:root {
    --bg-color: #1a202c;
    --surface-color: #2d3748;
    --primary-color: #4fd1c5;
    --text-color: #e2e8f0;
    --border-color: #4a5568;
    --piano-white: #ffffff;
    --piano-black: #2d3748;
    --pitch-color: #f6e05e;
    --hover-color: #81e6d9;
}

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

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

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
}

.title {
    font-size: 1.25rem;
    font-weight: 600;
}

.actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

/* --- View Toggle Switch --- */
.view-switch-label {
    position: relative;
    display: flex;
    align-items: center;
    background-color: var(--bg-color);
    border-radius: 999px;
    padding: 4px;
    cursor: pointer;
    border: 1px solid var(--border-color);
}
.view-switch-checkbox {
    display: none;
}
.toggle-option {
    padding: 0.3rem 1rem;
    font-size: 0.9rem;
    z-index: 1;
    transition: color 0.3s ease;
}
.view-switch-label::before {
    content: '';
    position: absolute;
    width: calc(50% - 4px);
    height: calc(100% - 8px);
    background-color: var(--primary-color);
    border-radius: 999px;
    transition: transform 0.3s ease-in-out;
    left: 4px;
}
.view-switch-checkbox:checked + .view-switch-label::before {
    transform: translateX(100%);
}
.view-switch-checkbox:not(:checked) + .view-switch-label .toggle-option:last-child,
.view-switch-checkbox:checked + .view-switch-label .toggle-option:first-child {
    color: var(--text-color);
}
.view-switch-checkbox:checked + .view-switch-label .toggle-option:last-child,
.view-switch-checkbox:not(:checked) + .view-switch-label .toggle-option:first-child {
    color: var(--bg-color);
    font-weight: 600;
}


/* --- Record Button --- */
.record-button {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: 8px;
    background-color: var(--primary-color);
    color: var(--bg-color);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
}
.record-button:hover {
    background-color: var(--hover-color);
}
.record-button:active {
    transform: scale(0.98);
}
.record-button.recording {
    background-color: #e53e3e; /* Red color for recording */
    color: var(--text-color);
}

#main_container {
    padding-top: 70px; /* Height of the header */
}

#canvas {
    position: absolute;
    top: 70px; /* Match main_container padding */
    left: 0;
    width: 100%;
    height: calc(100vh - 70px);
}

/* Responsive Design */
@media (max-width: 768px) {
    .controls {
        flex-direction: column;
        padding: 0.5rem;
        height: auto;
    }
    .title {
        margin-bottom: 0.5rem;
    }
    .actions {
        width: 100%;
        justify-content: space-around;
    }
    #main_container, #canvas {
        padding-top: 110px;
        top: 110px;
        height: calc(100vh - 110px);
    }
}