@font-face {
    font-family: 'Kanit';
    src: url('../assets/fonts/Kanit/Kanit-Light.ttf');
}

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    outline: none;
    font-family: 'Kanit';
    user-select: none;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(0, 0, 0, .85);
}

#calculator_container {
    background-color: rgba(0, 0, 0, .60);
    height: 450px;
    width: 300px;
    display: flex;
    justify-content: center;
    flex-direction: column;
    padding: .5rem;
    gap: 5px;
}

#container_expression {
    border: 1px solid #33333360;
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    color: #f5f5f5;
    padding: 0 1.5rem;
    overflow: auto;
}

#expression {
    font-size: 1.1rem;
    letter-spacing: .1rem;
}

#container_options {
    flex: 4.5;
    display: flex;
    justify-content: center;
}

#container_first_options {
    flex: 2.5;
    display: flex;
    flex-wrap: wrap;
}

#container_second_options {
    flex: .7;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

.button {
    width: 70px;
    min-height: 55px;
    background-color: transparent;
    border: none;
    color: #f5f5f5;
    transition: .4s;
    cursor: pointer;
    font-size: 1rem;
}

.button:hover {
    color: rgba(0, 0, 0, .85);
    background-color: #f5f5f5;
}

#calculate {
    width: 70px;
    min-height: 55px;
    background-color: transparent;
    border: none;
    color: #f5f5f5;
    transition: .4s;
    cursor: pointer;
    font-size: 1rem;    
}

#calculate:hover {
    color: rgba(0, 0, 0, .85);
    background-color: #f5f5f5;    
}

#zero {
    width: 100%;
}