* {
    box-sizing: border-box;
}

html {
    margin: 0;
    padding: 0;
    height: 100%;
    width: 100%;
}

header {
    text-align: center;
    flex: 0 1 auto;
}

body {
    box-sizing: border-box;
    margin-left: 10%;
    margin-right: 10%;
    margin-top: 0;
    margin-bottom: 0;
    background-color:#f0f8ff;
    display: flex;
    flex-flow: column;
    width: auto;
    min-height: 100vh;
}

header h3 {
    margin-top: 1.5em;
}

.arrow {
    background-color: #BFBAB8;
    border: none;
    color: white;
    width: 100%;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 24px;
    border-radius: 12px;
    user-select: none;
    flex: 0 1 auto;
}

.up {
    padding: 15px 10px 8px 10px;
    margin-bottom: 0.75%;
}

.down {
    padding: 2px 10px 15px 10px;
    margin-top: 0.75%;
}

.arrow:hover {
    background-color: #706A67;
}

.arrow:disabled {
    background-color: #f0f8ff;
    color: #f0f8ff;
}

.digit-navigation {
    flex: 1 1 auto;
    display: flex;
    flex-flow: column;
    margin: 10px;
}

#pi-digits-list {
    font-size: 24px;
    letter-spacing: 0.4em;
    line-height: 1.75em;
    font-family: monospace;
    resize: none;
    width: 100%;
    padding: 0;
    flex: 1 1 auto;
}

#give-up {
    display: block;
    margin-left: auto; 
    margin-right: 1.5%;
    font-size: medium;
}

footer {
    margin-top: 1%;
    margin-bottom: 1%;
    font-size: small;
}

.caption {
    text-align: center;
    margin: 1% 0 0 0;
}