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.choice-option{display:flex;align-items:center;gap:9px;border:1px solid var(--line);border-radius:11px;padding:10px;font-size:12px}
.choice-option input{accent-color:var(--primary)}
.answer-box{border:1px solid var(--line);border-radius:13px;padding:14px;margin-top:12px}
.answer-box.selected{border-color:#93a8ff;background:#f6f8ff}
.answer-option{display:flex;align-items:flex-start;gap:10px;padding:11px 12px;border:1px solid var(--line);border-radius:11px;margin:8px 0;font-size:12px;line-height:1.5;cursor:pointer}
.answer-option:has(input:checked){border-color:#8da3ff;background:#f3f6ff}
.answer-option input{margin-top:2px;accent-color:var(--primary)}
.student-task{padding:19px;margin-bottom:12px}
.student-task-head{display:flex;align-items:flex-start;gap:12px}
.student-task-body{margin-top:15px}
.student-task h3{font-size:14px;margin:0 0 7px}
.question-text{font-size:13px;line-height:1.85;color:#34425b}
.task-foot{border-top:1px solid var(--line);padding-top:13px;margin-top:15px;display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap}
.lock-screen{padding:44px 20px;text-align:center}
.lock-screen .lock-icon{font-size:38px;margin-bottom:13px}
.lock-screen h2{font-size:20px;margin:0 0 9px}
.lock-screen p{font-size:12px;color:var(--muted);line-height:1.8;max-width:460px;margin:0 auto 18px}
.segmented{display:flex;background:#f0f3f8;padding:4px;border-radius:10px;gap:3px}
.segmented button{border:0;background:transparent;border-radius:7px;padding:8px 10px;font-size:11px;color:#718098}
.segmented button.active{background:white;color:var(--primary);box-shadow:0 2px 6px #17243b12;font-weight:800}
.resource-card{padding:17px;display:flex;align-items:center;gap:13px}
.resource-icon{width:44px;height:44px;border-radius:13px;background:#f0f3ff;display:grid;place-items:center;font-size:21px}
.resource-info{flex:1;min-width:0}
.resource-info strong{font-size:12px;display:block}
.resource-info small{font-size:10px;color:var(--muted);display:block;margin-top:5px}
.toast-wrap{position:fixed;top:90px;right:22px;z-index:50;display:grid;gap:9px;pointer-events:none}
.toast{background:#17243b;color:#fff;padding:12px 16px;border-radius:12px;box-shadow:0 10px 30px #14234435;font-size:12px;animation:slidein .2s ease;max-width:340px}
@keyframes slidein{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}
.small-muted{font-size:11px;color:var(--muted)}
.kpi-line{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:13px 0;font-size:12px}
.kpi-line span{color:var(--muted)}
.kpi-line strong{font-size:13px}
.profile-card{display:flex;align-items:center;gap:15px;padding:20px;background:linear-gradient(120deg,#eef2ff,#f4fbff);border:1px solid #e0e7ff;border-radius:16px;margin-bottom:16px}
.profile-big{width:58px;height:58px;border-radius:18px;background:linear-gradient(135deg,#315efb,#18b8b0);color:white;display:grid;place-items:center;font-size:21px;font-weight:800}
.profile-card h3{margin:0;font-size:16px}
.profile-card p{margin:5px 0 0;color:var(--muted);font-size:11px}
.hidden{display:none!important}
@media(max-width:1100px){.sidebar{width:220px}.content{padding:23px 22px}.topbar{padding:0 22px}.stats{grid-template-columns:repeat(2,minmax(0,1fr))}.two-col{grid-template-columns:1fr}.three-col{grid-template-columns:1fr 1fr}}
@media(max-width:760px){.app{display:block}.sidebar{width:100%;padding:12px;gap:12px}.brand{padding:2px 8px 10px}.nav-label,.sidebar-bottom{display:none}.nav{display:flex;overflow:auto;padding-bottom:2px}.nav button{flex-shrink:0;padding:9px 11px;font-size:11px}.nav-icon{width:auto}.topbar{height:auto;min-height:65px;padding:12px 15px;gap:10px;flex-wrap:wrap}.top-title{font-size:14px}.user-chip{display:none}.content{padding:20px 14px}.page-head{display:block}.page-head .actions{margin-top:15px}.stats{gap:10px}.stat-card{padding:15px}.stat-value{font-size:24px}.three-col{grid-template-columns:1fr}.form-grid{grid-template-columns:1fr}.full{grid-column:auto}.choice-grid{grid-template-columns:1fr}.task-actions{width:100%}.task-row{flex-wrap:wrap}.task-actions .btn{flex:1}.phase-actions{gap:3px}.card{padding:16px}.role-switch button{padding:8px 10px}}

/* v2 classroom refinements */
.phase{cursor:pointer;transition:border-color .18s,background .18s,transform .18s}
.phase:hover{border-color:#b9c8ff;transform:translateY(-1px)}
.phase:focus-visible{outline:3px solid #315efb40;outline-offset:2px}
.phase-index{cursor:pointer}
.flow-controls{display:flex;gap:7px;flex-wrap:wrap;align-items:center}
.batch-item{border:1px solid var(--line);border-radius:14px;padding:15px;margin:12px 0;background:#fbfcff}
.batch-item-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:12px}
.batch-item-head strong{font-size:12px}
.resource-preview{margin:12px 0;padding:12px;border:1px solid var(--line);border-radius:12px;background:#f8fafd;min-height:40px;font-size:12px;color:var(--muted)}
.resource-preview img{max-width:100%;max-height:360px;display:block;margin:0 auto;border-radius:10px}
.resource-preview video{width:100%;max-height:360px;border-radius:10px;background:#101c35}
.resource-preview iframe{width:100%;height:340px;border:0;border-radius:8px;background:#fff}
.resource-preview a{color:var(--primary);font-weight:700;text-decoration:none}
.resource-preview a:hover{text-decoration:underline}
.flow-nav-btn{border:1px solid #dce4f0;background:white;border-radius:10px;padding:9px 12px;font-size:11px;font-weight:750;color:#4c5c75}
.flow-nav-btn:hover{border-color:#9eb1ff;color:var(--primary)}
.temporary-banner{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;padding:14px 16px;background:#fff7e7;border:1px solid #f4dfad;border-radius:14px;margin-bottom:16px;color:#805b11;font-size:12px}