:root {
    color-scheme: dark;
    --bg: #151b1d;
    --card: #1c2426;
    --panel: #273235;
    --text: #f3f4ec;
    --muted: #b8c4c2;
    --accent: #c7e99b;
    --accent-text: #182019;
    --line: #3d4d4f;
    --focus: #d8b77b;
    --shadow: 0 12px 32px #00000018;
    --mono: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.6;
    background: var(--bg);
    color: var(--text);
}
:root[data-theme="light"] {
    color-scheme: light;
    --bg: #f3f2ec;
    --card: #fffefa;
    --panel: #e9ece3;
    --text: #202b29;
    --muted: #52615b;
    --accent: #3d6335;
    --accent-text: #fff;
    --line: #bcc8b8;
    --focus: #795224;
    --shadow: 0 12px 32px #283c2810;
}
@media (prefers-color-scheme: light) {
    :root:not([data-theme]) {
        color-scheme: light;
        --bg: #f3f2ec;
        --card: #fffefa;
        --panel: #e9ece3;
        --text: #202b29;
        --muted: #52615b;
        --accent: #3d6335;
        --accent-text: #fff;
        --line: #bcc8b8;
        --focus: #795224;
        --shadow: 0 12px 32px #283c2810;
    }
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; }
a { color: var(--accent); text-underline-offset: .22em; }
a:hover { text-decoration-thickness: 2px; }
:where(a, button, input, select, summary):focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }
h1, h2, h3 { line-height: 1.2; text-wrap: balance; letter-spacing: -.025em; }
h1 { font-size: clamp(2.25rem, 5vw, 4rem); max-width: 20ch; margin-block: 16px 24px; font-weight: 750; letter-spacing: -.055em; line-height: 1.06; }
h2 { font-size: clamp(1.4rem, 3vw, 1.85rem); margin-block: 0 20px; }
h3 { font-size: 1.1rem; margin-top: 28px; }
p, li, dd { max-width: 72ch; overflow-wrap: anywhere; }
button, input, select { font: inherit; }
button { cursor: pointer; }
button:disabled, fieldset:disabled { cursor: not-allowed; }
.container { width: min(1160px, 100% - 32px); margin-inline: auto; }
.site-header { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; padding-block: 20px; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 1.35rem; font-weight: 750; letter-spacing: -.045em; text-decoration: none; color: var(--text); min-height: 44px; }
.brand small { display: block; font-size: .65rem; letter-spacing: .18em; text-transform: uppercase; color: var(--muted); font-weight: 550; }
.brand-mark { display: inline-flex; justify-content: center; align-items: center; width: 42px; height: 42px; border: 1px solid var(--accent); border-radius: 50%; color: var(--accent); background: var(--panel); }
nav { display: flex; flex-wrap: wrap; gap: 4px; }
nav a { display: inline-flex; align-items: center; min-height: 44px; padding: 8px 12px; border-radius: 4px; text-decoration: none; color: var(--muted); }
nav a:hover { background: var(--panel); color: var(--text); }
nav a[aria-current] { background: var(--panel); color: var(--accent); box-shadow: inset 0 -2px var(--accent); }
.theme-toggle { min-height: 44px; padding: 8px 12px; color: var(--muted); background: transparent; border: 1px solid var(--line); border-radius: 6px; font-size: .85rem; }
main { padding-block: 32px 56px; }
main > section, main > p { margin-block: 32px; }
.page-intro { padding-block: 12px 24px; }
.page-intro > p { color: var(--muted); font-size: 1.05rem; }
.eyebrow { font-family: var(--mono); font-size: .75rem !important; text-transform: uppercase; font-weight: 600; letter-spacing: .1em; color: var(--accent) !important; }
.eyebrow::before { content: ""; display: inline-block; width: 22px; height: 8px; margin-right: 12px; border-block: 2px solid currentColor; vertical-align: .08em; }
.feature-note { font-size: .8rem !important; margin-top: 24px; padding-top: 16px; border-top: 1px solid var(--line); }
.panel { background: var(--card); border: 1px solid var(--line); padding: clamp(18px, 3vw, 32px); border-radius: 12px; margin-block: 24px; }
.tool-hero > .panel { border-top: 3px solid var(--accent); box-shadow: var(--shadow); }
.tool-hero > .panel > h2 { font-size: clamp(1.3rem, 2.4vw, 1.65rem); letter-spacing: -.035em; }
.panel > p { color: var(--muted); }
