:root{--primary: #4caf50;--primary-hover: #45a049;--secondary: #2196f3;--secondary-hover: #1e88e5;--accent: #ff9800;--accent-hover: #f57c00;--bg: #f5f7fa;--card-bg: #ffffff;--text: #333333;--text-light: #666666;--border: #e0e0e0;--success: #4caf50;--error: #f44336;--radius: 16px;--shadow: 0 8px 16px rgba(0, 0, 0, .05);--font-family: "Inter", "Outfit", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-family);background-color:var(--bg);color:var(--text);line-height:1.6;-webkit-tap-highlight-color:transparent}#app{max-width:600px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column}header{padding:24px;text-align:center;background:var(--card-bg);box-shadow:0 2px 4px #00000005;border-bottom:1px solid var(--border)}header h1{font-size:24px;color:var(--primary);margin-bottom:4px}header p{font-size:14px;color:var(--text-light)}main{flex:1;padding:16px;overflow-y:auto}nav{display:flex;justify-content:space-around;background:var(--card-bg);padding:12px;border-top:1px solid var(--border);position:sticky;bottom:0}.nav-item{display:flex;flex-direction:column;align-items:center;gap:4px;text-decoration:none;font-size:12px;color:var(--text-light);cursor:pointer;transition:color .2s}.nav-item.active{color:var(--primary)}.nav-icon{width:24px;height:24px}.section-title{font-size:18px;margin:20px 0 12px;color:var(--text);padding-left:4px;border-left:4px solid var(--primary)}.symbols-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(70px,1fr));gap:12px;margin-bottom:24px}.symbol-card{background:var(--card-bg);height:80px;display:flex;flex-direction:column;align-items:center;justify-content:center;border-radius:var(--radius);box-shadow:var(--shadow);cursor:pointer;transition:transform .2s,box-shadow .2s,background .2s;border:1px solid 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slideUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.card-header{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:24px}.big-symbol{font-size:64px;font-weight:800;color:var(--primary);line-height:1}.card-title{text-align:right}.card-title h2{font-size:20px;color:var(--text)}.card-title p{color:var(--text-light);font-size:14px}.memory-box{background:#fdf2f8;border-radius:var(--radius);padding:20px;margin-bottom:24px;position:relative}.memory-box:before{content:"💡 记忆小助手";display:block;font-weight:700;color:#db2777;margin-bottom:8px;font-size:14px}.memory-text{font-size:16px;color:#831843;line-height:1.5}.hint-text{font-size:14px;color:var(--text-light);margin-bottom:20px;padding-left:12px;border-left:3px solid #e0e0e0}.examples-list{display:grid;gap:12px}.example-item{display:flex;align-items:center;justify-content:space-between;background:#f8fafc;padding:12px 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