/* =====================================
   Calculator Theme Variables
   ===================================== */
:root {
    --screen-bg: #000000;
    --btn-bg: #d8d9db;
    --btn-hover: #ebebeb;
    --btn-active: #bbbcbe;
    --fn-btn-bg: #df974c;
    --fn-btn-hover: #dfb07e;
    --fn-btn-active: #dd8d37;
    --borders: #000000;
    --text-color-1: #000000;
    --text-color-2: #ffffff;
}

html {
    box-sizing: border-box;
}

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

body {
    padding: 0;
    margin: 0;
}

.wrapper-1,
.wrapper-2 {
    width: 400px;
}

/* =====================================
   Table Version Styles
   ===================================== */
table {
    width: 100%;
    border-collapse: collapse;
}

td {
    padding: 0;
    border: 2px solid var(--borders);
}

/* =====================================
   Calculator Button Styles
   ===================================== */
.btn,
.fn-btn {
    width: 100%;
    height: 60px;
    font-size: 18px;
    cursor: pointer;
    border: none;
    border-radius: 4px;
    transition: background 0.2s, color 0.2s, outline 0.2s;
}

.btn:hover,
.btn:focus {
    background-color: #e0e0e0;
    outline: 2px solid #333;
    outline-offset: 2px;
}

.btn {
    background-color: var(--btn-bg);
    color: var(--text-color-1);
}

.btn:hover,
.btn:focus {
    background-color: var(--btn-hover);
    color: #000;
}

.btn:active {
    background-color: var(--btn-active);
}

.fn-btn {
    background-color: var(--fn-btn-bg);
    color: var(--text-color-2);
}

.fn-btn:hover,
.fn-btn:focus {
    background-color: var(--fn-btn-hover);
    outline: 2px solid #fff;
    outline-offset: 2px;
    color: #222;
}

.fn-btn:active {
    background-color: var(--fn-btn-active);
}

/* =====================================
   Calculator Input Styles
   ===================================== */
.calc-input {
    width: 100%;
    height: 60px;
    font-size: 24px;
    text-align: right;
    padding: 0 10px;
    border: none;
    background-color: var(--screen-bg);
    color: var(--text-color-2);
    border-radius: 4px;
}

/* =====================================
   Class Solution Styles
   ===================================== */
.wrapper-2 {
    background-color: var(--screen-bg);
    color: var(--text-color-2);
    margin: 0 auto;
    padding: 20px;
    border-radius: 8px;
}

.screen {
    text-align: right;
    font-family: 'Courier New', Courier, monospace;
    padding: 20px 5px;
    font-size: 40px;
    border-radius: 4px;
}

.calc-button-row {
    display: flex;
    flex-flow: row nowrap;
    justify-content: space-around;
    margin-bottom: 0.5%;
}

.calc-button {
    background-color: var(--btn-bg);
    color: var(--text-color-1);
    border: none;
    font-size: 40px;
    height: 100px;
    flex-basis: 24.5%;
    border-radius: 4px;
    transition: background 0.2s, color 0.2s, outline 0.2s;
}

.calc-button:hover,
.calc-button:focus {
    background-color: var(--btn-hover);
    outline: 2px solid #333;
    outline-offset: 2px;
}

.calc-button:active {
    background-color: var(--btn-active);
}

.double {
    flex-basis: 49.7%;
}

.triple {
    flex-basis: 74.8%;
}

.calc-button:last-child {
    background-color: var(--fn-btn-bg);
    color: var(--text-color-2);
}

.calc-button:last-child:hover,
.calc-button:last-child:focus {
    background-color: var(--fn-btn-hover);
    outline: 2px solid #fff;
    outline-offset: 2px;
    color: #222;
}

.calc-button:last-child:active {
    background-color: var(--fn-btn-active);
}

/* =====================================
   Responsive Design
   ===================================== */
@media (max-width: 500px) {
    .wrapper-1,
    .wrapper-2 {
        width: 98%;
        min-width: 0;
        padding: 5px;
    }
    .screen {
        font-size: 24px;
        padding: 10px 2px;
    }
    .calc-button {
        font-size: 24px;
        height: 60px;
    }
}