/* --- DESIGN SYSTEM & VARIABLES --- */
:root {
    /* Color Palette - Premium Light Theme */
    --bg-app: #faf9f6;          /* Warm porcelain background */
    --bg-card: #ffffff;         /* Pure white cards */
    --bg-card-hover: #fcfbfa;
    --bg-control: #f3f0e9;      /* Smooth cream gray for controls */
    --bg-control-hover: #eae6db;
    
    --border-color: #eae6db;    /* Subtle separation lines */
    --border-color-focus: #c2ba9d;
    
    /* Text Colors */
    --text-primary: #2d2c2a;    /* Off-black slate */
    --text-secondary: #706e67;  /* Muted warm gray */
    --text-tertiary: #b0aca2;   /* Very light gray/label */
    
    /* Instrument Themes */
    --color-kick: #ff6b6b;      /* Sunset Coral */
    --color-snare: #7048e8;     /* Deep Violet */
    --color-hat: #0ca678;       /* Emerald Teal */
    --color-perc: #f59f00;      /* Warm Amber */
    
    --color-playhead: #1098ad;  /* Cyan Playhead */
    
    /* Font Stack */
    --font-main: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(45, 44, 42, 0.03);
    --shadow-md: 0 8px 16px rgba(45, 44, 42, 0.05);
    --shadow-lg: 0 16px 32px rgba(45, 44, 42, 0.08);
    --shadow-inner: inset 0 2px 4px rgba(45, 44, 42, 0.04);
    
    /* Borders */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-round: 9999px;
}

/* --- RESET & BASIC STYLES --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-app);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    padding: 2rem 1.5rem;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* --- APP CONTAINER LAYOUT --- */
.app-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* --- HEADER & TABS NAVIGATION --- */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    flex-wrap: wrap;
    gap: 1rem;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 32px;
    height: 32px;
    color: var(--text-primary);
    animation: pulse-logo 2s infinite ease-in-out;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Tabs system */
.tabs-nav {
    display: flex;
    background-color: var(--bg-control);
    padding: 0.25rem;
    border-radius: var(--radius-round);
    border: 1px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem 1.25rem;
    border-radius: var(--radius-round);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.tab-btn:hover {
    color: var(--text-primary);
}

.tab-btn.active {
    color: var(--bg-card);
    background-color: var(--text-primary);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.35s ease;
}

.header-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--bg-card);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-round);
    border: 1px solid var(--border-color);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
}

.pulse-dot {
    width: 8px;
    height: 8px;
    background-color: #37b24d;
    border-radius: 50%;
    position: relative;
}

.pulse-dot::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: inherit;
    border-radius: inherit;
    animation: outer-pulse 1.5s infinite ease-out;
}

/* --- MAIN PANEL GRID --- */
.app-main {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.panel {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* --- CARDS & PANELS --- */
.card {
    background-color: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.card-tag {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
    background-color: var(--bg-app);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-round);
}

/* --- RHYTHM CARD SPECIALS --- */
.rhythm-card {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.navigation-arrows {
    display: flex;
    gap: 0.5rem;
}

.btn {
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 600;
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-primary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.btn:hover {
    background-color: var(--bg-app);
    border-color: var(--border-color-focus);
}

.btn:active {
    transform: scale(0.97);
}

.btn-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    padding: 0;
}

.btn-icon svg {
    width: 18px;
    height: 18px;
}

.btn-nav svg {
    color: var(--text-secondary);
}

.rhythm-details {
    margin-bottom: 1.5rem;
}

.rhythm-title {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -1px;
    line-height: 1.1;
    margin-bottom: 0.25rem;
    color: var(--text-primary);
}

.rhythm-genre {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.rhythm-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.rhythm-meta-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: 1.25rem 0;
    margin-bottom: 1.5rem;
}

.meta-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.meta-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-tertiary);
}

.meta-val {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* Rhythm Chips Selector */
.rhythm-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.rhythm-chip {
    padding: 0.4rem 0.8rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-round);
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.rhythm-chip:hover {
    background-color: var(--bg-app);
    border-color: var(--border-color-focus);
}

.rhythm-chip.active {
    background-color: var(--text-primary);
    color: var(--bg-card);
    border-color: var(--text-primary);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

/* --- PLAYBACK CONTROLS PANEL --- */
.controls-card {
    padding: 1.25rem;
}

.controls-row {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.btn-primary {
    background-color: var(--text-primary);
    color: var(--bg-card);
    border: 1px solid var(--text-primary);
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    box-shadow: 0 4px 12px rgba(45, 44, 42, 0.15);
}

