*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}html{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{line-height:1.5}button{border:none;background:none;font:inherit;cursor:pointer;outline:none}button:focus-visible{outline:2px solid var(--color-btn-operator);outline-offset:2px}:root{--color-bg-primary: #ffffff;--color-bg-secondary: #f8f9fa;--color-bg-gradient-start: #ffffff;--color-bg-gradient-end: #f0f0f5;--color-primary: #9775fa;--color-primary-light: #b197fc;--color-secondary: #7950f2;--color-accent: #d0bfff;--color-display-bg: rgba(240, 240, 250, .8);--color-button-number: #f8f9fa;--color-button-operator: linear-gradient(135deg, #b197fc 0%, #d0bfff 100%);--color-button-function: #e9ecef;--color-button-clear: #ff6b6b;--color-button-equals: #51cf66;--color-text: #212529;--color-text-secondary: rgba(33, 37, 41, .6);--color-error: #ff6b6b;--color-shadow: rgba(0, 0, 0, .1);--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 16px;--spacing-lg: 24px;--spacing-xl: 32px;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 24px;--font-family: "Inter", "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--font-size-display-result: 48px;--font-size-display-expression: 24px;--font-size-button: 18px;--font-weight-light: 300;--font-weight-regular: 400;--font-weight-medium: 500;--shadow-container: 0 20px 60px rgba(0, 0, 0, .3);--shadow-button: 0 4px 12px rgba(0, 0, 0, .2);--shadow-display: inset 0 2px 8px rgba(0, 0, 0, .3);--transition-fast: .15s ease;--transition-normal: .2s ease;--transition-slow: .3s ease;--calculator-max-width: 420px;--button-gap: 8px}@media (max-width: 768px){:root{--font-size-display-result: 36px;--font-size-display-expression: 18px;--font-size-button: 16px;--calculator-max-width: 100%;--spacing-lg: 16px}}@media (max-width: 480px){:root{--font-size-display-result: 32px;--font-size-button: 14px;--button-gap: 6px}}body{font-family:var(--font-family);background:linear-gradient(135deg,var(--color-bg-primary) 0%,var(--color-bg-secondary) 100%);min-height:100vh;display:flex;align-items:center;justify-content:center;padding:var(--spacing-lg);color:var(--color-text)}.calculator-container{width:100%;max-width:var(--calculator-max-width)}.calculator{background:#ffffffb3;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(151,117,250,.2);border-radius:var(--radius-xl);padding:var(--spacing-lg);box-shadow:var(--shadow-container);position:relative}.display{background:var(--color-display-bg);border-radius:var(--radius-lg);padding:var(--spacing-lg);margin-bottom:var(--spacing-lg);box-shadow:var(--shadow-display);min-height:120px;display:flex;flex-direction:column;justify-content:flex-end;text-align:right;overflow:hidden}.expression{font-size:var(--font-size-display-expression);font-weight:var(--font-weight-light);color:var(--color-text-secondary);min-height:30px;margin-bottom:var(--spacing-sm);word-wrap:break-word}.result{font-size:var(--font-size-display-result);font-weight:var(--font-weight-light);color:var(--color-text);word-wrap:break-word;transition:color var(--transition-normal)}.result.error{color:var(--color-error);animation:shake .3s ease}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-5px)}75%{transform:translate(5px)}}.buttons{display:grid;grid-template-columns:repeat(5,1fr);gap:var(--button-gap)}@media (max-width: 768px){.calculator{border-radius:0}}@media (max-width: 480px){body{padding:0}.display{min-height:100px}}.btn{padding:var(--spacing-md);border-radius:var(--radius-md);font-size:var(--font-size-button);font-weight:var(--font-weight-medium);color:var(--color-text);transition:all var(--transition-fast);box-shadow:var(--shadow-button);-webkit-user-select:none;user-select:none;-webkit-tap-highlight-color:transparent;min-height:60px;display:flex;align-items:center;justify-content:center}.btn:hover{filter:brightness(1.2);transform:translateY(-2px)}.btn:active,.btn.active{transform:scale(.95);box-shadow:0 