/* Sound Design Course Styles */

/* Course Layout */
.course-layout {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.course-sidebar {
    width: 280px;
    background: var(--dark-surface);
    border-right: 1px solid var(--dark-border);
    padding: 1.5rem;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    flex-shrink: 0;
}

.sidebar-header {
    margin-bottom: 2rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--muted);
    font-size: 0.875rem;
    margin-bottom: 1rem;
    transition: color 0.2s;
}

.back-link:hover {
    color: var(--accent);
}

.sidebar-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--light);
    line-height: 1.3;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-bottom: 2rem;
}

.sidebar-link {
    padding: 0.625rem 0.875rem;
    border-radius: 0.5rem;
    color: var(--muted);
    font-size: 0.875rem;
    transition: all 0.2s;
}

.sidebar-link:hover {
    color: var(--light);
    background: rgba(255, 255, 255, 0.05);
}

.sidebar-link.active {
    color: var(--accent);
    background: rgba(167, 139, 250, 0.1);
}

.sidebar-meta {
    padding-top: 1.5rem;
    border-top: 1px solid var(--dark-border);
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--muted);
    font-size: 0.8125rem;
}

.meta-item svg {
    opacity: 0.7;
}

/* Main Content */
.course-main {
    flex: 1;
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 3rem 4rem;
}

/* Course Header Banner */
.course-header-banner {
    text-align: center;
    padding: 3rem 2rem;
    margin-bottom: 2rem;
    background: linear-gradient(135deg, rgba(167, 139, 250, 0.1) 0%, rgba(139, 92, 246, 0.05) 100%);
    border-radius: 1rem;
    border: 1px solid rgba(167, 139, 250, 0.2);
}

.course-category-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(167, 139, 250, 0.2);
    color: var(--accent);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: 1rem;
    margin-bottom: 1rem;
}

.course-header-banner h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--light);
    margin-bottom: 0.5rem;
}

.course-subtitle {
    color: var(--muted);
    font-size: 1.125rem;
}

/* Lesson Sections */
.lesson-section {
    padding: 3rem 0;
    border-bottom: 1px solid var(--dark-border);
}

.lesson-section:last-child {
    border-bottom: none;
}

.lesson-header {
    margin-bottom: 2rem;
}

.lesson-number {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.lesson-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--light);
}

/* Prose Content */
.prose {
    color: var(--muted);
    line-height: 1.75;
}

.prose p {
    margin-bottom: 1.25rem;
}

.prose .lead {
    font-size: 1.125rem;
    color: var(--light);
    line-height: 1.7;
}

.prose h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--light);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.prose ul, .prose ol {
    margin-bottom: 1.25rem;
    padding-left: 1.5rem;
}

.prose li {
    margin-bottom: 0.5rem;
}

.prose strong {
    color: var(--light);
    font-weight: 600;
}

.prose a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.prose a:hover {
    color: var(--light);
}

/* Interactive Containers */
.interactive-container {
    margin: 2rem 0;
    background: var(--dark-surface);
    border: 1px solid var(--dark-border);
    border-radius: 0.75rem;
    overflow: hidden;
}

.interactive-container.full-width {
    margin-left: -1rem;
    margin-right: -1rem;
}

.interactive-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    background: rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid var(--dark-border);
}

.interactive-label {
    font-size: 0.625rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    padding: 0.25rem 0.5rem;
    background: rgba(167, 139, 250, 0.15);
    border-radius: 0.25rem;
}

.interactive-title {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--light);
}

.interactive-body {
    padding: 1.5rem;
}

/* Buttons */
.btn-play, .btn-secondary, .btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.btn-play {
    background: var(--accent);
    color: var(--dark);
}

.btn-play:hover {
    background: var(--light);
    transform: translateY(-1px);
}

.btn-play:active {
    transform: translateY(0);
}

.btn-play-large {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    background: var(--accent);
    color: var(--dark);
}

.btn-play-large:hover {
    background: var(--light);
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: var(--muted);
    border: 1px solid var(--dark-border);
}

.btn-secondary:hover {
    color: var(--light);
    border-color: var(--muted);
}