.btn-primary:hover {
    background-color: var(--text-secondary);
    border-color: var(--text-secondary);
}

.btn-play {
    min-width: 160px;
    height: 48px;
    font-weight: 700;
    font-size: 0.95rem;
    border-radius: var(--radius-round);
}

.btn-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-content svg {
    width: 18px;
    height: 18px;
}

.hidden {
    display: none !important;
}

.divider {
    width: 1px;
    height: 40px;
    background-color: var(--border-color);
}

/* BPM controls */
.bpm-control-group, .volume-control-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    flex-grow: 1;
    min-width: 150px;
}

.control-label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
}

.bpm-interactive {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-control);
    border-radius: var(--radius-sm);
    padding: 0.25rem;
    border: 1px solid var(--border-color);
}

.btn-tiny {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    border: none;
    background-color: var(--bg-card);
    box-shadow: var(--shadow-sm);
}

.btn-tiny:hover {
    background-color: var(--bg-app);
}

.bpm-display-container {
    font-weight: 800;
    font-size: 1.1rem;
    color: var(--text-primary);
    display: flex;
    align-items: baseline;
    gap: 2px;
}

.bpm-unit {
    font-size: 0.65rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Volume controls */
.volume-interactive {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    height: 38px;
}

.icon-volume {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
    flex-shrink: 0;
}

/* Custom sliders */
.slider {
    -webkit-appearance: none;
    width: 100%;
    height: 4px;
    border-radius: var(--radius-round);
    background: var(--bg-control);
    outline: none;
    transition: background 0.2s;
}

.slider-bpm {
    margin-top: 0.5rem;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--text-primary);
    cursor: pointer;
    border: 2px solid var(--bg-card);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
    transition: transform 0.1s ease;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--text-primary);
    cursor: pointer;
    border: 2px solid var(--bg-card);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
    transition: transform 0.1s ease;
}

.slider::-moz-range-thumb:hover {
    transform: scale(1.2);
}

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

.utility-buttons .btn {
    padding: 0.6rem 1rem;
    border-radius: var(--radius-round);
}

.utility-buttons .btn svg {
    width: 16px;
    height: 16px;
    margin-right: 0.4rem;
    color: var(--text-secondary);
}

/* --- STEP SEQUENCER GRID CARD --- */
.sequencer-card {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
}

/* Sequencer Headers */
.sequencer-headers {
    display: flex;
    margin-bottom: 0.75rem;
    padding-right: 1px; /* Account for grid borders */
}

.instrument-header-spacer {
    width: 120px;
    flex-shrink: 0;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-tertiary);
}

.steps-header-grid {
    display: grid;
    grid-template-columns: repeat(16, 1fr);
    gap: 6px;
    flex-grow: 1;
}

.step-num {
    text-align: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-tertiary);
}

.step-num.label-downbeat {
    color: var(--text-secondary);
    font-weight: 700;
}

.sequencer-grid-container {
    position: relative;
}

/* Playhead Track Overlay */
.playhead-track-overlay {
    position: absolute;
    left: 120px;
    right: 0;
    top: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 10;
}

.playhead-bar {
    width: calc(100% / 16);
    height: 100%;
    background: linear-gradient(180deg, rgba(16, 152, 173, 0.06) 0%, rgba(16, 152, 173, 0.02) 100%);
    border-left: 2px solid var(--color-playhead);
    border-right: 2px solid transparent;
    opacity: 0;
    transform: translateX(0);
    transition: opacity 0.1s ease;
    border-radius: 4px;
}

.playhead-bar.active {
    opacity: 1;
}

/* Sequencer Grid Rows */
.sequencer-rows-wrapper {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sequencer-row {
    display: flex;
    align-items: center;
}

.instrument-control {
    width: 120px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 0.5rem;
}

.instrument-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--border-color);
}

.sequencer-row[data-instrument="kick"] .instrument-indicator { background-color: var(--color-kick); }
.sequencer-row[data-instrument="snare"] .instrument-indicator { background-color: var(--color-snare); }
.sequencer-row[data-instrument="hat"] .instrument-indicator { background-color: var(--color-hat); }
.sequencer-row[data-instrument="perc"] .instrument-indicator { background-color: var(--color-perc); }

.btn-instrument-audition {
    background: none;
    border: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    text-align: left;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: background-color 0.1s ease;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.btn-instrument-audition:hover {
    background-color: var(--bg-control);
}

