:root {
    color-scheme: light;

    /* Theme: changing this value recolors the main interactive language. */
    --color-primary: #2f6f9f;
    --color-primary-strong: color-mix(in srgb, var(--color-primary), black 14%);
    --color-primary-soft: color-mix(in srgb, var(--color-primary), white 90%);
    --color-on-primary: #fff;

    --color-page: #f5f6f2;
    --color-surface: #fff;
    --color-text: #203b35;
    --color-text-muted: #64716b;
    --color-border: #dfe5df;
    --color-danger: #982929;
    --color-warning-text: #744716;
    --color-warning-surface: #fff0d7;
    --color-focus: #aa6225;
    --color-chord: #855016;

    --radius-control: 12px;
    --radius-card: 18px;
    --control-height: 48px;
    --control-padding: 10px 14px;
    --transition-control: 140ms ease;

    /* Backward-compatible semantic aliases used by existing screens. */
    --bg: var(--color-page);
    --surface: var(--color-surface);
    --ink: var(--color-text);
    --muted: var(--color-text-muted);
    --line: var(--color-border);
    --accent: var(--color-primary);
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.55 system-ui, -apple-system, "Segoe UI", sans-serif; overflow-wrap: anywhere; }
body::after { content: ""; position: fixed; inset: 0; z-index: 80; background: color-mix(in srgb, var(--color-page), transparent 18%); opacity: 0; visibility: hidden; pointer-events: none; transition: opacity 160ms ease, visibility 0s linear 180ms; -webkit-backdrop-filter: blur(3px); backdrop-filter: blur(3px); }
body.app-is-navigating::after { opacity: 1; visibility: visible; transition-delay: 0s; }
a { color: inherit; }
button, input, select, textarea { font: inherit; }
button, .button, input, select, textarea { transition: border-color var(--transition-control), background-color var(--transition-control), color var(--transition-control), box-shadow var(--transition-control), transform var(--transition-control); }
input:not([type="hidden"]):not([type="checkbox"]):not([type="radio"]), select, textarea { min-width: 0; min-height: var(--control-height); padding: var(--control-padding); border: 1px solid var(--color-border); border-radius: var(--radius-control); background: var(--color-surface); color: var(--color-text); }
input:not([type="hidden"]):not([type="checkbox"]):not([type="radio"]):hover, select:hover, textarea:hover { border-color: color-mix(in srgb, var(--color-primary), var(--color-border) 60%); }
input:not([type="hidden"]):not([type="checkbox"]):not([type="radio"]):focus, select:focus, textarea:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-soft); }
button { min-height: var(--control-height); padding: var(--control-padding); border: 1px solid var(--color-border); border-radius: var(--radius-control); background: var(--color-surface); color: var(--color-text); cursor: pointer; }
button:hover:not(:disabled) { background: var(--color-primary-soft); border-color: color-mix(in srgb, var(--color-primary), var(--color-border) 55%); }
button:active:not(:disabled), .button:active { transform: translateY(1px); }
button:disabled { opacity: .5; cursor: default; }
[hidden] { display: none !important; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
:focus-visible { outline: 3px solid var(--color-focus); outline-offset: 4px; }
.app-shell { max-width: 840px; margin: auto; padding: env(safe-area-inset-top) max(20px, env(safe-area-inset-right)) calc(82px + env(safe-area-inset-bottom)) max(20px, env(safe-area-inset-left)); }
.app-header { min-height: 88px; display: flex; align-items: center; justify-content: space-between; gap: 12px; border-bottom: 1px solid var(--line); }
.brand { min-height: 48px; display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 700; font-size: 17px; }
.brand img { flex: 0 0 auto; border-radius: 11px; }
.connection-status { color: var(--color-warning-text); background: var(--color-warning-surface); border-radius: 20px; padding: 4px 9px; font-size: 12px; white-space: nowrap; }
