/* font */
@font-face {
    font-family: 'Charis SIL';
    src: url('../font/CharisSIL-Regular.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
}
/* body section */
body {
   font-family: Charis SIL;
   display: flex;
   flex-direction: column;
   align-items: center;
   justify-content: center;
   min-height: 100vh;
   margin: 0;
}
/* table */
.impossible {
    background-color: #d1d4da;
}
table {
font-size: 18px;
text-align: center;
border-spacing: 0.15em;
}
th {
padding: 0.15em;
line-height: 100%;
font-weight: bold;
}
th:nth-child(odd) {
background-color: #6f4;
}
th:nth-child(even) {
background-color: #ccffc1;
}
tr:first-child th:first-child {
background-color: white !important;
}
td {
padding: 0.1em;
background-color: #eeffea;
}
/* audio */
.audio {
    cursor: pointer;
}
.problem {
    background-color: #faa;
    border: 1px solid #f00;
    padding: 0 1em;
    margin: 1em auto;
    max-width: 37em;
}
/* buttons to see other html files */
.btn {
background-color: green;
border-radius: 30px;
text-decoration: none;
color: black;
display: inline-block;
    padding: 12px 20px;
    text-align: center;
    white-space: normal;
    word-wrap: break-word;
    min-width: 200px;
    max-width: 400px;
    line-height: 1.3;
    box-sizing: border-box;
}