:root{
  --bg:#0e0f22; --panel:#171933; --panel2:#20233f; --border:#32365c;
  --text:#f3f2ff; --muted:#9b9fc9; --accent:#8b7bff; --accent2:#ffb454;
  --warn:#ffb454; --bad:#ff6b81; --good:#3ddc97; --radius:16px;
  --user-bg: radial-gradient(circle at 15% -10%, #3a2e78 0%, transparent 45%),
             radial-gradient(circle at 100% 0%, #1c3a5e 0%, transparent 40%), #0e0f22;
}
*{box-sizing:border-box}
body{margin:0;font-family:'Inter',system-ui,-apple-system,sans-serif;background:var(--user-bg);color:var(--text);min-height:100vh}
h1,h2,h3{font-family:'Poppins',sans-serif}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-thumb{background:var(--panel2);border-radius:8px}
.app{display:flex;min-height:100vh}
nav{width:236px;background:linear-gradient(180deg,#181a38,#141631);border-right:1px solid var(--border);padding:20px 12px;flex-shrink:0}
nav h1{font-size:1.15rem;margin:4px 8px 22px;color:var(--text);letter-spacing:.3px;display:flex;align-items:center;gap:8px}
nav h1 .logo{background:linear-gradient(135deg,var(--accent),#5b8cff);width:32px;height:32px;border-radius:9px;display:flex;align-items:center;justify-content:center;font-size:1.1rem;box-shadow:0 3px 10px rgba(139,123,255,.4)}
nav button{display:flex;align-items:center;gap:10px;width:100%;text-align:left;background:none;border:none;border-left:3px solid transparent;color:var(--muted);padding:11px 12px;margin-bottom:2px;border-radius:10px;cursor:pointer;font-size:.92rem;font-family:inherit;font-weight:500}
nav button:hover{background:var(--panel2);color:var(--text)}
nav button.active{background:linear-gradient(90deg,rgba(139,123,255,.22),rgba(139,123,255,.05));color:#fff;border-left:3px solid var(--accent)}
main{flex:1;padding:26px 36px 60px;max-width:920px}
#hud{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:18px;align-items:center}
.hud-pill{background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:9px 16px;font-size:.85rem;display:flex;align-items:center;gap:7px;box-shadow:0 2px 8px rgba(0,0,0,.2)}
.hud-pill b{color:var(--accent2);font-family:'Poppins',sans-serif}
.hud-pill.warn{border-color:var(--accent2);background:rgba(255,180,84,.08)}
h2{margin-top:0;color:var(--text);font-weight:700;letter-spacing:.2px}
.card{background:linear-gradient(160deg,var(--panel),#161834);border:1px solid var(--border);border-radius:var(--radius);padding:22px;margin-bottom:16px;box-shadow:0 6px 20px rgba(0,0,0,.22);transition:transform .15s ease, box-shadow .15s ease}
.pill{display:inline-block;background:var(--panel2);border:1px solid var(--border);border-radius:20px;padding:3px 12px;font-size:.78rem;color:var(--muted);margin-right:6px}
input[type=text],input[type=password],input[type=number],input[type=datetime-local],textarea,select{width:100%;background:#0c0d1f;border:1px solid var(--border);color:var(--text);border-radius:10px;padding:11px 13px;font-family:inherit;font-size:1rem}
input:focus,textarea:focus,select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(139,123,255,.25)}
label{font-size:.85rem;color:var(--muted);display:block;margin:10px 0 4px}
button.btn{background:linear-gradient(135deg,var(--accent),#6a5bef);color:#fff;border:none;padding:11px 20px;border-radius:10px;cursor:pointer;font-size:.95rem;font-weight:600;font-family:inherit;margin-top:10px;margin-right:8px;transition:transform .1s ease,box-shadow .1s ease;box-shadow:0 3px 0 #4a3fc4}
button.btn:active{transform:translateY(2px);box-shadow:0 1px 0 #4a3fc4}
button.btn.secondary{background:var(--panel2);color:var(--text);border:1px solid var(--border);box-shadow:0 3px 0 rgba(0,0,0,.3)}
button.btn.good{background:var(--good);color:#06281a;box-shadow:0 3px 0 #1f9967}
button.btn.bad{background:var(--bad);color:#330a10;box-shadow:0 3px 0 #a13343}
button.btn:disabled{opacity:.5;cursor:not-allowed}
.choice{display:block;width:100%;text-align:left;background:var(--panel2);border:1px solid var(--border);color:var(--text);padding:12px 15px;border-radius:10px;margin-bottom:8px;cursor:pointer;font-family:inherit;font-size:.95rem;transition:transform .1s ease}
.choice:not(:disabled):hover{transform:translateX(3px);border-color:var(--accent)}
.choice.correct{border-color:var(--good);background:#123324}
.choice.wrong{border-color:var(--bad);background:#331717}
.feedback{border-left:3px solid var(--accent);padding:12px 15px;background:var(--panel2);border-radius:0 10px 10px 0;margin-top:12px}
.badge{display:inline-block;background:var(--warn);color:#332200;padding:2px 10px;border-radius:12px;font-size:.75rem;font-weight:bold;margin-left:6px}
.small{font-size:.85rem;color:var(--muted)}
table{width:100%;border-collapse:collapse;font-size:.9rem}
td,th{border-bottom:1px solid var(--border);padding:7px 8px;text-align:left}
.streakbox{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:14px}
.stat{background:linear-gradient(160deg,var(--panel),#161834);border:1px solid var(--border);border-radius:14px;padding:14px 22px;text-align:center;box-shadow:0 4px 14px rgba(0,0,0,.2);transition:transform .15s ease}
.stat:hover{transform:translateY(-3px)}
.stat .num{font-size:1.7rem;font-family:'Poppins',sans-serif;color:var(--accent2);font-weight:700}
.bar{height:9px;background:#0c0d1f;border-radius:6px;overflow:hidden;border:1px solid var(--border)}
.bar>div{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));transition:width .5s ease}
@keyframes flamepulse{0%,100%{transform:scale(1)}50%{transform:scale(1.18)}}
.flame{display:inline-block;animation:flamepulse 1.4s infinite}
#toastWrap{position:fixed;top:16px;right:16px;z-index:999;display:flex;flex-direction:column;gap:8px}
.toast{background:var(--panel2);border:1px solid var(--accent);color:var(--text);padding:10px 16px;border-radius:10px;box-shadow:0 4px 14px rgba(0,0,0,.4);animation:toastin .25s ease, toastout .4s ease 2.2s forwards;font-size:.9rem}
@keyframes toastin{from{opacity:0;transform:translateX(30px)}to{opacity:1;transform:translateX(0)}}
@keyframes toastout{to{opacity:0;transform:translateX(30px)}}
.confetti{position:fixed;top:-10px;width:8px;height:14px;z-index:998;border-radius:2px;animation:fall linear forwards}
@keyframes fall{to{transform:translateY(105vh) rotate(360deg);opacity:.2}}
#levelupModal,.modal-overlay{position:fixed;inset:0;background:rgba(10,10,20,.72);display:flex;align-items:center;justify-content:center;z-index:1000}
#levelupModal .box,.modal-box{background:var(--panel);border:2px solid var(--accent2);border-radius:18px;padding:32px 40px;text-align:center;animation:pop .3s ease;max-width:420px}
@keyframes pop{from{transform:scale(.7);opacity:0}to{transform:scale(1);opacity:1}}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:700px){.grid2{grid-template-columns:1fr}.app{flex-direction:column}nav{width:100%;display:flex;overflow-x:auto;padding:12px}nav h1{display:none}nav button{white-space:nowrap;border-left:none;border-bottom:3px solid transparent}nav button.active{border-left:none;border-bottom:3px solid var(--accent)}main{padding:18px}}

