:root{--bg:#f7f7f9;--accent:#111;--muted:#666;--card:#fff}*{box-sizing:border-box}body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial;margin:0;background:var(--bg);color:#111}.app-layout{display:flex;min-height:100vh}.sidebar{width:260px;background:var(--accent);color:#fff;padding:20px;display:flex;flex-direction:column}.sidebar .brand h1{margin:0;font-size:18px}.sidebar .muted{opacity:.85}.menu{margin-top:18px;display:flex;flex-direction:column;gap:8px}.menu-item{color:#fff;text-decoration:none;padding:8px 10px;border-radius:6px;display:inline-block}.menu-item:hover{background:#ffffff08}.menu-button{width:100%;background:#fff;color:var(--accent);border-radius:8px;padding:10px;font-weight:700}.content{flex:1;padding:28px}nav{background:var(--accent);color:#fff;padding:12px 18px;display:flex;align-items:center;gap:12px}nav a{color:#fff;margin-right:12px;text-decoration:none;font-weight:600}nav .spacer{flex:1}main{padding:24px;max-width:1100px;margin:0 auto}.container{background:var(--card);padding:18px;border-radius:8px;box-shadow:0 2px 6px #0000000f}h1,h2,h3{margin:0 0 12px}.levels-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px}.level-card{background:var(--card);border-radius:8px;padding:12px;box-shadow:0 1px 4px #0000000f;display:flex;flex-direction:column;gap:10px}.level-card img{width:100%;height:140px;object-fit:cover;border-radius:6px;border:1px solid #eee}.meta{font-size:13px;color:var(--muted);word-break:break-all}.toolbar{display:flex;gap:8px;align-items:center}button{background:#111;color:#fff;border:none;padding:8px 12px;border-radius:6px;cursor:pointer}button.secondary{background:#eee;color:#111}textarea{font-family:monospace}.small{font-size:13px;color:var(--muted)}.card{background:var(--card);border-radius:8px;padding:14px;box-shadow:0 1px 6px #12141c0f;margin-bottom:16px}.row{display:flex;gap:12px;align-items:flex-start;flex-wrap:wrap}.col-left{width:420px;min-width:320px}.col-right{flex:1;min-width:280px}.simulator-wrap{display:flex;flex-direction:column;align-items:center;gap:12px}.section-title{margin:0 0 8px;font-size:16px}.form-row{display:flex;gap:12px;align-items:center;margin-bottom:8px}.form-row label{width:160px;color:#333}.small-muted{font-size:13px;color:#666}.btn{padding:8px 12px;border-radius:6px;border:none;cursor:pointer}.btn.primary{background:#1f6feb;color:#fff}.btn.secondary{background:#f2f4f8;color:#111}.btn.danger{background:#ff6b6b;color:#fff}.hash-panel{font-family:monospace;background:#f6f8fb;padding:8px;border-radius:6px}