/* Study guide library v2 page (study-guide-v2.php). Uses the tokens in modern.css. */

body.sg2-page { background: var(--ink-50); }

/* Breadcrumb */
.sg2-crumbs { background: #fff; border-bottom: 1px solid var(--ink-150); }
.sg2-crumbs ol { max-width: 1160px; margin: 0 auto; padding: .75rem 1.5rem; list-style: none; display: flex; flex-wrap: wrap; gap: .35rem .5rem; font-size: 13px; color: var(--ink-400); }
.sg2-crumbs li { display: inline-flex; align-items: center; gap: .35rem; min-width: 0; }
.sg2-crumbs li + li::before { content: "/"; color: var(--ink-300); margin-right: .5rem; }
.sg2-crumbs a { color: var(--ink-500); }
.sg2-crumbs a:hover { color: var(--blue-600); }
.sg2-crumbs li[aria-current] { color: var(--ink-800); font-weight: 500; max-width: 320px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; display: block; }

/* Layout */
.sg2-layout { max-width: 1160px; margin: 0 auto; padding: 2.25rem 1.5rem 4.5rem; display: grid; grid-template-columns: minmax(0, 1fr) 270px; gap: 2.75rem; align-items: start; }
.sg2-main { min-width: 0; max-width: 780px; }
.sg2-body, .sg-block { max-width: 100%; }
.sg2-side { display: flex; flex-direction: column; gap: 1rem; position: sticky; top: calc(var(--header-h, 64px) + 20px); }
@media (max-width: 960px) {
    .sg2-layout { grid-template-columns: minmax(0, 1fr); gap: 1.5rem; }
    .sg2-side { position: static; }
    .sg2-toc { display: none; }
}
@media (max-width: 640px) {
    .sg2-layout { padding: 1.5rem 1rem 3rem; }
    .sg2-crumbs ol { padding: .65rem 1rem; }
    .sg2-crumbs li[aria-current] { max-width: 100%; }
}

/* Header */
.sg2-head { margin-bottom: 1.5rem; }
.sg2-badges { display: flex; flex-wrap: wrap; gap: .4rem; margin-bottom: .9rem; }
.sg2-badge { display: inline-flex; align-items: center; gap: .3rem; padding: .2rem .55rem; border-radius: var(--r-sm); font-size: 12px; font-weight: 500; }
.sg2-badge-domain { background: var(--blue-50); color: var(--blue-700); box-shadow: inset 0 0 0 1px var(--blue-100); }
.sg2-badge-domain:hover { background: var(--blue-100); }
.sg2-badge-free { background: var(--success-soft); color: var(--success); }
.sg2-badge-sub { background: var(--ink-100); color: var(--ink-700); }
.sg2-title { font-size: clamp(1.7rem, 4vw, 2.45rem); letter-spacing: -0.035em; line-height: 1.13; color: var(--ink-950); margin: 0 0 .8rem; overflow-wrap: anywhere; }
.sg2-meta { display: flex; flex-wrap: wrap; gap: .35rem 1.1rem; margin: 0 0 1rem; font-size: 13px; color: var(--ink-500); }
.sg2-meta span { display: inline-flex; align-items: center; gap: .35rem; }
.sg2-meta svg { color: var(--blue-600); flex-shrink: 0; }
.sg2-excerpt { font-size: var(--text-lg); line-height: 1.6; color: var(--ink-600); margin: 0; }