section { scroll-margin-top: 24px; min-width: 0; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: 12px 20px; border: 1px solid transparent; border-radius: 6px; background: var(--accent); color: var(--accent-text); font-weight: 700; text-decoration: none; line-height: 1.4; text-align: center; }
.page-intro > .button { gap: 24px; }
.page-intro > .button::after { content: "↗"; font-size: 1.15em; font-weight: 400; }
.button:hover { filter: brightness(1.05); }
.notice { border-inline-start: 3px solid var(--accent); padding: 10px 14px; color: var(--muted); background: var(--panel); border-radius: 0 8px 8px 0; font-size: .9rem; }
.site-footer { padding-block: 24px; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }
.skip-link { position: absolute; left: 16px; top: -160px; padding: 12px; background: var(--card); z-index: 2; }
.skip-link:focus { top: 8px; }
li + li { margin-top: 10px; }
ol, ul { padding-left: 24px; }
details { border-bottom: 1px solid var(--line); padding-block: 8px; }
summary { cursor: pointer; min-height: 48px; padding-block: 12px; font-weight: 650; }
details[open] { padding-bottom: 16px; }
details[open] > summary { color: var(--accent); }
dt { font-weight: 700; margin-top: 20px; }
dd { color: var(--muted); margin: 6px 0 0; }
.instrument { border-top: 1px solid var(--line); padding-top: 20px; margin-block: 24px; }
.instrument-label { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; color: var(--muted); font-family: var(--mono); font-size: .75rem; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--muted); }
.status-tag { margin-left: auto; padding: 3px 8px; border: 1px solid var(--line); border-radius: 6px; font-size: .65rem; text-transform: uppercase; letter-spacing: .06em; }
.stereo-display { display: grid; grid-template-columns: minmax(0, 1fr) 24px minmax(0, 1fr); align-items: center; gap: 8px; padding-block: 24px; text-align: center; }
.speaker { display: flex; flex-direction: column; align-items: center; gap: 6px; }
.speaker > span { width: 72px; height: 72px; display: grid; place-items: center; border: 1px solid var(--line); box-shadow: inset 0 0 0 10px var(--panel); border-radius: 50%; color: var(--accent); font-size: 1.2rem; }
.speaker strong { font-size: .9rem; font-weight: 600; }
.speaker small, .stereo-divider { color: var(--muted); font-size: .8rem; }
fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
legend { font-size: .85rem; font-weight: 600; margin-bottom: 12px; }
.device-options { display: flex; flex-wrap: wrap; gap: 8px; }
.device-options label { flex: 1 1 130px; display: flex; align-items: center; min-height: 48px; gap: 8px; padding: 10px; border: 1px solid var(--line); border-radius: 6px; font-size: .85rem; }
.device-options label:has(input:checked) { border-color: var(--accent); background: var(--panel); }
input[type="radio"] { width: 18px; height: 18px; accent-color: var(--accent); flex-shrink: 0; }
.primary-control { width: 100%; margin-top: 20px; }
.button:disabled { background: var(--panel); color: var(--muted); border-color: var(--line); filter: none; }
.control-help { font-size: .75rem; color: var(--muted); margin-bottom: 0; }
.mic-display, .tone-display { text-align: center; padding: 24px 0; }
[data-mic-status] { font-size: .85rem; }
.mic-display strong { display: block; }
.mic-symbol { display: grid; place-items: center; width: 72px; height: 72px; border: 1px solid var(--line); background: var(--panel); border-radius: 50%; color: var(--accent); margin: 0 auto 12px; font-size: 2rem; }
.mic-display p, .tone-display p { font-size: .85rem; color: var(--muted); margin-block: 8px; }
.meter-label { display: flex; justify-content: space-between; gap: 12px; font-size: .75rem; color: var(--muted); margin-bottom: 8px; }
.input-meter { height: 10px; background: var(--panel); border: 1px solid var(--line); border-radius: 5px; }
.input-meter > span { display: block; height: 100%; width: 100%; background: var(--accent); border-radius: 5px; transform: scaleX(0); transform-origin: left; }
.mic-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-block: 16px; }
.mic-actions > button { flex: 1 1 170px; min-height: 48px; }
[data-mic-source] { width: 100%; min-height: 48px; padding: 10px; color: var(--text); background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
[data-mic-phase="recording"] .mic-symbol, [data-mic-phase="live"] .mic-symbol { border-color: var(--accent); }
