:root{--bg: #f5f7fb;--card-bg: #ffffff;--border: #e2e8f0;--text-primary: #0f172a;--text-secondary: #475569;--blue: #1d4ed8;--blue-light: #dbeafe;--blue-dark: #0f3ea8;--operator: #60a5fa;--operator-text: #0f172a;--accent: #0f172a;--success: #10b981;--danger: #ef4444;--memory: #0ea5e9;--font-display: "Inter", "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft Yahei", sans-serif}body{background:var(--bg);font-family:var(--font-display);color:var(--text-primary)}body.modal-open{overflow:hidden}.page{max-width:1100px;margin:0 auto;padding:0rem 1.5rem 4rem}.hero{text-align:center;margin-bottom:2rem}.hero h1{font-size:2.5rem;font-weight:700;margin-bottom:.75rem}.hero p{font-size:1.1rem;color:var(--text-secondary);line-height:1.6;max-width:720px;margin:0 auto}.calculator-wrapper{display:flex;justify-content:center;margin-bottom:2.5rem}.scientific-calculator{width:100%;background:#f1f5f9;border-radius:24px;padding:2rem;box-shadow:0 25px 65px #0f172a1f;border:1px solid #e2e8f0}.history-bar{display:flex;justify-content:space-between;align-items:center;margin-bottom:.75rem;padding:0 .5rem}.latest-history{font-size:.9rem;color:#94a3b8;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history-more{background:none;border:none;color:#94a3b8;font-size:.8rem;cursor:pointer;visibility:hidden}.history-more:hover{color:var(--blue)}.calc-display{background:white;border-radius:16px;padding:1rem 1.5rem;box-shadow:inset 0 2px 4px #0000000d;margin-bottom:.5rem;border:1px solid #e2e8f0}.calc-input{width:100%;border:none;font-size:1.4rem;color:var(--text-primary);background:transparent;outline:none;padding:.25rem 0}.calc-status{padding:0 .5rem;min-height:2rem;display:flex;align-items:center}.result-label{font-size:1.5rem;color:var(--blue);font-weight:700;cursor:pointer;position:relative;padding:2px 8px;border-radius:8px;transition:background .2s}.result-label:hover{background:#f1f5f9}.copy-tooltip{position:absolute;bottom:105%;left:50%;transform:translate(-50%);background:white;color:#94a3b8;padding:5px 10px;border-radius:8px;font-size:.75rem;font-weight:400;pointer-events:none;white-space:nowrap;box-shadow:0 4px 12px #0000000d;border:1px solid #f1f5f9;display:flex;align-items:center;gap:4px;animation:tooltipFadeInUp .3s cubic-bezier(.16,1,.3,1) forwards}@keyframes tooltipFadeInUp{0%{opacity:0;transform:translate(-50%,6px) scale(.98)}to{opacity:1;transform:translate(-50%) scale(1)}}.copy-icon{color:#10b981;opacity:.7;display:flex;align-items:center}.calc-main-grid{margin-top:1.25rem;display:grid;grid-template-columns:1fr 1fr;gap:.6rem}.calc-group{display:grid;grid-template-columns:repeat(5,1fr);gap:.6rem}.calc-btn{height:58px;border-radius:12px;border:1px solid rgba(15,23,42,.08);font-size:1rem;font-weight:600;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .1s;background:#e2e8f0;box-shadow:0 4px #cbd5e1;margin-bottom:4px}.calc-btn:hover{transform:translateY(-1px);box-shadow:0 5px #cbd5e1}.calc-btn:active{transform:translateY(3px);box-shadow:0 1px #cbd5e1}.btn-num{background:#ffffff;box-shadow:0 4px #d1d5db;border:1px solid #e5e7eb}.btn-num:hover{box-shadow:0 5px #d1d5db}.btn-num:active{box-shadow:0 1px #d1d5db}.btn-func{background:#e0f2fe;color:#0369a1;box-shadow:0 4px #bae6fd}.btn-func:hover{box-shadow:0 5px #bae6fd}.btn-func:active{box-shadow:0 1px #bae6fd}.btn-operator{background:#c7d2fe;color:#3730a3;box-shadow:0 4px #a5b4fc}.btn-operator:hover{box-shadow:0 5px #a5b4fc}.btn-operator:active{box-shadow:0 1px #a5b4fc}.btn-accent{background:#3b82f6;color:#fff;box-shadow:0 4px #2563eb}.btn-accent:hover{box-shadow:0 5px #2563eb}.btn-accent:active{box-shadow:0 1px #2563eb}.btn-equals{background:linear-gradient(135deg,#10b981,#059669);color:#fff;box-shadow:0 