/* 수심달 가이드 · 책장 넘기기 리더 공통 스타일 (book.js와 함께 사용) */
:root{
  --pink:#FF6971; --pink-soft:#FFEDEE; --pink-deep:#E0505C; --pink-press:#E85F66;
  --violet:#918AFF; --violet-soft:#E7E3FF; --violet-deep:#4B43C9;
  --ink:#2F2F31; --ink-70:#5A5A5E; --ink-50:#85898A; --ink-30:#C3C3C3; --line:#E8E8EC;
  --bg:#F6F5F8; --card:#FFFFFF;
  --ok:#2E8B57; --ok-soft:#E4F5E6; --gold:#8A6500; --gold-soft:#FFF6D6; --warn:#B2600A; --warn-soft:#FFF4E5; --info:#1E4DB0; --info-soft:#E9F0FF;
  --top:56px; --bottom:66px; --gutter:96px;
  --ease:cubic-bezier(.22,1,.36,1);
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:"Pretendard Variable",Pretendard,-apple-system,BlinkMacSystemFont,system-ui,Roboto,"Helvetica Neue","Segoe UI","Apple SD Gothic Neo","Noto Sans KR","Malgun Gothic",sans-serif;font-size:16px;line-height:1.6;word-break:keep-all;-webkit-font-smoothing:antialiased;overscroll-behavior:none}
a{color:var(--pink-deep)}
button{font:inherit;color:inherit}
::selection{background:rgba(255,105,113,.25)}

.bk{position:fixed;inset:0;display:flex;flex-direction:column;height:100vh;height:100dvh;background:
  radial-gradient(900px 500px at 8% -10%, rgba(255,105,113,.10), transparent 60%),
  radial-gradient(800px 500px at 100% 110%, rgba(145,138,255,.12), transparent 60%),
  var(--bg)}

/* ── 상단 바 ─────────────────────────────── */
.bk-top{height:var(--top);flex:none;display:flex;align-items:center;gap:10px;padding:0 14px;background:rgba(255,255,255,.82);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-bottom:1px solid var(--line);z-index:5}
.bk-home{display:inline-flex;align-items:center;gap:6px;text-decoration:none;color:var(--ink-70);font-weight:700;font-size:13px;padding:7px 10px;border-radius:999px;border:1px solid var(--line);background:#fff;white-space:nowrap}
.bk-home:hover{border-color:var(--pink);color:var(--pink-deep)}
.bk-home svg{width:14px;height:14px}
.bk-titlebox{flex:1;min-width:0;display:flex;flex-direction:column;justify-content:center;line-height:1.2}
.bk-guide{font-weight:800;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bk-chap{font-size:12px;color:var(--pink-deep);font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.bk-actions{display:flex;gap:6px;align-items:center}
.bk-pill{display:inline-flex;align-items:center;gap:6px;background:#fff;border:1px solid var(--line);border-radius:999px;padding:7px 11px;font-size:13px;font-weight:700;color:var(--ink-70);cursor:pointer;text-decoration:none;white-space:nowrap}
.bk-pill:hover{border-color:var(--pink);color:var(--pink-deep)}
.bk-pill svg{width:14px;height:14px}
.bk-count{font-variant-numeric:tabular-nums;font-size:12.5px;font-weight:700;color:var(--ink-50);padding:0 4px;white-space:nowrap}

/* ── 무대 ─────────────────────────────────── */
.bk-stage{position:relative;flex:1;min-height:0}
.bk-page{position:absolute;inset:14px var(--gutter);display:grid;grid-template-columns:minmax(0,1.18fr) minmax(320px,.92fr);background:var(--card);border-radius:24px;overflow:hidden;box-shadow:0 20px 60px -30px rgba(30,30,40,.25),0 1px 0 rgba(0,0,0,.03);max-width:1240px;margin:0 auto}
.bk-page.in-r{animation:bk-in-r .42s var(--ease) both}
.bk-page.in-l{animation:bk-in-l .42s var(--ease) both}
@keyframes bk-in-r{from{opacity:0;transform:translateX(56px)}to{opacity:1;transform:none}}
@keyframes bk-in-l{from{opacity:0;transform:translateX(-56px)}to{opacity:1;transform:none}}
.bk-page.out-l{animation:bk-out-l .26s ease-in both}
.bk-page.out-r{animation:bk-out-r .26s ease-in both}
@keyframes bk-out-l{to{opacity:0;transform:translateX(-40px)}}
@keyframes bk-out-r{to{opacity:0;transform:translateX(40px)}}