/* Body */
.sg2-body { background: #fff; border: 1px solid var(--ink-200); border-radius: var(--r-xl); padding: 2rem 2.4rem; font-size: var(--text-base); line-height: 1.78; color: var(--ink-700); overflow-wrap: anywhere; }
@media (max-width: 640px) { .sg2-body { padding: 1.25rem 1.1rem; } }
.sg2-body h2 { font-size: 1.4rem; letter-spacing: -0.02em; line-height: 1.3; color: var(--ink-950); margin: 2.25rem 0 .75rem; padding-top: 1.6rem; border-top: 1px solid var(--ink-150); scroll-margin-top: calc(var(--header-h, 64px) + 16px); }
.sg2-body > h2:first-child { margin-top: 0; padding-top: 0; border-top: 0; }
.sg2-body h3 { font-size: 1.12rem; color: var(--ink-950); margin: 1.6rem 0 .5rem; letter-spacing: -0.01em; }
.sg2-body h4 { font-size: 1rem; color: var(--ink-900); margin: 1.25rem 0 .4rem; }
.sg2-body p { margin: 0 0 1rem; }
.sg2-body ul, .sg2-body ol { margin: 0 0 1.1rem 1.4rem; }
.sg2-body ul { list-style: disc; }
.sg2-body ol { list-style: decimal; }
.sg2-body li { margin-bottom: .4rem; padding-left: .15rem; }
.sg2-body li::marker { color: var(--blue-500); }
.sg2-body strong { color: var(--ink-950); font-weight: 600; }
.sg2-body a { color: var(--blue-600); text-decoration: underline; text-underline-offset: 2px; }
.sg2-body sup.sg-ref { font-size: .68em; line-height: 0; margin-left: 1px; }
.sg2-body sup.sg-ref a { text-decoration: none; font-weight: 600; padding: 0 1px; }
.sg2-body sup.sg-ref a:hover { text-decoration: underline; }
.sg2-body.is-teaser { -webkit-mask-image: linear-gradient(to bottom, #000 82%, rgba(0,0,0,.25) 100%); mask-image: linear-gradient(to bottom, #000 82%, rgba(0,0,0,.25) 100%); }

/* Key facts */
.sg2-body .sg-keyfacts { background: var(--blue-50); border: 1px solid var(--blue-100); border-radius: var(--r-lg); padding: 1.1rem 1.3rem; margin: 1rem 0 1.4rem; }
.sg2-body .sg-keyfacts > :last-child { margin-bottom: 0; }
.sg2-body .sg-keyfacts ul { margin-left: 1.2rem; }
.sg2-body .sg-keyfacts li::marker { color: var(--blue-700); }

/* Tables */
.sg2-body .sg-table-scroll { overflow-x: auto; margin: 1.25rem 0 .35rem; border: 1px solid var(--ink-200); border-radius: var(--r-lg); -webkit-overflow-scrolling: touch; }
.sg2-body .sg-table-scroll > table { margin: 0; }
.sg2-body table { max-width: none; }
.sg2-body svg { max-width: 100%; height: auto; }
.sg2-body table.sg-table, .sg2-body .sg-table-scroll > table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); line-height: 1.5; min-width: 480px; overflow-wrap: normal; word-break: normal; }
@media (max-width: 640px) { .sg2-body figure.sg-figure { padding: .6rem; } .sg2-body table.sg-table td, .sg2-body table.sg-table th { padding: .5rem .7rem; } }
.sg2-body table.sg-table caption { caption-side: top; text-align: left; padding: .75rem 1rem .55rem; font-weight: 600; color: var(--ink-900); background: #fff; border-bottom: 1px solid var(--ink-200); }
.sg2-body table.sg-table th { background: var(--ink-50); color: var(--ink-700); font-weight: 600; text-align: left; padding: .6rem 1rem; border-bottom: 1px solid var(--ink-200); vertical-align: bottom; }
.sg2-body table.sg-table td { padding: .6rem 1rem; border-bottom: 1px solid var(--ink-150); vertical-align: top; }
.sg2-body table.sg-table tr:last-child td { border-bottom: 0; }
.sg2-body table.sg-table tbody tr:nth-child(even) td { background: #fcfbf8; }
.sg2-body p.sg-source { font-size: 12.5px; line-height: 1.5; color: var(--ink-500); margin: .35rem 0 1.4rem; }
.sg2-body p.sg-source a { color: var(--ink-600); }

