:root{--bg:#f8fafc;--surface:#fff;--surface-2:#f1f5f9;--text:#0f172a;--muted:#64748b;--border:#e2e8f0;--accent:#4f46e5;--accent-soft:#eef2ff;--warn:#b45309;--warn-soft:#fffbeb}
@media (prefers-color-scheme:dark){:root{--bg:#080b16;--surface:#111727;--surface-2:#1e273c;--text:#f1f5f9;--muted:#94a3b8;--border:#273149;--accent:#818cf8;--accent-soft:#1a2138;--warn:#fbbf24;--warn-soft:#241d0e}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);line-height:1.75;-webkit-font-smoothing:antialiased;
font-family:"SUITE",system-ui,-apple-system,"Segoe UI",Roboto,"Apple SD Gothic Neo","Malgun Gothic",sans-serif}
.skip{position:absolute;left:-9999px}
.skip:focus{left:8px;top:8px;z-index:10;background:var(--accent);color:#fff;padding:8px 14px;border-radius:8px}
.topbar{display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between;
padding:14px 20px;border-bottom:1px solid var(--border);background:var(--surface);position:sticky;top:0;z-index:5}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:1.05rem;color:var(--text);text-decoration:none}
.brand img{border-radius:7px}
.topbar nav{display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.topbar nav a{color:var(--muted);text-decoration:none;font-size:.92rem;padding:6px 10px;border-radius:8px}
.topbar nav a:hover{color:var(--text);background:var(--surface-2)}
.topbar nav a.cta{background:var(--accent);color:#fff;font-weight:700}
main{max-width:820px;margin:0 auto;padding:24px 20px 12px}
.crumbs{font-size:.85rem;color:var(--muted);margin-bottom:18px}
.crumbs a{color:var(--muted)}
.crumbs .sep{margin:0 6px;opacity:.6}
h1{font-size:1.9rem;line-height:1.35;margin:0 0 14px;letter-spacing:-.02em}
h2{font-size:1.3rem;margin:38px 0 12px;padding-top:14px;border-top:1px solid var(--border);letter-spacing:-.01em}
h3{font-size:1.05rem;margin:24px 0 8px}
p{margin:0 0 14px}
a{color:var(--accent)}
.lead{font-size:1.08rem;color:var(--text);background:var(--accent-soft);border-left:3px solid var(--accent);
padding:14px 16px;border-radius:0 10px 10px 0;margin-bottom:24px}
.muted{color:var(--muted);font-size:.9rem}
ul,ol{margin:0 0 14px;padding-left:22px}
li{margin-bottom:7px}
.wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px}
table{border-collapse:collapse;width:100%;min-width:420px;font-size:.94rem;background:var(--surface);border-radius:10px;overflow:hidden}
caption{text-align:left;color:var(--muted);font-size:.86rem;padding-bottom:8px}
th,td{border:1px solid var(--border);padding:9px 12px;text-align:left}
th{background:var(--surface-2);font-weight:700}
td.num,th.num{text-align:center;font-variant-numeric:tabular-nums}
.grid{display:grid;gap:12px;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));margin-bottom:18px}
.card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:14px 16px;text-decoration:none;color:var(--text)}
a.card:hover{border-color:var(--accent)}
.card .t{font-weight:800;font-size:1.05rem;margin-bottom:4px}
.card .d{color:var(--muted);font-size:.88rem;line-height:1.6}
.tag{display:inline-block;font-size:.75rem;font-weight:700;padding:2px 8px;border-radius:999px;background:var(--surface-2);color:var(--muted);margin-right:6px}
.tag.easy{background:#dcfce7;color:#166534}
.tag.medium{background:#fef3c7;color:#92400e}
.tag.hard{background:#fee2e2;color:#991b1b}
@media (prefers-color-scheme:dark){.tag.easy{background:#052e16;color:#86efac}.tag.medium{background:#292109;color:#fcd34d}.tag.hard{background:#2d0f0f;color:#fca5a5}}
.note{background:var(--warn-soft);border:1px solid var(--border);border-left:3px solid var(--warn);padding:12px 16px;border-radius:0 10px 10px 0;margin-bottom:18px}
.qa{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:4px 16px;margin-bottom:12px}
.qa h3{margin:14px 0 6px;font-size:1rem}
.qa p{color:var(--muted)}
.pager{display:flex;justify-content:space-between;gap:12px;margin:32px 0 8px;font-size:.92rem}
.foot{max-width:820px;margin:0 auto;padding:22px 20px 44px;border-top:1px solid var(--border);color:var(--muted);font-size:.88rem}
.foot p{margin:0 0 6px}