.bk-visual{position:relative;display:flex;overflow:auto;padding:28px;background:linear-gradient(135deg,#FFF3F4 0%,#F7F4FF 100%);border-right:1px solid var(--line)}
.bk-visual::before{content:"";position:absolute;inset:0;pointer-events:none;background:radial-gradient(60% 50% at 30% 20%,rgba(255,255,255,.7),transparent 70%)}
.bk-visual>*{margin:auto;position:relative;max-width:100%}
.bk-text{position:relative;display:flex;flex-direction:column;overflow:auto;padding:30px 32px 30px}
.bk-text .bk-pn{font-size:12px;font-weight:700;color:var(--ink-30);font-variant-numeric:tabular-nums;margin-bottom:12px}
.bk-who{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.bk-who img{width:64px;height:64px;object-fit:contain;filter:drop-shadow(0 8px 12px rgba(20,20,20,.12));animation:bk-bob 3.6s ease-in-out infinite}
.bk-who span{font-size:12.5px;color:var(--ink-50);font-weight:700}
@keyframes bk-bob{0%,100%{transform:translateY(0)}50%{transform:translateY(-4px)}}
.bk-eyebrow{display:inline-flex;align-items:center;background:var(--pink-soft);color:var(--pink-deep);font-weight:800;font-size:12px;padding:4px 11px;border-radius:999px;margin-bottom:10px;letter-spacing:.2px}
.bk-eyebrow.violet{background:var(--violet-soft);color:var(--violet-deep)}
.bk-eyebrow.good{background:var(--ok-soft);color:var(--ok)}
.bk-eyebrow.gold{background:var(--gold-soft);color:var(--gold)}
.bk-eyebrow.warn{background:var(--warn-soft);color:var(--warn)}
.bk-text h2{margin:0 0 10px;font-size:clamp(20px,2.3vw,26px);line-height:1.3;letter-spacing:-.3px;text-wrap:balance}
.bk-body{color:var(--ink-70);font-size:15.5px}
.bk-body p{margin:0 0 10px}
.bk-body p:last-child{margin-bottom:0}
.bk-body ul,.bk-body ol{margin:0 0 10px;padding-left:20px}
.bk-body li{margin:3px 0}
.bk-body strong{color:var(--ink);font-weight:700}
.bk-body em.hl{font-style:normal;background:linear-gradient(180deg,transparent 58%,rgba(255,105,113,.28) 58%);padding:0 2px}
.bk-callout{display:flex;gap:10px;align-items:flex-start;border:1px solid #D7D2FF;background:var(--violet-soft);color:var(--violet-deep);border-radius:12px;padding:11px 14px;margin-top:14px;font-size:14px;font-weight:600;line-height:1.5}
.bk-callout svg{width:16px;height:16px;flex:none;margin-top:2px}
.bk-callout.warn{border-color:#FFD2D4;background:var(--pink-soft);color:var(--pink-deep)}
.bk-callout.good{border-color:#BFE6D2;background:var(--ok-soft);color:var(--ok)}
.bk-callout.gold,.bk-callout.tip{border-color:#FFE5AD;background:var(--gold-soft);color:var(--gold)}
.bk-callout.info{border-color:#C9D9FF;background:var(--info-soft);color:var(--info)}
.bk-callout a{color:inherit}
.bk-cta{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.bk-btn{display:inline-flex;align-items:center;gap:8px;background:var(--pink);color:#fff;text-decoration:none;font-weight:800;padding:11px 18px;border-radius:999px;border:0;cursor:pointer;font-size:14.5px;box-shadow:0 8px 20px -10px rgba(255,105,113,.8);transition:transform .15s,background .15s}
.bk-btn:hover{background:var(--pink-press);transform:translateY(-1px)}
.bk-btn.ghost{background:#fff;color:var(--pink-deep);border:1px solid var(--pink);box-shadow:none}
.bk-btn.ghost:hover{background:var(--pink-soft)}
.bk-btn.violet{background:var(--violet);box-shadow:0 8px 20px -10px rgba(145,138,255,.9)}
.bk-btn svg{width:15px;height:15px}
.bk-items{list-style:none;margin:8px 0 0;padding:0;display:grid;gap:6px}
.bk-items li{display:flex;gap:10px;align-items:flex-start;background:#FAFAFC;border:1px solid var(--line);border-radius:10px;padding:8px 11px}
.bk-items .k{width:22px;height:22px;flex:none;border-radius:50%;background:var(--pink-soft);color:var(--pink-deep);font-weight:800;font-size:11px;display:flex;align-items:center;justify-content:center;margin-top:1px}
.bk-items b{display:block;font-size:14px}
.bk-items span{font-size:13px;color:var(--ink-70);line-height:1.45}

/* 표지·마무리 */
.bk-page.cover{grid-template-columns:1fr}
.bk-page.cover .bk-visual{display:none}
.bk-page.cover .bk-text{align-items:center;text-align:center;justify-content:center;padding:36px 48px;background:
  radial-gradient(520px 320px at 50% 0%,rgba(255,105,113,.10),transparent 70%),
  radial-gradient(420px 300px at 100% 100%,rgba(145,138,255,.12),transparent 70%),#fff}
.bk-page.cover .bk-hero{position:relative;width:min(240px,32vh);height:min(240px,32vh);margin:0 auto 14px}
.bk-page.cover .bk-hero::before{content:"";position:absolute;inset:8% 8% -2%;border-radius:50%;background:radial-gradient(circle,rgba(255,105,113,.20),rgba(255,105,113,0) 70%);filter:blur(6px)}
.bk-page.cover .bk-hero img{position:relative;width:100%;height:100%;object-fit:contain;filter:drop-shadow(0 16px 20px rgba(20,20,20,.14));animation:bk-float 4.5s ease-in-out infinite}
@keyframes bk-float{0%,100%{transform:translateY(0) rotate(0)}50%{transform:translateY(-8px) rotate(-1.5deg)}}
.bk-page.cover .bk-who{display:none}
.bk-page.cover h2{font-size:clamp(24px,3.2vw,36px);max-width:720px}
.bk-page.cover .bk-body{max-width:640px;font-size:16px}
.bk-page.cover .bk-callout{max-width:560px;text-align:left}
.bk-page.cover .bk-cta{justify-content:center}
.bk-page.cover .bk-pn{position:absolute;top:18px;left:22px;margin:0}
.bk-page.cover .bk-ch-label{font-size:13px;font-weight:800;color:var(--pink-deep);letter-spacing:.4px;margin-bottom:8px}