.pwa-update { min-height: 36px; border: 0; border-radius: 18px; padding: 6px 12px; color: var(--color-on-primary); background: var(--color-primary); font: inherit; font-size: 13px; font-weight: 700; cursor: pointer; }
main { padding-top: 30px; }
.eyebrow { margin: 0 0 8px; font-size: 12px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
h1 { margin: 0 0 24px; font-size: clamp(30px, 6vw, 40px); line-height: 1.2; letter-spacing: -.035em; }
h2 { margin: 18px 0 10px; font-size: 23px; line-height: 1.3; letter-spacing: -.025em; }
.placeholder { background: var(--surface); border: 1px solid var(--line); border-radius: 24px; padding: 26px 22px; min-height: 280px; }
.placeholder p { max-width: 440px; margin: 0 0 24px; color: var(--muted); }
.section-mark { display: inline-grid; place-items: center; width: 44px; height: 44px; border-radius: 14px; background: var(--color-primary-soft); color: var(--color-primary); font-size: 14px; font-weight: 700; }
.stage-label { display: inline-block; font-size: 12px; color: var(--muted); border: 1px solid var(--line); padding: 5px 11px; border-radius: 20px; }
.bottom-nav { position: fixed; bottom: 0; inset-inline: 0; z-index: 20; background: var(--surface); border-top: 1px solid var(--line); padding: 4px max(12px, env(safe-area-inset-right)) calc(4px + env(safe-area-inset-bottom)) max(12px, env(safe-area-inset-left)); }
.nav-inner { display: flex; gap: 8px; max-width: 520px; margin: auto; }
.nav-item { flex: 1; min-height: 48px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 1px; border-radius: 12px; text-decoration: none; font-size: 11px; line-height: 1.3; font-weight: 600; color: var(--muted); -webkit-tap-highlight-color: transparent; }
.nav-item { transition: color 200ms ease, background-color 200ms ease, transform 180ms ease; }
.nav-item[aria-current="page"] { color: var(--color-primary); background: var(--color-primary-soft); }
.nav-item:active { transform: scale(.96); }
.nav-item svg { width: 21px; height: 21px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.button { display: inline-flex; min-height: var(--control-height); align-items: center; justify-content: center; border: 1px solid var(--color-primary); border-radius: var(--radius-control); padding: var(--control-padding); background: var(--color-primary); color: var(--color-on-primary); font-weight: 650; text-decoration: none; cursor: pointer; }
.button:hover { border-color: var(--color-primary-strong); background: var(--color-primary-strong); }
.button-secondary { background: var(--color-surface); color: var(--color-primary); border-color: var(--color-border); }
.button-secondary:hover { background: var(--color-primary-soft); border-color: var(--color-primary); }
.button-danger { background: var(--color-surface); color: var(--color-danger); border-color: color-mix(in srgb, var(--color-danger), var(--color-border) 65%); }
.button-danger:hover { background: color-mix(in srgb, var(--color-danger), white 93%); border-color: var(--color-danger); }
.song-link, .service-link { transition: background-color 220ms ease, border-color 220ms ease, box-shadow 220ms ease, transform 180ms ease; }
.song-link:hover, .service-link:hover { box-shadow: 0 8px 24px rgb(20 45 38 / .06); }
.song-link:active, .service-link:active { transform: scale(.988); }
.skip-link { position: fixed; top: -100px; left: 16px; z-index: 10; padding: 12px; background: white; }
.skip-link:focus { top: 12px; }
.app-header { flex-wrap: wrap; gap: 8px; }
.account-link { display: inline-flex; align-items: center; min-height: 48px; padding: 8px; font-weight: 600; text-decoration: none; }
.auth-card { max-width: 480px; padding: 22px; background: white; border: 1px solid var(--line); border-radius: 18px; }
.auth-form { display: grid; gap: 10px; }
.auth-form input { width: 100%; }
.auth-card button { border: 0; cursor: pointer; justify-content: center; margin-top: 12px; }
.auth-error { color: var(--color-danger); }
.auth-name { font-size: 20px; font-weight: 600; }
.auth-card dt { color: var(--muted); margin-top: 12px; }
.auth-card dd { margin: 4px 0 18px; }
