/* AI 시대 기초 학력 강의 — index.html·page.html 공용.
xn-ui 키트(/static/shared/xn-ui.css, body.xn-app.xn-app-light) 위에 '차분한 학당' 색과 긴 글 조판을 얹는다.
밝은 화면은 상아색 종이 + 먹색 글자, 어두운 화면(prefers-color-scheme)은 깊은 남색.
공용 조각(_site_foot·_related·_site_guide·_channel)이 --bg·--card·--border·--accent·--accent2·--text·--muted·--ok 를
그대로 쓰므로 이 이름들은 밝은·어두운 화면 모두에서 다시 정의한다(md/content-guide.md "밝은 배경 사이트").
과정마다 색이 하나씩 있다: [data-track] 의 --tc. */
body.bx {
--bg: #f7f5ef; --bg2: #efebe1; --surface: #fffdf8; --surface-2: #f3efe5; --card: #fffdf8;
--border: #e4ddcd; --border-strong: #d3cab5;
--text: #1c2230; --text-sub: #3b4252; --sub: #3b4252; --muted: #5f6676; --faint: #6b7280;
--accent: #2b3a67; --accent-2: #b0812a; --accent2: #b0812a; --grad: linear-gradient(135deg, #2b3a67, #4a5d96);
--ok: #1f8a5b; --ok-soft: #e2f3ea; --bad: #c0392b; --bad-soft: #fbe9e6;
--tip-soft: #fbf3dc; --tip-line: #e7cf8f;
--shadow: 0 1px 2px rgba(40, 32, 15, .05), 0 10px 26px -16px rgba(40, 32, 15, .28);
--aurora-1: 7%; --aurora-2: 6%; --aurora-3: 4%;
--barh: 52px;
--t-korean: #b4432c; --t-english: #2c62c9; --t-math: #6d44c7; --t-science: #13805f; --t-ai: #a8700c;
color-scheme: light;
background: var(--bg); color: var(--text);
font-family: 'Pretendard', 'Segoe UI', system-ui, -apple-system, sans-serif;
line-height: 1.7; margin: 0;
}
@media (prefers-color-scheme: dark) {
body.bx {
--bg: #0e1320; --bg2: #131a2b; --surface: #151c2e; --surface-2: #1b2338; --card: #151c2e;
--border: #273150; --border-strong: #34406a;
--text: #e9ecf4; --text-sub: #c6ccdb; --sub: #c6ccdb; --muted: #9aa3b8; --faint: #8d96ab;
--accent: #9fb2ef; --accent-2: #e2b65c; --accent2: #e2b65c; --grad: linear-gradient(135deg, #4a5fae, #6278c8);
--ok: #4cc58c; --ok-soft: #14301f; --bad: #f08a7c; --bad-soft: #3a1c18;
--tip-soft: #2c2614; --tip-line: #6b5a26;
--shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 12px 28px -16px rgba(0, 0, 0, .7);
--t-korean: #f08b74; --t-english: #7fa8f5; --t-math: #b39af2; --t-science: #5fd0a7; --t-ai: #e8b85a;
color-scheme: dark;
}
}
@media (max-width: 480px) { body.bx { --barh: 46px; } }
body.bx [data-track="korean"] { --tc: var(--t-korean); }
body.bx [data-track="english"] { --tc: var(--t-english); }
body.bx [data-track="math"] { --tc: var(--t-math); }
body.bx [data-track="science"] { --tc: var(--t-science); }
body.bx [data-track="ai"] { --tc: var(--t-ai); }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
.bx a { color: inherit; }
.bx [hidden] { display: none !important; }
/* .bx a 가 키트의 버튼 글자색(:where — 특이도 0)을 이기지 않게 */
.bx a.xn-btn { color: #fff; }
.bx a.xn-btn.xn-btn--ghost { color: var(--text); }
.bx .kw { word-break: var(--xn-wb, keep-all); overflow-wrap: anywhere; }
.bx-wrap { max-width: 1040px; margin: 0 auto; padding: 0 16px; }
.bx-read { max-width: 720px; }
.bx-sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
/* ── 홈: 히어로 ── */
.bx-hero { position: relative; margin: 26px 0 8px; padding: 34px 22px 28px; border-radius: 28px; text-align: center; overflow: hidden;
background: radial-gradient(120% 90% at 50% -10%, color-mix(in srgb, var(--accent) 10%, transparent), transparent 60%), var(--surface);
border: 1px solid var(--border); box-shadow: var(--shadow); }
.bx-hero::before { content: ''; position: absolute; inset: 0 0 auto 0; height: 4px;
background: linear-gradient(90deg, var(--t-korean), var(--t-english), var(--t-math), var(--t-science), var(--t-ai)); }
.bx-eyebrow { display: inline-flex; align-items: center; gap: 6px; padding: 5px 12px; border-radius: 999px; font-size: .8rem; font-weight: 800;
letter-spacing: .02em; color: var(--accent); background: color-mix(in srgb, var(--accent) 9%, transparent); }
.bx-h1 { margin: 14px 0 12px; font-size: clamp(1.75rem, 6vw, 2.6rem); font-weight: 900; letter-spacing: -.035em; line-height: 1.25; }
.bx-h1 .ico { display: inline-block; margin-right: 6px; }
.bx-lead { max-width: 36em; margin: 0 auto; font-size: 1.04rem; line-height: 1.85; color: var(--text-sub); word-break: var(--xn-wb, keep-all); }
.bx-lead + .bx-lead { margin-top: 10px; }
.bx-sign { margin-top: 14px; font-size: .86rem; font-weight: 700; color: var(--muted); }
.bx-stats { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 18px; }
.bx-stats span { display: inline-flex; align-items: baseline; gap: 5px; padding: 7px 14px; border-radius: 999px; background: var(--surface-2);
border: 1px solid var(--border); font-size: .84rem; font-weight: 700; color: var(--text-sub); }
