:root{--lesson-ad-width:160px;--lesson-ad-gap:var(--page-shell-gutter)}.lesson-page-shell{width:100%;max-width:calc(1200px + (2 * var(--lesson-ad-width)) + (2 * var(--lesson-ad-gap)));margin:0 auto;padding:0 var(--page-shell-gutter) calc(var(--page-shell-top-offset) + 2rem)}.lesson-skyscraper{display:none;margin-top:var(--page-shell-top-offset)}@media (min-width:1280px){.lesson-page-shell{display:grid;grid-template-columns:var(--lesson-ad-width) minmax(0,1fr) var(--lesson-ad-width);column-gap:var(--lesson-ad-gap);align-items:flex-start;justify-content:center}.lesson-skyscraper{display:block;position:sticky;top:var(--page-shell-top-offset);align-self:flex-start;max-height:calc(100vh - var(--page-shell-top-offset) - var(--page-shell-bottom-offset))}.lesson-skyscraper--left{grid-column:1;justify-self:start}.lesson-skyscraper--right{grid-column:3;justify-self:end}.lesson-frame{grid-column:2;justify-self:stretch}}.lesson-skyscraper-slot{--ui-skyscraper-width:var(--lesson-ad-width)}.lesson-frame{margin:var(--page-shell-top-offset) 0 0}.lesson-shell{display:flex;flex-direction:column;gap:1.5rem}.lesson-breadcrumbs{font-size:0.85rem;color:rgba(var(--brand-text-color-rgb,15,23,42),0.7)}.lesson-breadcrumbs ol{list-style:none;display:flex;gap:0.5rem;padding:0;margin:0;flex-wrap:wrap}.lesson-breadcrumbs a{text-decoration:none;color:inherit}.lesson-hero h1{font-size:clamp(2rem,6vw,3rem);font-weight:700;margin:0}.lesson-hero p{margin:0}.lesson-objectives{border-radius:var(--global-border-radius);padding:1rem 1.25rem;border:1px solid var(--page-frame-color)}.lesson-body{display:flex;flex-direction:column;gap:1.25rem}.lesson-content-panel{display:flex;flex-direction:column;gap:1.5rem}.lesson-nav-panel{display:flex;flex-direction:column;gap:0.75rem;margin-top:0.5rem}.lesson-nav-card{border-radius:var(--global-border-radius);border:1px solid var(--page-frame-color);padding:1rem;text-decoration:none;color:inherit;display:flex;flex-direction:column;gap:0.35rem}.lesson-nav-card:focus-visible{outline:2px solid var(--brand-color,#6366f1);outline-offset:2px}@media (min-width:640px){.lesson-nav-panel{flex-direction:row}.lesson-nav-card{flex:1}}.lesson-nav-card.is-disabled{opacity:0.6;cursor:default}.lesson-nav-label{font-size:0.7rem;letter-spacing:0.14em;text-transform:uppercase;color:rgba(var(--brand-text-color-rgb,15,23,42),0.7)}.lesson-nav-title{font-weight:600}.lesson-section-label{font-size:0.75rem;letter-spacing:0.18em;text-transform:uppercase;color:rgba(var(--brand-text-color-rgb,15,23,42),0.7)}.lesson-module-text{font-size:0.8rem;letter-spacing:0.16em;text-transform:uppercase;color:rgba(var(--brand-text-color-rgb,15,23,42),0.7)}.lesson-content{font-size:1rem;line-height:1.7}[data-theme="dark"] .lesson-content{--tw-prose-body:var(--brand-text-color);--tw-prose-headings:var(--brand-text-color);--tw-prose-lead:rgba(var(--brand-text-color-rgb),0.9);--tw-prose-links:var(--brand-color);--tw-prose-bold:var(--brand-text-color);--tw-prose-counters:rgba(var(--brand-text-color-rgb),0.7);--tw-prose-bullets:rgba(var(--brand-text-color-rgb),0.7);--tw-prose-captions:rgba(var(--brand-text-color-rgb),0.7);color:var(--brand-text-color)}.lesson-content .lesson-draft-message{color:rgba(var(--brand-text-color-rgb,15,23,42),0.95);font-weight:500}.lesson-content h2,.lesson-content h3,.lesson-content h4{margin-top:1.5rem;font-weight:600}.lesson-content p{margin:1rem 0}.lesson-content iframe,.lesson-content video,.lesson-content embed{display:block;width:100%;max-width:100%;aspect-ratio:16 / 9;height:auto;border:0;background:var(--video-bg,#000);margin:1rem 0}.lesson-content .wp-video,.lesson-content .wp-video-shortcode{width:100%;max-width:100%}.lesson-inline-ad{padding:0.75rem 0}.lesson-progress-card{border:1px solid var(--page-frame-color);border-radius:var(--global-border-radius);overflow:hidden;background:var(--brand-surface-color,#f8fafc)}.lesson-progress-summary{display:flex;align-items:center;gap:0.75rem;padding:0.85rem 