@import"https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500&display=swap";:root{--primary: #0891B2;--primary-light: #67E8F9;--primary-dark: #22d3ee;--accent: #10B981;--accent-light: #064e3b;--bg: #0f172a;--card: #1e293b;--text: #e2e8f0;--text-muted: #94a3b8;--success: #4ade80;--warning: #fbbf24;--info: #74B9FF;--border: #334155;--shadow: 0 4px 24px rgba(0,0,0,.3);--radius: 16px}.hero[data-astro-cid-ntnfletl]{background:linear-gradient(135deg,#0f172a,#164e63,#0f172a);color:#fff;padding:80px 24px 60px;text-align:center;position:relative;overflow:hidden}.hero[data-astro-cid-ntnfletl]:before{content:"f(x)";position:absolute;font-size:200px;font-weight:700;opacity:.07;top:-20px;right:-30px;font-family:Fira Code,monospace}.hero[data-astro-cid-ntnfletl] h1[data-astro-cid-ntnfletl]{font-size:3rem;font-weight:700;margin-bottom:12px}.hero[data-astro-cid-ntnfletl] p[data-astro-cid-ntnfletl]{font-size:1.2rem;opacity:.9;max-width:600px;margin:0 auto}.nav-bar[data-astro-cid-ntnfletl]{background:#1e293b;position:sticky;top:0;z-index:100;box-shadow:0 2px 12px #0000004d;overflow-x:auto}.nav-inner[data-astro-cid-ntnfletl]{display:flex;max-width:1100px;margin:0 auto;padding:0 16px;gap:4px}.nav-inner[data-astro-cid-ntnfletl] button[data-astro-cid-ntnfletl]{padding:14px 18px;background:none;border:none;color:var(--text-muted);font-size:.9rem;font-weight:500;white-space:nowrap;border-bottom:3px solid transparent;transition:all .2s;cursor:pointer;font-family:inherit}.nav-inner[data-astro-cid-ntnfletl] button[data-astro-cid-ntnfletl]:hover,.nav-inner[data-astro-cid-ntnfletl] button[data-astro-cid-ntnfletl].active{color:var(--primary-light);border-bottom-color:var(--primary)}.container[data-astro-cid-ntnfletl]{max-width:900px;margin:0 auto;padding:40px 24px}.section[data-astro-cid-ntnfletl]{margin-bottom:60px;display:none}.section[data-astro-cid-ntnfletl].active{display:block}.section-number[data-astro-cid-ntnfletl]{display:inline-block;background:var(--primary);color:#fff;width:36px;height:36px;border-radius:50%;text-align:center;line-height:36px;font-weight:700;font-size:.95rem;margin-right:12px;vertical-align:middle}.section-title[data-astro-cid-ntnfletl]{font-size:1.8rem;font-weight:700;color:var(--primary-light);margin-bottom:8px;display:inline;vertical-align:middle}.section-subtitle[data-astro-cid-ntnfletl]{font-size:1rem;color:var(--text-muted);margin-bottom:28px;margin-top:6px}.card[data-astro-cid-ntnfletl]{background:var(--card);border-radius:var(--radius);padding:28px 32px;margin-bottom:24px;box-shadow:var(--shadow);border-left:4px solid var(--primary)}.card[data-astro-cid-ntnfletl].accent{border-left-color:var(--accent)}.card[data-astro-cid-ntnfletl].success{border-left-color:var(--success)}.card[data-astro-cid-ntnfletl].info{border-left-color:var(--info)}.card[data-astro-cid-ntnfletl].warning{border-left-color:var(--warning)}.card[data-astro-cid-ntnfletl] h3[data-astro-cid-ntnfletl]{font-size:1.15rem;font-weight:600;margin-bottom:12px;color:var(--primary-light)}.card[data-astro-cid-ntnfletl].accent h3[data-astro-cid-ntnfletl]{color:#34d399}.card[data-astro-cid-ntnfletl].success