:root{
  --bg:#0b1222;--panel:#0f172a;--muted:#94a3b8;--text:#e5e7eb;
  --accent:#4f46e5;--accent-2:#6366f1;--border:#1f2937;
  --bad:#ef4444;--ok:#10b981;
  --card-grad: linear-gradient(180deg,rgba(255,255,255,.06),rgba(255,255,255,.03));
  --shadow: 0 10px 30px rgba(0,0,0,.25);
  --radius:16px;
}
*{box-sizing:border-box} html,body{height:100%}
body{margin:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,sans-serif;background:radial-gradient(1200px 800px at 70% -10%,#1e293b 0,#0b1222 45%,#000 100%);color:var(--text)}
.wrap{max-width:1100px;margin:32px auto;padding:0 18px}
h1{margin:0 0 8px;font-weight:800} p{color:var(--muted);margin:0 0 16px}
.card{background:var(--card-grad);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}
.section{padding:16px} .hint{color:var(--muted);font-size:12px;margin-top:-6px;padding:0 18px 12px}

/* Topbar */
.topbar{display:none;align-items:center;justify-content:space-between;gap:12px;background:var(--card-grad);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:12px 16px;margin-bottom:16px}
.me{color:var(--muted);font-size:14px}
.btn-ghost{padding:10px 12px;border-radius:10px;border:1px solid var(--border);background:#0b1020;color:#e5e7eb;cursor:pointer;text-decoration:none;display:inline-block}
.btn-ghost:hover{outline:2px solid var(--accent)}
.btn-ghost.primary{border-color:#4338ca;box-shadow:inset 0 0 0 1px #4338ca}

/* Form */
form{display:grid;gap:12px;padding:18px} label{font-size:14px;color:var(--muted)}
input,button{width:100%;padding:12px 14px;border-radius:12px;border:1px solid var(--border);background:#0b1020;color:#e5e7eb}
input:focus{outline:2px solid var(--accent);border-color:var(--accent)} .row{display:grid;grid-template-columns:1fr;gap:12px}
@media (min-width:640px){.row{grid-template-columns:1fr 1fr}}
.btn{cursor:pointer;background:linear-gradient(90deg,#4338ca,var(--accent),var(--accent-2));border:none;font-weight:700;text-decoration:none;text-align:center;display:inline-block}
.btn:disabled{opacity:.6;cursor:not-allowed}
.status{padding:12px 18px;border-top:1px solid var(--border);font-size:14px} .ok{color:var(--ok)} .bad{color:var(--bad)}

/* Viewer */
.viewer-wrap{display:none;gap:16px;margin-top:16px}
@media (min-width:900px){.viewer-wrap{grid-template-columns: 320px 1fr}}
.side{background:var(--card-grad);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:12px}
.side h3{margin:4px 8px 10px;font-size:14px;color:var(--muted);font-weight:700}
.search{width:100%;padding:10px 12px;border-radius:10px;border:1px solid var(--border);background:#0b1020;color:#e5e7eb;margin:0 6px 10px}
.list{max-height:520px;overflow:auto;padding:4px}
.item{padding:10px 12px;border-radius:12px;border:1px solid var(--border);background:#0b1020;cursor:pointer;margin:8px;transition:background .15s,transform .05s}
.item:hover{background:#121733} .item.active{outline:2px solid var(--accent);background:#151c3a}
.i-title{font-weight:800;font-size:14px}
.i-sub{font-size:12px;color:var(--muted);margin-top:4px;display:flex;justify-content:space-between;gap:8px}
.badge{background:rgba(34,197,94,.15);border:1px solid rgba(34,197,94,.25);color:#34d399;border-radius:999px;padding:2px 8px;font-size:11px;font-weight:800}
.main{background:var(--card-grad);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px}
.main .head{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}
.main .title{font-weight:800;font-size:18px} .main .meta{color:var(--muted);font-size:12px}
.cards{margin-top:12px;display:grid;gap:12px} @media (min-width:720px){.cards{grid-template-columns: 1fr 1fr}}
.card-grade{background:#0b1020;border:1px solid var(--border);border-radius:14px;padding:14px}
.cg-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}
.cg-chip{font-size:11px;font-weight:800;padding:6px 10px;border-radius:999px;color:#fff;background:linear-gradient(135deg,#06b6d4,#0ea5e9)}
.cg-chip.quiz{background:linear-gradient(135deg,#22c55e,#16a34a)} .score{font-size:24px;font-weight:900}
.excellent{color:#16a34a} .good{color:#0ea5e9} .avg{color:#f59e0b} .poor{color:#ef4444}
.cg-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:10px}
.kv{border:1px dashed var(--border);border-radius:10px;padding:10px}
.k{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.3px} .v{font-size:14px;font-weight:600}
.note{margin-top:10px;padding-top:10px;border-top:1px dashed var(--border);font-size:13px}