/* 시각 요소 */
.bk-frame{display:inline-block;background:#1A1A1D;border-radius:20px;padding:12px;box-shadow:0 30px 50px -22px rgba(20,20,20,.35),inset 0 0 0 1px rgba(255,255,255,.06);position:relative;line-height:0}
.bk-frame::before,.bk-frame::after{content:"";position:absolute;top:50%;transform:translateY(-50%);width:3px;height:48px;border-radius:999px;background:#0d0d0f}
.bk-frame::before{left:-3px}.bk-frame::after{right:-3px}
.bk-frame .cam{position:absolute;top:5px;left:50%;transform:translateX(-50%);width:5px;height:5px;border-radius:50%;background:#0d0d0f}
.bk-frame img{display:block;max-width:100%;max-height:calc(100dvh - 240px);width:auto;height:auto;border-radius:8px;background:#fff;cursor:zoom-in}
.bk-frame.white img{background:#fff}
.bk-browser{display:inline-block;background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:0 24px 50px -24px rgba(20,20,20,.3);line-height:0;max-width:100%}
.bk-browser .bar{display:flex;align-items:center;gap:6px;padding:8px 12px;background:#F5F5F7;border-bottom:1px solid var(--line);line-height:1.2}
.bk-browser .bar i{width:10px;height:10px;border-radius:50%;background:#E1E1E6;display:inline-block}
.bk-browser .bar span{margin-left:6px;flex:1;background:#fff;border:1px solid var(--line);border-radius:6px;padding:3px 10px;font-size:11px;color:var(--ink-50);overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
.bk-browser img{display:block;max-width:100%;max-height:calc(100dvh - 250px);width:auto;height:auto;cursor:zoom-in}
.bk-plain{display:inline-block;background:#fff;border:1px solid var(--line);border-radius:14px;padding:8px;box-shadow:0 24px 50px -24px rgba(20,20,20,.3);line-height:0;max-width:100%}
.bk-plain img{display:block;max-width:100%;max-height:calc(100dvh - 240px);width:auto;height:auto;border-radius:8px;cursor:zoom-in}
.bk-cap{display:block;text-align:center;font-size:12.5px;color:var(--ink-50);margin-top:10px;line-height:1.4}
.bk-shotwrap{text-align:center}
.bk-two{display:grid;grid-template-columns:1fr 1fr;gap:16px;align-items:start;width:100%}
.bk-two .bk-frame img,.bk-two .bk-browser img,.bk-two .bk-plain img{max-height:calc(100dvh - 300px)}

.bk-stages{display:grid;gap:12px;width:100%}
.bk-stages.n7,.bk-stages.n4{grid-template-columns:repeat(4,1fr)}
.bk-stages.n3{grid-template-columns:repeat(3,1fr)}
.bk-stages.n2{grid-template-columns:repeat(2,1fr)}
.bk-stages.n1{grid-template-columns:minmax(0,520px);justify-content:center}
.bk-stage-card{background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;display:flex;flex-direction:column;box-shadow:0 10px 24px -18px rgba(20,20,20,.25);animation:bk-up .5s var(--ease) both}
.bk-stage-card:nth-child(2){animation-delay:.05s}.bk-stage-card:nth-child(3){animation-delay:.1s}.bk-stage-card:nth-child(4){animation-delay:.15s}.bk-stage-card:nth-child(5){animation-delay:.2s}.bk-stage-card:nth-child(6){animation-delay:.25s}.bk-stage-card:nth-child(7){animation-delay:.3s}
@keyframes bk-up{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
.bk-stage-card .sh{display:flex;gap:8px;align-items:center;padding:8px 10px;border-bottom:1px solid var(--line);font-weight:800;font-size:13px;line-height:1.2}
.bk-stage-card .n{width:22px;height:22px;border-radius:50%;background:var(--pink);color:#fff;font-size:11px;font-weight:800;display:flex;align-items:center;justify-content:center;flex:none}
.bk-stage-card img{width:100%;height:118px;object-fit:contain;background:#F3F3F6;display:block;padding:6px;cursor:zoom-in}
.bk-stage-card .tip{padding:8px 10px;font-size:12px;color:var(--ink-50);line-height:1.45;margin-top:auto}

.bk-chat{width:min(100%,560px);background:#fff;border-radius:16px;overflow:hidden;border:1px solid var(--line);box-shadow:0 24px 50px -24px rgba(20,20,20,.3);line-height:1.5}
.bk-chat .hd{display:flex;align-items:center;gap:8px;padding:9px 14px;border-bottom:1px solid var(--line);font-size:12.5px;font-weight:800}
.bk-chat .hd img{width:22px;height:22px;border-radius:50%;object-fit:cover;border:1px solid var(--line)}
.bk-chat .hd small{margin-left:auto;font-weight:700;color:var(--ink-30);font-size:11px}
.bk-chat .body{background:#FAFAFC;padding:14px;display:flex;flex-direction:column;gap:10px}
.bk-msg{max-width:84%;padding:9px 13px;border-radius:16px;font-size:13.5px;line-height:1.5;white-space:pre-line;animation:bk-up .4s var(--ease) both}
.bk-msg.student{align-self:flex-end;background:var(--pink);color:#fff;border-bottom-right-radius:5px;font-weight:600}
.bk-mline{display:flex;gap:8px;align-items:flex-end;max-width:92%;animation:bk-up .4s var(--ease) both}
.bk-mline img{width:26px;height:26px;border-radius:50%;flex:none;border:1px solid var(--line);background:#fff;object-fit:cover}
.bk-mline .bk-msg{background:#fff;border:1px solid var(--line);border-bottom-left-radius:5px;max-width:100%;animation:none}
.bk-msg b{color:var(--pink-deep)}
.bk-chat .in{display:flex;align-items:center;padding:9px 14px;border-top:1px solid var(--line);font-size:12px;color:var(--ink-30)}
.bk-chat .in i{margin-left:auto;width:16px;height:16px;border-radius:50%;background:rgba(255,105,113,.35)}