/* Figures */
.sg2-body figure.sg-figure { margin: 1.5rem 0; padding: 1rem; background: var(--ink-50); border: 1px solid var(--ink-200); border-radius: var(--r-lg); scroll-margin-top: calc(var(--header-h, 64px) + 16px); }
.sg2-body figure.sg-figure img, .sg2-body figure.sg-figure svg { display: block; height: auto; max-width: 100%; margin: 0 auto; border-radius: var(--r-md, 8px); }
.sg2-body figure.sg-figure svg { width: 100%; }
.sg2-body figure.sg-figure img { width: auto; }
.sg2-body figure.sg-figure img { background: #fff; }
.sg2-body figure.sg-figure svg { color: var(--ink-800); background: #fff; }
.sg2-body figure.sg-figure figcaption { margin-top: .7rem; font-size: 13.5px; line-height: 1.55; color: var(--ink-600); }
.sg2-body figure.sg-figure figcaption strong:first-child { color: var(--ink-900); }

/* Memory aids */
.sg2-body .sg-mnemonics { background: #fff; border: 1px solid var(--ink-200); border-radius: var(--r-lg); padding: 1.1rem 1.3rem; margin: 1rem 0 1.4rem; }
.sg2-body .sg-mnemonics p { margin: 0 0 .7rem; }
.sg2-body .sg-mnemonics > :last-child { margin-bottom: 0; }

/* Worked calculation */
.sg2-body .sg-calc { border: 1.5px solid var(--blue-200, #c9d8f5); border-radius: var(--r-lg); padding: 1.1rem 1.3rem; margin: 1.25rem 0; background: #fff; box-shadow: 0 2px 10px rgba(15,35,64,.06); font-variant-numeric: tabular-nums; }
.sg2-body .sg-calc > :last-child { margin-bottom: 0; }
.sg2-body .sg-calc code, .sg2-body .sg-calc .sg-calc-line { font-family: var(--font-mono); font-size: 13.5px; }

/* Exam traps */
.sg2-body .sg-traps { background: var(--warning-soft); border: 1px solid #f3dcae; border-radius: var(--r-lg); padding: 1.1rem 1.3rem; margin: 1rem 0 1.4rem; color: var(--ink-800); }
.sg2-body .sg-traps > :last-child { margin-bottom: 0; }
.sg2-body .sg-traps li::marker { color: var(--warning); }

/* Quick review */
.sg2-body ol.sg-quick-review { list-style: none; counter-reset: qr; margin: 1rem 0 0; padding: 0; border: 1px solid var(--ink-200); border-radius: var(--r-lg); overflow: hidden; }
.sg2-body ol.sg-quick-review li { counter-increment: qr; position: relative; margin: 0; padding: .6rem 1rem .6rem 3rem; border-bottom: 1px solid var(--ink-150); }
.sg2-body ol.sg-quick-review li:last-child { border-bottom: 0; }
.sg2-body ol.sg-quick-review li::before { content: counter(qr); position: absolute; left: 1rem; top: .62rem; font-family: var(--font-mono); font-size: 12px; font-weight: 600; color: var(--blue-700); background: var(--blue-50); border-radius: 4px; min-width: 1.4rem; text-align: center; line-height: 1.5rem; }

/* Gate (subscriber teaser) */
.sg2-gate { background: #fff; border: 1px solid var(--ink-200); border-radius: var(--r-xl); padding: 1.75rem 2rem; margin-top: 1.25rem; }
.sg2-gate-icon { width: 42px; height: 42px; display: flex; align-items: center; justify-content: center; border-radius: var(--r-lg); background: var(--blue-50); border: 1px solid var(--blue-100); color: var(--blue-600); margin-bottom: .9rem; }
.sg2-gate h2 { font-size: var(--text-xl); letter-spacing: -0.02em; margin: 0 0 .4rem; }
.sg2-gate p { font-size: var(--text-sm); color: var(--ink-600); margin: 0 0 1rem; max-width: 560px; }
.sg2-gate .sg2-gate-list-h { font-family: var(--font-mono); font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-500); margin: 0 0 .4rem; }
.sg2-gate-list { list-style: none; margin: 0 0 1.25rem; padding: 0; display: grid; gap: .3rem; }
.sg2-gate-list li { display: flex; align-items: center; gap: .5rem; font-size: var(--text-sm); color: var(--ink-800); }
.sg2-gate-list li.is-open svg { color: var(--success); }
.sg2-gate-list li.is-locked { color: var(--ink-500); }
.sg2-gate-list li svg { flex-shrink: 0; }
.sg2-gate-btns { display: flex; flex-wrap: wrap; gap: .5rem; }
@media (max-width: 640px) { .sg2-gate { padding: 1.25rem 1.1rem; } }

