:root {
    --bg: #F9F9F9;
    --surface: #FFFFFF;
    --text: #1a1a1a;
    --text-soft: #6b6b6b;
    --border: #ECECEC;
    --gold: #C9A961;
    --gold-soft: #E8D9B0;
    --midnight: #1B2845;
    --coral: #E76F51;
    --green: #6BAF6E;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.12);
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, "Helvetica Neue", sans-serif;
    font-weight: 300;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    display: flex;
    justify-content: center;
    padding: 48px 20px;
}

main {
    width: 100%;
    max-width: 720px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.app-header {
    text-align: center;
    margin-bottom: 48px;
}

.app-header h1 {
    font-size: 28px;
    font-weight: 500;
    letter-spacing: -0.02em;
    color: var(--midnight);
}

.app-header .subtitle {
    margin-top: 8px;
    color: var(--text-soft);
    font-size: 15px;
}

.toggle-switch {
    margin-top: 18px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-soft);
    letter-spacing: 0.04em;
    user-select: none;
}

.toggle-switch input { display: none; }

.toggle-track {
    width: 38px;
    height: 22px;
    background: var(--border);
    border-radius: 999px;
    position: relative;
    transition: background 200ms var(--ease);
}

.toggle-thumb {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 18px;
    height: 18px;
    background: #fff;
    border-radius: 50%;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
    transition: left 200ms var(--ease);
}

.toggle-switch input:checked + .toggle-track {
    background: var(--gold);
}

.toggle-switch input:checked + .toggle-track .toggle-thumb {
    left: 18px;
}

.toggle-switch input:checked ~ .toggle-text {
    color: var(--midnight);
}

.detected-key {
    text-align: center;
    margin-bottom: 24px;
    padding: 14px 20px;
    background: linear-gradient(135deg, rgba(201, 169, 97, 0.08), rgba(27, 40, 69, 0.04));
    border: 1px solid var(--gold-soft);
    border-radius: 14px;
}

.detected-key .label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-soft);
}

.detected-key .value {
    margin-top: 4px;
    font-size: 24px;
    font-weight: 500;
    color: var(--midnight);
    letter-spacing: -0.02em;
}

.detected-key .detail {
    font-size: 12px;
    color: var(--text-soft);
    margin-top: 4px;
}

/* === Views === */
.view {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: opacity 400ms var(--ease), transform 400ms var(--ease);
}

.view.hidden {
    display: none;
}

/* === Live display === */
.live-display {
    width: 100%;
    text-align: center;
    margin-bottom: 32px;
}

.note-display {
    font-size: 84px;
    font-weight: 300;
    letter-spacing: -0.04em;
    color: var(--midnight);
    line-height: 1;
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 6px;
    min-height: 84px;
}

#octave {
    font-size: 32px;
    color: var(--text-soft);
    font-weight: 300;
}

#cents-label {
    margin-top: 12px;
    font-size: 14px;
    color: var(--text-soft);
    letter-spacing: 0.04em;
    text-transform: uppercase;
    min-height: 18px;
    transition: color 200ms var(--ease);
}

#meter {
    margin: 24px auto 0;
    width: 320px;
    max-width: 100%;
}

.meter-track {
    position: relative;
    height: 44px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 22px;
    box-shadow: var(--shadow-sm) inset;
}

.meter-tick {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    font-size: 11px;
    color: var(--text-soft);
    letter-spacing: 0.05em;
}

.meter-tick-left { left: 14px; }
.meter-tick-right { right: 14px; }
.meter-tick-center {
    left: 50%;
    transform: translate(-50%, -50%);
    width: 1px;
    height: 14px;
    background: var(--border);
    color: transparent;
}

#meter-needle {
    position: absolute;
    top: 6px;
    bottom: 6px;
    width: 4px;
    left: 50%;
    background: var(--gold);
    border-radius: 2px;
    transform: translateX(-50%);
    transition: left 80ms linear, background 200ms var(--ease);
    box-shadow: 0 0 12px rgba(201, 169, 97, 0.4);
}