h3[data-astro-cid-ntnfletl]{color:#4ade80}.card[data-astro-cid-ntnfletl].info h3[data-astro-cid-ntnfletl]{color:#74b9ff}.def-box[data-astro-cid-ntnfletl]{background:linear-gradient(135deg,#0c4a6e,#064e3b);border-radius:12px;padding:20px 24px;margin:16px 0;border:1px solid var(--border)}.def-box[data-astro-cid-ntnfletl] .label[data-astro-cid-ntnfletl]{font-size:.75rem;text-transform:uppercase;letter-spacing:1px;color:var(--primary-light);font-weight:700;margin-bottom:6px}.def-box[data-astro-cid-ntnfletl] p[data-astro-cid-ntnfletl]{font-size:1rem}.formula[data-astro-cid-ntnfletl]{background:#1e1e2e;color:#cdd6f4;font-family:Fira Code,monospace;padding:18px 24px;border-radius:10px;margin:16px 0;font-size:1.05rem;text-align:center;letter-spacing:.5px}.formula[data-astro-cid-ntnfletl] .hl[data-astro-cid-ntnfletl]{color:#a6e3a1;font-weight:600}.formula[data-astro-cid-ntnfletl] .accent[data-astro-cid-ntnfletl]{color:#f9e2af}.formula[data-astro-cid-ntnfletl] .green[data-astro-cid-ntnfletl]{color:#f38ba8}.example[data-astro-cid-ntnfletl]{background:#1a1a2e;border-radius:12px;padding:20px 24px;margin:16px 0;border:1px solid #3d3a50}.example[data-astro-cid-ntnfletl] .tag[data-astro-cid-ntnfletl]{display:inline-block;background:#f59e0b;color:#fff;padding:2px 10px;border-radius:20px;font-size:.75rem;font-weight:600;margin-bottom:10px}.steps[data-astro-cid-ntnfletl]{counter-reset:step;margin:16px 0}.step[data-astro-cid-ntnfletl]{display:flex;gap:16px;margin-bottom:16px;align-items:flex-start}.step[data-astro-cid-ntnfletl]:before{counter-increment:step;content:counter(step);flex-shrink:0;width:30px;height:30px;background:var(--primary);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:.85rem}.step-content[data-astro-cid-ntnfletl]{flex:1}.exercise[data-astro-cid-ntnfletl]{background:#162032;border:2px dashed var(--border);border-radius:12px;padding:24px;margin:16px 0}.exercise[data-astro-cid-ntnfletl] .tag[data-astro-cid-ntnfletl]{display:inline-block;background:var(--success);color:#0f172a;padding:2px 10px;border-radius:20px;font-size:.75rem;font-weight:600;margin-bottom:10px}.exercise[data-astro-cid-ntnfletl] input[data-astro-cid-ntnfletl][type=text]{border:2px solid var(--border);border-radius:8px;padding:8px 14px;font-family:Fira Code,monospace;font-size:.95rem;width:120px;transition:border .2s;background:#0f172a;color:var(--text)}.exercise[data-astro-cid-ntnfletl] input[data-astro-cid-ntnfletl]:focus{outline:none;border-color:var(--primary);background:#1e293b}.check-btn[data-astro-cid-ntnfletl]{background:var(--primary);color:#fff;border:none;padding:10px 24px;border-radius:10px;cursor:pointer;font-weight:600;font-size:.9rem;transition:all .2s;margin-top:12px}.check-btn[data-astro-cid-ntnfletl]:hover{background:#0e7490;transform:translateY(-1px)}.feedback[data-astro-cid-ntnfletl]{margin-top:10px;padding:10px 16px;border-radius:8px;font-weight:500;display:none}.feedback[data-astro-cid-ntnfletl].correct{display:block;background:#065f46;color:#4ade80}.feedback[data-astro-cid-ntnfletl].incorrect{display:block;background:#7f1d1d;color:#f87171}.hint-toggle[data-astro-cid-ntnfletl]{background:none;border:1px