1.1rem;cursor:pointer;font-size:0.875rem;list-style:none;user-select:none;background:rgba(var(--brand-color-rgb,37,99,235),0.05);border-bottom:1px solid transparent;transition:background 0.15s ease}.lesson-progress-card[open] .lesson-progress-summary{border-bottom-color:var(--page-frame-color)}.lesson-progress-summary::-webkit-details-marker{display:none}.lesson-progress-summary::marker{content:none}.lesson-progress-summary:hover{background:rgba(var(--brand-color-rgb,37,99,235),0.1)}.lesson-progress-summary:focus-visible{outline:2px solid var(--brand-color,#6366f1);outline-offset:-2px}.lesson-progress-summary-title{font-weight:600;flex:1;color:rgba(var(--brand-text-color-rgb,15,23,42),0.9);display:flex;align-items:center;gap:0.5rem}.lesson-progress-summary-title::before{content:"";display:inline-block;width:0.45rem;height:0.45rem;border-right:2px solid var(--song-brand-color,var(--brand-color));border-bottom:2px solid var(--song-brand-color,var(--brand-color));transform:rotate(-45deg) translate(-1px,1px);transition:transform 0.2s ease;flex-shrink:0}.lesson-progress-card[open] .lesson-progress-summary-title::before{transform:rotate(45deg) translate(-1px,-1px)}.lesson-progress-summary-count{font-size:0.72rem;font-weight:700;color:var(--on-brand-color,#fff);background:var(--song-brand-color,var(--brand-color));padding:0.15rem 0.55rem;border-radius:999px;white-space:nowrap;flex-shrink:0}.lesson-progress-bar{width:100%;height:0.3rem;background:rgba(var(--brand-color-rgb,37,99,235),0.1);overflow:hidden}.lesson-progress-bar-fill{height:100%;background:var(--song-brand-color,var(--brand-color));transition:width 0.3s ease}.lesson-progress-steps{list-style:none;padding:0.6rem 1rem 0.75rem;margin:0;display:flex;flex-direction:column;gap:0.05rem}.lesson-progress-step{display:flex;align-items:center;gap:0.6rem;font-size:0.83rem;padding:0.3rem 0.4rem;border-radius:calc(var(--global-border-radius) / 2);transition:background 0.1s ease}.lesson-progress-step--active{font-weight:600;background:rgba(var(--brand-color-rgb,37,99,235),0.06)}.lesson-progress-step-link{color:inherit;text-decoration:none}.lesson-progress-step-link:hover,.lesson-progress-step-link:focus-visible{color:var(--song-brand-color,var(--brand-color));text-decoration:underline}.lesson-progress-step-index{width:1.35rem;height:1.35rem;border-radius:calc(var(--global-border-radius) / 2);border:1px solid var(--page-frame-color);display:inline-flex;align-items:center;justify-content:center;font-size:0.68rem;font-weight:700;flex-shrink:0;transition:background 0.15s ease,border-color 0.15s ease}.lesson-progress-step--done .lesson-progress-step-index{color:var(--song-brand-color,var(--brand-color));border-color:var(--song-brand-color,var(--brand-color));background:rgba(var(--brand-color-rgb,37,99,235),0.08)}.lesson-progress-step--active .lesson-progress-step-index{background:var(--song-brand-color,var(--brand-color));border-color:var(--song-brand-color,var(--brand-color));color:var(--on-brand-color,#fff)}.lesson-progress-step--pending .lesson-progress-step-title{color:rgba(var(--brand-text-color-rgb,15,23,42),0.65)}.lesson-progress-step.is-draft .lesson-progress-step-title{color:rgba(var(--brand-text-color-rgb,15,23,42),0.4)}.chord-widget-group{display:flex;flex-wrap:wrap;gap:0.5rem;margin:1rem 0}.chord-widget{display:inline-flex;flex-direction:column;align-items:center;gap:0.25rem;margin:0.5rem;vertical-align:top}.chord-widget__label{font-size:0.8rem;text-align:center;color:var(--brand-text-color,#0f172a)}.chord-widget__audio{display:flex;gap:0.4rem;justify-content:center;flex-wrap:wrap}.chord-widget__play-btn{display:inline-flex;align-items:center;justify-content:center;padding:0.3rem 0.75rem;min-height:44px;border-radius:var(--global-border-radius);border:1px solid