.mic-symbol { position: relative; }
.mic-symbol::before, .mic-symbol::after { content: ""; position: absolute; inset: -8px; border: 1px solid var(--accent); border-radius: 50%; opacity: 0; pointer-events: none; }
[data-mic-phase="recording"] .mic-symbol::before, [data-mic-phase="recording"] .mic-symbol::after { opacity: var(--input-activity, 0); transform: scale(var(--input-ring-scale, 1)); transition: transform .1s linear, opacity .1s linear; }
[data-mic-phase="recording"] .mic-symbol::after { inset: -16px; }
[data-mic-phase="recording"] [data-mic-icon] { transform: scale(var(--input-icon-scale, 1)); transition: transform .1s linear; }
[data-mic-output="true"] .mic-symbol { border-color: var(--accent); }
[data-mic-output="true"] .mic-symbol::before { animation: sound-ring 1.6s linear infinite; }
[data-mic-output="true"] .mic-symbol::after { animation: sound-ring 1.6s .8s linear infinite; }
[data-mic-output="true"] .speaker-glyph { animation: sound-cone .7s ease-in-out infinite alternate; }
.tone-display > strong { color: var(--accent); font-family: var(--mono); font-size: 3rem; letter-spacing: -.065em; font-variant-numeric: tabular-nums; }
.tone-display > strong span { font-size: 1rem; margin-left: 8px; color: var(--muted); }
.tone-fields { display: grid; grid-template-columns: 1fr; gap: 12px; }
.tone-fields label { display: block; margin-bottom: 6px; font-size: .85rem; }
.tone-fields input, .tone-fields select { width: 100%; min-width: 0; min-height: 48px; padding: 10px; color: var(--text); background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
[data-tone-range] { width: 100%; min-height: 44px; accent-color: var(--accent); touch-action: none; }
[data-tone-status] { min-height: 4.8em; }
[data-tone-settings] > label { display: block; margin-top: 12px; }
[data-tone] .preset-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); margin-top: 16px; }
[data-tone] [aria-pressed="true"] { border-color: var(--accent); color: var(--accent); }
[data-tone-phase="playing"] .tone-symbol { border-color: var(--accent); }
[data-tone-phase="playing"] .tone-symbol::before { animation: sound-ring 1.6s linear infinite; }
[data-tone-phase="playing"] .tone-symbol::after { animation: sound-ring 1.6s .8s linear infinite; }
[data-tone-phase="playing"] .speaker-glyph { animation: sound-cone .7s ease-in-out infinite alternate; }
@media (min-width: 768px) { .tone-fields { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); } [data-tone] .preset-list { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.preset-list { display: flex; flex-wrap: wrap; gap: 8px; }
.preset-list button { flex: 1 1 80px; min-height: 44px; padding: 8px; background: var(--panel); color: var(--muted); border: 1px solid var(--line); border-radius: 8px; font-size: .8rem; }
.preset-list .selected { border-color: var(--accent); color: var(--accent); }
.safety-check { display: flex; align-items: center; gap: 10px; min-height: 48px; margin-top: 16px; font-size: .9rem; }
.safety-check input, .troubleshooting-checklist input { width: 20px; height: 20px; flex-shrink: 0; accent-color: var(--accent); }
.signal-buttons, .answer-buttons, .playback-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-block: 16px; }
.signal-buttons button, .answer-buttons button { min-height: 48px; flex: 1 1 130px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 6px; color: var(--text); background: var(--panel); }
.signal-buttons button:not(:disabled):hover, .answer-buttons button:not(:disabled):hover, .preset-list button:not(:disabled):hover, .secondary:not(:disabled):hover { border-color: var(--accent); }
.signal-buttons button[aria-pressed="true"] { border-color: var(--accent); box-shadow: inset 0 -2px var(--accent); }
.answer-buttons button:disabled { color: var(--muted); opacity: .65; }
.playback-actions > * { flex: 1 1 160px; min-height: 48px; }
.playback-actions > a { display: flex; align-items: center; justify-content: center; padding: 10px; }
.secondary { background: var(--panel); border-color: var(--line); color: var(--text); }
.stop-button { background: transparent; border-color: var(--line); color: var(--text); }
.stop-button:disabled { opacity: .55; }