.bx-stats b { font-size: 1.05rem; font-weight: 900; color: var(--text); font-variant-numeric: tabular-nums; }
.bx-hero-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 20px; }
.bx-notice { max-width: 720px; margin: 14px auto 0; padding: 12px 16px; border-radius: 14px; font-size: .9rem; line-height: 1.6;
background: var(--tip-soft); border: 1px solid var(--tip-line); color: var(--text); }
/* ── 진도 ── */
.bx-prog { margin: 22px 0 6px; padding: 18px 20px; border-radius: 22px; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); }
.bx-prog-h { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 8px; }
.bx-prog-h h2 { margin: 0; font-size: 1.1rem; font-weight: 900; }
.bx-prog-h .num { font-size: .9rem; font-weight: 800; color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-bars { display: grid; gap: 10px; margin-top: 14px; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); }
.bx-bar { display: grid; gap: 6px; text-decoration: none; padding: 10px 12px; border-radius: 14px; background: var(--surface-2); border: 1px solid var(--border); }
.bx-bar:hover { border-color: var(--tc, var(--accent)); }
.bx-bar .lbl { display: flex; justify-content: space-between; gap: 8px; font-size: .86rem; font-weight: 800; }
.bx-bar .lbl small { font-weight: 700; color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-meter { position: relative; height: 8px; border-radius: 99px; background: color-mix(in srgb, var(--text) 9%, transparent); overflow: hidden; }
.bx-meter i { position: absolute; inset: 0 auto 0 0; width: 0; border-radius: 99px; background: var(--tc, var(--accent)); transition: width .5s ease; }
@media (prefers-reduced-motion: reduce) { .bx-meter i { transition: none; } }
.bx-prog-foot { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 14px; font-size: .86rem; color: var(--muted); }
.bx-prog-foot .bx-continue[hidden] { display: none; }
.bx-nostore { font-size: .8rem; color: var(--muted); }
/* ── 홈: 과정 카드 ── */
.bx-sec-h { margin: 40px 0 14px; }
.bx-sec-h h2 { margin: 0; font-size: 1.35rem; font-weight: 900; letter-spacing: -.025em; }
.bx-sec-h p { margin: 4px 0 0; color: var(--muted); font-size: .95rem; }
.bx-tracks { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.bx-track { position: relative; display: flex; flex-direction: column; padding: 20px 20px 16px; border-radius: 22px; background: var(--surface);
border: 1px solid var(--border); box-shadow: var(--shadow); overflow: hidden; }
.bx-track::before { content: ''; position: absolute; inset: 0 auto 0 0; width: 5px; background: var(--tc); }
.bx-track-top { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.bx-track-ico { flex: 0 0 auto; width: 48px; height: 48px; border-radius: 14px; display: flex; align-items: center; justify-content: center; font-size: 1.6rem;
background: color-mix(in srgb, var(--tc) 12%, var(--surface)); border: 1px solid color-mix(in srgb, var(--tc) 30%, transparent); }
.bx-track h3 { margin: 0; font-size: 1.18rem; font-weight: 900; letter-spacing: -.02em; }
.bx-track h3 small { display: block; font-size: .78rem; font-weight: 800; color: var(--tc); letter-spacing: .02em; }
.bx-track-top:hover h3 { text-decoration: underline; text-decoration-color: var(--tc); text-underline-offset: 4px; }
.bx-track > p { margin: 12px 0 0; font-size: .93rem; color: var(--text-sub); line-height: 1.7; }
.bx-track .bx-meter { margin-top: 14px; }
.bx-track-list { list-style: none; margin: 12px 0 0; padding: 0; display: grid; gap: 2px; counter-reset: l; }
.bx-track-list li { counter-increment: l; }
.bx-track-list a { display: flex; gap: 8px; align-items: baseline; padding: 5px 4px; border-radius: 8px; text-decoration: none; font-size: .9rem; color: var(--text-sub); }
.bx-track-list a::before { content: counter(l, decimal-leading-zero); flex: 0 0 auto; font-size: .74rem; font-weight: 800; color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-track-list a:hover { background: var(--surface-2); color: var(--text); }
.bx-track-list .is-done a { color: var(--muted); }
.bx-track-list .is-done a::after { content: '✓'; margin-left: auto; padding-left: 6px; font-weight: 900; color: var(--ok); }
.bx-track-more { margin-top: 12px; }
.bx-track-more summary { cursor: pointer; font-size: .86rem; font-weight: 800; color: var(--tc); list-style: none; }
.bx-track-more summary::-webkit-details-marker { display: none; }
.bx-track-more summary::after { content: ' ▾'; }
.bx-track-more[open] summary::after { content: ' ▴'; }