/* html 레이아웃용 공용 조각 */
.bk-card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 18px;box-shadow:0 10px 24px -18px rgba(20,20,20,.25)}
.bk-card h4{margin:0 0 6px;font-size:15px}
.bk-card p{margin:0;font-size:13.5px;color:var(--ink-70)}
.bk-grid2{display:grid;grid-template-columns:1fr 1fr;gap:10px;width:100%}
.bk-grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;width:100%}
.bk-table{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden;font-size:13.5px;line-height:1.45}
.bk-table th,.bk-table td{padding:9px 11px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top}
.bk-table th{background:#FAFAFC;font-size:12.5px;color:var(--ink-70);font-weight:700}
.bk-table tr:last-child td{border-bottom:0}
.bk-tag{display:inline-block;padding:2px 8px;border-radius:6px;font-size:12px;font-weight:700;white-space:nowrap}
.bk-tag.up{background:var(--ok-soft);color:var(--ok)}
.bk-tag.stay{background:var(--warn-soft);color:var(--warn)}
.bk-tag.down{background:var(--pink-soft);color:var(--pink-deep)}
.bk-tag.next{background:var(--violet-soft);color:var(--violet-deep)}
.bk-flow{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.bk-flow .m{background:var(--pink-soft);color:var(--pink-deep);font-weight:800;padding:8px 14px;border-radius:10px;font-size:14px}
.bk-flow .m.big{background:var(--violet-soft);color:var(--violet-deep)}
.bk-flow .arr{color:var(--ink-30);font-weight:800}
.bk-steps{list-style:none;margin:0;padding:0;display:grid;gap:8px;width:100%}
.bk-steps li{display:grid;grid-template-columns:32px 1fr;gap:12px;align-items:start;background:#fff;border:1px solid var(--line);border-radius:12px;padding:11px 13px;animation:bk-up .45s var(--ease) both}
.bk-steps li:nth-child(2){animation-delay:.05s}.bk-steps li:nth-child(3){animation-delay:.1s}.bk-steps li:nth-child(4){animation-delay:.15s}.bk-steps li:nth-child(5){animation-delay:.2s}.bk-steps li:nth-child(6){animation-delay:.25s}
.bk-steps .n{width:28px;height:28px;border-radius:50%;background:var(--pink);color:#fff;font-weight:800;display:flex;align-items:center;justify-content:center;font-size:13px}
.bk-steps b{display:block;font-size:14px}
.bk-steps span{font-size:13px;color:var(--ink-70);line-height:1.45}
.bk-promptbox{width:100%;background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:0 10px 24px -18px rgba(20,20,20,.25)}
.bk-promptbox .bar{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line);background:#FAFAFC;flex-wrap:wrap;line-height:1.3}
.bk-promptbox .bar b{font-size:13.5px}
.bk-promptbox .bar small{display:block;color:var(--ink-50);font-size:11.5px}
.bk-promptbox pre{margin:0;padding:12px 14px;max-height:min(46dvh,420px);overflow:auto;white-space:pre-wrap;word-break:break-word;font-family:ui-monospace,Consolas,"Pretendard Variable",monospace;font-size:12px;line-height:1.55;color:var(--ink)}
.bk-popup{width:min(100%,380px);background:#fff;border:1px solid var(--line);border-radius:22px;padding:22px 20px;text-align:center;box-shadow:0 20px 40px -20px rgba(0,0,0,.25);line-height:1.4}
.bk-popup img{width:96px;height:96px;object-fit:contain}
.bk-popup h4{margin:10px 0 6px;font-size:22px;font-weight:900}
.bk-popup p{margin:0 0 14px;color:var(--ink-70);font-size:14px}
.bk-popup .bt{display:flex;gap:8px}
.bk-popup .bt span{flex:1;border-radius:12px;padding:10px 6px;font-weight:800;font-size:14px}
.bk-popup .bt .w{background:#fff;color:var(--pink);border:1px solid var(--pink-soft)}
.bk-popup .bt .p{background:var(--pink);color:#fff;line-height:1.25}
.bk-popup .bt .p small{display:block;font-size:11px;font-weight:700;opacity:.95}
.bk-grades{display:grid;gap:8px;width:100%}
.bk-grade{display:flex;gap:12px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:10px 14px;background:#fff;line-height:1.35}
.bk-grade .g{width:36px;height:36px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:900;font-size:17px;flex:none;background:#EDEDF0;color:var(--ink-50)}
.bk-grade b{display:block;font-size:14px}
.bk-grade span{font-size:12.5px;color:var(--ink-70)}
.bk-grade .chip{margin-left:auto;flex:none;font-size:11.5px;font-weight:700;padding:3px 10px;border-radius:999px;background:#EDEDF0;color:var(--ink-70)}
.bk-grade.s{border-color:var(--pink);background:var(--pink-soft)}
.bk-grade.s .g,.bk-grade.s .chip{background:var(--pink);color:#fff}
.bk-grade.a{border-color:#F3D9A8;background:var(--warn-soft)}
.bk-grade.a .g,.bk-grade.a .chip{background:var(--warn);color:#fff}
.bk-ex{border:1px dashed var(--ink-30);background:#FAFAFC;border-radius:10px;padding:10px 14px;margin-top:10px;text-align:left}
.bk-ex small{display:block;color:var(--pink-deep);font-weight:800;font-size:11px;letter-spacing:.4px}
.bk-ex p{margin:4px 0 0;color:var(--ink)}
.bk-tiers{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;width:100%}
.bk-tier{border:1px solid var(--line);border-radius:12px;padding:16px 12px;text-align:center;background:#fff;line-height:1.3}
