:root {
    --container-bg: black;
    --container-border: red;
    --buttons-border: yellow;
    --screen-bg: white;
    --screen-text: black;
    --button-bg: rgb(228, 227, 227);
    --button-hover: rgb(255, 255, 255);
    --clear-bg: red;
    --clear-text: white;
    --operator-bg: orange;
}

.dark-theme {
    --container-bg: #222;
    --container-border: #ff5555;
    --buttons-border: #ffcc00;
    --screen-bg: #505050;
    --screen-text: #f0f0f0;
    --button-bg: #4a4a4a;
    --button-hover: #5a5a5a;
    --clear-bg: #6b0808;
    --clear-text: white;
    --operator-bg: rgb(112, 73, 0);
}

html {
    font-size: 62.5%;
    box-sizing: border-box;
}

*, *::before, *::after{
    margin: 0;
    padding: 0;
    box-sizing: inherit;
}

body {
    font-family: Arial, sans-serif;
    height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
    transition: background-color 0.3s;
}

body.dark-theme {
    background-color: #121212;
}

.calculator-container{
    position: absolute;
    top:50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    background-color: var(--container-bg);
    border-radius: 8%;
    /* border: 2px solid var(--container-border); */
    padding: 40px;
    transition: background-color 0.3s, border-color 0.3s;
}

.calculator-screen{
    width: 100%;
    height: 80px;
    background-color: var(--screen-bg);
    color: var(--screen-text);
    font-size: 5rem;
    text-align: right;
    padding-right: 10px;
    border: none;
    border: 2px solid black;
    border-radius: 20px;
    transition: background-color 0.3s, color 0.3s;
}

.calculator-buttons{
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    padding: 15px;
    padding-bottom: 5px;
    /* border: 2px solid var(--buttons-border); */
    transition: border-color 0.3s;
}

button{
    height: 60px;
    background-color: var(--button-bg);
    color: var(--screen-text);
    font-size: 2.5rem;
    font-weight: bold;
    border: none;
    margin: 7px;
    padding: 1rem;
    border-radius: 30px;
    flex: 1 0 17%;
    transition: background-color 0.3s, color 0.3s;
}
.equal-button {
    flex: 0 0 70%; /* Takes up 66% of the row */
}

.backspace-button {
    flex: 0 0 20%; /* Takes up 33% of the row */
}
.all-clear{
    background-color: var(--clear-bg);
    color: var(--clear-text);
}

.equal-button{
    width: 66%;
}
.operator-button{
    background-color: var(--operator-bg);
    color: var(--screen-text);
}
button:hover{
    background-color: var(--button-hover);
    cursor: pointer;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 100;
}

.theme-switch {
    display: none;
}

.theme-switch-label {
    display: inline-block;
    width: 60px;
    height: 30px;
    background-color: #ccc;
    border-radius: 15px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.3s;
}

.theme-switch-label::after {
    content: "";
    position: absolute;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background-color: white;
    top: 2px;
    left: 2px;
    transition: transform 0.3s;
}

.theme-switch:checked + .theme-switch-label {
    background-color: #66bb6a;
}

.theme-switch:checked + .theme-switch-label::after {
    transform: translateX(30px);
}

.theme-switch-label span {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}

.theme-switch-label span:first-child {
    left: 8px;
}

.theme-switch-label span:last-child {
    right: 8px;
}