.btn-primary {
    background: var(--accent);
    color: var(--dark);
}

.btn-primary:hover {
    background: var(--light);
}

.btn-create-sound {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 1.25rem 2.5rem;
    background: linear-gradient(135deg, var(--accent) 0%, #8b5cf6 100%);
    color: var(--dark);
    font-size: 1.125rem;
    font-weight: 700;
    border: none;
    border-radius: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 20px rgba(167, 139, 250, 0.3);
}

.btn-create-sound:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(167, 139, 250, 0.4);
}

.btn-create-sound:active {
    transform: translateY(0);
}

.btn-reset {
    background: transparent;
    color: var(--muted);
    border: 1px solid var(--dark-border);
    padding: 0.75rem 1.25rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-reset:hover {
    color: var(--light);
    border-color: var(--muted);
}

/* Sound Generator */
.sound-generator {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
}

.generator-hint {
    margin-top: 1rem;
    color: var(--muted);
    font-size: 0.875rem;
}

/* Three Sliders Demo */
.three-sliders-demo {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.slider-group {
    display: grid;
    grid-template-columns: 100px 1fr 50px;
    align-items: center;
    gap: 1rem;
}

.slider-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--light);
}

.slider-value {
    font-size: 0.8125rem;
    color: var(--muted);
    text-align: right;
}

/* Range Sliders */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: var(--dark-border);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.1s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

/* Select Dropdowns */
select {
    background: var(--dark);
    color: var(--light);
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
    cursor: pointer;
    outline: none;
}

select:focus {
    border-color: var(--accent);
}

/* Building Blocks Grid */
.building-blocks-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin: 1.5rem 0;
}

.block-card {
    background: rgba(167, 139, 250, 0.1);
    border: 1px solid rgba(167, 139, 250, 0.2);
    border-radius: 0.75rem;
    padding: 1.25rem;
}

.block-card h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

.block-card p {
    font-size: 0.875rem;
    color: var(--muted);
    margin: 0;
}

/* Pitch Explorer */
.pitch-explorer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.pitch-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    max-width: 400px;
}

.pitch-controls input[type="range"] {
    flex: 1;
}

.freq-display {
    font-family: monospace;
    font-size: 1rem;
    color: var(--accent);
    min-width: 80px;
    text-align: right;
}

/* Waveform Selector */
.waveform-selector {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.waveform-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.wave-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.5rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.wave-btn svg {
    width: 40px;
    height: 20px;
}

.wave-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.wave-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

/* Envelope Demo */
.envelope-demo, .movement-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.envelope-buttons, .movement-buttons {
    display: flex;
    gap: 0.5rem;
}

.env-btn, .mov-btn {
    padding: 0.625rem 1.25rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.5rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.env-btn:hover, .mov-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.env-btn.active, .mov-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

/* Combined Blocks */
.combined-blocks {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.block-controls {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.block-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
}

/* Filter Demo */
.filter-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.filter-controls {
    width: 100%;
    max-width: 400px;
}

.filter-controls.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.filter-controls.three-col {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1rem;
}

/* Sweep Demo */
.sweep-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.sweep-controls {
    width: 100%;
    max-width: 300px;
}

/* Filter Types */
.filter-types {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.filter-type-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 0.5rem 1rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.filter-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

/* Filter Envelope Demo */
.filter-env-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

/* ADSR Demo */
.adsr-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.adsr-controls {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    width: 100%;
    max-width: 500px;
}

.adsr-slider {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.adsr-slider label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
}

.adsr-slider input[type="range"] {
    width: 100%;
}

.adsr-slider span {
    font-size: 0.75rem;
    color: var(--muted);
    font-family: monospace;
}

/* ADSR Presets */
.adsr-presets {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.preset-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.preset-btn {
    padding: 0.5rem 1rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.preset-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.preset-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

.preset-description {
    text-align: center;
    font-size: 0.875rem;
    color: var(--muted);
    padding: 1rem;
    background: var(--dark);
    border-radius: 0.5rem;
    min-height: 3rem;
}

/* Filter ADSR */
.filter-adsr {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.dual-envelope-display {
    width: 100%;
    max-width: 500px;
}

.filter-adsr-controls {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    width: 100%;
    max-width: 400px;
}