var(--page-frame-color,rgba(0,0,0,0.1));background:transparent;color:var(--brand-text-color,#0f172a);cursor:pointer;font-size:0.75rem;white-space:nowrap;transition:background 0.15s ease,border-color 0.15s ease}.chord-widget__play-btn:hover{background:rgba(var(--brand-color-rgb,37,99,235),0.06);border-color:rgba(var(--brand-color-rgb,37,99,235),0.3)}.chord-widget__play-btn:focus-visible{outline:2px solid var(--brand-color,#6366f1);outline-offset:2px}.chord-widget__play-btn.is-playing{background:rgba(var(--brand-color-rgb,37,99,235),0.1);border-color:var(--brand-color,#6366f1);color:var(--brand-color,#6366f1)}.lesson-chord-transition{display:flex;flex-direction:column;align-items:center;gap:0.75rem;padding:1.25rem;border:1px solid var(--page-frame-color);border-radius:var(--global-border-radius);background:var(--brand-surface-color);margin:1.25rem 0}.lesson-chord-transition__chords{display:flex;align-items:center;gap:1rem;flex-wrap:wrap;justify-content:center}.lesson-chord-transition__arrow{font-size:1.5rem;color:rgba(var(--brand-text-color-rgb,15,23,42),0.4);flex-shrink:0}.lesson-chord-transition__controls{display:flex;justify-content:center}.lesson-chord-transition__listen{display:inline-flex;align-items:center;gap:0.4rem;padding:0.4rem 1rem;min-height:44px;border-radius:999px;border:1px solid rgba(var(--brand-color-rgb,37,99,235),0.4);background:rgba(var(--brand-color-rgb,37,99,235),0.06);color:var(--brand-color,#6366f1);cursor:pointer;font-size:0.85rem;font-weight:600;transition:background 0.15s ease,border-color 0.15s ease}.lesson-chord-transition__listen:hover{background:rgba(var(--brand-color-rgb,37,99,235),0.12);border-color:var(--brand-color,#6366f1)}.lesson-chord-transition__listen:focus-visible{outline:2px solid var(--brand-color,#6366f1);outline-offset:2px}.lesson-chord-transition__listen.is-playing{background:var(--brand-color,#6366f1);color:var(--on-brand-color,#fff);border-color:var(--brand-color,#6366f1)}.tab-widget{margin:1.5rem 0;overflow-x:auto}.tab-diagram{display:block;font-family:monospace}.tab-bg{fill:var(--page-frame-bg,#f8fafc)}[data-theme="dark"] .tab-bg{fill:var(--page-frame-bg,#1e293b)}.tab-string{stroke:var(--brand-text-color,#0f172a);stroke-width:1;opacity:0.35}.tab-bar{stroke:var(--brand-text-color,#0f172a);opacity:0.55}.tab-bar--open{opacity:0.8}.tab-string-label{fill:var(--brand-text-color,#0f172a);opacity:0.75}.tab-note-bg{fill:var(--page-frame-bg,#f8fafc)}[data-theme="dark"] .tab-note-bg{fill:var(--page-frame-bg,#1e293b)}.tab-note-bg{transition:fill 0.12s ease}.tab-note-text{fill:var(--brand-text-color,#0f172a);font-weight:600;transition:fill 0.12s ease}.tab-note.is-current .tab-note-bg{fill:var(--song-brand-color,var(--brand-color))}.tab-note.is-current .tab-note-text{fill:var(--on-brand-color,#fff)}.tab-widget.is-playing .tab-note:not(.is-current) .tab-note-bg{fill:rgba(var(--brand-color-rgb,37,99,235),0.08)}.tab-widget.is-playing .tab-note:not(.is-current) .tab-note-text{opacity:0.4}.tab-technique{fill:var(--song-brand-color,var(--brand-color))}.tab-widget__play{display:inline-flex;align-items:center;gap:0.35rem;padding:0.35rem 1rem;min-height:44px;border-radius:999px;border:1px solid rgba(var(--brand-color-rgb,37,99,235),0.4);background:rgba(var(--brand-color-rgb,37,99,235),0.05);color:var(--song-brand-color,var(--brand-color));cursor:pointer;font-size:0.85rem;font-weight:600;margin-top:0.75rem;transition:background 0.15s ease,border-color 0.15s ease}.tab-widget__play:hover{background:rgba(var(--brand-color-rgb,37,99,235),0.1);border-color:var(--song-brand-color,var(--brand-color))}.tab-widget__play:focus-visible{outline:2px solid var(--song-brand-color,var(--brand-color));outline-offset:2px}.tab-widget__play.is-playing{background:var(--song-brand-color,var(--brand-color));color:var(--on-brand-color,#fff);border-color:var(--song-brand-color,var(--brand-color))}