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

input[type="range"].effect-mix-slider {
    -webkit-appearance: none;
    appearance: none;
    height: 5px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    outline: none;
}

input[type="range"].effect-mix-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 8px;
    height: 18px;
    background: #5ddc62;
    border-radius: 2px;
    cursor: pointer;
}

input[type="range"].effect-mix-slider::-moz-range-thumb {
    width: 8px;
    height: 18px;
    background: #5ddc62;
    border-radius: 2px;
    cursor: pointer;
    border: none;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #3a4657, #4a5667);
    color: #fff;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    backdrop-filter: blur(10px);
}

h1 {
    font-size: 2.5em;
    font-weight: 300;
}

.midi-status {
    display: flex;
    align-items: center;
    gap: 15px;
}

#midi-status {
    padding: 10px 15px;
    border-radius: 20px;
    font-weight: bold;
}

#midi-status.connected {
    background: #4CAF50;
}

#midi-status.disconnected {
    background: #f44336;
}

button {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    cursor: pointer;
    transition: all 0.3s ease;
}

button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

.channel-panel, .synth-controls.channel-panel {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px;
    border-radius: 8px;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    min-height: 0;
}

#reset-channel {
    float: right;
    margin-top: -4px;   /* Fine-tune alignment with text */
    padding: 4px 10px;
    font-size: 0.9rem;
    background: #ff9800;
    color: #000;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    margin-left: 10px;
}

#save-channel {
    float: right;
    margin-top: -4px;   /* Fine-tune alignment with text */
    padding: 4px 10px;
    font-size: 0.9rem;
    background: #5ddc62; 
    color: #000;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    margin-left: 10px;
}

.synth-controls h2 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 1.3em;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding-bottom: 10px;
}

.channel-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    gap: 6px;
    height: 100%;
    max-height: none;
}

.channel-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
    height: 100%;
    min-height: 0;
}

.channel-item:hover {
    background: rgba(255, 255, 255, 0.2);
}

.channel-item.active {
    background: rgba(76, 175, 80, 0.3);
    outline: 2px solid #4CAF50;
    outline-offset: -2px;
}

.channel-item.has-active-notes {
    background: rgba(255, 193, 7, 0.2);
    outline: 2px solid #FFC107;
    outline-offset: -2px;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0% {
        background: rgba(255, 193, 7, 0.2);
    }
    50% {
        background: rgba(255, 193, 7, 0.4);
    }
    100% {
        background: rgba(255, 193, 7, 0.2);
    }
}

.channel-item h4 {
    margin: 0 0 4px 0;
    font-size: 1em;
    font-weight: bold;
}

.channel-item p {
    margin: 0;
    font-size: 0.85em;
    opacity: 0.8;
    line-height: 1.2;
}

.channel-volume-control {
    margin-top: 6px;
    padding-top: 6px;
}

input[type="range"].channel-volume-slider {
    width: 100%;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    outline: none;
    border-radius: 2px;
    margin-bottom: 10px;
    cursor: pointer;
}

input[type="range"].channel-volume-slider::-webkit-slider-thumb {
    appearance: none;
    width: 8px;
    height: 14px;
    background: #5ddc62;
    border-radius: 2px;
    cursor: pointer;
}

input[type="range"].channel-volume-slider::-moz-range-thumb {
    width: 8px;
    height: 14px;
    background: #5ddc62;
    border-radius: 2px;
    cursor: pointer;
    border: none;
}

.volume-value {
    font-size: 0.7em;
    color: #ccc;
    font-weight: normal;
    display: block;
    text-align: center;
}

.control-section h3 {
    margin-bottom: 15px;
    color: #5ddc62;
}

.control-group {
    margin-bottom: 15px;
}

.control-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.control-group select,
.control-group input[type="range"] {
    width: 100%;
    margin-bottom: 5px;
}

.control-group span {
    font-size: 0.9em;
    opacity: 0.8;
}

.filter-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

.adsr-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.adsr-controls > div {
    background: rgba(255, 255, 255, 0.05);
    padding: 10px;
    border-radius: 5px;
}

.keyboard-section {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
    backdrop-filter: blur(10px);
}

.virtual-keyboard {
    display: flex;
    justify-content: center;
    padding: 20px;
    overflow-x: auto;
    position: relative;
    gap: 0;
}

.piano-key {
    cursor: pointer;
    user-select: none;
    transition: all 0.1s ease;
    flex-shrink: 0;
}

.white-key {
    width: 40px;
    height: 120px;
    background: #fff;
    border: 1px solid #ccc;
    color: #333;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 10px;
    border-radius: 0 0 5px 5px;
    margin: 0 1px;
}

.white-key:hover {
    background: #f0f0f0;
}

.white-key.active {
    background: #4CAF50;
    transform: translateY(2px);
}

.black-key {
    width: 25px;
    height: 80px;
    background: #333;
    color: #fff;
    border-radius: 0 0 3px 3px;
    z-index: 3;
    margin: 0 -12.5px;
    position: relative;
    align-self: flex-start;
    font-size: 10px;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 5px;
}

