@import"https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap";:root{--bg: #0A0A0B;--surface: #15151A;--primary: #7C5CFA;--primary-dark: #6447E0;--accent: #8B5CF6;--text: #FAFAFA;--text-muted: #9CA3AF;--border: #27272A;--success: #22C55E;--warning: #F59E0B;--danger: #EF4444;--radius: 12px;--shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04)}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--text);font-family:Inter,-apple-system,BlinkMacSystemFont,PingFang SC,Microsoft YaHei,sans-serif;min-height:100vh;display:flex;justify-content:center;align-items:center}.app{max-width:800px;width:100%;padding:20px}.header{text-align:center;margin-bottom:24px}.title{font-size:1.8rem;font-weight:600;color:var(--text);display:flex;align-items:center;justify-content:center;gap:8px}.cloud-badge{font-size:.75rem;background:var(--surface);color:var(--text-muted);padding:2px 8px;border-radius:20px;border:1px solid var(--border)}.loading-text{font-size:.85rem;color:var(--text-muted);margin-top:8px}.calculator-container{display:flex;gap:20px;background:var(--surface);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}.calculator{flex:1}.display-section{background:var(--bg);border-radius:var(--radius);padding:16px;margin-bottom:16px;min-height:80px;display:flex;flex-direction:column;justify-content:flex-end;align-items:flex-end}.expression{font-size:.9rem;color:var(--text-muted);min-height:20px}.display{font-size:2.2rem;font-weight:600;color:var(--text);word-break:break-all}.buttons{display:flex;flex-direction:column;gap:8px}.button-row{display:flex;gap:8px}.btn{flex:1;height:52px;border:none;border-radius:var(--radius);font-size:1.2rem;font-weight:500;cursor:pointer;transition:background .15s,transform .1s;display:flex;align-items:center;justify-content:center;background:var(--bg);color:var(--text);outline:none}.btn:hover{filter:brightness(1.2)}.btn:active{transform:scale(.95)}.btn-number{background:var(--bg);color:var(--text)}.btn-operator{background:var(--primary);color:#fff}.btn-operator:hover{background:var(--primary-dark)}.btn-function{background:var(--surface);color:var(--text-muted);border:1px solid var(--border)}.btn-clear{background:var(--danger);color:#fff}.btn-clear:hover{background:#dc2626}.btn-equals{background:var(--accent);color:#fff;font-weight:700}.history-panel{width:200px;flex-shrink:0;display:flex;flex-direction:column;background:var(--bg);border-radius:var(--radius);padding:12px}.history-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px;font-size:.85rem;font-weight:500;color:var(--text-muted)}.btn-icon{background:transparent;border:none;color:var(--text-muted);cursor:pointer;padding:4px}.btn-icon:hover{color:var(--danger)}.history-list{flex:1;overflow-y:auto;max-height:320px}.history-item{padding:8px 4px;border-bottom:1px solid var(--border);cursor:pointer;transition:background .1s}.history-item:hover{background:#7c5cfa1a}.history-expression{font-size:.8rem;color:var(--text-muted)}.history-result{font-size:.9rem;color:var(--text);font-weight:500}.history-empty{text-align:center;color:var(--text-muted);padding:20px 0;font-size:.85rem}