.bx-track-go { margin-top: auto; padding-top: 14px; display: flex; gap: 8px; }
.bx-track-go a { font-size: .86rem; font-weight: 800; text-decoration: none; color: var(--tc); }
/* ── 홈: 어디서 시작할까 ── */
.bx-start { display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.bx-start-card { padding: 16px 18px; border-radius: 18px; background: var(--surface); border: 1px solid var(--border); }
.bx-start-card h3 { margin: 0 0 8px; font-size: 1rem; font-weight: 900; display: flex; gap: 8px; align-items: center; }
.bx-start-card ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.bx-start-card a { display: flex; gap: 8px; align-items: baseline; text-decoration: none; font-size: .92rem; font-weight: 600; color: var(--text-sub); }
.bx-start-card a:hover { color: var(--text); text-decoration: underline; text-underline-offset: 3px; }
.bx-start-card a .tag { flex: 0 0 auto; font-size: .72rem; font-weight: 800; padding: 1px 8px; border-radius: 999px;
color: var(--tc); background: color-mix(in srgb, var(--tc) 11%, transparent); }
.bx-how { counter-reset: h; list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
.bx-how li { counter-increment: h; position: relative; padding: 14px 16px 14px 50px; border-radius: 16px; background: var(--surface-2); border: 1px solid var(--border); font-size: .92rem; line-height: 1.6; }
.bx-how li::before { content: counter(h); position: absolute; left: 14px; top: 13px; width: 26px; height: 26px; border-radius: 50%;
display: flex; align-items: center; justify-content: center; font-size: .82rem; font-weight: 900; color: #fff; background: var(--accent); }
@media (prefers-color-scheme: dark) { .bx-how li::before { color: #0e1320; } }
.bx-how b { display: block; font-size: .95rem; }
/* ── 빵부스러기(본문 위) ── */
.bx-crumb { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; padding-top: 22px; font-size: .88rem; color: var(--muted); }
.bx-crumb a { text-decoration: none; }
.bx-crumb a:hover { color: var(--text); text-decoration: underline; }
.bx-crumb .sep { opacity: .5; }
/* ── 과정 페이지 ── */
.bx-thead { padding: 18px 0 6px; }
.bx-chip { display: inline-flex; align-items: center; gap: 6px; padding: 4px 11px; border-radius: 999px; font-size: .8rem; font-weight: 800;
color: var(--tc, var(--accent)); background: color-mix(in srgb, var(--tc, var(--accent)) 11%, transparent); text-decoration: none; }
.bx-thead h1, .bx-lhead h1 { margin: 12px 0 10px; font-size: clamp(1.6rem, 5.4vw, 2.3rem); font-weight: 900; letter-spacing: -.035em; line-height: 1.3; }
.bx-thead h1 .ico { margin-right: 6px; }
.bx-sum { font-size: 1.06rem; line-height: 1.8; color: var(--text-sub); margin: 0; }
.bx-prose p { font-size: 1.02rem; line-height: 1.85; margin: 0 0 14px; }
.bx-for { margin: 18px 0 0; padding: 16px 18px; border-radius: 16px; background: var(--surface-2); border: 1px solid var(--border); }
.bx-for b { display: block; margin-bottom: 6px; font-size: .92rem; }
.bx-for ul { margin: 0; padding-left: 20px; font-size: .95rem; line-height: 1.7; }
.bx-lessons { list-style: none; margin: 18px 0 0; padding: 0; display: grid; gap: 10px; }
.bx-lesson { position: relative; }
.bx-lesson > a { display: grid; grid-template-columns: 48px minmax(0, 1fr) auto; gap: 14px; align-items: start; padding: 16px 18px; border-radius: 18px;
text-decoration: none; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); transition: border-color .15s ease, transform .15s ease; }
.bx-lesson > a:hover { border-color: var(--tc); transform: translateY(-1px); }
.bx-lesson .no { width: 48px; height: 48px; border-radius: 14px; display: flex; flex-direction: column; align-items: center; justify-content: center;
font-weight: 900; font-size: 1.1rem; line-height: 1; color: var(--tc); background: color-mix(in srgb, var(--tc) 10%, transparent); font-variant-numeric: tabular-nums; }
.bx-lesson .no small { font-size: .62rem; font-weight: 800; margin-top: 3px; }
.bx-lesson strong { display: block; font-size: 1.04rem; font-weight: 800; line-height: 1.45; }
.bx-lesson p { margin: 4px 0 0; font-size: .9rem; line-height: 1.6; color: var(--muted); }
.bx-lesson .min { font-size: .78rem; font-weight: 700; color: var(--muted); white-space: nowrap; padding-top: 3px; }
.bx-lesson.is-done .no { background: var(--ok); color: #fff; }
.bx-lesson.is-done .no::after { content: '✓'; font-size: .7rem; }
.bx-lesson.is-done .no small { display: none; }
.bx-track-prog { margin-top: 18px; display: grid; gap: 8px; }