.bk-tier small{display:block;color:var(--ink-50);font-size:12px;font-weight:700}
.bk-tier b{display:block;font-size:22px;color:var(--pink-deep);margin:6px 0 4px}
.bk-tier span{font-size:12.5px;color:var(--ink-70)}
.bk-form{width:min(100%,460px);background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 18px;box-shadow:0 10px 24px -18px rgba(20,20,20,.25);line-height:1.4}
.bk-form .t{font-size:12.5px;color:var(--ink-50);font-weight:700;margin-bottom:8px}
.bk-form .row{display:flex;align-items:center;justify-content:space-between;gap:12px;border-bottom:1px solid var(--line);padding:10px 0;font-size:14px}
.bk-form .row:last-child{border-bottom:0}
.bk-form .lb{font-size:13px;color:var(--ink-50)}
.bk-form .v{font-weight:600}
.bk-form .pbtn{background:#fff;border:2px solid var(--pink);color:var(--pink-deep);font-weight:800;font-size:12.5px;padding:5px 11px;border-radius:8px;box-shadow:0 0 0 3px rgba(255,105,113,.25);white-space:nowrap}
.bk-menugrid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;width:100%}
.bk-menu{background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 14px;line-height:1.4;animation:bk-up .45s var(--ease) both}
.bk-menu b{display:block;font-size:14.5px;margin-bottom:2px}
.bk-menu span{font-size:12.5px;color:var(--ink-70)}
.bk-dl{display:grid;grid-template-columns:auto 1fr;gap:8px 16px;margin:0;font-size:15px;text-align:left}
.bk-dl dt{color:var(--ink-50);font-size:13px;font-weight:700}
.bk-dl dd{margin:0;font-weight:800;font-variant-numeric:tabular-nums}
.bk-signal{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;width:100%}
.bk-signal div{border:1px solid var(--line);border-radius:12px;padding:12px;background:#fff;font-size:13px;color:var(--ink-70);line-height:1.45}
.bk-signal b{display:block;font-size:14px;color:var(--ink);margin-bottom:4px}
.dot{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:6px;vertical-align:middle}
.bk-pen{display:flex;gap:10px;align-items:flex-start;background:#FAFAFC;border:1px solid var(--line);border-radius:10px;padding:11px 13px;margin-top:10px;text-align:left}
.bk-pen .sw{width:16px;height:16px;border-radius:50%;flex:none;margin-top:3px}
.bk-pen b{display:block;font-size:14px;margin-bottom:2px}
.bk-pen span{font-size:13px;color:var(--ink-70)}
.bk-quote{border-left:4px solid var(--violet);padding:6px 14px;margin:10px 0;color:var(--ink);font-size:15px;background:#FAFAFC;border-radius:0 10px 10px 0;text-align:left}
.bk-quote small{display:block;color:var(--ink-50);font-size:12px;margin-top:4px}
.bk-ba{display:grid;grid-template-columns:1fr 1fr;gap:10px;width:100%}
.bk-ba div{border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:#fff;font-size:13.5px;line-height:1.45;text-align:left}
.bk-ba div.after{border-color:var(--ok);background:var(--ok-soft)}
.bk-ba .lb{display:inline-block;font-size:11px;font-weight:900;color:#fff;background:var(--ink-70);padding:2px 8px;border-radius:6px;margin-bottom:6px}
.bk-ba div.after .lb{background:var(--ok)}
.bk-ba ul{margin:0;padding-left:18px}
.bk-wrongs{display:grid;gap:8px;width:100%}
.bk-wrongs div{display:flex;gap:12px;align-items:center;border:1px solid #F3D9A8;background:var(--warn-soft);border-radius:10px;padding:10px 12px;font-size:13.5px;line-height:1.4;text-align:left}
.bk-wrongs .k{width:30px;height:30px;border-radius:8px;background:var(--warn);color:#fff;font-weight:900;display:flex;align-items:center;justify-content:center;flex:none}
.bk-wrongs b{display:block;font-size:14px}
.bk-wrongs span{color:var(--ink-70)}
.bk-player{width:min(100%,520px);background:#fff;border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:0 24px 50px -24px rgba(20,20,20,.3);line-height:1.3}
.bk-player .hd{display:flex;align-items:center;gap:8px;padding:10px 14px;border-bottom:1px solid var(--line);font-size:12.5px}
.bk-player .hd b{display:block;font-size:13.5px}
.bk-player .hd small{color:var(--ink-50);font-size:11px}
.bk-player .live{margin-left:auto;background:var(--pink-soft);color:var(--pink-deep);font-weight:900;font-size:10px;padding:3px 8px;border-radius:999px}
.bk-player .scr{position:relative;aspect-ratio:16/9;background:linear-gradient(135deg,#2B2B31,#141416);display:flex;align-items:center;justify-content:center}
.bk-player .scr i{width:54px;height:54px;border-radius:50%;background:rgba(255,255,255,.95);display:flex;align-items:center;justify-content:center}
.bk-player .scr i::after{content:"";border-left:16px solid var(--pink);border-top:10px solid transparent;border-bottom:10px solid transparent;margin-left:4px}
.bk-player .ctl{display:flex;align-items:center;gap:10px;padding:10px 14px;font-size:11px;color:var(--ink-50)}
.bk-player .ctl .bar{flex:1;height:4px;border-radius:999px;background:#E5E5EA;overflow:hidden}
.bk-player .ctl .bar i{display:block;width:42%;height:100%;background:var(--pink)}
.bk-hl{outline:3px solid var(--pink);outline-offset:2px;border-radius:6px}