/* Blocks rendered from tables: Test yourself, Practise, Credits, References */
.sg-block { background: #fff; border: 1px solid var(--ink-200); border-radius: var(--r-xl); padding: 1.6rem 2rem; margin-top: 1.25rem; scroll-margin-top: calc(var(--header-h, 64px) + 16px); }
.sg-block > h2 { font-size: 1.3rem; letter-spacing: -0.02em; color: var(--ink-950); margin: 0 0 .35rem; }
.sg-block .sg-block-lead { font-size: var(--text-sm); color: var(--ink-500); margin: 0 0 1.1rem; }
@media (max-width: 640px) { .sg-block { padding: 1.2rem 1.05rem; } }

/* MCQ */
.sg-mcq { border: 1px solid var(--ink-200); border-radius: var(--r-lg); padding: 1.1rem 1.2rem; margin: 0 0 1rem; background: #fff; }
.sg-mcq fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
.sg-mcq legend { padding: 0; margin: 0 0 .8rem; display: block; width: 100%; }
.sg-mcq-num { display: block; font-family: var(--font-mono); font-size: 11px; font-weight: 500; letter-spacing: .06em; text-transform: uppercase; color: var(--blue-700); margin-bottom: .3rem; }
.sg-mcq-stem { display: block; font-size: var(--text-base); font-weight: 600; line-height: 1.55; color: var(--ink-950); }
.sg-mcq-options { display: grid; gap: .45rem; }
.sg-mcq-opt { position: relative; display: flex; align-items: flex-start; gap: .65rem; padding: .65rem .85rem; border: 1px solid var(--ink-200); border-radius: var(--r-md, 8px); cursor: pointer; font-size: var(--text-sm); line-height: 1.5; color: var(--ink-800); transition: border-color .12s, background .12s; }
.sg-mcq-opt:hover { border-color: var(--blue-300); background: var(--blue-50); }
.sg-mcq-opt input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.sg-mcq-letter { flex-shrink: 0; width: 24px; height: 24px; border-radius: 50%; border: 1px solid var(--ink-300); display: inline-flex; align-items: center; justify-content: center; font-family: var(--font-mono); font-size: 12px; font-weight: 600; color: var(--ink-600); background: #fff; }
.sg-mcq-text { flex: 1; min-width: 0; padding-top: 1px; }
.sg-mcq-mark { flex-shrink: 0; display: inline-flex; padding-top: 3px; }
.sg-mcq-opt:has(input:checked) { border-color: var(--blue-600); background: var(--blue-50); box-shadow: 0 0 0 1px var(--blue-600); }
.sg-mcq-opt:has(input:checked) .sg-mcq-letter { background: var(--blue-600); border-color: var(--blue-600); color: #fff; }
.sg-mcq-opt:has(input:focus-visible) { outline: 2px solid var(--blue-600); outline-offset: 2px; }
.sg-mcq .sg-mcq-opt.is-correct { border-color: var(--success); background: var(--success-soft); box-shadow: 0 0 0 1px var(--success); }
.sg-mcq .sg-mcq-opt.is-correct .sg-mcq-letter { background: var(--success); border-color: var(--success); color: #fff; }
.sg-mcq .sg-mcq-opt.is-correct .sg-mcq-mark { color: var(--success); }
.sg-mcq .sg-mcq-opt.is-wrong { border-color: var(--danger); background: var(--danger-soft); box-shadow: 0 0 0 1px var(--danger); }