4px #047857}.btn-equals:hover{box-shadow:0 5px #047857}.btn-equals:active{box-shadow:0 1px #047857}.btn-danger{background:#fee2e2;color:#b91c1c;box-shadow:0 4px #fecaca}.btn-danger:hover{box-shadow:0 5px #fecaca}.btn-danger:active{box-shadow:0 1px #fecaca}.btn-mode{background:#f1f5f9;color:var(--text-secondary);font-size:.8rem;box-shadow:0 4px #e2e8f0}.btn-mode:hover{box-shadow:0 5px #e2e8f0}.btn-mode:active{box-shadow:0 1px #e2e8f0}.modal{position:fixed;z-index:1000;left:0;top:0;width:100%;height:100%;background:rgba(0,0,0,.5);backdrop-filter:blur(4px);display:none;align-items:center;justify-content:center}.modal-content{background:white;border-radius:24px;max-width:500px;width:90%;max-height:80vh;display:flex;flex-direction:column;box-shadow:0 25px 50px #0003;animation:modalSlideUp .3s ease-out}@keyframes modalSlideUp{0%{transform:translateY(20px);opacity:0}to{transform:translateY(0);opacity:1}}.modal-header{padding:1.5rem;font-size:1.2rem;font-weight:600;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center}.modal-history-list{padding:1rem;overflow-y:auto}.history-item{padding:1rem;border-radius:12px;background:#f8fafc;margin-bottom:.5rem;cursor:pointer}.history-item:hover{background:#f1f5f9}.history-expr{font-size:.85rem;color:var(--text-secondary)}.history-res{font-size:1.1rem;font-weight:700;color:var(--blue)}.modal-footer{padding:1rem;text-align:right;border-top:1px solid var(--border)}.btn-clear-all{background:#fee2e2;color:#b91c1c;border:none;padding:.6rem 1.2rem;border-radius:12px;font-weight:600;cursor:pointer}.features-card,.shortcuts-card{background:white;border-radius:24px;padding:2rem;margin-top:2rem;box-shadow:0 10px 30px #0000000d}.page .tools-inline-ad{width:100%}.shortcuts-card h2,.features-card h2{text-align:center;margin-bottom:1.5rem;font-size:1.8rem;color:var(--text-primary)}.shortcuts-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:1.25rem}.shortcut-item{display:flex;align-items:center;gap:1rem;padding:.75rem 1rem;background:#f8fafc;border-radius:12px;border:1px solid #e2e8f0}kbd{display:inline-block;padding:3px 6px;font-family:monospace;font-size:.85rem;background:#f1f5f9;border:1px solid #cbd5e1;border-bottom-width:2px;border-radius:6px}.features-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1.5rem;margin-top:1rem}.feature-item{padding:1.5rem;border-radius:16px;background:#f8fafc;display:flex;flex-direction:column;align-items:center;text-align:center;border:1px solid #e2e8f0;transition:all .2s}.feature-item:hover{transform:translateY(-5px);box-shadow:0 10px 20px #0000000d;border-color:var(--blue-light)}.feature-icon{width:48px;height:48px;background:var(--blue-light);color:var(--blue);border-radius:12px;display:flex;align-items:center;justify-content:center;margin-bottom:1rem}@media (max-width: 768px){.page{padding:0 .75rem 3rem}.hero{margin-bottom:1.5rem}.hero h1{font-size:1.5rem;margin-bottom:.5rem}.hero p{font-size:.8rem;padding:0 .5rem}.scientific-calculator{padding:.75rem;border-radius:16px}.calc-display{padding:.75rem 1rem;border-radius:12px}.calc-input{font-size:1.2rem}.result-label{font-size:1.3rem}.calc-main-grid{grid-template-columns:1fr;gap:.5rem}.calc-btn{height:50px;font-size:.9rem;border-radius:10px}.shortcuts-grid{grid-template-columns:1fr}.features-card,.shortcuts-card{padding:1.5rem 1rem}.features-card h2,.shortcuts-card h2{font-size:1.4rem}}@media (max-width: 480px){.page{padding:0 .5rem 2rem}.calc-group{gap:.35rem}.calc-btn{height:46px}}.aw-footer-wrap{margin-top:4rem}.aw-footer{padding:30px 0;font-size:12px;text-align:center;color:#666;border-top:1px solid #ddd}.footer-text-copyright a{color:#666;text-decoration:none}.footer-text-copyright a:hover{color:var(--blue)}