/* ── 좌우 화살표(PC) ───────────────────────── */
.bk-arrow{position:absolute;top:50%;transform:translateY(-50%);width:56px;height:56px;border-radius:50%;border:1px solid var(--line);background:#fff;display:flex;align-items:center;justify-content:center;cursor:pointer;box-shadow:0 10px 24px -12px rgba(20,20,20,.35);transition:transform .15s,background .15s,color .15s,opacity .2s;z-index:3;color:var(--ink-70)}
.bk-arrow svg{width:22px;height:22px}
.bk-arrow.prev{left:calc((var(--gutter) - 56px)/2)}
.bk-arrow.next{right:calc((var(--gutter) - 56px)/2);background:var(--pink);color:#fff;border-color:var(--pink)}
.bk-arrow.prev:hover{transform:translateY(-50%) translateX(-2px);border-color:var(--pink);color:var(--pink-deep)}
.bk-arrow.next:hover{transform:translateY(-50%) translateX(2px);background:var(--pink-press)}
.bk-arrow[disabled]{opacity:.25;cursor:default;transform:translateY(-50%)}

/* 탭 영역(모바일) */
.bk-tap{position:absolute;top:0;bottom:0;width:38%;z-index:2;background:transparent;border:0;padding:0;cursor:pointer;display:none;-webkit-tap-highlight-color:transparent}
.bk-tap.l{left:0}.bk-tap.r{right:0;width:62%}
.bk-zoom{position:absolute;right:10px;bottom:10px;z-index:3;display:none;align-items:center;gap:5px;background:rgba(255,255,255,.92);border:1px solid var(--line);border-radius:999px;padding:6px 10px;font-size:12px;font-weight:700;color:var(--ink-70);box-shadow:0 6px 16px -8px rgba(0,0,0,.3)}
.bk-zoom svg{width:13px;height:13px}

/* ── 하단 바 ─────────────────────────────── */
.bk-bottom{height:var(--bottom);flex:none;display:flex;align-items:center;gap:12px;padding:0 16px;background:rgba(255,255,255,.86);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-top:1px solid var(--line);z-index:5;padding-bottom:env(safe-area-inset-bottom)}
.bk-nav{display:inline-flex;align-items:center;gap:6px;height:40px;padding:0 16px;border-radius:999px;border:1px solid var(--line);background:#fff;font-weight:800;font-size:14px;cursor:pointer;color:var(--ink-70);white-space:nowrap;text-decoration:none;transition:background .15s,transform .15s}
.bk-nav svg{width:15px;height:15px}
.bk-nav.next{background:var(--pink);color:#fff;border-color:var(--pink);box-shadow:0 8px 20px -10px rgba(255,105,113,.8)}
.bk-nav.next:hover{background:var(--pink-press)}
.bk-nav.prev:hover{border-color:var(--pink);color:var(--pink-deep)}
.bk-nav[disabled]{opacity:.35;cursor:default}
.bk-prog{flex:1;display:flex;flex-direction:column;gap:5px;min-width:0}
.bk-segs{display:flex;gap:3px;height:6px}
.bk-seg{position:relative;height:100%;border-radius:999px;background:rgba(0,0,0,.08);overflow:hidden;cursor:pointer;min-width:6px}
.bk-seg i{position:absolute;left:0;top:0;bottom:0;background:var(--pink);border-radius:999px;transition:width .35s var(--ease)}
.bk-seg.cur i{background:var(--pink)}
.bk-seg:hover{background:rgba(0,0,0,.14)}
.bk-progtext{display:flex;justify-content:space-between;font-size:11.5px;color:var(--ink-50);font-weight:700;line-height:1;white-space:nowrap;overflow:hidden}
.bk-progtext b{color:var(--ink-70);overflow:hidden;text-overflow:ellipsis}
.bk-keyhint{font-size:11.5px;color:var(--ink-30);font-weight:600;white-space:nowrap}