.btn-instrument-audition svg {
    width: 12px;
    height: 12px;
    opacity: 0;
    color: var(--text-secondary);
    transition: opacity 0.15s ease;
}

.btn-instrument-audition:hover svg {
    opacity: 1;
}

/* 16 Steps Button Grid */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(16, 1fr);
    gap: 6px;
    flex-grow: 1;
}

.step-btn {
    aspect-ratio: 1 / 1;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-app);
    cursor: pointer;
    transition: all 0.12s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: var(--shadow-inner);
    position: relative;
    overflow: hidden;
}

/* Alternating beat block background shading for readability */
.step-btn[data-step-index="4"],
.step-btn[data-step-index="5"],
.step-btn[data-step-index="6"],
.step-btn[data-step-index="7"],
.step-btn[data-step-index="12"],
.step-btn[data-step-index="13"],
.step-btn[data-step-index="14"],
.step-btn[data-step-index="15"] {
    background-color: #f2efe7; /* Slightly darker shade for beats 2 and 4 */
}

.step-btn:hover {
    border-color: var(--border-color-focus);
    transform: scale(1.05);
}

.step-btn:active {
    transform: scale(0.95);
}

/* active step button styles */
.step-btn.active {
    border: none;
    transform: scale(1.02);
}

.sequencer-row[data-instrument="kick"] .step-btn.active {
    background-color: var(--color-kick);
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.4), inset 0 -2px 0 rgba(0, 0, 0, 0.15);
}

.sequencer-row[data-instrument="snare"] .step-btn.active {
    background-color: var(--color-snare);
    box-shadow: 0 4px 12px rgba(112, 72, 232, 0.4), inset 0 -2px 0 rgba(0, 0, 0, 0.15);
}

.sequencer-row[data-instrument="hat"] .step-btn.active {
    background-color: var(--color-hat);
    box-shadow: 0 4px 12px rgba(12, 166, 120, 0.4), inset 0 -2px 0 rgba(0, 0, 0, 0.15);
}

.sequencer-row[data-instrument="perc"] .step-btn.active {
    background-color: var(--color-perc);
    box-shadow: 0 4px 12px rgba(245, 159, 0, 0.4), inset 0 -2px 0 rgba(0, 0, 0, 0.15);
}

/* Playhead flash effect when step plays */
.step-btn.playing {
    filter: brightness(1.25) saturate(1.1);
}

/* Step Sequencer Footer */
.sequencer-footer {
    display: flex;
    margin-top: 0.75rem;
}

.beat-groups-labels {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px; /* Matches grid groupings visually */
    flex-grow: 1;
}

.beat-group-label {
    text-align: center;
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-tertiary);
    border-top: 1px solid var(--border-color);
    padding-top: 0.5rem;
}

/* --- TABS: DAW-STYLE PIANO ROLL GRID (4 STEPS) --- */
.piano-keyboard-spacer {
    width: 100px;
    flex-shrink: 0;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-tertiary);
    letter-spacing: 0.5px;
}

.piano-roll-rows-wrapper {
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.piano-roll-row {
    display: flex;
    align-items: stretch;
    height: 32px;
}

/* Keys column */
.piano-key {
    width: 100px;
    flex-shrink: 0;
    border: 1px solid #dcdad0;
    border-radius: 4px 0 0 4px;
    font-family: inherit;
    font-weight: 700;
    font-size: 0.75rem;
    text-align: right;
    padding-right: 0.65rem;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    cursor: pointer;
    transition: all 0.1s ease;
    box-shadow: var(--shadow-sm);
    position: relative;
    user-select: none;
}

.piano-key.white-key {
    background-color: #ffffff;
    color: var(--text-secondary);
}

.piano-key.black-key {
    background-color: #212529;
    color: #f8f9fa;
    border-color: #121416;
    z-index: 5;
}

.piano-key:hover {
    background-color: var(--bg-control-hover);
}

.piano-key.black-key:hover {
    background-color: #343a40;
}

.piano-key.playing {
    background-color: var(--color-playhead) !important;
    color: white !important;
    transform: translateX(2px);
}

/* Piano steps grid container (4 Columns) */
.triad-steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr) !important;
    gap: 6px;
    flex-grow: 1;
    padding-left: 6px;
}

.triad-step-btn {
    border: 1px solid var(--border-color);
    background-color: var(--bg-app);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.12s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: var(--shadow-inner);
}

