:root{--navy:#102d55;--blue:#1768ac;--gold:#f2b632;--ink:#172033;--muted:#64748b;--paper:#f5f7fb}*{box-sizing:border-box}body{margin:0;font:16px/1.5 system-ui,sans-serif;color:var(--ink);background:linear-gradient(135deg,#edf4fb,#fff)}button,.button{border:0;border-radius:10px;background:var(--blue);color:#fff;padding:.75rem 1rem;font-weight:700;cursor:pointer;text-decoration:none}button:disabled{opacity:.5}.app-shell{width:min(1000px,100%);min-height:100vh;margin:auto;padding:24px;display:flex;flex-direction:column}.hero{display:flex;gap:18px;align-items:center}.hero h1{margin:.1rem 0;font-size:clamp(1.7rem,4vw,2.7rem)}.eyebrow{color:var(--blue);font-weight:800;text-transform:uppercase;font-size:.78rem;letter-spacing:.08em}.mark{width:72px;height:72px;display:grid;place-items:center;border-radius:18px;background:var(--navy);color:var(--gold);font-weight:900}.ghost{margin-left:auto;background:#e7eef7;color:var(--navy)}.examples{display:flex;gap:8px;overflow:auto;padding:18px 0}.examples button{background:#fff;color:var(--navy);border:1px solid #cad6e4;white-space:nowrap}.conversation{height:52vh;overflow:auto;background:#fff;border:1px solid #dbe3ee;border-radius:18px;padding:18px}.message{display:flex;gap:10px;margin:14px 0}.message.student{flex-direction:row-reverse}.avatar{width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--navy);color:#fff;font-size:.75rem;font-weight:800}.bubble{max-width:78%;background:#edf2f7;padding:12px 15px;border-radius:4px 16px 16px}.student .bubble{background:var(--blue);color:#fff;border-radius:16px 4px 16px 16px}.sources{border-top:1px solid #ccd5df;margin-top:10px;padding-top:8px;font-size:.86rem}.feedback{display:flex;gap:6px;margin-top:8px}.feedback button{padding:5px 8px;font-size:.75rem}.composer{display:flex;gap:10px;margin-top:12px}.composer textarea{flex:1;border:1px solid #b8c5d6;border-radius:12px;padding:12px;font:inherit;resize:none}.status{min-height:24px;color:#b45309}.disclaimer{font-size:.8rem;color:var(--muted);text-align:center}.sr-only{position:absolute;clip:rect(0,0,0,0)}.admin-nav{background:var(--navy);padding:16px 5%;display:flex;justify-content:space-between}.admin-nav a{color:#fff;text-decoration:none;font-weight:700}.admin-nav nav{display:flex;gap:16px;align-items:center}.admin-nav form{margin:0}.admin-main,.login-card{width:min(1100px,92%);margin:35px auto}.login-card{max-width:420px;background:#fff;padding:30px;border-radius:16px}.login-card label{display:block;margin:12px 0}.login-card input{display:block;width:100%;padding:10px}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.stats article,.panel{padding:22px;background:#fff;border-radius:14px}.stats strong{display:block;font-size:2rem}table{width:100%;border-collapse:collapse;background:#fff;margin-top:18px}th,td{text-align:left;padding:11px;border-bottom:1px solid #e2e8f0}.actions{display:flex;gap:6px}.danger,.flash.error{background:#b42318}.flash{padding:12px;color:#fff;background:#237a46;border-radius:8px}@media(max-width:650px){.hero{align-items:flex-start;flex-wrap:wrap}.mark{width:52px;height:52px}.ghost{margin-left:0}.app-shell{padding:14px}.conversation{height:55vh}.bubble{max-width:88%}.stats{grid-template-columns:1fr}.admin-nav,.admin-nav nav{flex-wrap:wrap}table{font-size:.82rem;display:block;overflow:auto}}