:root{
  --dna-primary:#4f46e5;
  --dna-primary-2:#7c3aed;
  --dna-accent:#0ea5e9;
  --dna-success:#16a34a;
  --dna-warning:#d97706;
  --dna-danger:#dc2626;
  --dna-ink:#172033;
  --dna-muted:#64748b;
  --dna-soft:#f6f8fc;
  --dna-line:#e6eaf1;
  --dna-sidebar:#111827;
}
html,body{min-height:100%}
body{background:var(--dna-soft);color:var(--dna-ink);font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif}
a{text-decoration:none}
.app-shell{min-height:100vh}
.app-sidebar{width:280px;background:linear-gradient(180deg,#111827 0%,#18213a 100%);color:#fff;position:fixed;inset:0 auto 0 0;z-index:1040;overflow-y:auto;box-shadow:10px 0 30px rgba(15,23,42,.08)}
.app-main{margin-left:280px;min-height:100vh}
.app-topbar{height:72px;background:rgba(255,255,255,.94);backdrop-filter:blur(14px);border-bottom:1px solid var(--dna-line);position:sticky;top:0;z-index:1020}
.brand-mark{width:42px;height:42px;border-radius:14px;background:linear-gradient(135deg,#818cf8,#7c3aed);display:grid;place-items:center;color:#fff;box-shadow:0 8px 22px rgba(79,70,229,.28)}
.brand-title{font-weight:800;letter-spacing:-.02em}
.brand-sub{font-size:.76rem;color:#94a3b8}
.sidebar-link{display:flex;align-items:center;gap:.75rem;padding:.78rem .9rem;margin:.22rem .55rem;border-radius:12px;color:#cbd5e1;font-weight:600}
.sidebar-link:hover,.sidebar-link.active{background:rgba(255,255,255,.10);color:#fff}
.sidebar-link i{font-size:1.08rem;width:22px;text-align:center}
.sidebar-section{font-size:.68rem;letter-spacing:.12em;text-transform:uppercase;color:#64748b;font-weight:800;padding:1rem 1.45rem .35rem}
.page-wrap{padding:24px 28px 48px}
.page-title{font-weight:800;letter-spacing:-.025em;margin-bottom:.25rem}
.page-subtitle{color:var(--dna-muted);margin:0}
.card-dna{border:1px solid var(--dna-line);border-radius:18px;box-shadow:0 8px 28px rgba(15,23,42,.045);overflow:hidden}
.card-dna .card-header{background:#fff;border-bottom:1px solid var(--dna-line);padding:1rem 1.15rem}
.card-dna .card-body{padding:1.15rem}
.metric-card{position:relative;min-height:138px}
.metric-icon{width:46px;height:46px;border-radius:14px;display:grid;place-items:center;font-size:1.3rem}
.metric-value{font-size:2rem;font-weight:850;letter-spacing:-.04em}
.metric-label{color:var(--dna-muted);font-size:.9rem}
.bg-soft-primary{background:#eef2ff;color:#4f46e5}
.bg-soft-info{background:#e0f2fe;color:#0284c7}
.bg-soft-success{background:#dcfce7;color:#15803d}
.bg-soft-warning{background:#fef3c7;color:#b45309}
.bg-soft-danger{background:#fee2e2;color:#b91c1c}
.badge-soft{background:#f1f5f9;color:#475569;border:1px solid #e2e8f0}
.progress-thin{height:8px;background:#edf1f7}
.progress-thin .progress-bar{border-radius:999px}
.mastery-row{padding:.78rem 0;border-bottom:1px dashed #e7ebf1}.mastery-row:last-child{border-bottom:0}
.dna-score{font-weight:800}
.priority-rank{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;background:#eef2ff;color:#4f46e5;font-weight:800}
.error-pill{display:inline-flex;align-items:center;gap:.35rem;border:1px solid #e5e7eb;border-radius:999px;padding:.35rem .55rem;background:#fff;font-size:.78rem;font-weight:700}
.question-card{max-width:900px;margin-inline:auto}
.answer-option{position:relative;display:block;border:1.5px solid #e2e8f0;border-radius:15px;padding:1rem 1.1rem;margin:.7rem 0;cursor:pointer;transition:.18s ease;background:#fff}
.answer-option:hover{border-color:#818cf8;background:#f8f7ff;transform:translateY(-1px)}
.answer-option input{position:absolute;opacity:0}
.answer-option:has(input:checked){border-color:#4f46e5;background:#eef2ff;box-shadow:0 0 0 3px rgba(79,70,229,.08)}
.option-key{width:30px;height:30px;border-radius:9px;background:#f1f5f9;display:inline-grid;place-items:center;font-weight:800;margin-right:.55rem}
.answer-option:has(input:checked) .option-key{background:#4f46e5;color:#fff}
.feedback-box{border-radius:16px;padding:1rem 1.1rem}
.feedback-good{background:#ecfdf3;border:1px solid #bbf7d0}
.feedback-bad{background:#fff1f2;border:1px solid #fecdd3}
.knowledge-node{border:1px solid #e5e7eb;border-radius:14px;padding:.8rem;background:#fff}
.table-modern{--bs-table-bg:transparent}
.table-modern thead th{font-size:.78rem;color:#64748b;text-transform:uppercase;letter-spacing:.045em;border-bottom:1px solid #e5e7eb}
.table-modern td{vertical-align:middle}
.empty-state{padding:2.5rem;text-align:center;color:#64748b}
.empty-state i{font-size:2.25rem;color:#cbd5e1}
.login-page{min-height:100vh;background:
 radial-gradient(circle at 15% 15%,rgba(99,102,241,.22),transparent 28%),
 radial-gradient(circle at 85% 80%,rgba(14,165,233,.18),transparent 30%),
 #f7f8fc}
.login-card{max-width:430px;border:1px solid rgba(255,255,255,.5);border-radius:22px;box-shadow:0 22px 70px rgba(30,41,59,.12)}
.login-side{background:linear-gradient(135deg,#312e81 0%,#4f46e5 45%,#0ea5e9 100%);color:#fff;border-radius:26px;min-height:560px;position:relative;overflow:hidden}
.login-side:before{content:"";position:absolute;width:300px;height:300px;border-radius:50%;border:55px solid rgba(255,255,255,.08);right:-90px;top:-80px}
.login-side:after{content:"";position:absolute;width:260px;height:260px;border-radius:50%;background:rgba(255,255,255,.06);left:-90px;bottom:-90px}
.offcanvas-dna{background:#111827;color:#fff}
.chart-wrap{position:relative;min-height:300px}
.student-chip{display:inline-flex;align-items:center;gap:.45rem;background:#f8fafc;border:1px solid #e2e8f0;border-radius:999px;padding:.34rem .65rem;font-size:.8rem}
.form-control,.form-select{border-color:#dbe2ea;border-radius:12px;padding:.68rem .8rem}
.form-control:focus,.form-select:focus{border-color:#818cf8;box-shadow:0 0 0 .22rem rgba(79,70,229,.12)}
.btn{border-radius:12px;font-weight:700}
.btn-primary{--bs-btn-bg:#4f46e5;--bs-btn-border-color:#4f46e5;--bs-btn-hover-bg:#4338ca;--bs-btn-hover-border-color:#4338ca}
.alert{border-radius:14px}
.footer-note{font-size:.78rem;color:#94a3b8}
@media(max-width:991.98px){
  .app-sidebar{display:none}
  .app-main{margin-left:0}
  .page-wrap{padding:20px 16px 38px}
}