:root{--bg:#f4f5f7;--card:#fff;--text:#17212b;--muted:#65717e;--accent:#b3261e;--ok:#1b7f3a;--bad:#b42318;--line:#d9dee4}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text)}button,select,input{font:inherit}.shell{max-width:760px;margin:auto;min-height:100vh;padding:16px 16px 88px}.top{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}.brand{font-weight:800;font-size:1.25rem}.sub{color:var(--muted);font-size:.9rem}.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:18px;box-shadow:0 4px 18px #0000000d;margin-bottom:14px}.hero h1{margin:.2rem 0;font-size:1.8rem}.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.tile{min-height:108px;text-align:left;border:1px solid var(--line);background:var(--card);border-radius:16px;padding:16px;cursor:pointer}.tile strong{display:block;font-size:1.05rem;margin-bottom:6px}.tile span{color:var(--muted);font-size:.9rem}.primary{border:0;background:var(--accent);color:white;border-radius:12px;padding:13px 16px;font-weight:700;cursor:pointer}.secondary{border:1px solid var(--line);background:white;border-radius:12px;padding:11px 14px;cursor:pointer}.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.between{justify-content:space-between}.progress{height:8px;background:#e6e9ed;border-radius:99px;overflow:hidden}.progress>div{height:100%;background:var(--accent)}.q{font-size:1.22rem;font-weight:700;line-height:1.45;margin:18px 0}.choice{width:100%;display:flex;gap:12px;align-items:flex-start;text-align:left;border:1px solid var(--line);background:white;border-radius:13px;padding:13px;margin:9px 0;cursor:pointer}.choice.selected{outline:3px solid #b3261e30;border-color:var(--accent)}.choice.correct{border-color:var(--ok);background:#edf8f0}.choice.wrong{border-color:var(--bad);background:#fff0ee}.letter{font-weight:800;min-width:24px}.feedback{border-radius:13px;padding:14px;margin-top:14px}.feedback.ok{background:#edf8f0;color:#125d2d}.feedback.bad{background:#fff0ee;color:#8a1c13}.stat{font-size:1.8rem;font-weight:800}.small{font-size:.85rem;color:var(--muted)}.nav{position:fixed;bottom:0;left:0;right:0;background:#fffffff2;backdrop-filter:blur(12px);border-top:1px solid var(--line);padding:10px max(12px,env(safe-area-inset-right)) calc(10px + env(safe-area-inset-bottom));display:flex;justify-content:center;gap:8px}.nav button{border:0;background:transparent;padding:10px 14px;border-radius:10px}.nav button.active{background:#f1dedc;color:var(--accent);font-weight:700}.filters{display:grid;grid-template-columns:1fr 1fr;gap:10px}.filters select,.filters input{width:100%;padding:11px;border:1px solid var(--line);border-radius:10px;background:white}.listq{border-bottom:1px solid var(--line);padding:13px 0}.badge{display:inline-block;padding:4px 8px;border-radius:99px;background:#eef1f4;color:#4c5966;font-size:.75rem}.star{border:0;background:transparent;font-size:1.5rem;cursor:pointer}@media(max-width:520px){.grid{grid-template-columns:1fr}.filters{grid-template-columns:1fr}.shell{padding:12px 12px 86px}}
.compact{padding:8px 12px}.button-link{display:inline-block;text-decoration:none}.avatar-button{width:42px;height:42px;border-radius:50%;border:1px solid var(--line);overflow:hidden;background:var(--card);font-weight:800;cursor:pointer;padding:0}.avatar-button img{width:100%;height:100%;object-fit:cover}.profile-picture{width:72px;height:72px;border-radius:50%;object-fit:cover}.profile-card h2{margin:0 0 4px}.sync-status{margin:16px 0;padding:10px 12px;border-radius:12px;background:#edf8f0;color:#125d2d;font-weight:700}.privacy-note{margin-top:18px;line-height:1.5}.danger-button{border:1px solid var(--bad);color:var(--bad);background:white;border-radius:12px;padding:11px 14px;cursor:pointer}.card hr{border:0;border-top:1px solid var(--line);margin:18px 0}select{padding:11px;border:1px solid var(--line);border-radius:10px;background:white}
.explain{margin-top:10px;line-height:1.45;color:inherit}.notice{padding:11px 12px;background:#fff7df;border:1px solid #ead18a;border-radius:12px;font-size:.9rem}.answer-line{font-weight:600}.admin-user{padding:14px 0;border-bottom:1px solid var(--line)}.admin-controls{margin-top:10px;gap:20px}.session-detail{border-bottom:1px solid var(--line);padding:12px 0}.session-detail summary{cursor:pointer}.attempt-list{margin-top:10px}.attempt{padding:10px;border-radius:10px;margin:7px 0}.attempt-ok{background:#edf8f0}.attempt-bad{background:#fff0ee}

.pending-shell{min-height:100vh;display:grid;place-items:center;padding:24px;background:var(--bg,#f7f3ef)}
.pending-card{width:min(520px,100%);text-align:center;background:#fff;border-radius:20px;padding:36px;box-shadow:0 12px 40px rgba(0,0,0,.08)}
.pending-card h1{margin-top:0}
.pending-card p{line-height:1.55}
.study-reference{margin-top:12px;padding-top:10px;border-top:1px solid rgba(127,127,127,.25);font-size:.9rem}.study-reference a{text-decoration:underline}

.memory-tip{margin-top:12px;padding:10px 12px;border-left:4px solid var(--primary,#2563eb);background:rgba(37,99,235,.08);border-radius:6px}.study-reference ul{margin:8px 0 0 20px;padding:0}.study-reference li{margin:4px 0}