:root {
    --bg-dark: #0A0A2E;
    --bg-panel: #14143D;
    --primary: #00FF87;
    --accent: #FF6B6B;
    --text-main: #FFFFFF;
    --text-muted: #8E8EA8;
    --grid-bg: #1E1E4F;
    --grid-border: #2D2D6A;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.synth-container {
    background-color: var(--bg-dark);
    width: 100%;
    max-width: 1200px;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background-color: var(--bg-panel);
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    border: 1px solid var(--grid-border);
}

h1 {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: 2px;
    color: var(--primary);
    text-shadow: 0 0 10px rgba(0, 255, 135, 0.4);
}

.master-controls {
    display: flex;
    gap: 20px;
    align-items: center;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.control-group label {
    font-size: 12px;
    color: var(--text-muted);
}

/* UI Elements */
.btn {
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: 'Inter', sans-serif;
    border: none;
}

.btn.primary {
    background-color: var(--primary);
    color: var(--bg-dark);
    box-shadow: 0 0 15px rgba(0, 255, 135, 0.3);
}

.btn.primary:hover {
    background-color: #00DB75;
    transform: translateY(-2px);
    box-shadow: 0 0 20px rgba(0, 255, 135, 0.5);
}

.btn.outline {
    background-color: transparent;
    color: var(--accent);
    border: 1px solid var(--accent);
}

.btn.outline:hover {
    background-color: rgba(255, 107, 107, 0.1);
}

.btn.large {
    padding: 15px 30px;
    font-size: 18px;
}

/* Range Sliders */
input[type=range] {
    -webkit-appearance: none;
    width: 100%;
    background: transparent;
}
input[type=range]:focus {
    outline: none;
}
input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    cursor: pointer;
    background: var(--grid-bg);
    border-radius: 3px;
    border: 1px solid var(--grid-border);
}
input[type=range]::-webkit-slider-thumb {
    height: 16px;
    width: 16px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    -webkit-appearance: none;
    margin-top: -6px;
    box-shadow: 0 0 10px var(--primary);
}

select {
    background-color: var(--grid-bg);
    color: var(--text-main);
    border: 1px solid var(--grid-border);
    padding: 8px;
    border-radius: 6px;
    font-family: inherit;
    outline: none;
}

/* Oscilloscope */
.visualizer {
    background-color: var(--bg-panel);
    border-radius: 12px;
    padding: 10px;
    border: 1px solid var(--grid-border);
    display: flex;
    justify-content: center;
}

canvas {
    width: 100%;
    max-width: 800px;
    height: 150px;
    border-radius: 8px;
    background-color: #030310;
    box-shadow: inset 0 0 20px rgba(0,0,0,0.8);
}

/* Modules */
.synth-modules {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.module {
    background-color: var(--bg-panel);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--grid-border);
}

.module h2 {
    font-size: 14px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 15px;
    border-bottom: 1px solid var(--grid-border);
    padding-bottom: 8px;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.controls.column {
    flex-direction: column;
}

.control {
    flex: 1;
    min-width: 60px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control.flex-row {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}

.control label {
    font-size: 11px;
    color: #A0A0C0;
    display: flex;
    justify-content: space-between;
}
.control .val {
    color: var(--primary);
    font-variant-numeric: tabular-nums;
}

/* Sequencer */
.sequencer-section {
    background-color: var(--bg-panel);
    border-radius: 12px;
    padding: 20px;
    border: 1px solid var(--grid-border);
}

.seq-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.seq-header h2 {
    font-size: 16px;
    color: var(--text-main);
}

#sequencer-grid {
    display: grid;
    gap: 4px;
    overflow-x: auto;
    padding-bottom: 10px;
}

.seq-row {
    display: grid;
    grid-template-columns: 40px repeat(16, minmax(35px, 1fr));
    gap: 4px;
}

.seq-label {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 8px;
    font-size: 12px;
    color: var(--text-muted);
    font-weight: bold;
}

.step {
    aspect-ratio: 1;
    background-color: var(--grid-bg);
    border-radius: 4px;
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.1s;
}

.step:hover {
    background-color: var(--grid-border);
}

.step.active {
    background-color: var(--primary);
    box-shadow: 0 0 10px var(--primary);
}

.step.active.playing {
    background-color: #FFFFFF;
    box-shadow: 0 0 15px #FFFFFF;
}

.step.playing {
    border-color: var(--primary);
    background-color: rgba(0, 255, 135, 0.2);
}

.seq-row:nth-child(even) .step {
    background-color: rgba(30,30,79, 0.5);
}

.seq-row:nth-child(even) .step:hover {
    background-color: var(--grid-border);
}

.seq-row:nth-child(even) .step.active {
    background-color: var(--accent);
    box-shadow: 0 0 10px var(--accent);
}

.seq-row:nth-child(even) .step.active.playing {
    background-color: #FFFFFF;
    box-shadow: 0 0 15px #FFFFFF;
}

/* Piano Keyboard */
.keyboard-section {
    padding: 0 10px;
}

.piano {
    display: flex;
    height: 120px;
    position: relative;
    border-radius: 0 0 8px 8px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.key {
    flex: 1;
    background-color: #F8F9FA;
    border: 1px solid #DEE2E6;
    border-radius: 0 0 5px 5px;
    cursor: pointer;
    position: relative;
    transition: background-color 0.1s;
}

.key.black {
    background-color: #212529;
    border: 1px solid #000;
    height: 65%;
    width: 4%;
    position: absolute;
    z-index: 2;
    margin-left: -2%;
    border-radius: 0 0 4px 4px;
}

.key:active, .key.pressed {
    background-color: #E9ECEF;
    box-shadow: inset 0 5px 10px rgba(0,0,0,0.1);
}

.key.black:active, .key.black.pressed {
    background-color: #343A40;
}

.overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(10, 10, 46, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

.overlay.hidden {
    display: none;
}

.modal {
    background: var(--bg-panel);
    padding: 40px;
    border-radius: 16px;
    border: 1px solid var(--grid-border);
    text-align: center;
    max-width: 400px;
}

.modal h2 {
    color: var(--primary);
    margin-bottom: 15px;
}

.modal p {
    color: var(--text-muted);
    margin-bottom: 25px;
    line-height: 1.5;
}

@media (max-width: 800px) {
    .piano { height: 80px; }
    .master-controls { flex-wrap: wrap; }
    #oscilloscope { height: 100px; }
}