/* ── 목차 ─────────────────────────────────── */
.bk-scrim{position:fixed;inset:0;background:rgba(30,30,40,.35);backdrop-filter:blur(3px);-webkit-backdrop-filter:blur(3px);z-index:40;opacity:0;pointer-events:none;transition:opacity .25s}
.bk-scrim.on{opacity:1;pointer-events:auto}
.bk-toc{position:fixed;top:0;right:0;bottom:0;width:min(400px,92vw);background:#fff;z-index:41;display:flex;flex-direction:column;box-shadow:-20px 0 60px -30px rgba(0,0,0,.35);transform:translateX(105%);transition:transform .35s var(--ease)}
.bk-toc.on{transform:none}
.bk-toc .hd{display:flex;align-items:center;justify-content:space-between;padding:14px 16px;border-bottom:1px solid var(--line)}
.bk-toc .hd b{font-size:16px}
.bk-toc .x{width:34px;height:34px;border-radius:50%;border:1px solid var(--line);background:#fff;display:flex;align-items:center;justify-content:center;cursor:pointer}
.bk-toc .x svg{width:15px;height:15px}
.bk-toc .list{flex:1;overflow:auto;padding:12px}
.bk-tch{border:1px solid var(--line);border-radius:14px;margin-bottom:10px;overflow:hidden}
.bk-tch .h{display:flex;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line);cursor:pointer;background:#fff}
.bk-tch .h:hover{background:#FAFAFC}
.bk-tch .h .num{font-size:11px;font-weight:800;color:var(--pink-deep)}
.bk-tch .h b{display:block;font-size:14px;line-height:1.25}
.bk-tch .h small{display:block;color:var(--ink-50);font-size:12px}
.bk-tch .h .pr{margin-left:auto;font-size:11.5px;font-weight:700;color:var(--ink-50);font-variant-numeric:tabular-nums;white-space:nowrap}
.bk-tch.cur .h{background:var(--pink-soft)}
.bk-tch ul{list-style:none;margin:0;padding:6px}
.bk-tch li button{width:100%;display:flex;gap:10px;align-items:flex-start;text-align:left;background:none;border:0;padding:7px 10px;border-radius:8px;cursor:pointer;font-size:13px;color:var(--ink-70);line-height:1.35}
.bk-tch li button:hover{background:#FAFAFC}
.bk-tch li button.cur{background:var(--pink-soft);color:var(--pink-deep);font-weight:700}
.bk-tch li button .pn{font-size:11px;font-weight:800;color:var(--ink-30);min-width:20px;margin-top:2px;font-variant-numeric:tabular-nums}
.bk-tch li button.cur .pn{color:var(--pink-deep)}
.bk-toc .ft{padding:12px 16px;border-top:1px solid var(--line);display:flex;flex-direction:column;gap:8px}
.bk-toc .ft a{display:flex;align-items:center;gap:8px;text-decoration:none;color:var(--ink-70);font-weight:700;font-size:13.5px;padding:9px 12px;border-radius:10px;border:1px solid var(--line)}
.bk-toc .ft a:hover{border-color:var(--pink);color:var(--pink-deep)}
.bk-toc .ft a svg{width:14px;height:14px}

/* ── 힌트 · 토스트 · 라이트박스 ───────────── */
.bk-hint{position:fixed;inset:0;z-index:60;display:flex;align-items:center;justify-content:center;padding:24px;background:rgba(30,30,40,.62);backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px);opacity:0;pointer-events:none;transition:opacity .3s}
.bk-hint.on{opacity:1;pointer-events:auto}
.bk-hint .box{max-width:360px;text-align:center;color:#fff}
.bk-hint .hand{position:relative;height:84px;margin-bottom:8px;display:flex;align-items:center;justify-content:center}
.bk-hint .hand .arr{position:absolute;top:50%;transform:translateY(-50%);font-size:28px;font-weight:900;opacity:.6;animation:bk-pulse 2.4s ease-in-out infinite}
.bk-hint .hand .arr.l{left:22%}.bk-hint .hand .arr.r{right:22%;animation-delay:1.2s}
.bk-hint .hand .h{width:58px;height:58px;border-radius:50%;background:#fff;color:var(--pink);display:flex;align-items:center;justify-content:center;box-shadow:0 12px 30px -10px rgba(0,0,0,.5);animation:bk-swipe 2.4s ease-in-out infinite}
.bk-hint .hand .h svg{width:28px;height:28px}
.bk-hint .kb{display:inline-flex;gap:8px;margin-bottom:10px}
.bk-hint .kb span{display:inline-flex;align-items:center;justify-content:center;min-width:44px;height:40px;padding:0 10px;border-radius:9px;background:#fff;color:var(--ink);font-weight:800;box-shadow:0 4px 0 #cfcfd6;font-size:15px}
@keyframes bk-swipe{0%,100%{transform:translateX(-30px) rotate(-6deg)}50%{transform:translateX(30px) rotate(6deg)}}
@keyframes bk-pulse{0%,100%{opacity:.35}50%{opacity:1}}
.bk-hint h3{margin:0 0 6px;font-size:20px}
.bk-hint p{margin:0 0 16px;font-size:14.5px;color:rgba(255,255,255,.85)}
.bk-hint .ok{display:inline-flex;align-items:center;gap:6px;background:#fff;color:var(--pink-deep);font-weight:800;border:0;border-radius:999px;padding:11px 22px;cursor:pointer;font-size:14.5px}
.bk-hint small{display:block;margin-top:12px;color:rgba(255,255,255,.55);font-size:12px}
.bk-toast{position:fixed;left:50%;bottom:calc(var(--bottom) + 14px);transform:translate(-50%,20px);background:#2F2F31;color:#fff;border-radius:14px;padding:10px 12px 10px 16px;display:flex;align-items:center;gap:12px;font-size:13.5px;box-shadow:0 20px 40px -18px rgba(0,0,0,.5);z-index:45;opacity:0;pointer-events:none;transition:opacity .3s,transform .3s var(--ease);max-width:92vw}
.bk-toast.on{opacity:1;pointer-events:auto;transform:translate(-50%,0)}
.bk-toast button{background:var(--pink);color:#fff;border:0;border-radius:999px;padding:7px 12px;font-weight:800;font-size:13px;cursor:pointer;white-space:nowrap}
.bk-toast .x{background:none;color:rgba(255,255,255,.6);padding:4px 6px;font-size:16px;line-height:1}
.bk-lb{position:fixed;inset:0;z-index:70;background:rgba(15,15,20,.9);display:none;align-items:center;justify-content:center;padding:20px;cursor:zoom-out}
.bk-lb.on{display:flex}
.bk-lb img{max-width:96vw;max-height:88vh;border-radius:10px;background:#fff;box-shadow:0 30px 80px -20px rgba(0,0,0,.8)}
.bk-lb .cap{position:absolute;bottom:22px;left:0;right:0;text-align:center;color:rgba(255,255,255,.75);font-size:13px}
.bk-lb .x{position:absolute;top:16px;right:16px;width:40px;height:40px;border-radius:50%;background:rgba(255,255,255,.15);color:#fff;border:0;font-size:20px;cursor:pointer}
.bk-end-note{font-size:13px;color:var(--ink-50);margin-top:14px}