.step-indicator { font-size: .85rem; font-weight: 650; color: var(--accent); margin-top: 24px; }
.answer-group { border-block: 1px solid var(--line); padding-block: 16px; margin-block: 24px; }
.answer-group legend { padding-right: 12px; font-size: 1rem; }
.distortion-label { display: block; margin-block: 20px 8px; font-size: .85rem; }
[data-distortion] { width: 100%; min-height: 48px; max-width: 100%; padding: 10px 8px; color: var(--text); background: var(--panel); border: 1px solid var(--line); border-radius: 8px; font-size: .9rem; }
.error-notice { border: 1px solid var(--accent); border-inline-start-width: 4px; padding: 12px; border-radius: 8px; color: var(--text); }
.error-notice::before { content: "! "; font-weight: 750; }
.speaker[data-active] > span { border-color: var(--accent); background: var(--panel); }
[data-playback] .speaker { appearance: none; min-width: 0; min-height: 44px; padding: 8px 4px; color: var(--text); background: transparent; border: 0; border-radius: 12px; }
[data-playback] .speaker:disabled { opacity: .65; }
[data-playback] .speaker:not(:disabled):hover { background: var(--panel); }
[data-playback] .speaker-emblem { position: relative; width: 88px; height: 88px; box-shadow: inset 0 0 0 8px var(--panel); display: flex; flex-direction: column; justify-content: center; gap: 2px; }
.channel-letter { color: var(--muted); font-family: var(--mono); font-size: .65rem; font-weight: 750; line-height: 1; }
.speaker-glyph { position: relative; z-index: 1; }
[data-playback] .speaker-emblem::before, [data-playback] .speaker-emblem::after { content: ""; position: absolute; inset: -1px; border: 1px solid var(--accent); border-radius: 50%; opacity: 0; pointer-events: none; }
[data-playback] .speaker[data-active] .speaker-emblem::before { animation: sound-ring 1.6s linear infinite; }
[data-playback] .speaker[data-active] .speaker-emblem::after { animation: sound-ring 1.6s .8s linear infinite; }
[data-playback] .speaker[data-active] .speaker-glyph { animation: sound-cone .7s ease-in-out infinite alternate; }
@keyframes sound-ring { 0% { transform: scale(1); opacity: .65; } 100% { transform: scale(1.32); opacity: 0; } }
@keyframes sound-cone { from { transform: scale(.96); } to { transform: scale(1.06); } }
.repeat-button { position: relative; overflow: hidden; isolation: isolate; }
.repeat-progress-fill { position: absolute; inset: 0; background: var(--accent); opacity: .14; transform: scaleX(0); transform-origin: left; transition: transform .1s linear; pointer-events: none; z-index: -1; }
.repeat-caption { position: relative; }
.playback-result { border-top: 1px solid var(--line); margin-top: 24px; padding-top: 8px; }
.playback-result:focus { outline: 3px solid var(--focus); outline-offset: 6px; }
.playback-result h4 { margin-bottom: 8px; }
.result-summary { border-inline-start: 3px solid var(--accent); padding-left: 12px; font-weight: 600; }
.troubleshooting-checklist { padding: 0; list-style: none; }
.troubleshooting-checklist label { display: flex; align-items: flex-start; gap: 10px; min-height: 48px; padding-block: 8px; }
.troubleshooting-checklist input { margin-top: 4px; }
@media (max-width: 767px) {
    .signal-buttons { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .signal-buttons > [data-signal="center"] { grid-column: 1 / -1; }
}
@media (min-width: 768px) {
    .container { width: min(1160px, 100% - 64px); }
    main { padding-top: 48px; }
    .tool-hero { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); align-items: start; gap: 40px; }
    .tool-hero .page-intro { padding-top: 48px; position: sticky; top: 24px; }
    .tool-hero .page-intro h1 { max-width: 13ch; }
    main > section { padding-top: 24px; border-top: 1px solid var(--line); }
    main > section.panel { padding-top: 32px; }
    .tool-hero .panel { margin-top: 0; }
    .site-footer { display: flex; justify-content: space-between; gap: 16px; align-items: center; }
}
@media (max-width: 420px) {
    .site-header { gap: 12px 8px; }
    .site-header > nav { order: 3; width: 100%; }
    .site-header > nav a { flex: 1; justify-content: center; padding-inline: 8px; }
    .theme-toggle { max-width: 125px; }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}