@media (min-width: 700px) { main { padding-top: 44px; } .placeholder { padding: 36px; } }

.app-header-detail, .app-header-library { position: sticky; top: 0; z-index: 30; background: var(--bg); display: grid; grid-template-columns: 44px minmax(0, 1fr) 44px; min-height: 60px; gap: 0 8px; margin-top: calc(-1 * env(safe-area-inset-top)); margin-left: calc(-1 * max(20px, env(safe-area-inset-left))); margin-right: calc(-1 * max(20px, env(safe-area-inset-right))); padding: calc(8px + env(safe-area-inset-top)) max(20px, env(safe-area-inset-right)) 8px max(20px, env(safe-area-inset-left)); }
.header-icon { width: 44px; height: 44px; display: inline-flex; align-items: center; justify-content: center; border-radius: 12px; color: var(--accent); text-decoration: none; -webkit-tap-highlight-color: transparent; }
.header-icon:is(button) { min-height: 44px; padding: 0; border: 0; background: transparent; }
.header-icon:hover, .header-icon:active { background: var(--color-primary-soft); }
.header-icon svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.header-screen-title { text-align: center; font-size: 17px; line-height: 1.3; font-weight: 650; }
.app-header-detail .connection-status, .app-header-detail .pwa-update, .app-header-library .connection-status, .app-header-library .pwa-update { grid-column: 1 / -1; justify-self: center; margin-top: 6px; }
.header-search-panel { grid-column: 1 / -1; padding-top: 8px; }
.header-search-panel .song-search { width: 100%; }
.app-header-detail + main { padding-top: 24px; }
.app-header-library + main { padding-top: 18px; }
.app-header-detail + main > h1, .app-header-detail + main .song-detail-heading > h1 { font-size: clamp(26px, 5.5vw, 34px); margin-bottom: 20px; }

/* Cross-document transitions: calm enough to read, quick enough to stay responsive. */
@view-transition { navigation: auto; }
main { view-transition-name: page-content; }
.bottom-nav { view-transition-name: app-navigation; }
::view-transition { pointer-events: none; }
::view-transition-group(*) { animation-duration: 300ms; animation-timing-function: cubic-bezier(.2,.75,.25,1); }
::view-transition-old(root) { animation: screen-fade-out 180ms ease-out both; }
::view-transition-new(root) { animation: screen-fade-in 280ms ease-out both; }
::view-transition-old(page-content) { animation: screen-content-out 180ms ease-out both; }
::view-transition-new(page-content) { animation: screen-content-in 300ms cubic-bezier(.2,.75,.25,1) both; }
::view-transition-group(app-navigation),
::view-transition-new(app-navigation) { animation: none; }
::view-transition-old(app-navigation) { display: none; }
@keyframes screen-fade-out { to { opacity: 0; } }
@keyframes screen-fade-in { from { opacity: 0; } }
@keyframes screen-content-out { to { opacity: 0; transform: translateY(-4px); } }
@keyframes screen-content-in {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* First launch and delayed-navigation feedback. */
.app-intro { display: none; }
.app-intro-pending .app-intro { position: fixed; inset: 0; z-index: 1000; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 15px; overflow: hidden; background: var(--color-page); opacity: 1; transition: opacity 420ms ease, transform 420ms cubic-bezier(.2,.75,.25,1); }
.app-intro-pending .app-intro.app-intro-leaving { opacity: 0; transform: scale(1.025); }
.app-intro-icon { position: relative; z-index: 2; width: 112px; height: 112px; display: grid; place-items: center; border-radius: 34px; color: #55a9dc; background: color-mix(in srgb, #55a9dc, white 92%); box-shadow: 0 18px 48px color-mix(in srgb, #55a9dc, transparent 76%); animation: intro-float 1.8s ease-in-out infinite; }
.app-intro-icon svg { width: 78px; height: 78px; overflow: visible; fill: none; stroke: currentColor; stroke-width: 5.5; stroke-linecap: round; stroke-linejoin: round; }
.app-intro-icon ellipse { fill: color-mix(in srgb, #55a9dc, white 12%); stroke: none; transform-box: fill-box; transform-origin: center; animation: intro-note-pulse 1.2s ease-in-out infinite alternate; }
