body {
    font-family: courier, monospace;
    max-width: 760px;
    margin: 0 auto;
    padding: 0 16px 60px;
    line-height: 1.6;
    color: #222;
    background: #fff;
}

.top_link {
    float: right;
    margin-top: 12px;
}

header {
    text-align: center;
    padding-top: 30px;
    clear: both;
}

h1 {
    margin-bottom: 4px;
}

.subtitle {
    margin-top: 0;
    color: #666;
}

.byline {
    font-size: 0.85em;
    color: #777;
    max-width: 560px;
    margin: 10px auto 0;
}

.byline a {
    color: #555;
}

.prose {
    max-width: 680px;
    margin: 0 auto;
}

h2 {
    margin-top: 56px;
    border-bottom: 2px solid #ddd;
    padding-bottom: 6px;
    font-size: 1.25em;
}

p {
    margin: 14px 0;
}

/* ---- the slow figure ---- */

.figure-box {
    margin: 24px 0;
}

canvas {
    display: block;
    width: 100%;
    height: auto;
    max-width: 600px;
    margin: 0 auto;
    border: 2px solid grey;
    background: #fff;
}

.controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 10px;
    flex-wrap: wrap;
}

button {
    font-family: inherit;
    font-size: 1em;
    padding: 6px 14px;
    border: 2px solid #888;
    background: #f5f5f5;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background: #e8e8e8;
}

button:disabled {
    color: #999;
    cursor: default;
    background: #f5f5f5;
}

.status {
    color: #666;
    font-size: 0.9em;
    min-height: 1.4em;
}

/* ---- the kept list ---- */

.keep-box {
    background: #f4f4f4;
    border-left: 4px solid #bbb;
    padding: 12px 16px 14px;
    margin: 20px 0;
}

.keep-list {
    list-style: none;
    padding: 0;
    margin: 0 0 12px;
}

.keep-list li {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 4px 0;
}

.keep-list label {
    flex: 1 1 auto;
    cursor: pointer;
}

.keep-list input[type="checkbox"] {
    transform: translateY(2px);
}

.keep-list li.kept label {
    color: #111;
    font-weight: bold;
}

.keep-list .remove {
    border: none;
    background: none;
    color: #999;
    padding: 0 4px;
    font-size: 0.9em;
}

.keep-list .remove:hover {
    color: #222;
    background: none;
}

.keep-form {
    display: flex;
    gap: 8px;
}

.keep-form input {
    flex: 1 1 auto;
    font-family: inherit;
    font-size: 0.95em;
    padding: 6px 8px;
    border: 1px solid #bbb;
    border-radius: 4px;
    min-width: 0;
}

.keep-box .status {
    margin: 10px 0 0;
}

ul.plain {
    padding-left: 20px;
}

ul.plain li {
    margin-bottom: 10px;
}

footer {
    margin-top: 60px;
    text-align: center;
}

@media (max-width: 600px) {
    h2 {
        font-size: 1.1em;
    }
}