.bx-track-prog .lbl { display: flex; justify-content: space-between; font-size: .88rem; font-weight: 800; }
.bx-track-prog .lbl small { color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-others { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
/* ── 강의 페이지 ── */
.bx-lhead { padding: 14px 0 4px; }
.bx-lmeta { display: flex; flex-wrap: wrap; gap: 6px 14px; margin-top: 12px; font-size: .86rem; color: var(--muted); font-weight: 600; }
.bx-goals { margin: 20px 0 0; padding: 18px 20px; border-radius: 18px; background: color-mix(in srgb, var(--tc) 6%, var(--surface));
border: 1px solid color-mix(in srgb, var(--tc) 22%, var(--border)); }
.bx-goals b { display: flex; align-items: center; gap: 6px; font-size: .95rem; font-weight: 900; color: var(--tc); }
.bx-goals ul { list-style: none; margin: 8px 0 0; padding: 0; display: grid; gap: 6px; }
.bx-goals li { position: relative; padding-left: 26px; font-size: .98rem; line-height: 1.65; }
.bx-goals li::before { content: '◎'; position: absolute; left: 2px; top: 0; color: var(--tc); font-weight: 900; }
.bx-layout { display: grid; gap: 28px; margin-top: 8px; grid-template-columns: minmax(0, 1fr); }
.bx-layout > * { min-width: 0; }
@media (min-width: 1000px) { .bx-layout { grid-template-columns: minmax(0, 720px) 240px; justify-content: space-between; } }
.bx-toc { order: 2; }
@media (min-width: 1000px) { .bx-toc nav { position: sticky; top: calc(var(--barh) + 18px); max-height: calc(100vh - var(--barh) - 36px); overflow: auto; } }
.bx-toc b { display: block; font-size: .78rem; letter-spacing: .08em; color: var(--muted); margin-bottom: 8px; }
.bx-toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; border-left: 2px solid var(--border); }
.bx-toc a { display: block; padding: 6px 12px; margin-left: -2px; border-left: 2px solid transparent; text-decoration: none; font-size: .88rem; color: var(--muted); line-height: 1.45; }
.bx-toc a:hover { color: var(--text); }
.bx-toc a.on { color: var(--text); font-weight: 800; border-left-color: var(--tc); }
@media (max-width: 999px) {
.bx-toc { order: 0; position: sticky; top: var(--barh); z-index: 30; margin: 0 -16px; background: color-mix(in srgb, var(--bg) 92%, transparent);
backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.bx-toc nav { overflow-x: auto; scrollbar-width: none; padding: 8px 16px; }
.bx-toc nav::-webkit-scrollbar { display: none; }
.bx-toc b { display: none; }
.bx-toc ol { display: flex; gap: 6px; border: 0; width: max-content; }
.bx-toc a { white-space: nowrap; margin: 0; padding: 6px 12px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); font-size: .82rem; }
.bx-toc a.on { border-color: var(--tc); background: color-mix(in srgb, var(--tc) 10%, var(--surface)); }
}
.bx-art { order: 1; min-width: 0; }
.bx-sec { padding: 28px 0 6px; scroll-margin-top: calc(var(--barh) + 64px); border-top: 1px solid var(--border); }
.bx-sec:first-child { border-top: 0; padding-top: 6px; }
@media (min-width: 1000px) { .bx-sec { scroll-margin-top: calc(var(--barh) + 16px); } }
.bx-sec h2 { margin: 0 0 14px; font-size: clamp(1.22rem, 3.6vw, 1.42rem); font-weight: 900; letter-spacing: -.025em; line-height: 1.4; }
.bx-sec h2 .no { display: inline-block; min-width: 1.6em; color: var(--tc); font-variant-numeric: tabular-nums; }
.bx-sec p { margin: 0 0 16px; font-size: clamp(1rem, 2.6vw, 1.0625rem); line-height: 1.85; word-break: var(--xn-wb, keep-all); overflow-wrap: anywhere; }
.bx-sec ul.bx-list { margin: 0 0 16px; padding-left: 22px; display: grid; gap: 6px; font-size: 1rem; line-height: 1.75; }
.bx-sec ul.bx-list li::marker { color: var(--tc); }
.bx-formula { margin: 4px 0 18px; padding: 14px 18px; border-radius: 14px; background: var(--surface-2); border: 1px solid var(--border);
font-family: 'Pretendard', ui-monospace, 'SF Mono', Menlo, monospace; font-size: 1.02rem; line-height: 1.9; overflow-x: auto; font-variant-numeric: tabular-nums; }
.bx-formula div { white-space: pre-wrap; }
.bx-tablewrap { margin: 4px 0 18px; overflow-x: auto; border-radius: 14px; border: 1px solid var(--border); }
.bx-table { width: 100%; border-collapse: collapse; font-size: .93rem; line-height: 1.55; background: var(--surface); }
.bx-table caption { caption-side: top; text-align: left; padding: 10px 14px 0; font-size: .84rem; font-weight: 800; color: var(--muted); }
.bx-table th, .bx-table td { padding: 10px 14px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: top; }