/* ---- collapsible profile sections ---- */
details.section{background:var(--panel2);border:1px solid var(--border);border-radius:12px;margin-bottom:10px;overflow:hidden}
details.section summary{cursor:pointer;list-style:none;padding:13px 16px;font-weight:600;display:flex;align-items:center;gap:10px;user-select:none}
details.section summary::-webkit-details-marker{display:none}
details.section summary .chev{margin-left:auto;transition:transform .2s ease;color:var(--muted)}
details.section[open] summary .chev{transform:rotate(90deg)}
details.section .section-body{padding:2px 16px 16px}
details.section summary .icon{font-size:1.1rem}

/* ---- login pages ---- */
.auth-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}
.auth-card{width:100%;max-width:380px;background:linear-gradient(160deg,var(--panel),#161834);border:1px solid var(--border);border-radius:20px;padding:34px;box-shadow:0 12px 40px rgba(0,0,0,.4)}
.auth-card h1{display:flex;align-items:center;gap:10px;font-size:1.3rem;margin-bottom:4px}
.auth-card .logo{background:linear-gradient(135deg,var(--accent),#5b8cff);width:36px;height:36px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:1.2rem}
.error-text{color:var(--bad);font-size:.85rem;margin-top:8px}
.auth-card .btn{width:100%;margin-right:0}

/* ---- theme customizer ---- */
.swatch{width:34px;height:34px;border-radius:9px;cursor:pointer;border:2px solid transparent;display:inline-block}
.swatch.active{border-color:#fff}