:root {
    --sj-primary: #0f766e;
    --sj-primary-hover: #0b5f59;
    --sj-focus: #0ea5e9;
    --sj-text: #1f2933;
    --sj-muted: #5f6b7a;
    --sj-border: #d7dde5;
    --sj-surface: #ffffff;
    --sj-surface-muted: #f6f8fb;
    --sj-grid-border: #222831;
    --sj-grid-line: #a5afbb;
    --sj-grid-warning: #fff3cd;
    --sj-grid-error: #f8d7da;
}

html, body {
    color: var(--sj-text);
    font-family: var(--bs-font-sans-serif);
    background-color: var(--sj-surface);
}

a, .btn-link {
    color: #0b67a3;
}

.btn-primary {
    color: #fff;
    background-color: var(--sj-primary);
    border-color: var(--sj-primary);
}

.btn-primary:hover, .btn-primary:active, .btn-primary:first-child:active {
    color: #fff;
    background-color: var(--sj-primary-hover);
    border-color: var(--sj-primary-hover);
}

.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
    box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem var(--sj-focus);
}

.content {
    padding-top: 1rem;
    padding-bottom: 1rem;
}

.content > h1:first-child,
.content > article > h1:first-child {
    margin-bottom: 0.75rem;
}

h1 {
    font-size: 2rem;
    font-weight: 650;
    letter-spacing: 0;
}

h2, h3 {
    letter-spacing: 0;
}

@media (max-width: 640.98px) {
    h1 {
        font-size: 1.75rem;
    }
}

h1:focus {
    outline: none;
}

.valid.modified:not([type=checkbox]) {
    outline: 1px solid #26b050;
}

.invalid {
    outline: 1px solid #e50000;
}

.validation-message {
    color: #e50000;
}

.blazor-error-boundary {
    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
    padding: 1rem 1rem 1rem 3.7rem;
    color: white;
}

    .blazor-error-boundary::after {
        content: "An error has occurred."
    }

.darker-border-checkbox.form-check-input {
    border-color: #929292;
}

.form-floating > .form-control-plaintext::placeholder, .form-floating > .form-control::placeholder {
    color: var(--bs-secondary-color);
    text-align: end;
}

.form-floating > .form-control-plaintext:focus::placeholder, .form-floating > .form-control:focus::placeholder {
    text-align: start;
}

/* ── Sudoku grid ─────────────────────────────────────────────────── */
.sudokugrid {
    margin-top: 1rem;
    text-align: center;
    width: 100%;
}

.sudoku-board-scroll {
    max-width: 100%;
    overflow-x: auto;
    padding: 0.125rem 0 0.5rem;
    -webkit-overflow-scrolling: touch;
}

.sudokugrid table {
    background-color: #fff;
    border: 2px solid var(--sj-grid-border);
    border-collapse: collapse;
    display: table;
    margin: 0 auto;
    table-layout: fixed;
    text-align: center;
}

.sudokugrid caption {
    caption-side: top;
}

.sudokugrid td {
    border: 1px solid var(--sj-grid-line);
    overflow: hidden;
    padding: 0;
    text-align: center;
    vertical-align: middle;
}

.sudokugrid td.t { border-top: 2px solid var(--sj-grid-border); }
.sudokugrid td.l { border-left: 2px solid var(--sj-grid-border); }
.sudokugrid td.r { border-right: 2px solid var(--sj-grid-border); }
.sudokugrid td.b { border-bottom: 2px solid var(--sj-grid-border); }
.sudokugrid td.w {
    background-color: var(--sj-grid-warning);
    box-shadow: inset 0 0 0 2px #d39e00;
}
.sudokugrid td.e {
    background-color: var(--sj-grid-error);
    box-shadow: inset 0 0 0 2px #dc3545;
}

.sudokugrid input.sl {
    background-color: transparent;
    border: none;
    box-sizing: border-box;
    color: #000;
    display: block;
    font-style: normal;
    font-weight: bolder;
    height: 100%;
    line-height: 1;
    margin: 0;
    padding: 0;
    text-align: center;
    width: 100%;
}

.sudokugrid input.sl:focus {
    outline: none;
    box-shadow: inset 0 0 0 3px var(--sj-focus);
}

.sudokugrid input.sl[readonly] {
    background-color: var(--sj-surface-muted);
    color: #111827;
    cursor: default;
}

.sudokugrid input.v { color: #999; font-style: italic; font-weight: normal; }

.sudokugrid .options {
    align-items: center;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin-top: 1rem;
}

.sudokugrid .options input { margin-left: 5px; margin-right: 5px; }

/* 4×4 (factor 2) */
.factor_2 table { min-width: 368px; width: 368px; }
.factor_2 td { width: 92px; height: 92px; }
.factor_2 input.sl { font-size: 2.75rem; }

/* 9×9 (factor 3) */
.factor_3 table { min-width: 450px; width: 450px; }
.factor_3 td { width: 50px; height: 50px; }
.factor_3 input.sl { font-size: 1.5rem; }

/* 16×16 (factor 4) */
.factor_4 table { min-width: 560px; width: 560px; }
.factor_4 td { width: 35px; height: 35px; }
.factor_4 input.sl { font-size: 1.125rem; }

@media (max-width: 640.98px) {
    .factor_2 table { min-width: 312px; width: 312px; }
    .factor_2 td { width: 78px; height: 78px; }
    .factor_2 input.sl { font-size: 2.25rem; }
}

/* Status messages */
.info { padding: 8px 12px; margin: 10px 0; border-radius: 3px; }
.info.success { background-color: #e6efc2; border: 1px solid #c6d880; color: #264409; }
.info.notice  { background-color: #FFF6BF; border: 1px solid #FFD324; color: #514721; }

/* Reviews page */
.reviews-container {
    max-width: 900px;
    margin: 0 auto;
}

.review-item {
    border: 1px solid var(--sj-border);
    border-radius: 8px;
    margin-bottom: 1rem;
    padding: 1rem;
}

.review-item h2 {
    font-size: 1.35rem;
    margin-bottom: 0.5rem;
}

.review-item h2 a {
    text-decoration: none;
}

.review-item h2 a:hover {
    text-decoration: underline;
}

.review-standfirst {
    color: #555;
    line-height: 1.6;
    margin-bottom: 0.5rem;
}

.review-item hr {
    display: none;
    margin-top: 1.5rem;
    border: none;
    border-top: 1px solid #ddd;
}

.read-more {
    font-weight: 500;
}

.review-article {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem 0 2rem;
}

.review-article p,
.review-article li {
    line-height: 1.65;
}