.bx-table thead th { background: var(--surface-2); font-size: .84rem; font-weight: 800; white-space: nowrap; }
.bx-table tbody tr:last-child td, .bx-table tbody tr:last-child th { border-bottom: 0; }
.bx-table tbody th { font-weight: 800; }
.bx-pairs { list-style: none; margin: 4px 0 18px; padding: 0; display: grid; gap: 8px; }
.bx-pairs li { padding: 12px 14px; border-radius: 14px; background: var(--surface); border: 1px solid var(--border); display: grid; gap: 4px; }
.bx-pairs .x, .bx-pairs .o { display: flex; gap: 8px; align-items: baseline; font-size: 1rem; line-height: 1.6; }
.bx-pairs .x { color: var(--muted); }
.bx-pairs .x span { text-decoration: line-through; text-decoration-color: color-mix(in srgb, var(--bad) 70%, transparent); }
.bx-pairs .o span { font-weight: 700; }
.bx-pairs .x::before { content: '✗'; color: var(--bad); font-weight: 900; flex: 0 0 1em; }
.bx-pairs .o::before { content: '✓'; color: var(--ok); font-weight: 900; flex: 0 0 1em; }
.bx-pairs small { display: block; padding-left: calc(1em + 8px); font-size: .86rem; color: var(--muted); line-height: 1.55; }
.bx-ex { margin: 4px 0 18px; border-radius: 16px; border: 1px solid color-mix(in srgb, var(--tc) 28%, var(--border)); background: var(--surface); overflow: hidden; }
.bx-ex-q { padding: 14px 16px; background: color-mix(in srgb, var(--tc) 7%, var(--surface)); font-size: 1rem; line-height: 1.7; }
.bx-ex-q b { display: inline-block; margin-right: 6px; font-size: .78rem; font-weight: 900; color: #fff; background: var(--tc); padding: 2px 8px; border-radius: 6px; vertical-align: 2px; }
@media (prefers-color-scheme: dark) { .bx-ex-q b { color: #0e1320; } }
.bx-ex ol { margin: 0; padding: 12px 16px 4px 38px; display: grid; gap: 6px; font-size: .97rem; line-height: 1.7; }
.bx-ex ol li::marker { color: var(--tc); font-weight: 800; }
.bx-ex-a { margin: 6px 16px 14px; padding: 10px 12px; border-radius: 10px; background: var(--ok-soft); font-size: .97rem; line-height: 1.6; }
.bx-ex-a b { color: var(--ok); margin-right: 6px; }
.bx-tip { display: flex; gap: 10px; margin: 4px 0 18px; padding: 12px 14px; border-radius: 14px; background: var(--tip-soft); border: 1px solid var(--tip-line); font-size: .95rem; line-height: 1.65; }
.bx-box { margin: 28px 0 0; padding: 20px 20px 16px; border-radius: 20px; scroll-margin-top: calc(var(--barh) + 64px); }
@media (min-width: 1000px) { .bx-box { scroll-margin-top: calc(var(--barh) + 16px); } }
.bx-box h2 { margin: 0 0 12px; display: flex; align-items: center; gap: 8px; font-size: 1.2rem; font-weight: 900; letter-spacing: -.02em; }
.bx-key { background: var(--surface); border: 2px solid color-mix(in srgb, var(--tc) 40%, var(--border)); }
.bx-key ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.bx-key li { position: relative; padding-left: 24px; font-size: 1rem; line-height: 1.7; }
.bx-key li::before { content: ''; position: absolute; left: 4px; top: .62em; width: 9px; height: 9px; border-radius: 3px; background: var(--tc); }
.bx-quiz { background: var(--surface-2); border: 1px solid var(--border); }
.bx-quiz > p.hint { margin: -4px 0 14px; font-size: .9rem; color: var(--muted); }
.bx-q { margin: 0 0 14px; padding: 16px; border-radius: 16px; background: var(--surface); border: 1px solid var(--border); }
.bx-q legend, .bx-q .qt { display: block; padding: 0; margin: 0 0 10px; font-size: 1rem; font-weight: 800; line-height: 1.65; }
.bx-q legend .n, .bx-q .qt .n { color: var(--tc); margin-right: 4px; }
.bx-q fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
.bx-choices { display: grid; gap: 6px; }
.bx-choices label { display: flex; gap: 10px; align-items: flex-start; padding: 10px 12px; border-radius: 12px; border: 1px solid var(--border); cursor: pointer;
font-size: .97rem; line-height: 1.6; background: var(--surface); transition: border-color .15s ease, background .15s ease; }
.bx-choices label:hover { border-color: var(--tc); }
.bx-choices input { flex: 0 0 auto; margin-top: .35em; accent-color: var(--tc); width: 16px; height: 16px; }
.bx-choices .mk { flex: 0 0 auto; font-weight: 800; color: var(--muted); min-width: 1.3em; }
.bx-choices label:has(input:checked) { border-color: var(--tc); background: color-mix(in srgb, var(--tc) 7%, var(--surface)); }
.bx-q.is-right .bx-choices label.ans, .bx-q.is-wrong .bx-choices label.ans { border-color: var(--ok); background: var(--ok-soft); }
.bx-q.is-wrong .bx-choices label:has(input:checked) { border-color: var(--bad); background: var(--bad-soft); }