/* LFO Visualizer */
.lfo-visualizer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.lfo-controls {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 1.5rem;
    width: 100%;
    max-width: 400px;
}

/* LFO Destination Demos */
.lfo-destination-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.dest-controls {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    width: 100%;
    max-width: 350px;
}

/* Sync Demo */
.sync-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.tempo-display {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.tempo-label {
    color: var(--muted);
}

.tempo-value {
    color: var(--accent);
    font-weight: 600;
    font-family: monospace;
}

.sync-buttons {
    display: flex;
    gap: 0.5rem;
}

.sync-btn {
    padding: 0.5rem 0.875rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    color: var(--muted);
    font-size: 0.8125rem;
    font-family: monospace;
    cursor: pointer;
    transition: all 0.2s;
}

.sync-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.sync-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

.sync-target {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.sync-target label {
    font-size: 0.875rem;
    color: var(--muted);
}

/* Effects Demo */
.effects-demo {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.effect-controls {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.effect-buttons {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
}

/* Combined FX */
.combined-fx {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.fx-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.fx-section h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.combined-fx > button {
    grid-column: 1 / -1;
    justify-self: center;
}

/* Other FX */
.other-fx {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.fx-tabs {
    display: flex;
    gap: 0.5rem;
}

.fx-tab {
    padding: 0.5rem 1rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.fx-tab:hover {
    border-color: var(--accent);
    color: var(--light);
}

.fx-tab.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

.fx-description {
    text-align: center;
    font-size: 0.875rem;
    color: var(--muted);
    max-width: 400px;
}

.fx-control {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    max-width: 300px;
}

.fx-control label {
    font-size: 0.875rem;
    color: var(--muted);
    white-space: nowrap;
}

.fx-control input[type="range"] {
    flex: 1;
}

/* Layer Compare */
.layer-compare {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.layer-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.layer-btn {
    padding: 0.625rem 1.25rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.5rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.layer-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.layer-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

/* Two Osc Mixer */
.two-osc-mixer {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.two-osc-mixer > .synth-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.osc-column {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    background: var(--dark);
    border-radius: 0.5rem;
}

.osc-column h5 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.mixer-filter {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--dark-border);
}

/* Detune Explorer */
.detune-explorer {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.detune-visual {
    width: 100%;
    max-width: 300px;
}

.detune-note {
    font-size: 0.75rem;
    color: var(--muted);
}

/* Unison Demo */
.unison-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.unison-controls {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    width: 100%;
    max-width: 350px;
}

.voice-buttons {
    display: flex;
    gap: 0.5rem;
}

.voice-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.5rem;
    color: var(--muted);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.voice-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.voice-btn.active {
    background: rgba(167, 139, 250, 0.15);
    border-color: var(--accent);
    color: var(--accent);
}

/* Three Layer */
.three-layer {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.layer-row {
    display: grid;
    grid-template-columns: 1fr 2fr auto;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 1rem;
    background: var(--dark);
    border-radius: 0.5rem;
}

.layer-info {
    display: flex;
    flex-direction: column;
}

.layer-name {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--light);
}

.layer-desc {
    font-size: 0.75rem;
    color: var(--muted);
}

.solo-btn {
    padding: 0.375rem 0.75rem;
    background: transparent;
    border: 1px solid var(--dark-border);
    border-radius: 0.25rem;
    color: var(--muted);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
}

.solo-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.solo-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--dark);
}

/* Mini Synthesizer */
.mini-synth {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.synth-section {
    padding: 1rem;
    background: var(--dark);
    border-radius: 0.5rem;
}

.synth-section h5 {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 1rem;
}

.synth-row {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.synth-row.adsr-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

.osc-panel {
    flex: 1;
    min-width: 150px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 0.75rem;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 0.375rem;
}

.panel-label {
    font-size: 0.6875rem;
    font-weight: 600;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.control-mini {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    flex: 1;
    min-width: 80px;
}

.control-mini label {
    font-size: 0.6875rem;
    color: var(--muted);
    text-transform: uppercase;
}

