.stats-grid{display:grid;grid-template-columns:repeat(4, 1fr);gap:20px;margin-bottom:30px}.stat-card{background:white;border-radius:20px;padding:20px;display:flex;align-items:center;gap:16px;border:1px solid var(--gray-200);transition:all 0.3s}.stat-card:hover{transform:translateY(-4px);box-shadow:0 10px 30px rgba(0,0,0,0.1)}.stat-icon{width:50px;height:50px;background:linear-gradient(135deg, #e0e7ff, #f0f4ff);border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:24px;color:var(--primary-color)}.stat-value{font-size:1.6rem;font-weight:700;color:var(--gray-800)}.stat-label{font-size:0.75rem;color:var(--gray-500)}.category-tabs{display:flex;gap:10px;margin-bottom:24px;flex-wrap:wrap;border-bottom:1px solid var(--gray-200);padding-bottom:12px}.cat-btn{background:transparent;border:none;padding:8px 20px;border-radius:40px;cursor:pointer;font-size:0.85rem;transition:all 0.2s;color:var(--gray-600)}.cat-btn.active{background:var(--primary-color);color:white}.converter-main{background:var(--gray-50);border-radius:24px;padding:24px;margin-bottom:24px}.converter-row{display:grid;grid-template-columns:1fr 1fr 0.3fr 1fr 1fr;gap:16px;align-items:end}.converter-box label{display:block;font-size:0.7rem;color:var(--gray-500);margin-bottom:6px}.converter-input{width:100%;padding:12px 16px;border:1px solid var(--gray-300);border-radius:12px;font-size:1rem;background:white}.converter-input:focus{outline:none;border-color:var(--primary-color)}.result-input{background:var(--gray-100);font-weight:600;color:var(--primary-color)}.converter-select{width:100%;padding:12px 16px;border:1px solid var(--gray-300);border-radius:12px;font-size:0.95rem;background:white}.converter-select:focus{outline:none;border-color:var(--primary-color)}.converter-equals{font-size:1.5rem;font-weight:700;color:var(--gray-400);text-align:center;padding-bottom:12px}.swap-btn{display:flex;align-items:center;gap:8px;background:white;border:1px solid var(--gray-300);padding:8px 20px;border-radius:40px;cursor:pointer;font-size:0.85rem;margin:16px auto 0;transition:all 0.2s}.swap-btn:hover{background:var(--primary-color);color:white;border-color:var(--primary-color)}.quick-section{margin-bottom:24px}.quick-grid{display:grid;grid-template-columns:repeat(auto-fill, minmax(150px, 1fr));gap:10px;margin-top:16px}.quick-item{background:white;border:1px solid var(--gray-200);border-radius:12px;padding:12px;text-align:center;cursor:pointer;transition:all 0.2s}.quick-item:hover{border-color:var(--primary-color);transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,0.08)}.quick-item .value{font-weight:700;color:var(--primary-color)}.quick-item .label{font-size:0.7rem;color:var(--gray-500)}.table-section{margin-bottom:24px}.table-wrapper{overflow-x:auto;margin-top:16px}.unit-table{width:100%;border-collapse:collapse;font-size:0.85rem}.unit-table th,.unit-table td{padding:10px 12px;text-align:center;border:1px solid var(--gray-200)}.unit-table th{background:var(--gray-50);font-weight:600}.unit-table .cat-metric{background:#dbeafe}.unit-table .cat-imperial{background:#fef3c7}.unit-table .cat-chinese{background:#d1fae5}.unit-table .cat-astronomy{background:#fce7f3}.knowledge-grid{display:grid;grid-template-columns:repeat(4, 1fr);gap:20px;margin-top:20px}.knowledge-card{background:var(--gray-50);border-radius:16px;padding:20px;text-align:center}.knowledge-card i{font-size:28px;color:var(--primary-color);margin-bottom:12px}.knowledge-card h4{font-size:0.85rem;margin-bottom:8px}.knowledge-card p{font-size:0.75rem;color:var(--gray-500);line-height:1.5}@media (max-width:900px){.stats-grid{grid-template-columns:repeat(2, 1fr)}.converter-row{grid-template-columns:1fr 1fr}.converter-equals{display:none}.knowledge-grid{grid-template-columns:repeat(2, 1fr)}}@media (max-width:600px){.stats-grid{grid-template-columns:1fr}.converter-row{grid-template-columns:1fr}.category-tabs{flex-wrap:wrap}.knowledge-grid{grid-template-columns:1fr}}