.bx-q .res { display: none; margin: 10px 0 0; font-weight: 800; font-size: .92rem; }
.bx-q.is-right .res.ok, .bx-q.is-wrong .res.no { display: block; }
.bx-q .res.ok { color: var(--ok); } .bx-q .res.no { color: var(--bad); }
.bx-q textarea { width: 100%; min-height: 64px; padding: 10px 12px; border-radius: 12px; border: 1px solid var(--border); background: var(--surface); color: var(--text);
font: inherit; font-size: .97rem; line-height: 1.6; resize: vertical; }
.bx-ans { margin-top: 10px; border-radius: 12px; border: 1px dashed var(--border-strong); }
.bx-ans summary { cursor: pointer; padding: 9px 12px; font-size: .9rem; font-weight: 800; color: var(--tc); list-style: none; }
.bx-ans summary::-webkit-details-marker { display: none; }
.bx-ans summary::before { content: '▸ '; }
.bx-ans[open] summary::before { content: '▾ '; }
.bx-ans > div { padding: 0 12px 12px; font-size: .95rem; line-height: 1.7; }
.bx-ans > div b { color: var(--ok); }
.bx-ans > div p { margin: 4px 0 0; }
.bx-quiz-act { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.bx-score { font-weight: 900; font-size: 1rem; }
.bx-ask { background: linear-gradient(160deg, color-mix(in srgb, var(--accent) 8%, var(--surface)), var(--surface));
border: 1px solid color-mix(in srgb, var(--accent) 25%, var(--border)); }
.bx-ask > p.hint { margin: -4px 0 12px; font-size: .9rem; color: var(--muted); }
.bx-prompt { margin: 0 0 12px; border-radius: 14px; background: var(--surface); border: 1px solid var(--border); overflow: hidden; }
.bx-prompt .when { padding: 10px 14px 0; font-size: .86rem; font-weight: 800; color: var(--muted); }
.bx-prompt pre { margin: 0; padding: 8px 14px 12px; white-space: pre-wrap; word-break: var(--xn-wb, keep-all); overflow-wrap: anywhere;
font-family: 'Pretendard', system-ui, sans-serif; font-size: .98rem; line-height: 1.75; color: var(--text); }
.bx-prompt .cp { display: flex; justify-content: flex-end; padding: 0 10px 10px; }
.bx-prompt .cp button { min-height: 36px; padding: 6px 14px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface-2); color: var(--text);
font: inherit; font-size: .84rem; font-weight: 800; cursor: pointer; }
.bx-prompt .cp button:hover { border-color: var(--accent); }
.bx-prompt .cp button.done { border-color: var(--ok); color: var(--ok); }
.bx-src { margin: 22px 0 0; padding: 14px 16px; border-radius: 14px; border: 1px solid var(--border); font-size: .88rem; color: var(--muted); line-height: 1.65; }
.bx-src b { color: var(--text-sub); }
.bx-src ul { margin: 4px 0 0; padding-left: 18px; }
.bx-done { margin: 28px 0 0; padding: 20px; border-radius: 20px; text-align: center; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); }
.bx-done p { margin: 0 0 12px; font-size: .95rem; color: var(--text-sub); }
.bx-done button { min-width: 220px; }
.bx-done button[aria-pressed="true"] { background: var(--ok); box-shadow: none; }
.bx-done .bx-nostore { display: block; margin-top: 8px; }
.bx-nav { display: grid; gap: 10px; grid-template-columns: 1fr 1fr; margin: 22px 0 0; }
.bx-nav a { display: flex; flex-direction: column; gap: 4px; padding: 14px 16px; border-radius: 16px; text-decoration: none; background: var(--surface);
border: 1px solid var(--border); min-width: 0; transition: border-color .15s ease; }
.bx-nav a:hover { border-color: var(--tc); }
.bx-nav small { font-size: .8rem; font-weight: 800; color: var(--muted); }
.bx-nav strong { font-size: .95rem; line-height: 1.45; }
.bx-nav .next { text-align: right; grid-column: 2; }
@media (max-width: 520px) { .bx-nav { grid-template-columns: 1fr; } .bx-nav .next { grid-column: 1; } }
.bx-course { margin: 30px 0 0; padding: 18px 18px 14px; border-radius: 20px; background: var(--surface-2); border: 1px solid var(--border); }
.bx-course h2 { margin: 0 0 4px; font-size: 1.05rem; font-weight: 900; display: flex; gap: 8px; align-items: center; }
.bx-course .bx-meter { margin: 10px 0 8px; }
.bx-course ol { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.bx-course a { display: flex; gap: 10px; align-items: baseline; padding: 7px 8px; border-radius: 10px; text-decoration: none; font-size: .92rem; color: var(--text-sub); }
.bx-course a:hover { background: var(--surface); color: var(--text); }
.bx-course .n { flex: 0 0 2em; font-size: .78rem; font-weight: 900; color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-course li.cur a { background: var(--surface); color: var(--text); font-weight: 800; box-shadow: inset 3px 0 0 var(--tc); }