solid var(--border);padding:8px 16px;border-radius:8px;cursor:pointer;color:var(--primary-light);font-weight:500;font-size:.85rem;margin-top:8px;transition:all .2s}.hint-toggle[data-astro-cid-ntnfletl]:hover{background:#0c4a6e}.hint-content[data-astro-cid-ntnfletl]{display:none;background:#0c4a6e;padding:14px 18px;border-radius:8px;margin-top:8px;font-size:.95rem;line-height:1.8;color:var(--text)}.hint-content[data-astro-cid-ntnfletl].open{display:block}.math-table[data-astro-cid-ntnfletl]{width:100%;border-collapse:collapse;margin:16px 0;font-size:.95rem}.math-table[data-astro-cid-ntnfletl] th[data-astro-cid-ntnfletl]{background:var(--primary);color:#fff;padding:10px 16px;text-align:center;font-weight:600}.math-table[data-astro-cid-ntnfletl] td[data-astro-cid-ntnfletl]{border:1px solid var(--border);padding:10px 16px;text-align:center}.math-table[data-astro-cid-ntnfletl] tr[data-astro-cid-ntnfletl]:nth-child(2n){background:#162032}.graph-container[data-astro-cid-ntnfletl]{background:#162032;border:1px solid var(--border);border-radius:12px;padding:20px;margin:16px 0;text-align:center;overflow-x:auto}.graph-container[data-astro-cid-ntnfletl] svg[data-astro-cid-ntnfletl]{max-width:100%;height:auto}.tip[data-astro-cid-ntnfletl]{display:flex;gap:12px;background:#0c4a6e;padding:16px 20px;border-radius:10px;margin:16px 0;align-items:flex-start}.tip-icon[data-astro-cid-ntnfletl]{font-size:1.4rem;flex-shrink:0;margin-top:2px}.sign-table[data-astro-cid-ntnfletl]{border-collapse:collapse;margin:12px 0}.sign-table[data-astro-cid-ntnfletl] td[data-astro-cid-ntnfletl],.sign-table[data-astro-cid-ntnfletl] th[data-astro-cid-ntnfletl]{border:1px solid #555;padding:6px 14px;text-align:center;font-family:Fira Code,monospace;font-size:.9rem}.sign-table[data-astro-cid-ntnfletl] th[data-astro-cid-ntnfletl]{background:#0c4a6e;font-weight:600;color:var(--text)}.sign-table[data-astro-cid-ntnfletl] .pos[data-astro-cid-ntnfletl]{color:#4ade80;font-weight:700}.sign-table[data-astro-cid-ntnfletl] .neg[data-astro-cid-ntnfletl]{color:#f87171;font-weight:700}.sign-table[data-astro-cid-ntnfletl] .zero[data-astro-cid-ntnfletl]{color:#67e8f9;font-weight:700}h4[data-astro-cid-ntnfletl].sub{color:var(--primary-light);font-size:1.05rem;margin:20px 0 8px}.two-col[data-astro-cid-ntnfletl]{display:grid;grid-template-columns:1fr 1fr;gap:20px}@media(max-width:700px){.two-col[data-astro-cid-ntnfletl]{grid-template-columns:1fr}}@media(max-width:600px){.hero[data-astro-cid-ntnfletl] h1[data-astro-cid-ntnfletl]{font-size:2rem}.hero[data-astro-cid-ntnfletl]{padding:50px 16px 40px}.card[data-astro-cid-ntnfletl]{padding:20px}.section-title[data-astro-cid-ntnfletl]{font-size:1.4rem}}@media print{.nav-bar[data-astro-cid-ntnfletl]{display:none}.hero[data-astro-cid-ntnfletl]{padding:30px 16px}}.footer-area[data-astro-cid-ntnfletl]{text-align:center;padding:40px 20px;color:var(--text-muted);font-size:.85rem;border-top:1px solid var(--border)}.footer-area[data-astro-cid-ntnfletl] a[data-astro-cid-ntnfletl]{color:var(--primary-light);text-decoration:underline}