.sg-mcq .sg-mcq-opt.is-wrong .sg-mcq-letter { background: var(--danger); border-color: var(--danger); color: #fff; }
.sg-mcq .sg-mcq-opt.is-wrong .sg-mcq-mark { color: var(--danger); }
.sg-mcq input:disabled + .sg-mcq-letter { cursor: default; }
.sg-mcq fieldset:disabled .sg-mcq-opt, .sg-mcq .sg-mcq-opt:has(input:disabled) { cursor: default; }
.sg-mcq-actions { display: none; align-items: center; gap: .6rem; margin-top: .85rem; flex-wrap: wrap; }
.sg-mcq-retry { display: inline-flex; align-items: center; gap: .35rem; background: none; border: 0; padding: .35rem .2rem; font: inherit; font-size: 14px; font-weight: 500; color: var(--blue-600); cursor: pointer; text-decoration: underline; text-underline-offset: 2px; }
.sg-mcq-retry[hidden], .sg-mcq-check[hidden] { display: none; }
.sg-mcq-result { margin: .75rem 0 0; font-size: var(--text-sm); display: flex; align-items: center; gap: .4rem; min-height: 0; }
.sg-mcq-result:empty { display: none; }
.sg-mcq-result.is-right { color: var(--success); }
.sg-mcq-result.is-wrong { color: var(--danger); }
.sg-mcq-result.is-hint { color: var(--warning); }
.sg-mcq-result strong { color: inherit; }
.sg-mcq-explain, .sg-mcq-fallback { margin-top: .8rem; padding: .85rem 1rem; background: var(--ink-50); border: 1px solid var(--ink-150); border-radius: var(--r-md, 8px); font-size: var(--text-sm); line-height: 1.6; color: var(--ink-700); }
.sg-mcq-explain p, .sg-mcq-fallback p { margin: 0 0 .5rem; }
.sg-mcq-explain p:last-child, .sg-mcq-fallback p:last-child { margin-bottom: 0; }
.sg-mcq-key strong { color: var(--ink-950); }
.sg-mcq-ref { font-size: 12.5px; color: var(--ink-500); }
.sg-mcq-ref span { font-family: var(--font-mono); font-size: 10.5px; text-transform: uppercase; letter-spacing: .06em; margin-right: .3rem; }
.sg-mcq-ref a { color: var(--blue-600); }
.sg-mcq-fallback summary { cursor: pointer; font-weight: 600; color: var(--blue-700); }
.sg-mcq-fallback[open] summary { margin-bottom: .5rem; }
/* With JavaScript: buttons replace the no-JS fallback. */
.sg-js .sg-mcq-actions { display: flex; }
.sg-js .sg-mcq-fallback { display: none; }
.sg-score { display: flex; align-items: center; justify-content: space-between; gap: .75rem; flex-wrap: wrap; padding: .8rem 1rem; border-radius: var(--r-lg); background: var(--blue-50); border: 1px solid var(--blue-100); font-size: var(--text-sm); color: var(--blue-900); font-weight: 500; }
.sg-score:not(:has(.sg-score-text)) { display: none; }
html:not(.sg-js) .sg-score { display: none; }
.sg-score-cta { display: inline-flex; align-items: center; gap: .35rem; font-weight: 600; color: var(--blue-700); }
.sg-score-cta[hidden] { display: none; }

/* Practise */
.sg-prac-cta { display: flex; flex-wrap: wrap; align-items: center; gap: .6rem .9rem; margin-top: .4rem; }
.sg-prac-cta .btn { display: inline-flex; align-items: center; gap: .4rem; }
.sg-prac-note { font-size: 13px; color: var(--ink-500); }
.sg-prac-note a { color: var(--blue-600); text-decoration: underline; }

