:root{--n:#102a43;--b:#1f5b8f;--t:#167c72;--bg:#f4f7fb;--line:#dce5ee;--ok:#18794e;--bad:#b42318}
*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial;background:var(--bg);color:#17212b}
.wrap{max-width:1050px;margin:auto;padding:0 18px}.top{background:linear-gradient(135deg,var(--n),var(--b));color:#fff;padding:18px 0}
.row{display:flex;justify-content:space-between;align-items:center;gap:12px}.brand{font-size:22px;font-weight:800}
nav a{color:#fff;text-decoration:none;margin-left:12px}.card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px;box-shadow:0 8px 28px rgba(16,42,67,.05)}
main{padding:24px 0}.grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px}.stat b{font-size:26px;display:block}.stat span,.meta{color:#617283;font-size:12px}
.form{max-width:430px;margin:45px auto}.form input{width:100%;padding:11px;border:1px solid var(--line);border-radius:9px;margin:5px 0 14px}
.btn{border:0;background:var(--t);color:#fff;padding:11px 16px;border-radius:10px;font-weight:700;cursor:pointer;text-decoration:none;display:inline-block}
.choice{width:100%;text-align:left;background:#fff;border:1px solid var(--line);border-radius:11px;padding:13px;margin:8px 0;cursor:pointer}
.choice.good{background:#f0fdf4;border-color:#86efac}.choice.bad{background:#fff1f2;border-color:#fca5a5}
.question{font-size:21px;font-weight:800;line-height:1.35;margin:12px 0 18px}.feedback{margin-top:14px;padding:12px;border-radius:10px;display:none}
.feedback.show{display:block}.feedback.ok{background:#ecfdf3;color:var(--ok)}.feedback.no{background:#fff1f2;color:var(--bad)}.notice{background:#fff7ed;border:1px solid #fed7aa;color:#9a3412;padding:11px;border-radius:10px}
@media(max-width:760px){.grid{grid-template-columns:repeat(2,1fr)}.row{align-items:flex-start;flex-direction:column}}

/* v2 teaching/remediation layer */
.choice:disabled{cursor:not-allowed;opacity:.72}.remediation{margin-top:18px;padding:18px;border:1px solid #c9d9e8;border-radius:14px;background:#f8fbff}.rem-label{text-transform:uppercase;letter-spacing:.08em;font-size:11px;font-weight:800;color:#1f5b8f;margin-bottom:8px}.counter-question{font-size:18px;font-weight:750;line-height:1.4;margin-bottom:10px}.feedback.teach{background:#eef6ff;color:#164e7a}.feedback.neutral{background:#f3f7fb;color:#334e68}.btn.secondary{background:#e8eef5;color:#243b53}.pill{display:inline-block;background:#ecfdf3;color:#18794e;border:1px solid #bbf7d0;border-radius:999px;font-size:11px;font-weight:700;padding:2px 7px;margin-left:6px}.remediation-editor textarea{width:100%;padding:10px;border:1px solid var(--line);border-radius:9px;margin:5px 0 14px;font:inherit;resize:vertical}.remediation-editor label{font-weight:700;font-size:13px}.check{display:flex;align-items:center;gap:8px}.inline-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.inline-actions form{margin:0}

/* v3 instructor portal + remediation quality guard */
.quality{display:inline-block;border-radius:999px;padding:4px 9px;font-size:11px;font-weight:800;white-space:nowrap}.quality.pass{background:#ecfdf3;color:#18794e;border:1px solid #bbf7d0}.quality.fail{background:#fff1f2;color:#b42318;border:1px solid #fecaca}.quality-box{padding:10px 12px;border-radius:10px;margin:8px 0 14px;font-size:13px}.quality-box.pass{background:#f0fdf4;border:1px solid #bbf7d0;color:#166534}.quality-box.fail{background:#fff1f2;border:1px solid #fecaca;color:#991b1b}.quality-box ul{margin:6px 0 0;padding-left:18px}.concept-preview{background:#f8fafc;border:1px dashed #cbd5e1;border-radius:9px;padding:9px 11px;margin:-5px 0 14px;color:#475569;font-size:13px}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:14px}.table-wrap{overflow:auto}table{width:100%;border-collapse:collapse;font-size:13px}th,td{text-align:left;vertical-align:top;border-bottom:1px solid var(--line);padding:10px 8px}th{font-size:11px;text-transform:uppercase;letter-spacing:.05em;color:#64748b;background:#f8fafc}td a{color:#1f5b8f;text-decoration:none;font-weight:700}.mini-link{font-size:12px}.instructor-stats{grid-template-columns:repeat(4,1fr)}.stat-warn{border-color:#fed7aa;background:#fffaf4}.stat-bad{border-color:#fecaca;background:#fff7f7}.status-pending{background:#f8fafc;color:#475569;border-color:#cbd5e1}.status-edit{background:#fff7ed;color:#9a3412;border-color:#fed7aa}.status-rejected{background:#fff1f2;color:#b42318;border-color:#fecaca}.source-choice{padding:10px;border-radius:9px;border:1px solid transparent}.source-choice.source-correct{background:#f0fdf4;border-color:#bbf7d0}.card select{width:100%;padding:10px;border:1px solid var(--line);border-radius:9px;margin:5px 0 14px;background:#fff}.card hr{border:0;border-top:1px solid var(--line);margin:20px 0}
@media(max-width:900px){.two-col{grid-template-columns:1fr}.instructor-stats{grid-template-columns:repeat(2,1fr)}}