.black-key:hover {
    background: #555;
}

.black-key.active {
    background: #2E7D32;
    transform: translateY(2px);
}

.visualizer {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 10px;
    text-align: center;
    backdrop-filter: blur(10px);
}

#spectrum-analyzer {
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    background: rgba(0, 0, 0, 0.2);
}

.effects-section {
    margin-top: 20px;
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 30px;
    backdrop-filter: blur(10px);
}

.effects-section h2 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 1.3em;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding-bottom: 10px;
}

.effects-chain {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.effect-unit {
    background: rgba(255, 255, 255, 0.08);
    padding: 15px;
    border-radius: 8px;
    text-align: left;
}

.effect-header {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
}

.effect-toggle {
    width: 24px;
    height: 24px;
    margin-right: 12px;
    cursor: pointer;
    appearance: none;
    background-color: #4CAF50;
    border: 2px solid #00ff88;
    border-radius: 4px;
    position: relative;
    transition: all 0.3s ease;
}

.effect-toggle:checked {
    background-color: #00ff88;
    border-color: #00ff88;
}

.effect-toggle:checked::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #4CAF50;
    font-size: 16px;
    font-weight: bold;
}

.effect-title {
    cursor: pointer;
    flex: 1;
    text-align: center;
}

.effect-title h3 {
    margin: 0 0 5px 0;
    font-size: 1.1em;
    color: #5ddc62;
}

.effect-title h4 {
    margin: 0;
    font-size: 0.9em;
    color: #ccc;
    font-weight: normal;
}

.effect-unit input[type="range"]:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.effect-unit input[type="range"]:disabled + span {
    opacity: 0.4;
}

.effect-controls {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.effect-controls .control-group {
    margin-bottom: 0;
}

.effect-controls label {
    font-size: 0.9em;
    margin-bottom: 3px;
}

.effect-controls input[type="range"] {
    margin-bottom: 3px;
}

.effect-controls span {
    font-size: 0.8em;
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .channel-list {
        grid-template-columns: 1fr;
    }
    
    .adsr-controls {
        grid-template-columns: 1fr;
    }
    
    .white-key {
        width: 30px;
        height: 100px;
    }
    
    .black-key {
        width: 20px;
        height: 65px;
        margin-left: -10px;
        margin-right: -10px;
    }
}

input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    height: 5px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 15px;
    height: 15px;
    background: #5ddc62;
    border-radius: 50%;
    cursor: pointer;
}

input[type="range"]::-moz-range-thumb {
    width: 15px;
    height: 15px;
    background: #5ddc62;
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

select {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 5px;
    padding: 8px;
}

select option {
    background: #333;
    color: #fff;
}

/* ===== Random Note Panel ===== */
.random-note-section {
    margin-top: 20px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    text-align: center;
}

.random-note-section h2 {
    margin: 0 0 15px;
    font-size: 1.3rem;
    color: #00ff88;
}

.random-note-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.random-note-grid {
    display: grid;
    grid-template-columns: repeat(25, 1fr);
    gap: 3px;           /* Tighter spacing */
    width: 100%;
}

.random-note-btn {
    padding: 2px 1px;     /* Tighter horizontal padding */
    font-size: 0.7rem;    /* Smaller font size */
    border: 1px solid #555;
    background: #222;
    color: #eee;
    border-radius: 3px;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
    aspect-ratio: 1 / 1;  /* Square aspect ratio */
}

.random-note-btn:hover {
    background: #333;
}

.random-note-btn.active {
    background: #ff9800;   /* Orange, matching random note light */
    color: #000;
    border-color: #ff9800;
}

.random-note-controls {
    margin-top: 8px;   /* Halve top margin */
    text-align: center;
    font-size: 0.85rem; /* Scale down font size synchronously */
}

.random-note-controls label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: #ccc;
    cursor: pointer;
}

.random-note-controls input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #ff9800;   /* Orange, matching random note light */
}

/* ===== Random Note Highlight Color ===== */
.piano-key.random-active {
    background: #ff9800 !important; /* Orange, distinguish from green input light */
    color: #000 !important;
    border-color: #ff9800 !important;
}

/* Start playing full-screen overlay */
.start-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 1;
  transition: opacity .4s ease;
}
.start-overlay.fade-out {
  opacity: 0;
  pointer-events: none;
}

.start-audio-btn {
  padding: 1.2rem 2.4rem;
  font-size: 1.5rem;
  color: #fff;
  background: #4CAF50;          /* Primary green */
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background .25s, transform .25s;
}
.start-audio-btn:hover {
  background: #388E3C;
  transform: translateY(-2px);
}

/* Toast message style */
.toast-message {
    position: fixed;
    top: 40px;
    right: 40px;
    padding: 15px 20px;
    border-radius: 5px;
    color: #fff;
    z-index: 1001;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    opacity: 0;
    transform: translateX(100%);
    animation: slideIn 0.5s forwards;
}

@keyframes slideIn {
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.toast-message.success {
    background-color: rgb(76, 175, 80); /* Green */
}

.toast-message.error {
    background-color: rgb(244, 67, 54); /* Red */
}

.toast-message.info {
    background-color: rgb(158, 158, 158); /* Gray */
}