/* Credits and references */
.sg-credits ul { list-style: none; margin: .4rem 0 0; padding: 0; display: grid; gap: .5rem; }
.sg-credits li { font-size: 13.5px; line-height: 1.55; color: var(--ink-700); }
.sg-credit-n { font-family: var(--font-mono); font-size: 11px; font-weight: 600; color: var(--ink-500); text-transform: uppercase; letter-spacing: .04em; margin-right: .35rem; }
.sg-credits a, .sg-refs a { color: var(--blue-600); text-decoration: underline; text-underline-offset: 2px; overflow-wrap: anywhere; }
.sg-refs ol { margin: .4rem 0 0 1.5rem; padding: 0; list-style: decimal; display: grid; gap: .5rem; }
.sg-refs li { font-size: 13.5px; line-height: 1.55; color: var(--ink-700); padding-left: .2rem; scroll-margin-top: calc(var(--header-h, 64px) + 16px); }
.sg-refs li:target { background: var(--blue-50); border-radius: 4px; box-shadow: 0 0 0 4px var(--blue-50); }
.sg-refs li::marker { color: var(--ink-500); font-family: var(--font-mono); font-size: 12px; }

.sg2-report { font-size: 13px; color: var(--ink-500); margin: 1.25rem 0 0; }
.sg2-report a { color: var(--blue-600); }

/* Sidebar */
.sg2-card { background: #fff; border: 1px solid var(--ink-200); border-radius: var(--r-xl); padding: 1rem 1.15rem; }
.sg2-card-h { font-family: var(--font-mono); font-size: 11px; font-weight: 500; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-500); margin: 0 0 .5rem; }
.sg2-toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 1px; max-height: 60vh; overflow-y: auto; }
.sg2-toc a, .sg2-toc span { display: flex; align-items: center; gap: .35rem; padding: .3rem .4rem; border-radius: 6px; font-size: 13.5px; line-height: 1.35; color: var(--ink-700); }
.sg2-toc a:hover { background: var(--blue-50); color: var(--blue-700); }
.sg2-toc span { color: var(--ink-400); }
.sg2-related { list-style: none; margin: 0; padding: 0; }
.sg2-related li { border-bottom: 1px solid var(--ink-150); padding: .5rem 0; }
.sg2-related li:last-child { border-bottom: 0; padding-bottom: 0; }
.sg2-related a { display: block; font-size: 14px; font-weight: 500; line-height: 1.35; color: var(--ink-800); }
.sg2-related a:hover { color: var(--blue-600); }
.sg2-related span { display: block; font-size: 12px; color: var(--ink-500); margin-top: 2px; }
.sg2-cta { background: var(--blue-950); border-color: var(--blue-950); color: #fff; }
.sg2-cta .sg2-card-h { color: rgba(228,236,254,.7); }
.sg2-cta p { font-size: 13px; line-height: 1.5; color: rgba(228,236,254,.8); margin: 0 0 .85rem; }

/* Admin preview panel */
.sg-review { background: #fffbeb; border: 1px solid #fcd34d; border-radius: var(--r-xl); padding: 1.1rem 1.3rem; margin-bottom: 1.5rem; font-size: var(--text-sm); color: var(--ink-800); }
.sg-review-head { display: flex; align-items: center; gap: .45rem; font-weight: 600; color: #92400e; margin-bottom: .7rem; }
.sg-review-meta { display: flex; flex-wrap: wrap; gap: .4rem 1.4rem; margin: 0 0 .8rem; }
.sg-review-meta dt { font-family: var(--font-mono); font-size: 10.5px; text-transform: uppercase; letter-spacing: .06em; color: #92400e; }
.sg-review-meta dd { margin: 0; font-weight: 600; }
.sg-review-for { background: #fff; border: 1px solid #fde68a; border-radius: var(--r-md, 8px); padding: .7rem .9rem; margin-bottom: .8rem; }
.sg-review-for p { margin: .25rem 0 0; }
.sg-review h3 { font-size: 14px; margin: .2rem 0 .4rem; color: var(--ink-950); }
.sg-review ul { margin: 0 0 0 1.2rem; list-style: disc; display: grid; gap: .3rem; line-height: 1.55; }