:root{--primary-bg: #1c1c1c;--secondary-bg: #2c2c2c;--button-bg: #505050;--button-hover: #606060;--text-color: #ffffff;--operator-bg: #ff9f0a;--operator-hover: #ffb23f;--function-bg: #3c3c3c;--function-hover: #4c4c4c}[data-theme=light]{--primary-bg: #f0f0f0;--secondary-bg: #e0e0e0;--button-bg: #d4d4d2;--button-hover: #e5e5e3;--text-color: #000000;--operator-bg: #ff9f0a;--operator-hover: #ffb23f;--function-bg: #505050;--function-hover: #707070}*{margin:0;padding:0;box-sizing:border-box;font-family:Roboto,sans-serif}body{background-color:var(--primary-bg);color:var(--text-color);min-height:100vh;display:flex;justify-content:center;align-items:center;transition:background-color .3s}.app{display:flex;flex-direction:column;align-items:center;gap:20px;padding:20px}.calculator{background-color:var(--secondary-bg);border-radius:12px;padding:15px;box-shadow:0 10px 20px #0003;width:100%;max-width:600px}.display{background-color:transparent;padding:20px;margin-bottom:10px;text-align:right;font-size:2.5rem;min-height:60px;word-break:break-all;color:var(--text-color)}.buttons{display:grid;grid-template-columns:repeat(9,1fr);gap:1px}.button{background-color:var(--button-bg);border:none;aspect-ratio:1;font-size:1rem;cursor:pointer;transition:background-color .2s;color:var(--text-color);display:flex;align-items:center;justify-content:center;padding:0;width:100%;height:45px}.button:hover{background-color:var(--button-hover)}.button.operator{background-color:var(--operator-bg);color:#fff}.button.operator:hover{background-color:var(--operator-hover)}.button.function{background-color:var(--function-bg);color:#fff;font-size:.9rem}.button.function:hover{background-color:var(--function-hover)}.history{max-height:200px;overflow-y:auto;margin-top:20px;padding:10px;border-radius:8px;background-color:var(--primary-bg)}.history-item{padding:5px;border-bottom:1px solid var(--secondary-bg);color:var(--text-color)}