/* v6.4 DEV2A · student frozen assignment instance + practice hierarchy */
.v64-student-modal{width:min(980px,100%)}
.v64-student-body{gap:14px}
.v64-student-info{border:1px solid #dbe6f0;background:#f6f9fc;border-radius:10px;padding:10px 12px;color:#526176;font-size:12px;line-height:1.6;margin-bottom:12px}
.v64-student-card{display:grid;gap:8px}
.v64-student-card-title{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.v64-student-card-title h4{margin:0}
.v64-student-card-title>span{font-size:10px;font-weight:800;color:#2d638f;background:#eaf3fb;border:1px solid #d0e2f1;border-radius:6px;padding:3px 6px}
.v64-student-card-title>span.legacy{color:#6b7280;background:#f3f4f6;border-color:#e5e7eb}
.v64-student-meta{display:flex;flex-wrap:wrap;gap:6px}
.v64-student-meta span{font-size:10px;color:#607083;background:#f2f5f8;border-radius:6px;padding:4px 7px;font-weight:700}
.v64-student-range{border-top:1px dashed #dde4eb;padding-top:9px;display:grid;gap:8px}
.v64-student-range-head{display:flex;align-items:center;justify-content:space-between;gap:8px;flex-wrap:wrap}
.v64-student-range-head b{font-size:12px;color:#344256}
.v64-student-range-head span{font-size:10px;color:#8793a2}
.v64-student-range-groups{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px}
.v64-student-range-groups>div{display:flex;justify-content:space-between;gap:8px;border:1px solid #e2e7ed;border-radius:7px;padding:6px 8px;background:#fafbfc;color:#5a6878;font-size:11px}
.v64-student-range-groups>div b{color:#344256}
.v64-student-muted{font-size:11px;color:#8b96a5}

.v64-student-practice-nav{border:1px solid #dce4ec;border-radius:10px;background:#fff;padding:9px 10px;margin:0 0 10px;display:grid;gap:8px;box-shadow:0 2px 10px rgba(15,23,42,.035)}
.v64-student-practice-head{display:flex;align-items:center;justify-content:space-between;gap:8px}
.v64-student-practice-head b{font-size:12px;color:#344256}
.v64-student-practice-head span{font-size:10px;color:#8a95a3}
.v64-student-practice-filters{display:grid;grid-template-columns:repeat(2,minmax(0,1fr)) auto;gap:7px;align-items:end}
.v64-student-practice-filters label{display:grid;gap:4px;min-width:0}
.v64-student-practice-filters label>span,.v64-student-practice-level>span{font-size:9px;font-weight:800;color:#8490a0}
.v64-student-practice-filters select{width:100%;min-width:0;border:1px solid #d9e1e9;border-radius:8px;background:#f9fbfd;color:#344256;padding:7px 28px 7px 8px;font:inherit;font-size:11px;font-weight:700;outline:none}
.v64-student-practice-filters select:focus{border-color:#9cbce0;box-shadow:0 0 0 3px rgba(59,130,246,.07)}
.v64-student-practice-level{display:grid;gap:4px;min-width:64px}
.v64-student-practice-level b{display:flex;align-items:center;min-height:32px;font-size:11px;color:#2e5f88;background:#edf5fc;border:1px solid #d7e8f5;border-radius:8px;padding:0 9px;white-space:nowrap}
.v64-assignment-nav-hidden{display:none!important}

@media(max-width:760px){
  .v64-student-modal{width:100%}
  .v64-student-range-groups{grid-template-columns:1fr}
  .v64-student-practice-nav{padding:8px;margin-bottom:8px}
  .v64-student-practice-filters{grid-template-columns:1fr 1fr}
  .v64-student-practice-level{grid-column:1/-1;display:flex;align-items:center;justify-content:space-between;gap:8px}
  .v64-student-practice-level b{min-height:28px}
}
@media(max-width:430px){
  .v64-student-practice-head{align-items:flex-start}
  .v64-student-practice-filters{grid-template-columns:1fr}
  .v64-student-practice-level{grid-column:auto}
  .v64-student-card .v54-card-actions{display:grid;grid-template-columns:1fr 1fr}
  .v64-student-card .v54-card-actions button{width:100%}
}
@media(prefers-color-scheme:dark){
  .v64-student-info,.v64-student-range-groups>div,.v64-student-practice-nav{background:#0f172a;border-color:#334155;color:#cbd5e1}
  .v64-student-card-title>span{background:#12304a;border-color:#315d90;color:#bfdbfe}
  .v64-student-card-title>span.legacy{background:#172033;border-color:#334155;color:#cbd5e1}
  .v64-student-meta span{background:#172033;color:#cbd5e1}
  .v64-student-range,.v64-student-practice-nav{border-color:#334155}
  .v64-student-range-head b,.v64-student-range-groups>div b,.v64-student-practice-head b{color:#e5e7eb}
  .v64-student-practice-filters select{background:#111827;border-color:#334155;color:#e5e7eb}
  .v64-student-practice-level b{background:#12304a;border-color:#315d90;color:#dbeafe}
}