* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
}

header {
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #ecf0f3;
    transition: 0.3s;
}

.container {
    background: #ecf0f3;
    height: auto;
    width: 310px;
    box-shadow: inset 5px 5px 12px #ffffff,
        5px 5px 12px rgba(0, 0, 0, 0.16);
    padding: 10px;
    border-radius: 20px;
    transition: 0.3s;
}

input {
    width: 100%;
    font-size: 20px;
    box-shadow: inset -5px -5px 12px #ffffff,
        5px 5px 12px rgba(0, 0, 0, 0.16);
    outline: none;
    border: none;
    padding: 0px 15px;
    text-shadow: 0px 0px 2px #181A18;
    letter-spacing: 2px;
    background: #ecf0f3;
    margin-top: 0px;
    border-radius: 30px;
    height: 60px;
    margin-bottom: 20px;
    margin-top: 15px;
    text-align: right;
}

.userInput {
     width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

button {
    width: 45px;
    height: 45px;
    font-size: 19px;
    border-radius: 50%;
    cursor: pointer;
    margin: 10px;
    box-shadow: inset -5px -5px 12px #ffffff,
        5px 5px 12px rgba(0, 0, 0, 0.16);
    border: none;
    outline: none;
}

.dark {
    background: #181A18;
}

.dark button {
    border-radius: 50px;
    background: #181A18;
    box-shadow: inset -5px -5px 12px #141614,
        inset 5px 5px 12px #1c1e1c;
    color: #fff;

}

.dark input {
    box-shadow: inset -5px -5px 12px #141614,
        inset 5px 5px 12px #1c1e1c;
     background: #181A18;
    color: #fff;
    text-shadow: 0px 0px 2px #fff;
}

.dark .container {
    background: #181A18;
    box-shadow: inset 5px 5px 12px #141614,
        5px 5px 12px #1c1e1c;
}

.opera {
    color: #ff6a00;
    font-weight: 600;
}

.dark .opera {
    color: #ff6a00;
    font-weight: 600;
}

.dark h2 {
    color: #fff;
}

#btn {
    transition: 0.1s;
    margin: 0;
    width: 40px;
    height: 40px;
    font-size: 17px;
}

#atn {
    transition: 0.1s;
    margin: 0;
    border-radius: 0px;
    box-shadow: none;
}

.head {
    display: flex;
    justify-content: space-around;
    align-items: center;
}