.hub{min-height:100vh;display:flex;flex-direction:column}.hub-nav{display:flex;gap:24px}.hub-nav a,.breadcrumbs a{color:var(--muted);text-decoration:none}.hub-nav a:hover,.breadcrumbs a:hover{color:var(--mint)}.hub-intro{padding:68px 0 36px}.hub-intro h1{font-size:clamp(28px,4vw,42px);letter-spacing:-1.5px;line-height:1.4;margin:12px 0 16px}.hub-intro .subtitle{line-height:1.9}.category-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px;padding-bottom:64px}.category-card{display:flex;flex-direction:column;align-items:flex-start;padding:34px;background:var(--card);border:1px solid var(--border);border-radius:18px;color:var(--text);text-decoration:none;transition:border-color .2s,transform .2s}.category-card:hover{border-color:var(--mint);transform:translateY(-3px)}.category-symbol{display:grid;place-items:center;width:76px;height:76px;background:#9bf6cf14;color:var(--mint);border-radius:18px;font-size:30px;font-weight:800;margin-bottom:30px}.sentence-card .category-symbol{color:#b9b1ff;background:#b9b1ff14}.category-card h2{font-size:25px;margin:8px 0 14px}.category-card p:not(.eyebrow){color:var(--muted);line-height:1.9;margin:0 0 32px}.category-link{margin-top:auto;color:var(--mint);font-weight:700}.breadcrumbs{display:flex;flex-wrap:wrap;gap:12px;align-items:center;padding-top:26px;font-size:13px;color:var(--muted)}.breadcrumbs [aria-current]{color:var(--text)}.hub .footer{margin-top:auto;gap:16px}.empty-category{padding:40px;margin-bottom:64px}.availability{display:inline-block;color:#b9b1ff;background:#b9b1ff14;padding:7px 12px;border-radius:20px;font-size:12px}.empty-category h2{font-size:24px;margin:22px 0 14px}.empty-category p{color:var(--muted);line-height:1.9}.hub-button{display:inline-block;margin-top:22px;padding:14px 20px;border-radius:8px;background:var(--mint);color:#0b101b;font-weight:700;text-decoration:none}@media(max-width:640px){.hub-nav{gap:14px;font-size:12px}.hub-intro{padding:42px 0 26px}.category-grid{grid-template-columns:1fr;gap:18px;padding-bottom:40px}.category-card{padding:26px}.category-symbol{margin-bottom:20px}.empty-category{padding:26px}.empty-category h2{font-size:21px}.hub .footer{flex-wrap:wrap}}@media(prefers-reduced-motion:reduce){.category-card{transition:none}.category-card:hover{transform:none}}

.grammar-card .category-symbol{color:#ffd399;background:#ffd39914}.header .hub-nav{flex-wrap:wrap;justify-content:center}.header{gap:16px}@media(max-width:760px){.header{height:auto;min-height:94px;flex-wrap:wrap;padding-top:18px;padding-bottom:18px}.header .hub-nav{order:3;width:100%;gap:20px}.header-right .edition{display:none}}