* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f6f4ef;
    color: #1d1d1f;
}

.shell {
    width: min(980px, calc(100% - 32px));
    margin: 32px auto;
}

.topbar {
    display: flex;
    justify-content: space-between;
    gap: 24px;
    align-items: center;
    padding-bottom: 20px;
    border-bottom: 1px solid #d9d4c8;
}

h1,
h2,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 6px;
    font-size: 30px;
}

button {
    border: 0;
    border-radius: 6px;
    background: #215a8f;
    color: white;
    font-weight: 700;
    padding: 11px 16px;
    cursor: pointer;
}

button:hover {
    background: #17446f;
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin: 20px 0;
}

.stats div,
.panel,
.notice {
    background: white;
    border: 1px solid #dfd9cb;
    border-radius: 8px;
    padding: 18px;
}

.stats strong {
    display: block;
    font-size: 26px;
}

.stats span {
    color: #68645e;
}

.error {
    border-color: #b43b3b;
    background: #fff1f1;
}

.practice ol,
.review {
    padding-left: 24px;
}

.practice li,
.review li {
    margin: 14px 0;
}

label,
.prompt {
    display: block;
    font-weight: 700;
    margin-bottom: 7px;
}

input {
    width: min(420px, 100%);
    border: 1px solid #bcb6aa;
    border-radius: 6px;
    font-size: 18px;
    padding: 9px 10px;
}

.score {
    font-size: 22px;
    font-weight: 700;
}

.correct {
    color: #135c2d;
}

.wrong {
    color: #8a1f1f;
}

code {
    color: inherit;
    background: #f0eee7;
    padding: 2px 5px;
    border-radius: 4px;
}

@media (max-width: 680px) {
    .topbar,
    .stats {
        grid-template-columns: 1fr;
        display: grid;
    }
}