base.css

/* common CSS between dihybrid, monohybrid, linkage -- keeps things
   consistent more easily */

* {
    box-sizing: border-box;
}

@keyframes fadeIn {
    from {
        opacity: 0
    }

    to {
        opacity: 1
    }
}

div.fadein, td.fadein {
    animation: fadeIn 0.5s;
}


.hidden,
div.column_flow.hidden,
input[type="button"].hidden,
div.separator.hidden,
div#content > div.separator.hidden {
    display: none;
}

body {
    background-color: lightgray;
    display: flex;
    /* fixes bar at bottom of page somehow... */
}

p {
    margin: 0;
    padding: 0.5em 0;
}

div#content h1 {
    text-align: center;
    margin-top: 0;
    padding-top: 0.5em;
}

div#content h3 {
    margin-top: 0.2em;
    margin-bottom: 0.5em;
}

div#content {
    width: 80%;
    padding-left: 10px;
    padding-right: 10px;
    margin: auto;
    background-color: white;
    min-height: 100vh;
}

div#content>* {
    margin: 1rem 0;
}

input.highlighted,
textarea.highlighted,
select.highlighted {
    border: 3px red solid;
}

input.unhighlighted,
textarea.unhighlighted,
select.unhighlighted {
    border: 3px gray solid;
}

th.highlighted {
    box-shadow: inset 0 0 0px 3px red;
}

th.unhighlighted {
    box-shadow: inset 0 0 0px 3px gray;
}

img.highlighted {
    box-shadow: 0 0 0 3px red;
}

img.unhighlighted {
    box-shadow: 0 0 0 3px gray;
}

.instructions {
    border: 1px solid black;
    padding: 5px;
    margin-bottom: 1em;
}

.feedback {
    color: darkred;
    margin-top: 0.5em;
}

.explanation {
    color: darkblue;
    margin-top: 0.5em;
    border: solid darkblue thin;
    padding: 5px;
}

.vert_text {
    transform: rotate(-90deg);
    display: inline-block;
}


input[type="text"],
input[type="number"],
select {
    padding: 3px;
}

input[type="button"] {
    margin: 10px auto;
    font-size: 1.3em;
    font-weight: bold;
    padding: 5px;
    display: block;
    box-shadow: 3px 3px 3px 0px rgba(0, 0, 0, 0.5);
}

input[type="button"][disabled] {
    box-shadow: none;
    color: lightgray;
}

div.separator,
div#content > div.separator {
    width: 80%;
    margin: 15px auto;
    display: block;
    height: 2px;
    background: black;
}


.small_text {
    font-size: 0.8em;
}

.center {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}