/* ── 모바일 ───────────────────────────────── */
@media (max-width: 900px){
  :root{--top:52px;--bottom:64px;--gutter:0px}
  .bk-guide{font-size:13px}
  .bk-home span{display:none}
  .bk-home{padding:7px 9px}
  .bk-pill span{display:none}
  .bk-pill{padding:7px 9px}
  .bk-count{display:none}
  .bk-page{inset:0;border-radius:0;display:flex;flex-direction:column;box-shadow:none;max-width:none}
  .bk-visual{flex:none;max-height:47dvh;padding:14px 14px 12px;border-right:0;border-bottom:1px solid var(--line);align-items:center}
  .bk-frame{padding:8px;border-radius:14px}
  .bk-frame img,.bk-browser img,.bk-plain img{max-height:calc(47dvh - 62px)}
  .bk-two{gap:8px}
  .bk-two .bk-frame img,.bk-two .bk-browser img,.bk-two .bk-plain img{max-height:calc(47dvh - 70px)}
  .bk-cap{font-size:11.5px;margin-top:6px}
  .bk-text{flex:1;padding:16px 18px 24px}
  .bk-text h2{font-size:20px}
  .bk-body{font-size:14.5px}
  .bk-who img{width:48px;height:48px}
  .bk-page.cover .bk-text{padding:22px 20px 30px;justify-content:flex-start}
  .bk-page.cover .bk-hero{width:min(180px,26vh);height:min(180px,26vh)}
  .bk-page.cover h2{font-size:23px}
  .bk-page.cover .bk-body{font-size:15px}
  .bk-stages.n4,.bk-stages.n3{grid-template-columns:repeat(2,1fr)}
  .bk-stages.n7{grid-template-columns:repeat(4,1fr);gap:6px}
  .bk-stages{gap:8px}
  .bk-stage-card{border-radius:10px}
  .bk-stage-card .sh{padding:6px 7px;font-size:11px;gap:5px}
  .bk-stage-card .n{width:17px;height:17px;font-size:9.5px}
  .bk-stage-card img{height:70px;padding:4px}
  .bk-stages.n7 .bk-stage-card img{height:56px}
  .bk-stage-card .tip{display:none}
  .bk-grid3,.bk-menugrid,.bk-tiers,.bk-signal{grid-template-columns:1fr}
  .bk-grid2,.bk-ba{grid-template-columns:1fr}
  .bk-chat{width:100%}
  .bk-msg{font-size:12.5px;padding:8px 11px}
  .bk-promptbox pre{max-height:30dvh;font-size:11px}
  .bk-arrow{display:none}
  .bk-tap{display:block}
  .bk-zoom{display:inline-flex}
  .bk-bottom{padding:0 12px;gap:10px}
  .bk-nav{height:38px;padding:0 14px;font-size:13.5px}
  .bk-nav.prev span{display:none}
  .bk-nav.prev{padding:0 12px}
  .bk-keyhint{display:none}
  .bk-toc{top:auto;width:100%;height:min(82dvh,640px);border-radius:20px 20px 0 0;transform:translateY(105%);box-shadow:0 -20px 60px -30px rgba(0,0,0,.4)}
  .bk-toc.on{transform:none}
  .bk-toast{bottom:calc(var(--bottom) + 10px);font-size:13px}
}
@media (max-width: 900px) and (max-height: 640px){
  .bk-visual{max-height:40dvh}
  .bk-frame img,.bk-browser img,.bk-plain img{max-height:calc(40dvh - 60px)}
}
@media (min-width: 901px) and (max-height: 700px){
  .bk-page{inset:10px var(--gutter)}
  .bk-text{padding:20px 24px}
  .bk-visual{padding:18px}
  .bk-page.cover .bk-hero{width:min(180px,26vh);height:min(180px,26vh)}
}
@media (prefers-reduced-motion: reduce){
  .bk-page.in-r,.bk-page.in-l,.bk-page.out-l,.bk-page.out-r,.bk-stage-card,.bk-steps li,.bk-msg,.bk-mline,.bk-menu{animation:none!important}
  .bk-who img,.bk-page.cover .bk-hero img,.bk-hint .hand .h,.bk-hint .hand .arr{animation:none!important}
  .bk-toc,.bk-scrim,.bk-toast{transition:none}
}
@media print{
  .bk{position:static;height:auto}
  .bk-top,.bk-bottom,.bk-arrow,.bk-tap,.bk-zoom,.bk-toc,.bk-scrim,.bk-hint,.bk-toast{display:none!important}
}