/* === Toggle button === */
.toggle-btn {
    position: relative;
    width: 180px;
    height: 180px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    font-family: inherit;
    font-size: 18px;
    font-weight: 500;
    letter-spacing: 0.12em;
    color: var(--midnight);
    background: linear-gradient(145deg, #E8D9B0, #C9A961);
    box-shadow: var(--shadow-md);
    transition: transform 300ms var(--ease), box-shadow 300ms var(--ease), background 400ms var(--ease), color 300ms var(--ease);
    margin-top: 16px;
}

.toggle-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.toggle-btn:active {
    transform: translateY(0);
}

.toggle-btn.active {
    background: linear-gradient(145deg, #F08C70, #E76F51);
    color: #fff;
    animation: pulse 1.6s var(--ease) infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 8px 24px rgba(231, 111, 81, 0.3), 0 0 0 0 rgba(231, 111, 81, 0.4);
    }
    50% {
        box-shadow: 0 8px 24px rgba(231, 111, 81, 0.4), 0 0 0 18px rgba(231, 111, 81, 0);
    }
}

#waveform {
    margin-top: 40px;
    width: 100%;
    max-width: 640px;
    height: 120px;
    border-radius: 16px;
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
}

/* === Dashboard === */
.dashboard {
    width: 100%;
    background: var(--surface);
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
    animation: dashboardIn 500ms var(--ease);
}

@keyframes dashboardIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.score-card {
    text-align: center;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 28px;
}

.score-label {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-soft);
}

.score-value {
    font-size: 96px;
    font-weight: 300;
    color: var(--gold);
    line-height: 1.05;
    letter-spacing: -0.04em;
    margin-top: 4px;
}

.score-out-of {
    font-size: 14px;
    color: var(--text-soft);
}

.highlight-row {
    display: flex;
    gap: 16px;
    margin-bottom: 28px;
}

.highlight {
    flex: 1;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 16px 20px;
}

.highlight .label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-soft);
}

.highlight .value {
    margin-top: 6px;
    font-size: 22px;
    font-weight: 500;
    color: var(--midnight);
}

.highlight .detail {
    font-size: 13px;
    color: var(--text-soft);
    margin-top: 2px;
}

.highlight.best { border-color: var(--green); }
.highlight.worst { border-color: var(--coral); }

.table-wrap {
    overflow-x: auto;
    margin-bottom: 28px;
}

#per-note-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
}

#per-note-table th {
    text-align: left;
    padding: 12px 16px;
    font-weight: 500;
    color: var(--text-soft);
    border-bottom: 1px solid var(--border);
    text-transform: uppercase;
    font-size: 11px;
    letter-spacing: 0.08em;
}

#per-note-table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border);
}

#per-note-table tbody tr:last-child td {
    border-bottom: none;
}

#per-note-table tbody tr.row-best { background: rgba(107, 175, 110, 0.08); }
#per-note-table tbody tr.row-worst { background: rgba(231, 111, 81, 0.06); }

.precision-bar {
    display: inline-block;
    width: 100px;
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    overflow: hidden;
    vertical-align: middle;
    margin-right: 8px;
}

.precision-bar > span {
    display: block;
    height: 100%;
    border-radius: 3px;
}

.secondary-btn {
    display: block;
    margin: 0 auto;
    background: transparent;
    border: 1px solid var(--midnight);
    color: var(--midnight);
    padding: 12px 28px;
    border-radius: 999px;
    font-family: inherit;
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 0.08em;
    cursor: pointer;
    transition: background 200ms var(--ease), color 200ms var(--ease);
}

.secondary-btn:hover {
    background: var(--midnight);
    color: #fff;
}

@media (max-width: 520px) {
    .note-display { font-size: 64px; }
    .toggle-btn { width: 150px; height: 150px; font-size: 16px; }
    .dashboard { padding: 28px 20px; }
    .highlight-row { flex-direction: column; }
    .score-value { font-size: 72px; }
}