.bx-course li.is-done a::after { content: '✓'; margin-left: auto; padding-left: 6px; color: var(--ok); font-weight: 900; }
.bx-progline { position: fixed; left: 0; right: 0; top: var(--barh); height: 3px; z-index: 40; pointer-events: none; }
.bx-progline i { display: block; height: 100%; width: 0; background: var(--tc, var(--accent)); }
.bx-back { max-width: 720px; margin: 18px auto 30px; padding: 0 16px; font-size: .9rem; }
.bx-back a { color: var(--muted); }
/* ── 연습 문제(practice.js) — 생성기(수학)와 문항 은행(영어·국어) ── */
.bx-prac { background: linear-gradient(170deg, color-mix(in srgb, var(--tc) 7%, var(--surface-2)), var(--surface-2) 60%);
border: 1px solid color-mix(in srgb, var(--tc) 30%, var(--border)); }
.bx-prac > p.hint { margin: -4px 0 10px; font-size: .92rem; color: var(--text-sub); line-height: 1.7; }
.bx-prac-types { list-style: none; margin: 0 0 12px; padding: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.bx-prac-types li { padding: 4px 10px; border-radius: 999px; font-size: .8rem; font-weight: 700; color: var(--text-sub);
background: var(--surface); border: 1px solid var(--border); }
.bx-prac-nojs { margin: 0 0 4px; padding: 10px 12px; border-radius: 12px; font-size: .88rem; color: var(--muted); background: var(--surface); border: 1px dashed var(--border-strong); }
.bx-prac-bar { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 12px; margin: 4px 0 10px; }
.bx-seg { display: inline-flex; padding: 3px; border-radius: 12px; background: var(--surface); border: 1px solid var(--border); }
.bx-seg button { min-height: 36px; padding: 4px 14px; border: 0; border-radius: 9px; background: transparent; color: var(--muted);
font: inherit; font-size: .86rem; font-weight: 800; cursor: pointer; }
.bx-seg button[aria-pressed="true"] { background: var(--tc); color: #fff; }
@media (prefers-color-scheme: dark) { .bx-seg button[aria-pressed="true"] { color: #0e1320; } }
.bx-seg button:focus-visible { outline: 2px solid var(--tc); outline-offset: 1px; }
.bx-streak { font-size: .86rem; font-weight: 700; color: var(--muted); font-variant-numeric: tabular-nums; }
.bx-streak b { color: var(--text); font-weight: 900; }
.bx-streak .sep { margin: 0 6px; }
.bx-prac-card { padding: 16px; border-radius: 16px; background: var(--surface); border: 1px solid var(--border); }
.bx-prac-meta { margin: 0 0 4px; font-size: .78rem; font-weight: 800; color: var(--tc); letter-spacing: .02em; }
.bx-prac-meta:empty { display: none; }
.bx-prac-q { margin: 0 0 12px; font-size: 1.04rem; font-weight: 800; line-height: 1.7; overflow-wrap: anywhere; }
.bx-prac-fields { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
.bx-prac-field { display: grid; gap: 4px; min-width: 0; }
.bx-prac-field label { font-size: .82rem; font-weight: 800; color: var(--text-sub); }
.bx-prac-field input { width: 100%; box-sizing: border-box; min-height: 44px; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--border-strong);
background: var(--surface); color: var(--text); font: inherit; font-size: 16px; font-variant-numeric: tabular-nums; }
.bx-prac-field input:focus { outline: 2px solid color-mix(in srgb, var(--tc) 60%, transparent); outline-offset: 1px; border-color: var(--tc); }
.bx-prac-field input.is-right { border-color: var(--ok); background: var(--ok-soft); }
.bx-prac-field input.is-wrong { border-color: var(--bad); background: var(--bad-soft); }
.bx-prac-act { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.bx-prac-fb { margin: 10px 0 0; min-height: 1.5em; font-size: .92rem; font-weight: 800; color: var(--muted); }
.bx-prac-fb:empty { min-height: 0; margin: 0; }
.bx-prac-fb.ok { color: var(--ok); } .bx-prac-fb.no { color: var(--bad); } .bx-prac-fb.mid { color: var(--accent-2); }
.bx-prac-sol { margin-top: 10px; padding: 12px 14px; border-radius: 12px; background: color-mix(in srgb, var(--tc) 6%, var(--surface)); border: 1px solid var(--border);
font-size: .95rem; line-height: 1.7; }
.bx-prac-sol > b { color: var(--tc); margin-right: 4px; }
.bx-prac-sol ol { margin: 6px 0 0; padding-left: 22px; display: grid; gap: 4px; overflow-wrap: anywhere; }
.bx-prac-sol ol li::marker { color: var(--tc); font-weight: 800; }
.bx-prac-sol .a { margin: 8px 0 0; padding: 8px 10px; border-radius: 10px; background: var(--ok-soft); overflow-wrap: anywhere; }
.bx-prac-sol .a b { color: var(--ok); margin-right: 6px; }
