:root{--bg: #0f1420;--bg-elevated: #161d2e;--bg-card: #1a2336;--border: #2a3550;--border-soft: #212a40;--text: #e9edf7;--text-dim: #9aa5c0;--text-faint: #6c7897;--accent: #5ee6c8;--accent-dim: #3fae94;--accent-ink: #06251f;--amber: #f2b866;--rose: #ef8896;--easy: #5ee6c8;--medium: #f2b866;--hard: #ef8896;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 18px;--font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;--font-serif: Georgia, "Iowan Old Style", "Palatino Linotype", Palatino, serif;--font-mono: "SFMono-Regular", "JetBrains Mono", Consolas, Menlo, monospace;--shadow-card: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px -8px rgba(0,0,0,.5)}*{box-sizing:border-box}html,body{height:100%;margin:0}body{background:radial-gradient(1200px 600px at 10% -10%,#17233a 0%,transparent 60%),radial-gradient(1000px 500px at 100% 0%,#14261f 0%,transparent 55%),var(--bg);color:var(--text);font-family:var(--font-sans);font-size:15px;line-height:1.55;-webkit-font-smoothing:antialiased}h1,h2,h3{font-family:var(--font-serif);font-weight:600;letter-spacing:-.01em;margin:0}code,pre{font-family:var(--font-mono)}a{color:inherit;text-decoration:none}::selection{background:var(--accent);color:var(--accent-ink)}.container{max-width:1080px;margin:0 auto;padding:0 24px}.btn{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-sans);font-weight:600;font-size:14px;padding:11px 20px;border-radius:999px;border:1px solid transparent;cursor:pointer;transition:transform .15s ease,background .15s ease,border-color .15s ease}.btn:active{transform:scale(.97)}.btn--primary{background:var(--accent);color:var(--accent-ink)}.btn--primary:hover{background:#7ceeda}.btn--ghost{background:transparent;border-color:var(--border);color:var(--text);border-width:1px;border-style:solid}.btn--ghost:hover{border-color:var(--accent-dim);color:var(--accent)}.btn:disabled{opacity:.4;cursor:not-allowed}.pill{display:inline-flex;align-items:center;font-size:11.5px;font-weight:600;letter-spacing:.02em;text-transform:uppercase;padding:4px 10px;border-radius:999px;border:1px solid var(--border);color:var(--text-dim)}.pill--easy{color:var(--easy);border-color:#5ee6c859;background:#5ee6c814}.pill--medium{color:var(--medium);border-color:#f2b86659;background:#f2b86614}.pill--hard{color:var(--hard);border-color:#ef889659;background:#ef889614}