:root{--bg-primary: var(--var-main-bg-color);--bg-secondary: linear-gradient(145deg, #f8fafc 0%, #e2e8f0 100%);--bg-secondary-solid: #f1f5f9;--bg-tertiary: #e2e8f0;--bg-hover: rgba(59, 130, 246, .1);--text-primary: var(--var-font-color);--text-secondary: var(--var-gray-500);--accent-primary: var(--var-button-bg-color);--accent-secondary: rgba(59, 130, 246, .12);--accent-hover: var(--var-button-hover-bg-color);--border-color: var(--var-border-color);--error-color: var(--var-red);--calc-shadow: 0 20px 60px rgba(0, 0, 0, .1), 0 8px 25px rgba(0, 0, 0, .08);--calc-shadow-sm: 0 2px 8px rgba(0, 0, 0, .06);--calc-glow: rgba(59, 130, 246, .15);--btn-shadow: 0 2px 4px rgba(0, 0, 0, .05);--btn-shadow-hover: 0 4px 12px rgba(59, 130, 246, .2);--display-gradient: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);--sci-btn-bg: linear-gradient(145deg, #475569 0%, #334155 100%);--sci-btn-text: #93c5fd;--mode-btn-bg: linear-gradient(145deg, #4b5563 0%, #374151 100%);--mode-btn-text: #a5b4fc;--op-btn-gradient: linear-gradient( 145deg, rgba(59, 130, 246, .15) 0%, rgba(59, 130, 246, .08) 100% );--equals-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%)}html.dark-theme{--bg-primary: var(--var-main-bg-color);--bg-secondary: linear-gradient(145deg, #1e293b 0%, #0f172a 100%);--bg-secondary-solid: #1e293b;--bg-tertiary: #334155;--bg-hover: rgba(59, 130, 246, .15);--text-primary: var(--var-font-color);--text-secondary: var(--var-gray-400);--accent-primary: var(--var-button-bg-color);--accent-secondary: rgba(59, 130, 246, .2);--accent-hover: var(--var-button-hover-bg-color);--border-color: var(--var-border-color);--error-color: var(--var-red);--calc-shadow: 0 25px 80px rgba(0, 0, 0, .4), 0 10px 30px rgba(0, 0, 0, .3);--calc-shadow-sm: 0 2px 8px rgba(0, 0, 0, .2);--calc-glow: rgba(59, 130, 246, .2);--btn-shadow: 0 2px 4px rgba(0, 0, 0, .2);--btn-shadow-hover: 0 4px 16px rgba(59, 130, 246, .3);--display-gradient: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);--sci-btn-bg: linear-gradient(145deg, #374151 0%, #1f2937 100%);--sci-btn-text: #93c5fd;--mode-btn-bg: linear-gradient(145deg, #4b5563 0%, #374151 100%);--mode-btn-text: #c7d2fe;--op-btn-gradient: linear-gradient( 145deg, rgba(59, 130, 246, .25) 0%, rgba(59, 130, 246, .12) 100% );--equals-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%)}.calculator-container{display:flex;gap:1.5rem;padding:1.5rem;max-width:950px;margin:0 auto;animation:fadeInUp .5s ease-out}@keyframes fadeInUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{transform:scale(1)}50%{transform:scale(.97)}}@keyframes shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.calculator{flex:1;max-width:320px;background:var(--bg-secondary);border-radius:20px;padding:1.25rem;box-shadow:var(--calc-shadow);border:1px solid rgba(255,255,255,.1);backdrop-filter:blur(10px);position:relative;overflow:hidden}.calculator:before{content:"";position:absolute;top:0;left:0;right:0;height:1px;background:linear-gradient(90deg,transparent,rgba(255,255,255,.3),transparent)}.calculator{max-width:560px}.display{background:var(--display-gradient);border-radius:16px;padding:1.25rem;margin-bottom:1rem;min-height:90px;position:relative;box-shadow:var(--calc-shadow-sm),inset 0 2px 4px #00000005;border:1px solid rgba(0,0,0,.04);transition:box-shadow .3s ease}.display:focus-within{box-shadow:var(--calc-shadow-sm),0 0 0 3px var(--calc-glow)}.btn-history{position:absolute;top:.75rem;left:.75rem;background:var(--bg-hover);border:none;cursor:pointer;color:var(--text-secondary);opacity:.7;transition:all .2s