.bx-prac-choices { display: grid; gap: 6px; }
.bx-prac-choice { display: flex; gap: 10px; align-items: flex-start; width: 100%; min-height: 44px; padding: 10px 12px; border-radius: 12px; text-align: left;
border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-size: .98rem; line-height: 1.5; cursor: pointer;
transition: border-color .15s ease, background .15s ease; }
.bx-prac-choice:hover { border-color: var(--tc); }
.bx-prac-choice .mk { flex: 0 0 auto; font-weight: 800; color: var(--muted); min-width: 1.3em; }
.bx-prac-choice[aria-disabled="true"] { cursor: default; }
.bx-prac-choice.is-right { border-color: var(--ok); background: var(--ok-soft); }
.bx-prac-choice.is-wrong { border-color: var(--bad); background: var(--bad-soft); }
.bx-prac-help { margin: 10px 0 0; font-size: .8rem; color: var(--muted); line-height: 1.6; }
.bx-bank { margin-top: 12px; border-radius: 12px; border: 1px dashed var(--border-strong); background: var(--surface); }
.bx-bank summary { cursor: pointer; padding: 10px 12px; font-size: .9rem; font-weight: 800; color: var(--tc); list-style: none; }
.bx-bank summary::-webkit-details-marker { display: none; }
.bx-bank summary::before { content: '▸ '; }
.bx-bank[open] summary::before { content: '▾ '; }
.bx-bank > ol { margin: 0; padding: 0 14px 12px 34px; display: grid; gap: 10px; font-size: .92rem; line-height: 1.6; }
.bx-bank .q { margin: 0; font-weight: 700; overflow-wrap: anywhere; }
.bx-bank .c { list-style: none; margin: 2px 0 0; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 12px; color: var(--muted); }
.bx-bank .c li::before { content: '· '; }
.bx-bank .c li.ans { color: var(--ok); font-weight: 800; }
.bx-bank .w { margin: 2px 0 0; color: var(--text-sub); }
.bx-bank .w b { color: var(--ok); }
/* ── 홈: 학습 경로 ── */
.bx-paths { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.bx-path { display: flex; flex-direction: column; padding: 18px 18px 16px; border-radius: 22px; background: var(--surface); border: 1px solid var(--border); box-shadow: var(--shadow); min-width: 0; }
.bx-path h3 { margin: 0; display: flex; align-items: center; gap: 10px; font-size: 1.08rem; font-weight: 900; letter-spacing: -.02em; }
.bx-path h3 .ico { flex: 0 0 auto; width: 40px; height: 40px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 1.3rem;
background: color-mix(in srgb, var(--accent) 10%, var(--surface)); border: 1px solid color-mix(in srgb, var(--accent) 22%, transparent); }
.bx-path > p { margin: 10px 0 0; font-size: .9rem; color: var(--text-sub); line-height: 1.65; }
.bx-path .meta { margin-top: 8px; font-size: .78rem; font-weight: 800; color: var(--muted); }
.bx-path ol { list-style: none; margin: 12px 0 0; padding: 0; counter-reset: p; display: grid; gap: 2px; }
.bx-path li { counter-increment: p; position: relative; }
.bx-path li + li::before { content: ''; position: absolute; left: 12px; top: -6px; height: 12px; border-left: 2px dotted var(--border-strong); }
.bx-path li a { display: flex; gap: 10px; align-items: baseline; padding: 6px 4px; border-radius: 10px; text-decoration: none; font-size: .9rem; color: var(--text-sub); min-width: 0; }
.bx-path li a::before { content: counter(p); flex: 0 0 auto; width: 24px; height: 24px; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center;
font-size: .74rem; font-weight: 900; color: var(--tc); background: color-mix(in srgb, var(--tc) 12%, var(--surface)); align-self: center; }
.bx-path li a:hover { background: var(--surface-2); color: var(--text); }
.bx-path li a .tag { flex: 0 0 auto; font-size: .7rem; font-weight: 800; color: var(--tc); }
.bx-path li a .t { min-width: 0; }
.bx-path li.is-done a { color: var(--muted); }
.bx-path li.is-done a::before { content: '✓'; color: #fff; background: var(--ok); }
@media (prefers-color-scheme: dark) { .bx-path li.is-done a::before { color: #0e1320; } }
.bx-path .go { margin-top: auto; padding-top: 14px; }
@media print {
.bx-toc, .bx-progline, .bx-done, .xnetba-bar, .xnfoot, .bx-prompt .cp, .bx-quiz-act, .bx-prac-app, .bx-prac-nojs { display: none !important; }
.bx-ans { border: 0; } .bx-ans > div { display: block !important; }
}
/* 화면 언어로 번역되지 않은 과정(국어·영어 — 한국어 전용)의 표시 */
.bx-kolabel { display: inline-block; margin: 6px 0 0; padding: 1px 8px; border-radius: 999px; font-size: .72rem; font-weight: 800;
color: var(--tc, #6b7280); border: 1px solid currentColor; opacity: .85; vertical-align: middle; }
.xn-chip .bx-kolabel { margin: 0 0 0 6px; }