.control-mini select,
.control-mini input[type="range"] {
    width: 100%;
}

.control-mini select {
    padding: 0.375rem 0.5rem;
    font-size: 0.75rem;
}

.synth-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--dark-border);
}

.preset-section {
    display: flex;
    gap: 0.5rem;
}

.preset-load-btn {
    padding: 0.5rem 1rem;
    background: transparent;
    border: 1px solid var(--dark-border);
    border-radius: 0.375rem;
    color: var(--muted);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: all 0.2s;
}

.preset-load-btn:hover {
    border-color: var(--accent);
    color: var(--light);
}

.play-section {
    display: flex;
    gap: 0.75rem;
}

/* Boxes */
.principle-box, .practice-box, .summary-box {
    margin: 2rem 0;
    padding: 1.5rem;
    border-radius: 0.75rem;
}

.principle-box {
    background: linear-gradient(135deg, rgba(167, 139, 250, 0.1) 0%, rgba(139, 92, 246, 0.05) 100%);
    border: 1px solid rgba(167, 139, 250, 0.2);
}

.principle-box h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

.principle-box p {
    color: var(--light);
    margin-bottom: 0.5rem;
}

.principle-box p:last-child {
    margin-bottom: 0;
}

.practice-box {
    background: var(--dark-surface);
    border: 1px solid var(--dark-border);
}

.practice-box h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--light);
    margin-bottom: 1rem;
}

.practice-box ul, .practice-box ol {
    color: var(--muted);
    padding-left: 1.25rem;
    margin-bottom: 1rem;
}

.practice-box li {
    margin-bottom: 0.375rem;
}

.practice-box p {
    color: var(--muted);
    font-size: 0.875rem;
}

.summary-box {
    background: var(--dark);
    border: 1px solid var(--dark-border);
}

.summary-box h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--light);
    margin-bottom: 1rem;
}

.summary-box p {
    color: var(--muted);
    margin-bottom: 0.5rem;
}

.summary-box ul {
    color: var(--muted);
    padding-left: 1.25rem;
}

.summary-box li {
    margin-bottom: 0.375rem;
}

/* CTA Section */
.cta-section {
    padding-top: 3rem;
}

.cta-box {
    text-align: center;
    padding: 3rem 2rem;
    background: linear-gradient(135deg, rgba(167, 139, 250, 0.1) 0%, rgba(139, 92, 246, 0.05) 100%);
    border: 1px solid rgba(167, 139, 250, 0.2);
    border-radius: 1rem;
}

.cta-box h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--light);
    margin-bottom: 0.5rem;
}

.cta-box p {
    color: var(--muted);
    margin-bottom: 1.5rem;
}

.cta-form {
    display: flex;
    gap: 0.75rem;
    max-width: 400px;
    margin: 0 auto;
}

.cta-form input[type="email"] {
    flex: 1;
    padding: 0.75rem 1rem;
    background: var(--dark);
    border: 1px solid var(--dark-border);
    border-radius: 0.5rem;
    color: var(--light);
    font-size: 0.875rem;
}

.cta-form input[type="email"]:focus {
    outline: none;
    border-color: var(--accent);
}

.cta-form button {
    padding: 0.75rem 1.5rem;
}

/* Canvas */
canvas {
    display: block;
    width: 100%;
    height: auto;
    background: var(--dark);
    border-radius: 0.5rem;
}

/* Mobile Responsive */
@media (max-width: 1024px) {
    .course-sidebar {
        display: none;
    }

    .course-main {
        padding: 1.5rem;
    }
}

@media (max-width: 768px) {
    .course-header-banner h1 {
        font-size: 1.75rem;
    }

    .building-blocks-grid {
        grid-template-columns: 1fr;
    }

    .block-controls {
        grid-template-columns: 1fr;
    }

    .adsr-controls {
        grid-template-columns: repeat(2, 1fr);
    }

    .effect-controls {
        grid-template-columns: 1fr;
    }

    .combined-fx {
        grid-template-columns: 1fr;
    }

    .two-osc-mixer > .synth-row {
        grid-template-columns: 1fr;
    }

    .synth-row.adsr-row {
        grid-template-columns: repeat(2, 1fr);
    }

    .synth-controls {
        flex-direction: column;
        gap: 1rem;
    }

    .cta-form {
        flex-direction: column;
    }
}