ease;padding:.4rem;border-radius:8px;display:none}.btn-history:hover{opacity:1;background:var(--accent-secondary);color:var(--accent-primary);transform:scale(1.05)}.display-content{padding-top:.5rem}.expression{font-size:.9rem;color:var(--text-secondary);min-height:1.5em;word-wrap:break-word;text-align:right;opacity:.8;font-weight:500;letter-spacing:.5px}.result{width:100%;font-size:2.25rem;font-weight:700;color:var(--text-primary);text-align:right;background:transparent;border:none;outline:none;font-family:SF Pro Display,Segoe UI,system-ui,sans-serif;letter-spacing:-.5px;transition:color .2s ease}.result::placeholder{color:var(--text-secondary);font-size:1rem;font-weight:400;opacity:.6}.buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:.6rem}.scientific-buttons{grid-template-columns:repeat(7,1fr)}.btn-calc{padding:.85rem .5rem;font-size:1.05rem;font-weight:600;border:none;border-radius:12px;cursor:pointer;background:var(--bg-primary);color:var(--text-primary);transition:all .2s cubic-bezier(.4,0,.2,1);user-select:none;min-height:48px;box-shadow:var(--btn-shadow);position:relative;overflow:hidden}.btn-calc:after{content:"";position:absolute;top:50%;left:50%;width:100%;height:100%;background:radial-gradient(circle,rgba(255,255,255,.3) 0%,transparent 60%);transform:translate(-50%,-50%) scale(0);transition:transform .4s ease;pointer-events:none}.btn-calc:hover{background:var(--bg-hover);transform:translateY(-2px);box-shadow:var(--btn-shadow-hover)}.btn-calc:active{transform:translateY(0) scale(.96);box-shadow:var(--btn-shadow)}.btn-calc:active:after{transform:translate(-50%,-50%) scale(2)}.btn-calc sup{font-size:.7em;vertical-align:super}.btn-op{background:var(--op-btn-gradient);color:var(--accent-primary);font-weight:700;font-size:1.2rem}.btn-op:hover{background:var(--accent-primary);color:#fff;box-shadow:0 4px 15px #3b82f659}.btn-func{background:var(--bg-tertiary);color:var(--text-secondary);font-weight:600}.btn-func:hover{background:var(--bg-hover);color:var(--accent-primary)}.btn-sci{background:var(--sci-btn-bg);color:var(--sci-btn-text);font-size:.9rem;font-weight:600;border:1px solid rgba(255,255,255,.05)}.btn-sci:hover{background:linear-gradient(145deg,#4b5563,#374151);color:#bfdbfe;box-shadow:0 4px 12px #93c5fd26}.btn-mode{background:var(--mode-btn-bg);color:var(--mode-btn-text);font-size:.85rem;font-weight:600;border:1px solid rgba(255,255,255,.05)}.btn-mode:hover{background:linear-gradient(145deg,#6366f1,#4f46e5);color:#fff}.btn-mode.active,.btn-func.active{background:var(--equals-gradient);color:var(--var-white);box-shadow:0 4px 15px #6366f14d}.btn-equals{background:var(--equals-gradient);color:var(--var-white);font-weight:700;font-size:1.3rem;position:relative;overflow:hidden}.btn-equals:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.2),transparent);transition:left .5s ease}.btn-equals:hover{background:linear-gradient(135deg,#2563eb,#7c3aed);box-shadow:0 6px 20px #3b82f666;transform:translateY(-2px)}.btn-equals:hover:before{left:100%}.btn-equals-wide{grid-column:span 4}.history-panel{margin-top:1rem;padding:1rem;background:transparent;border:1px solid var(--border-color);border-radius:8px}.history-header{display:flex;justify-content:space-between;align-items:center;padding-bottom:.75rem;border-bottom:1px solid var(--border-color);margin-bottom:.75rem;font-weight:600;font-size:.9rem;color:var(--text-primary)}.btn-clear-history{background:transparent;border:none;cursor:pointer;font-size:1rem;opacity:.6;transition:opacity .2s ease;padding:.25rem .5rem;border-radius:4px}.btn-clear-history:hover{opacity:1}.history-list{flex:1;overflow-y:auto;max-height:400px;padding-right:.25rem}.history-list::-webkit-scrollbar{width:4px}.history-list::-webkit-scrollbar-track{background:transparent}.history-list::-webkit-scrollbar-thumb{background:var(--accent-secondary);border-radius:4px}.history-list::-webkit-scrollbar-thumb:hover{background:var(--accent-primary)}.history-item{padding:.625rem;border-radius:4px;margin-bottom:.5rem;cursor:pointer;transition:background .2s ease;border:none}.history-item:hover{background:var(--bg-hover)}.history-expression{font-size:.875rem;color:var(--text-secondary);font-weight:500}.history-result{font-size:1.2rem;font-weight:700;color:var(--text-primary);margin-top:.25rem}.history-empty{text-align:center;color:var(--text-secondary);padding:2.5rem 1rem;font-size:.9rem;opacity:.7}@media(max-width:900px){.calculator-container{flex-direction:column;padding:1rem}.calculator{max-width:100%}.history-panel{max-width:100%;display:none}.history-panel.show{display:flex;animation:slideDown .3s ease-out}@keyframes slideDown{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.btn-history{display:block}}@media(max-width:480px){.scientific-buttons{grid-template-columns:repeat(7,1fr);gap:.3rem}.btn-calc{padding:.6rem .25rem;font-size:.85rem;min-height:42px;border-radius:10px}.btn-sci{font-size:.75rem}.result{font-size:1.75rem}.btn-equals-wide{grid-column:span 4}.calculator{padding:1rem;border-radius:16px}.display{border-radius:12px;padding:1rem}}.result.error{color:var(--error-color, #ef4444);animation:shake .4s ease}@keyframes shake{0%,to{transform:translate(0)}20%,60%{transform:translate(-5px)}40%,80%{transform:translate(5px)}}.btn-calc.active{background:var(--accent-primary);color:#fff;transform:scale(.95);box-shadow:0 0 15px var(--calc-glow)}.btn-calc[data-value="0"],.btn-calc[data-value="1"],.btn-calc[data-value="2"],.btn-calc[data-value="3"],.btn-calc[data-value="4"],.btn-calc[data-value="5"],.btn-calc[data-value="6"],.btn-calc[data-value="7"],.btn-calc[data-value="8"],.btn-calc[data-value="9"],.btn-calc[data-value="00"],.btn-calc[data-value="."]{font-weight:700;font-size:1.15rem}.btn-num{background:linear-gradient(145deg,var(--bg-primary) 0%,var(--bg-secondary-solid) 100%);font-weight:700;transition:all .2s cubic-bezier(.4,0,.2,1)}.btn-num:hover{background:linear-gradient(145deg,var(--bg-hover) 0%,var(--accent-secondary) 100%);color:var(--accent-primary);transform:translateY(-3px);box-shadow:0 6px 16px #3b82f633}html.dark-theme .btn-num{background:linear-gradient(145deg,#1e293b,#0f172a);border:1px solid rgba(255,255,255,.05)}html.dark-theme .btn-num:hover{background:linear-gradient(145deg,#334155,#1e293b);border-color:#3b82f64d}@media(min-width:1200px){.calculator-container{max-width:1150px;gap:2rem;padding:2rem}.calculator{max-width:420px;padding:1.75rem;border-radius:24px}.calculator{max-width:700px}.display{padding:1.5rem;margin-bottom:1.25rem;min-height:110px;border-radius:16px}.result{font-size:2.75rem}.expression{font-size:1.05rem}.buttons{gap:.85rem}.btn-calc{padding:1.1rem .75rem;font-size:1.25rem;min-height:58px;border-radius:14px}.btn-sci{font-size:1.05rem}.btn-mode{font-size:1rem}.history-panel{max-width:380px;padding:1.75rem;border-radius:24px}.history-list{max-height:500px}.history-result{font-size:1.35rem}}@media(min-width:1600px){.calculator-container{max-width:1400px;gap:2.5rem;padding:2.5rem}.calculator{max-width:520px;padding:2.25rem;border-radius:28px}.calculator{max-width:850px}.display{padding:1.75rem;margin-bottom:1.75rem;min-height:130px;border-radius:20px}.result{font-size:3.25rem}.expression{font-size:1.2rem}.buttons{gap:1.1rem}.btn-calc{padding:1.4rem 1rem;font-size:1.5rem;min-height:72px;border-radius:16px}.btn-sci{font-size:1.2rem}.btn-mode{font-size:1.1rem}.history-panel{max-width:450px;padding:2.25rem;border-radius:28px}.history-list{max-height:620px}.history-item{padding:.9rem;margin-bottom:.6rem;border-radius:12px}.history-expression{font-size:1.05rem}.history-result{font-size:1.6rem}}.btn-calc:focus-visible{outline:2px solid var(--accent-primary);outline-offset:2px}@media(prefers-reduced-motion:reduce){.calculator-container,.history-panel,.btn-calc,.btn-equals:before,.history-item{animation:none;transition:none}}