:root {
    --bg:           #0b0f14;
    --panel:        #151b23;
    --border:       #242c37;
    --text:         #e6edf3;
    --text-muted:   #8b96a3;
    --zone-silence: #6b7280;
    --zone-low:     #3b82f6;
    --zone-good:    #22c55e;
    --zone-loud:    #eab308;
    --zone-tooLoud: #ef4444;
    --zone-color:   var(--border);
}

/* Every component reads --zone-color: a data-zone attribute is all it takes to colour it. */
[data-zone="silence"] { --zone-color: var(--zone-silence); }
[data-zone="low"]     { --zone-color: var(--zone-low); }
[data-zone="good"]    { --zone-color: var(--zone-good); }
[data-zone="loud"]    { --zone-color: var(--zone-loud); }
[data-zone="tooLoud"] { --zone-color: var(--zone-tooLoud); }

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-user-select: none;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
}

html {
    overflow: hidden;
    overscroll-behavior: none;
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica", sans-serif;
}

#screen {
    width: 100vw;
    height: 100vh;  /* fallback for browsers without dvh support */
    height: 100dvh; /* dynamic viewport - iOS Safari toolbar */
}

/* ---------- Loading ---------- */

#progressBarContainer {
    position: fixed;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg);
    padding: 40px;
}

.loading-brand {
    font-size: 1.5em;
    font-weight: bold;
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-bottom: 32px;
}

.loading-bar-track {
    width: 100%;
    max-width: 320px;
    height: 6px;
    background: var(--panel);
    border-radius: 3px;
    overflow: hidden;
}

#progressBar {
    width: 0;
    height: 100%;
    background: var(--zone-good);
    transition: width 0.15s;
}

/* ---------- Layout ---------- */

.app {
    position: relative;
    height: 100%;
    max-width: 520px;
    margin: 0 auto;
    padding: max(12px, env(safe-area-inset-top)) 16px max(12px, env(safe-area-inset-bottom));
}

.start-view,
.meter-view {
    height: 100%;
    flex-direction: column;
}

.start-view {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
}

.meter-view {
    display: none;
    gap: 12px;
}

.app.listening .start-view {
    display: none;
}

.app.listening .meter-view {
    display: flex;
}

/* ---------- Buttons ---------- */

/* One style for every button; each class below only sets its size and place. */
button {
    font: inherit;
    font-weight: 600;
    background: transparent;
    border: 1px solid var(--zone-low);
    border-radius: 10px;
    color: var(--zone-low);
    cursor: pointer;
    transition: transform 0.1s;
}

button:active {
    transform: scale(0.97);
}

button:disabled {
    opacity: 0.6;
}

.btn-language {
    position: absolute;
    top: max(12px, env(safe-area-inset-top));
    left: 16px;
    z-index: 1;
    padding: 4px 10px;
    font-size: 0.8em;
    letter-spacing: 1px;
}

.btn-listen {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    font-size: 1.6em;
}

.actions {
    flex: none;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.actions button {
    padding: 10px;
}

.error {
    max-width: 300px;
    text-align: center;
    color: var(--zone-tooLoud);
}

/* ---------- Gauge and averages ---------- */

.level-row {
    flex: 1 1 auto;
    min-height: 0;
    display: flex;
    gap: 8px;
}

.gauge-container {
    flex: 1 1 auto;
    min-width: 0;
    min-height: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.gauge {
    width: 100%;
    height: 100%;
}

.gauge-zone {
    fill: none;
    stroke: var(--zone-color);
    stroke-width: 16;
}

.gauge-graduations line {
    stroke: var(--text-muted);
    stroke-width: 1;
}

.gauge-graduations line.major {
    stroke: var(--text);
    stroke-width: 1.5;
}

.gauge-graduations text {
    fill: var(--text-muted);
    font-size: 8px;
    text-anchor: middle;
    dominant-baseline: central;
}

/* Origin = VoiceMeterGauge.CX / CY. */
.gauge-needle {
    transform-box: view-box;
    transform-origin: 100px 96px;
    transition: transform 0.05s linear;
}

.gauge-needle line {
    stroke: var(--text);
    stroke-width: 3;
    stroke-linecap: round;
}

.gauge-needle circle {
    fill: var(--text);
}

.gauge-value {
    fill: var(--text);
    font-size: 22px;
    font-weight: 700;
    text-anchor: middle;
    font-variant-numeric: tabular-nums;
}

.gauge-label {
    fill: var(--zone-color);
    font-size: 11px;
    font-weight: 600;
    text-anchor: middle;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.averages {
    flex: none;
    width: 76px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 8px;
}

.average {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 8px 4px;
    border-radius: 10px;
    background: var(--panel);
    border: 1px solid var(--border);
    border-top: 3px solid var(--zone-color);
}

.average-value {
    font-size: 1.6em;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.average[data-zone]:not([data-zone=""]) .average-value {
    color: var(--zone-color);
}

.average-title {
    font-size: 0.75em;
    color: var(--text-muted);
}

/* ---------- History ---------- */

.history {
    position: relative;
    flex: none;
    height: clamp(64px, 14dvh, 120px);
    border-radius: 10px;
    background: var(--panel);
    border: 1px solid var(--border);
    overflow: hidden;
}

.history-canvas {
    display: block;
    width: 100%;
    height: 100%;
}

.history-title {
    position: absolute;
    top: 4px;
    left: 8px;
    font-size: 0.7em;
    color: var(--text-muted);
}

/* ---------- Thresholds ---------- */

.thresholds {
    flex: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 8px 12px;
    border-radius: 10px;
    background: var(--panel);
    border: 1px solid var(--border);
}

.threshold {
    display: grid;
    grid-template-columns: 7.5em 1fr 3.5em;
    align-items: center;
    gap: 8px;
    font-size: 0.85em;
}

.threshold-name {
    color: var(--text-muted);
}

.threshold-value {
    text-align: right;
    font-variant-numeric: tabular-nums;
}

.threshold input {
    width: 100%;
    accent-color: var(--zone-color);
}

@media (max-height: 560px) {
    .meter-view    { gap: 6px; }
    .average       { padding: 4px; }
    .average-value { font-size: 1.2em; }
    .history       { height: 56px; }
    .actions button { padding: 6px; }
}