.app-intro-title { position: relative; z-index: 2; color: var(--color-text); font-size: 22px; font-weight: 720; letter-spacing: -.025em; }
.app-intro-effects { position: absolute; width: 250px; height: 250px; }
.app-intro-effects::before, .app-intro-effects::after { content: ""; position: absolute; inset: 32px; border: 1px solid color-mix(in srgb, #55a9dc, transparent 66%); border-radius: 50%; animation: intro-ring 2s ease-out infinite; }
.app-intro-effects::after { animation-delay: 1s; }
.app-intro-effects i { position: absolute; width: 8px; height: 8px; border-radius: 50%; background: #55a9dc; opacity: .5; animation: intro-spark 1.8s ease-in-out infinite; }
.app-intro-effects i:nth-child(1) { top: 18%; left: 22%; }
.app-intro-effects i:nth-child(2) { top: 25%; right: 15%; animation-delay: -.5s; }
.app-intro-effects i:nth-child(3) { bottom: 20%; left: 14%; animation-delay: -.9s; }
.app-intro-effects i:nth-child(4) { right: 20%; bottom: 13%; animation-delay: -.25s; }
.app-intro-effects i:nth-child(5) { top: 6%; left: 52%; animation-delay: -.7s; }
.app-intro-bars { z-index: 2; display: flex; align-items: center; height: 18px; gap: 4px; }
.app-intro-bars i { width: 3px; height: 6px; border-radius: 3px; background: #55a9dc; animation: intro-bar .8s ease-in-out infinite alternate; }
.app-intro-bars i:nth-child(2), .app-intro-bars i:nth-child(4) { animation-delay: -.45s; }
.app-intro-bars i:nth-child(3) { animation-delay: -.7s; }
.app-loader { position: fixed; top: 50%; left: 50%; z-index: 90; display: flex; align-items: center; gap: 9px; min-height: 46px; padding: 9px 17px 9px 10px; border: 1px solid color-mix(in srgb, var(--color-primary), var(--color-border) 75%); border-radius: 24px; background: var(--color-surface); color: var(--color-text-muted); box-shadow: 0 16px 42px rgb(20 45 38 / .16); opacity: 0; visibility: hidden; transform: translate(-50%, calc(-50% + 10px)) scale(.94); transition: opacity 150ms ease, transform 220ms cubic-bezier(.2,.75,.25,1), visibility 0s linear 220ms; pointer-events: none; font-size: 14px; font-weight: 650; }
.app-is-navigating .app-loader { opacity: 1; visibility: visible; transform: translate(-50%, -50%) scale(1); transition-delay: 0s; }
.app-loader-note { width: 30px; height: 30px; display: grid; place-items: center; border-radius: 50%; background: var(--color-primary-soft); color: var(--color-primary); font-size: 21px; animation: loader-note 620ms ease-in-out infinite alternate; }
.app-is-navigating .app-loader::after { content: ""; position: absolute; left: 13px; right: 13px; bottom: -7px; height: 2px; border-radius: 2px; background: linear-gradient(90deg, transparent, var(--color-primary), transparent); transform-origin: left; animation: loader-progress 1.05s ease-in-out infinite; }
.motion-list-item { opacity: 0; transform: translateY(9px); transition: opacity 280ms ease, transform 320ms cubic-bezier(.2,.75,.25,1); transition-delay: calc(var(--motion-order, 0) * 24ms); }
.motion-list-item.is-visible { opacity: 1; transform: translateY(0); }
@keyframes intro-float { 50% { transform: translateY(-7px) rotate(-1deg); } }
@keyframes intro-note-pulse { to { transform: scale(1.08); } }
@keyframes intro-ring { from { opacity: .8; transform: scale(.65); } to { opacity: 0; transform: scale(1.35); } }
@keyframes intro-spark { 50% { opacity: .9; transform: scale(1.5) translateY(-4px); } }
@keyframes intro-bar { to { height: 18px; } }
@keyframes loader-note { to { transform: translateY(-3px) rotate(-8deg); } }
@keyframes loader-progress { 0% { opacity: .2; transform: scaleX(.12); } 50% { opacity: 1; transform: scaleX(1); } 100% { opacity: .2; transform: scaleX(.12); transform-origin: right; } }
@media (prefers-reduced-motion: reduce) {
    @view-transition { navigation: none; }
    ::view-transition-group(*),
    ::view-transition-old(*),
    ::view-transition-new(*) { animation: none !important; }
    *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
    .motion-list-item { opacity: 1; transform: none; }
}