2px 6px #0003}.btn-number{background:var(--color-button-number);border:1px solid rgba(151,117,250,.15)}.btn-zero{grid-column:span 1}.btn-operator{background:var(--color-button-operator);color:#fff}.btn-function{background:var(--color-button-function);border:1px solid rgba(151,117,250,.15);font-size:calc(var(--font-size-button) - 2px)}.btn-memory{background:var(--color-button-function);font-size:calc(var(--font-size-button) - 2px)}.btn-clear{background:var(--color-button-clear);font-weight:var(--font-weight-medium)}.btn-delete{background:var(--color-button-function)}.btn-equals{background:var(--color-button-equals);grid-column:span 2;font-size:calc(var(--font-size-button) + 4px)}.btn-constant{background:var(--color-button-function);font-style:italic}.btn:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}.history-toggle{position:absolute;top:10px;right:10px;background:#b197fc33;border:1px solid var(--color-primary);color:var(--color-text);padding:var(--spacing-sm) var(--spacing-md);border-radius:var(--radius-sm);font-size:14px;cursor:pointer;display:flex;align-items:center;gap:var(--spacing-xs);transition:all var(--transition-fast);z-index:10}.history-toggle:hover{background:#b197fc4d;transform:translateY(-1px)}.history-toggle svg{width:18px;height:18px}.history-panel{position:absolute;left:0;right:0;bottom:0;max-height:0;background:#fffffffa;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-top:1px solid var(--color-primary);box-shadow:0 -2px 10px #9775fa1a;overflow:hidden;transition:max-height var(--transition-normal) ease-in-out;z-index:5}.history-panel.active{max-height:300px}.history-header{padding:var(--spacing-md);display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid rgba(177,151,252,.2)}.history-header h3{margin:0;font-size:16px;font-weight:var(--font-weight-medium);color:var(--color-primary)}.history-clear{background:#ff6b6b33;border:1px solid var(--color-button-clear);color:var(--color-text);padding:6px 12px;border-radius:var(--radius-sm);font-size:12px;cursor:pointer;transition:all var(--transition-fast)}.history-clear:hover{background:#ff6b6b4d}.history-list{max-height:220px;overflow-y:auto;padding:var(--spacing-sm)}.history-list::-webkit-scrollbar{width:6px}.history-list::-webkit-scrollbar-track{background:#0003}.history-list::-webkit-scrollbar-thumb{background:var(--color-primary);border-radius:3px}.history-item{background:#f8f9facc;border:1px solid rgba(151,117,250,.15);border-radius:var(--radius-sm);padding:var(--spacing-sm) var(--spacing-md);margin-bottom:var(--spacing-xs);display:flex;justify-content:space-between;align-items:center;transition:all var(--transition-fast);cursor:pointer}.history-item:hover{background:#b197fc33;transform:translate(4px)}.history-item-content{flex:1}.history-item-expression{font-size:14px;color:var(--color-text-secondary);margin-bottom:2px}.history-item-result{font-size:16px;color:var(--color-primary);font-weight:var(--font-weight-medium)}.history-item-delete{background:transparent;border:none;color:var(--color-error);cursor:pointer;padding:4px 8px;opacity:0;transition:opacity var(--transition-fast);font-size:18px}.history-item:hover .history-item-delete{opacity:1}.history-item-delete:hover{color:#ff6b6b}.history-empty{text-align:center;padding:var(--spacing-lg);color:var(--color-text-secondary);font-size:14px}@media (max-width: 480px){.btn{min-height:50px;padding:var(--spacing-sm)}.btn-function,.btn-memory{font-size:calc(var(--font-size-button) - 3px)}.history-toggle{font-size:12px;padding:6px 10px}.history-panel.active{max-height:250px}}@keyframes buttonPress{0%{transform:scale(1)}50%{transform:scale(.95)}to{transform:scale(1)}}.btn.pressed{animation:buttonPress var(--transition-fast)}