*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--bg:#0b1120;--surface:#151d2e;--surface2:#1e293b;--border:#334155;--text:#f1f5f9;--muted:#94a3b8;--accent:#3b82f6;--accent2:#60a5fa;--green:#22c55e}
html{scroll-behavior:smooth}
body{font-family:system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);line-height:1.65;min-height:100vh;display:flex;flex-direction:column}
a{color:var(--accent2);text-decoration:none}a:hover{text-decoration:underline}
.container{max-width:920px;margin:0 auto;padding:0 1.25rem;width:100%}
.site-header{padding:2rem 0 1.25rem;border-bottom:1px solid var(--border)}
.site-header h1{font-size:clamp(1.4rem,4vw,1.85rem);font-weight:700}
.site-header h1 a{color:var(--text);text-decoration:none}
.site-header h1 span{color:var(--accent2)}
.site-header .tagline{color:var(--muted);margin-top:.4rem;max-width:42rem}
.site-header .stats{margin-top:.75rem;font-size:.85rem;color:var(--green);font-weight:600}
.toolbar{padding:1rem 0;position:sticky;top:0;z-index:10;background:rgba(11,17,32,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--border)}
#search{width:100%;padding:.7rem 1rem;border:1px solid var(--border);border-radius:10px;background:var(--surface);color:var(--text);font-size:1rem}
#search:focus{outline:2px solid var(--accent);border-color:var(--accent)}
.filters{display:flex;gap:.45rem;margin-top:.65rem;flex-wrap:wrap}
.filter-btn{padding:.4rem .85rem;border:1px solid var(--border);border-radius:20px;background:var(--surface);color:var(--muted);cursor:pointer;font-size:.8rem;transition:.15s}
.filter-btn.active,.filter-btn:hover{background:var(--accent);color:#fff;border-color:var(--accent)}
.q-list{padding:1.25rem 0 2.5rem;display:flex;flex-direction:column;gap:.6rem}
.q-card{display:flex;align-items:center;gap:.85rem;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:.9rem 1.1rem;transition:border-color .15s}
.q-card:hover{border-color:var(--accent)}
.q-card.hidden{display:none}
.q-card h2{font-size:.95rem;font-weight:600;flex:1;line-height:1.35}
.q-card h2 a{color:var(--text);text-decoration:none}
.q-card h2 a:hover{color:var(--accent2)}
.q-meta{font-size:.72rem;color:var(--muted);margin-top:.2rem;text-transform:capitalize}
.q-btn{padding:.5rem .95rem;background:var(--accent);color:#fff!important;border-radius:8px;font-size:.8rem;font-weight:600;white-space:nowrap;text-decoration:none!important}
.q-btn:hover{background:#2563eb}
.hero-seo{padding:1.5rem 0;border-bottom:1px solid var(--border)}
.hero-seo h2{font-size:1.1rem;margin-bottom:.5rem}
.hero-seo p{color:var(--muted);font-size:.92rem}
.site-footer{margin-top:auto;border-top:1px solid var(--border);padding:1.5rem 0;text-align:center;color:var(--muted);font-size:.82rem}
.site-footer a{color:var(--accent2)}
.paper-wrap{padding:1.5rem 0 2.5rem}
.paper-page{line-height:1.65;color:var(--text)}
.breadcrumb{font-size:.88rem;color:var(--muted);margin-bottom:1.25rem}
.breadcrumb a{color:var(--accent2);text-decoration:none}
.paper-header h1{font-size:clamp(1.3rem,4vw,1.8rem);line-height:1.25;margin-bottom:.5rem}
.paper-subtitle{color:var(--muted);margin-bottom:1rem}
.paper-tags{display:flex;flex-wrap:wrap;gap:.4rem;margin-bottom:1.25rem}
.tag{background:rgba(59,130,246,.15);color:var(--accent2);padding:.22rem .7rem;border-radius:6px;font-size:.76rem;font-weight:600;border:1px solid rgba(59,130,246,.25)}
.paper-actions{display:flex;flex-wrap:wrap;gap:.75rem;margin-bottom:2rem}
.btn-primary{background:var(--accent);color:#fff!important;padding:.75rem 1.3rem;border-radius:10px;font-weight:600;text-decoration:none!important;display:inline-block}
.btn-primary:hover{background:#2563eb}
.btn-secondary{border:1px solid var(--border);padding:.75rem 1.3rem;border-radius:10px;text-decoration:none!important;color:var(--muted)!important;display:inline-block}
.btn-secondary:hover{border-color:var(--accent);color:var(--text)!important}
.paper-intro,.paper-details,.study-guide,.faq,.related{margin-bottom:2rem}
.paper-page h2{font-size:1.12rem;margin-bottom:.75rem;color:var(--text)}
.details-table{width:100%;border-collapse:collapse;font-size:.93rem}
.details-table th,.details-table td{border:1px solid var(--border);padding:.55rem .8rem;text-align:left}
.details-table th{background:var(--surface2);width:34%;font-weight:600;color:var(--muted)}
.faq details{border:1px solid var(--border);border-radius:10px;padding:.85rem 1rem;margin-bottom:.55rem;background:var(--surface)}
.faq summary{cursor:pointer;font-weight:600}
.related ul{padding-left:1.25rem}
.related li{margin-bottom:.4rem}
.paper-footer{border-top:1px solid var(--border);padding-top:1rem;color:var(--muted)}
@media(max-width:600px){.q-card{flex-direction:column;align-items:flex-start}.paper-actions{flex-direction:column}}