:root {
    --bg-color: #1a1a1a;
    --panel-color: #2c2c2c;
    --display-bg: #1e4d22;
    --text-color: #e0e0e0;
    --accent-color: #00ff41;
    --font-7seg: 'Chakra Petch', 'Orbitron', sans-serif; /* 7-segment style font */
    --font-ui: 'Roboto Mono', monospace; /* UI font for readability */
    --border-color: #444;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle, #333 1px, transparent 1px);
    background-size: 20px 20px;
    font-family: var(--font-ui);
    color: var(--text-color);
    padding: 20px;
    box-sizing: border-box;
}

.synth-body {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 20px;
    background: #222;
    border-radius: 10px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5), inset 0 2px 2px rgba(255,255,255,0.1);
    border: 2px solid #111;
    width: 100%;
    max-width: 950px;
}

.display-section, .controls-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.module {
    background: var(--panel-color);
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 15px;
    box-shadow: inset 0 1px 1px rgba(255,255,255,0.05);
}
.module legend {
    padding: 0 10px;
    margin-left: 10px;
    font-size: 0.8em;
    font-weight: bold;
    color: #aaa;
}

.display-module {
    background: #111;
    border-color: #000;
}
.clock-display {
    font-family: var(--font-7seg); /* 7-segment font ONLY here */
    font-size: 3.5em;
    color: var(--accent-color);
    text-shadow: 0 0 5px var(--accent-color), 0 0 10px var(--accent-color);
    padding: 10px;
    background: var(--display-bg);
    border-radius: 5px;
    border: 2px solid #333;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
}
.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 10px;
}
.info-panel {
    background: var(--display-bg);
    border-radius: 5px;
    padding: 10px;
    font-family: var(--font-ui); /* Readable UI font */
    font-size: 1.2em;
    color: var(--accent-color);
    text-shadow: 0 0 3px var(--accent-color);
}
.freq-panel {
    display: flex;
    justify-content: space-between;
    padding: 10px;
}
.freq-value { min-width: 90px; text-align: left; }
.freq-label-h { font-weight: bold; color: #757575; }
.freq-label-m { font-weight: bold; color: #4285F4; }
.freq-label-s { font-weight: bold; color: #E63946; }

canvas#oscilloscopeCanvas {
    background: #000;
    border-radius: 5px;
    width: 100%;
    height: auto;
    aspect-ratio: 3.5 / 1;
}

#soundToggleButton {
    padding: 10px; border-radius: 5px; border: 1px solid #111; font-weight: bold; font-family: var(--font-ui); font-size: 1em; cursor: pointer; transition: all 0.2s; width: 100%; background: #c0392b; color: white; box-shadow: 0 2px 2px #111;
}
#soundToggleButton.on { background: #27ae60; }
#soundToggleButton:hover { filter: brightness(1.2); }

.control-group {
    background: var(--panel-color);
    border-radius: 5px;
    padding: 15px;
}
.group-label {
    display: block;
    margin-bottom: 10px;
    font-weight: bold;
    text-align: left;
    font-size: 0.8em;
    color: #aaa;
}
.waveform-controls, .volume-controls, .time-controls, .master-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
}

.synth-btn, #syncButton {
    padding: 8px; border-radius: 5px; border: 1px solid #111; background: #3d3d3d; color: var(--text-color); cursor: pointer; transition: all 0.2s; font-size: 0.9em; flex-grow: 1; box-shadow: 0 2px 2px #111;
}
.synth-btn:hover, #syncButton:hover { background: #4f4f4f; }
.synth-btn.active { background: var(--accent-color); color: #111; font-weight: bold; }

.slider-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    flex-grow: 1;
    font-size: 0.8em;
}
.slider-group.full-width { width: 100%; }
input[type="range"] {
    -webkit-appearance: none; width: 100%; height: 5px; background: #111; border-radius: 5px; outline: none;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; appearance: none; width: 15px; height: 25px; background: #ddd; border-radius: 3px; cursor: pointer; border: 1px solid #111;
}

input[type="number"] {
    width: 35px; height: 25px; border: 1px solid #111; background: #333; border-radius: 5px; color: var(--text-color); text-align: center; font-family: var(--font-ui);
}

@media (max-width: 850px) {
    body { padding: 10px; }
    .synth-body { grid-template-columns: 1fr; }
    .display-section { order: 1; }
    .controls-section { order: 2; }
}