/* Flash (center notify) */
.flash-backdrop{position:fixed; inset:0; display:none; align-items:center; justify-content:center;background:rgba(0,0,0,.45); z-index:99999}
.flash{width:min(560px,92vw); background:linear-gradient(180deg,rgba(15,23,42,.98),rgba(2,6,23,.96));
  border:1px solid var(--border); border-radius:18px; box-shadow:0 20px 60px rgba(0,0,0,.45);
  padding:22px 24px; text-align:center; transform:translateY(10px); opacity:0;
  transition:transform .18s ease, opacity .18s ease;}
.flash.show{ transform:translateY(0); opacity:1; }
.flash h3{margin:0 0 6px; font-size:18px}
.flash p{margin:0; color:#cbd5e1}
.flash.success h3{color:#22c55e}
.flash.error h3{color:#ef4444}
.flash.info h3{color:#60a5fa}

/* Toast */
.toast-wrap{position:fixed; right:16px; bottom:16px; z-index:99998; display:flex; flex-direction:column; gap:10px}
.toast{width:min(520px,calc(100vw - 32px)); background:linear-gradient(180deg,rgba(15,23,42,.98),rgba(2,6,23,.96));
  border:1px solid var(--border); border-radius:16px; box-shadow:var(--shadow); padding:14px 16px; display:flex; gap:12px; align-items:flex-start; animation:slideIn .25s ease}
.toast .icon{width:28px;height:28px;border-radius:999px;display:grid;place-items:center;background:linear-gradient(135deg,#22c55e,#16a34a);font-weight:900}
.toast .content{font-size:14px;line-height:1.4}
.toast .close{margin-left:auto;background:transparent;border:0;color:#9aa7c7;cursor:pointer;font-size:18px;line-height:1}
@keyframes slideIn{from{transform:translateY(10px);opacity:0} to{transform:translateY(0);opacity:1}}

/* Cards phụ */
.auto-card{margin:12px 12px 18px;background:linear-gradient(180deg,rgba(49,46,129,.25),rgba(2,6,23,.35));border:1px solid #312e81;border-radius:16px;box-shadow:var(--shadow);padding:14px}
.auto-card h3{margin:0 0 6px;color:#c7d2fe}
.steps{margin:8px 0 0;padding-left:18px;color:#cbd5e1}
.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:10px}
.pill{display:inline-flex;align-items:center;gap:6px;padding:6px 10px;border-radius:999px;border:1px dashed #6366f1;background:rgba(99,102,241,.08);color:#e0e7ff;font-size:12px}

.community{margin:12px;background:linear-gradient(180deg,rgba(34,197,94,.12),rgba(2,6,23,.35));border:1px solid rgba(34,197,94,.35);border-radius:16px;box-shadow:var(--shadow);padding:14px}
.community h3{margin:0 0 6px;color:#86efac}
.community p{margin:4px 0 10px;color:#bbf7d0}