.lsn-bar { position: sticky; top: 0; height: 4px; background: transparent; z-index: 20; }
.lsn-bar-fill { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--amber), #f59e0b); transition: width .1s linear; }
.lsn { padding: 18px 0 56px; background: var(--bg-alt); }
.lsn-wrap { max-width: 820px; }
.lsn-crumb { margin-bottom: 16px; color: var(--muted); font-size: .85rem; }
.lsn-crumb a { color: var(--blue-dark); font-weight: 700; text-decoration: none; }
.lsn-crumb span { margin: 0 4px; }
.lsn-head { display: flex; gap: 16px; align-items: flex-start; margin-bottom: 18px; }
.lsn-emoji { display: flex; flex: 0 0 auto; align-items: center; justify-content: center; width: 62px; height: 62px; border: 1px solid color-mix(in srgb, var(--accent) 25%, #fff); border-radius: 16px; background: color-mix(in srgb, var(--accent) 12%, #fff); font-size: 2rem; }
.lsn-head h1 { margin: 4px 0 6px; font-size: clamp(1.5rem, 4.5vw, 2.3rem); line-height: 1.2; }
.lsn-meta { color: var(--muted); font-size: .88rem; }
.lsn-jump { position: sticky; top: 4px; z-index: 5; display: flex; gap: 8px; overflow-x: auto; margin: 0 0 16px; padding: 12px 2px; background: var(--bg-alt); -webkit-overflow-scrolling: touch; }
.lsn-chip { flex: 0 0 auto; padding: 6px 13px; border: 1px solid var(--line); border-radius: 999px; background: #fff; color: var(--navy); font-size: .82rem; font-weight: 700; text-decoration: none; white-space: nowrap; }
.lsn-chip:hover { border-color: var(--navy); background: var(--navy); color: #fff; }
.lsn-sec { margin-bottom: 16px; padding: 22px 24px; scroll-margin-top: 56px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow-sm); }
.lsn-sec h2 { margin: 0 0 14px; color: var(--navy); font-family: 'Playfair Display', Georgia, serif; font-size: 1.3rem; }
.lsn-body { color: var(--ink); line-height: 1.7; }
.lsn-body p { margin: 0 0 12px; }
.lsn-body ul, .lsn-body ol { margin: 6px 0 14px; padding-left: 22px; }
.lsn-body li { margin-bottom: 8px; }
.lsn-body .hi, .lsn-body .tip, .lsn-body .trap, .lsn-body .ex { margin: 14px 0; padding: 11px 15px; border-radius: 8px; }
.lsn-body .hi { border-left: 4px solid var(--amber); background: #fffbeb; color: #9a5407; font-size: .92rem; }
.lsn-body .tip { border-left: 4px solid var(--blue); background: #f0f9ff; }
.lsn-body .trap { border-left: 4px solid var(--amber); background: #fff7ed; }
.lsn-body .ex { border-left: 4px solid #16a34a; background: #f0fdf4; }
.lsn-table-wrap { width: 100%; overflow-x: auto; margin: 12px 0; border: 1px solid var(--line); border-radius: 10px; -webkit-overflow-scrolling: touch; }
.lsn-body table { width: 100%; min-width: 620px; border-collapse: collapse; font-size: .9rem; }
.lsn-body th { padding: 9px 12px; background: var(--navy); color: #fff; text-align: left; white-space: nowrap; }
.lsn-body td { padding: 8px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.lsn-body tbody tr:nth-child(even) { background: var(--bg-alt); }
.lsn-check { margin-top: 14px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg-alt); }
.lsn-check summary { cursor: pointer; padding: 11px 13px; color: var(--navy); font-weight: 750; }
.lsn-check p { margin: 0; padding: 0 13px 13px; color: var(--body); }
.lsn-key { margin: 20px 0; padding: 22px 24px; border-radius: var(--radius); background: linear-gradient(135deg, var(--navy), #16335a); color: #fff; }
.lsn-key h2 { margin: 0 0 12px; color: #fff; font-family: 'Playfair Display', Georgia, serif; font-size: 1.25rem; }
.lsn-key ul { margin: 0; padding-left: 20px; }
.lsn-key li { margin-bottom: 9px; color: #e7eefb; line-height: 1.55; }
.lsn-source { margin: 16px 0; padding: 12px 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; color: var(--muted); font-size: .82rem; }
.lsn-source a { color: var(--blue-dark); font-weight: 700; }
.lsn-actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 8px; }
.lsn-complete { border: 2px solid #16a34a; background: #fff; color: #15803d; font-weight: 750; }
.lsn-complete.done { background: #16a34a; color: #fff; }
.lsn-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 22px 0 8px; }
.lsn-navlink { display: flex; flex-direction: column; gap: 3px; padding: 13px 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; text-decoration: none; box-shadow: var(--shadow-sm); }
.lsn-navlink span { color: var(--muted); font-size: .78rem; }
.lsn-navlink strong { color: var(--navy); font-size: .92rem; line-height: 1.3; }
.lsn-navlink.next { text-align: right; }
.lsn-foot { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--line); color: var(--muted); font-size: .86rem; text-align: center; }
.lsn-foot a { color: var(--blue-dark); font-weight: 700; }
@media (max-width: 560px) {
  .lsn-head { align-items: center; }
  .lsn-emoji { width: 52px; height: 52px; }
  .lsn-sec { padding: 16px; }
  .lsn-nav { grid-template-columns: 1fr; }
  .lsn-navlink.next { text-align: left; }
}