/* ════════════════════════════════════════════════════════════════════
   TERAN ILDIZ — study-board/board.css   (v70 · 11-QATLAM)
   Taxta interfeysi. Kaskad qatlamlar tizimiga qo'shiladi (v68).
   ════════════════════════════════════════════════════════════════════ */
@layer board {

  .sb-root {
    grid-column: 1 / -1;
    display: flex; flex-direction: column;
    height: calc(100dvh - 150px);
    min-height: 380px;
    border: 1px solid var(--rule);
    border-radius: var(--gl-r, 12px);
    overflow: hidden;
    background: var(--surf);
  }

  /* ── Asboblar paneli ── */
  .sb-bar {
    display: flex; align-items: center; gap: 3px;
    padding: 7px 9px;
    border-bottom: 1px solid var(--rule);
    overflow-x: auto; scrollbar-width: none;
    flex: 0 0 auto;
  }
  .sb-bar::-webkit-scrollbar { display: none; }
  .sb-tool, .sb-act {
    flex: 0 0 auto;
    width: 38px; height: 38px;
    display: inline-flex; align-items: center; justify-content: center;
    background: none; border: 1px solid transparent; border-radius: 8px;
    color: var(--muted); font-size: 13px; cursor: pointer;
    transition: background .12s, color .12s;
  }
  .sb-tool.on { background: rgba(10,186,181,.14); border-color: rgba(10,186,181,.42); color: var(--ink); }
  .sb-tool:focus-visible, .sb-act:focus-visible { outline: 2px solid var(--aqua, #0abab5); outline-offset: 1px; }
  .sb-sep { flex: 0 0 auto; width: 1px; height: 22px; background: var(--rule); margin: 0 5px; }
  .sb-colors { display: inline-flex; gap: 4px; flex: 0 0 auto; }
  .sb-color {
    width: 22px; height: 22px; border-radius: 50%;
    border: 2px solid transparent; cursor: pointer; padding: 0;
  }
  .sb-color.on { border-color: var(--ink); transform: scale(1.14); }

  /* ── Maydon ── */
  .sb-canvas-wrap { flex: 1 1 auto; position: relative; overflow: hidden; }
  .sb-canvas { display: block; width: 100%; height: 100%; touch-action: none; }

  /* ── Pastki tugmalar ── */
  .sb-foot {
    display: flex; gap: 6px; padding: 8px 9px;
    border-top: 1px solid var(--rule);
    overflow-x: auto; scrollbar-width: none;
    flex: 0 0 auto;
  }
  .sb-foot::-webkit-scrollbar { display: none; }
  .sb-btn {
    flex: 0 0 auto;
    display: inline-flex; align-items: center; gap: 6px;
    padding: 9px 12px;
    background: none; border: 1px solid var(--rule); border-radius: 8px;
    color: var(--ink); font-family: inherit;
    font-size: .74rem; font-weight: 600; letter-spacing: .02em;
    cursor: pointer; white-space: nowrap;
  }
  .sb-btn i { font-size: 11px; opacity: .75; }
  .sb-btn:focus-visible { outline: 2px solid var(--aqua, #0abab5); outline-offset: 1px; }
  /* Kutubxona tugmasi — taxtaning asosiy farqi, shu sabab ajratilgan */
  .sb-btn-key {
    background: rgba(232,196,106,.12);
    border-color: rgba(232,196,106,.42);
  }

  /* ── Tanlash oynasi ── */
  .sb-pick {
    position: fixed; inset: 0; z-index: 9800;
    background: rgba(8,10,12,.62);
    display: grid; place-items: center; padding: 16px;
  }
  .sb-pick-box {
    width: min(560px, 100%); max-height: 76dvh;
    display: flex; flex-direction: column;
    background: var(--surf); border: 1px solid var(--rule-strong);
    border-radius: 12px; overflow: hidden;
  }
  .sb-pick-top {
    display: flex; align-items: center; gap: 8px;
    padding: 11px 12px; border-bottom: 1px solid var(--rule);
  }
  .sb-pick-q {
    flex: 1; min-width: 0;
    background: var(--surf-2); border: 1px solid var(--rule);
    border-radius: 8px; padding: 10px 12px;
    color: var(--ink); font-family: inherit; font-size: .86rem;
  }
  .sb-pick-x {
    width: 38px; height: 38px; flex: 0 0 auto;
    background: none; border: 1px solid var(--rule); border-radius: 8px;
    color: var(--muted); cursor: pointer; font-size: 14px;
  }
  .sb-pick-list { overflow-y: auto; padding: 6px; }
  .sb-pick-item {
    display: flex; flex-direction: column; gap: 2px;
    width: 100%; text-align: left;
    padding: 10px 11px; margin-bottom: 3px;
    background: none; border: 0; border-left: 3px solid var(--gold, #e8c46a);
    border-radius: 0 7px 7px 0;
    color: var(--ink); font-family: inherit; cursor: pointer;
  }
  .sb-pick-item:hover { background: var(--surf-1); }
  .sb-pick-cat {
    font-size: .58rem; font-weight: 700; letter-spacing: .12em;
    text-transform: uppercase; color: var(--muted);
  }
  .sb-pick-ttl { font-size: .87rem; font-weight: 600; line-height: 1.25; }
  .sb-pick-none { padding: 26px; text-align: center; color: var(--dim); font-size: .82rem; }

  .sb-board-row { display: flex; align-items: stretch; gap: 4px; }
  .sb-board-row .sb-pick-item { flex: 1; margin-bottom: 0; }
  .sb-board-del {
    width: 42px; flex: 0 0 auto;
    background: none; border: 1px solid var(--rule); border-radius: 7px;
    color: var(--muted); cursor: pointer; font-size: 12px;
  }
  .sb-board-del:hover { color: var(--brand); border-color: var(--brand); }

  .sb-toast {
    position: fixed; left: 50%; bottom: 96px; transform: translateX(-50%);
    z-index: 9900; padding: 11px 18px;
    background: var(--chrome-bg); border: 1px solid var(--chrome-bdr);
    border-radius: 999px; color: var(--chrome-ink);
    font-size: .8rem; font-weight: 600;
  }

  /* ── Taxta ochiq: ish maydoniga joy bo'shatiladi ──
     Banner, o'ng ustun va sana qatori vaqtincha yashiriladi.
     Bo'limdan chiqilganda hammasi qaytadi. */
  body.sb-on #audioHeroBanner,
  body.sb-on .ti-rail,
  body.sb-on .ti-dateline,
  body.sb-on #ti-reco,
  body.sb-on .ed-topback { display: none; }
  body.sb-on .phd { margin-bottom: 8px; padding-top: 6px; }
  body.sb-on .pttl { font-size: 1.05rem; }
  body.sb-on .ti-portal { grid-template-columns: minmax(0, 1fr); }

  /* ── Telefon ── */
  @media (max-width: 719px) {
    .sb-root { height: calc(100dvh - 132px); border-radius: 10px; }
    .sb-tool, .sb-act { width: 44px; height: 44px; }   /* WCAG 2.5.5 */
    .sb-color { width: 26px; height: 26px; }
    .sb-btn { padding: 11px 12px; min-height: 44px; }
  }
  @media (max-width: 430px) {
    .sb-btn span, .sb-btn { font-size: .7rem; }
  }

  @media (prefers-reduced-motion: reduce) {
    .sb-color.on { transform: none; }
  }
}