/* Learn with me, direction B. Written Wed 4 Nov 2026 by Claude (builder B). Prefix bk-. */
.bk-hero { padding: clamp(36px, 5vw, 72px) 0 clamp(56px, 7vw, 100px); }
.bk-head { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); gap: 20px 56px; align-items: end; }
.bk-head .b-h1 { font-size: clamp(60px, 8.4vw, 150px); }
.bk-head .b-lead { margin-top: 0; }
.bk-price { margin: 16px 0 0; padding-top: 12px; border-top: 2px solid var(--b-fg); font-size: 16px; }
.bk-price b { font-weight: 600; }
.bk-price .b-date { display: block; margin-top: 4px; }

.bk-planner { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(24px, 4vw, 56px); margin-top: clamp(36px, 4vw, 56px); padding-top: 28px; border-top: 3px solid var(--b-fg); }
.bk-f { margin: 0 0 22px; padding: 0; border: 0; min-width: 0; }
.bk-f legend { padding: 0; margin-bottom: 10px; font: 400 var(--b-fs-5)/1 var(--b-mono); letter-spacing: .14em; text-transform: uppercase; color: var(--b-mute); }
.bk-row { display: flex; flex-wrap: wrap; gap: 0 28px; }
.bk-tracks { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 2px; background: var(--b-fg); border: 2px solid var(--b-fg); }
.bk-tr { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; min-height: 92px; padding: 10px; border: 0; background: var(--b-bg); color: var(--b-fg); text-align: left; cursor: pointer; font: 600 14px/1.15 var(--b-sans); }
.bk-tr b { font: 900 34px/.8 var(--b-disp); color: var(--b-acc); }
.bk-tr[aria-pressed=true] { background: var(--b-acc); color: var(--b-acc-ink); }
.bk-tr[aria-pressed=true] b { color: var(--b-acc-ink); }
.bk-tr:hover { outline: 2px solid var(--b-acc); outline-offset: -4px; }
.bk-seg { display: flex; flex-wrap: wrap; gap: 0; border: 2px solid var(--b-fg); width: max-content; max-width: 100%; }
.bk-seg button { min-height: 44px; min-width: 44px; padding: 0 12px; border: 0; border-right: 2px solid var(--b-fg); background: var(--b-bg); color: var(--b-fg); font: 600 14px/1 var(--b-sans); cursor: pointer; }
.bk-seg button:last-child { border-right: 0; }
.bk-seg button[aria-pressed=true] { background: var(--b-fg); color: var(--b-bg); }
.bk-tr:focus-visible, .bk-seg button:focus-visible { outline: 3px solid var(--b-acc); outline-offset: 2px; }

.bk-art { position: relative; height: clamp(240px, 26vw, 360px); background: var(--b-bg2); border: 2px solid var(--b-fg); }
.bk-art canvas { display: block; width: 100%; height: 100%; }
.bk-sum { margin: 18px 0 0; font: 900 clamp(26px, 2.4vw, 38px)/1.02 var(--b-disp); text-transform: uppercase; }
.bk-sum b { color: var(--b-acc); font-weight: 900; }
.bk-acts { margin-top: 18px; }
.b-btn:disabled, .b-q:disabled { opacity: .4; cursor: default; }
#bk-note { margin: 12px 0 0; }
.bk-list { list-style: none; margin: 18px 0 0; padding: 0; border-top: 2px solid var(--b-fg); }
.bk-list li { display: grid; grid-template-columns: 90px minmax(0, 1fr) auto; gap: 12px; padding: 9px 0; border-bottom: 1px solid var(--b-line); font-size: 15px; }
.bk-l-d { font: 400 13px/1.6 var(--b-mono); letter-spacing: .06em; text-transform: uppercase; color: var(--b-mute); }
.bk-l-t b { color: var(--b-acc); }
.bk-l-n { color: var(--b-mute); font-size: 13px; }
.bk-list .bk-l-more { display: block; color: var(--b-mute); font-size: 14px; }

.bk-o { min-height: 300px; }
.bk-o-pr { margin: 0; font: 900 clamp(56px, 6vw, 100px)/.85 var(--b-disp); color: var(--b-acc); }
.bk-o-pr small { display: block; font-size: 22px; letter-spacing: .04em; color: var(--b-fg); margin-bottom: 4px; }
.bk-o-q { font-size: clamp(30px, 3vw, 44px); line-height: .95; color: var(--b-fg); }
.bk-o .b-date { margin: 8px 0 0; }

.bk-qs { margin-top: 32px; border-top: 2px solid var(--b-fg); }
.bk-qs details { border-bottom: 2px solid var(--b-fg); }
.bk-qs summary { cursor: pointer; padding: 20px 0; list-style: none; font: 900 clamp(24px, 2.4vw, 36px)/1 var(--b-disp); text-transform: uppercase; }
.bk-qs summary::-webkit-details-marker { display: none; }
.bk-qs summary::after { content: '+'; float: right; color: var(--b-acc); }
.bk-qs details[open] summary::after { content: '\2212'; }
.bk-qs p { margin: 0 0 22px; max-width: 64ch; color: var(--b-mute); }

@media (max-width: 1000px) { .bk-planner { grid-template-columns: 1fr; } .bk-head { grid-template-columns: 1fr; } }
@media (max-width: 560px) {
  .bk-tracks { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .bk-tr { min-height: 64px; flex-direction: row; align-items: center; gap: 10px; }
  .bk-tr b { font-size: 26px; }
  .bk-seg { width: 100%; }
  .bk-seg button { flex: 1 1 0; padding: 0 6px; }
  #bk-time button { font-size: 13px; }
  .bk-art { height: 190px; }
  .bk-list { display: none; }
  .bk-tr { min-height: 50px; }
  .bk-hero { padding-top: 24px; }
  .bk-f { margin-bottom: 16px; }
  .bk-planner { margin-top: 24px; padding-top: 20px; }
}