/* Alternating columns shading for 4 steps triad roll */
.triad-step-btn[data-step-index="1"],
.triad-step-btn[data-step-index="3"] {
    background-color: #f2efe7; /* beats 2 and 4 shading */
}

.triad-step-btn:hover {
    border-color: var(--border-color-focus);
    transform: scale(1.03);
}

.triad-step-btn.active {
    background-color: var(--color-snare);
    box-shadow: 0 4px 10px rgba(112, 72, 232, 0.35), inset 0 -2px 0 rgba(0, 0, 0, 0.15);
    border: none;
}

.triad-step-btn.playing {
    filter: brightness(1.25) saturate(1.1);
}

/* Dual Chord Slots Layout */
.triad-comparison-container {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.chord-slot-box {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.85rem;
    background-color: var(--bg-app);
    display: flex;
    flex-direction: column;
    transition: border-color 0.2s ease;
}

.chord-slot-box#slot-a-box {
    border-left: 4px solid var(--color-kick);
}

.chord-slot-box#slot-b-box {
    border-left: 4px solid var(--color-snare);
}

.slot-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.slot-badge {
    font-size: 0.65rem;
    font-weight: 800;
    text-transform: uppercase;
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    color: white;
    letter-spacing: 0.5px;
}

.slot-badge.badge-a {
    background-color: var(--color-kick);
}

.slot-badge.badge-b {
    background-color: var(--color-snare);
}

.slot-steps-label {
    font-size: 0.65rem;
    font-weight: 700;
    color: var(--text-secondary);
}

.btn-compare {
    background: linear-gradient(135deg, var(--color-kick) 0%, var(--color-snare) 100%);
    border: none;
    color: white !important;
    box-shadow: 0 4px 12px rgba(112, 72, 232, 0.15);
    cursor: pointer;
}

.btn-compare:hover {
    filter: brightness(1.08);
    box-shadow: 0 6px 16px rgba(112, 72, 232, 0.25);
}

/* Chord Presets Chips */
.root-chips, .type-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    margin-top: 0.25rem;
    margin-bottom: 0.5rem;
}

.root-chip {
    padding: 0.25rem 0.45rem;
    font-size: 0.7rem;
    font-weight: 700;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s ease;
    min-width: 26px;
    text-align: center;
}

.root-chip.black-key {
    background-color: #f1ebd9;
}

.root-chip:hover {
    background-color: var(--bg-app);
    border-color: var(--border-color-focus);
}

.root-chip.active {
    background-color: var(--text-primary);
    color: var(--bg-card);
    border-color: var(--text-primary);
}

.type-chip {
    padding: 0.25rem 0.5rem;
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: var(--radius-round);
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s ease;
}

.type-chip:hover {
    background-color: var(--bg-app);
    border-color: var(--border-color-focus);
}

.type-chip.active {
    background-color: var(--color-snare);
    color: var(--bg-card);
    border-color: var(--color-snare);
}

.chord-slot-box#slot-a-box .type-chip.active {
    background-color: var(--color-kick);
    border-color: var(--color-kick);
}

.selector-group {
    margin-bottom: 0.5rem;
    display: flex;
    flex-direction: column;
}

.selector-group:last-child {
    margin-bottom: 0;
}

/* --- BOTTOM INSIGHTS ROW --- */
.insights-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

/* Visualizer Card */
.visualizer-card {
    display: flex;
    flex-direction: column;
}

.visualizer-status {
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--color-playhead);
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.visualizer-status::before {
    content: '';
    display: inline-block;
    width: 6px;
    height: 6px;
    background-color: currentColor;
    border-radius: 50%;
    animation: flash 1s infinite alternate;
}

.canvas-container {
    width: 100%;
    height: 160px;
    background-color: var(--bg-app);
    border-radius: var(--radius-sm);
    overflow: hidden;
    border: 1px solid var(--border-color);
    position: relative;
}

#visualizer-canvas {
    width: 100%;
    height: 100%;
    display: block;
}

/* Cultural Context Card */
.context-card {
    display: flex;
    flex-direction: column;
}

.context-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    height: 100%;
    justify-content: space-between;
}

.structure-breakdown h4 {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    letter-spacing: 0.5px;
}

.structure-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.structure-list li {
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.structure-list li::before {
    content: '→';
    color: var(--text-tertiary);
    font-weight: bold;
}

.musical-tip {
    display: flex;
    gap: 0.75rem;
    background-color: #f1f3f5;
    padding: 0.85rem;
    border-radius: var(--radius-sm);
    align-items: flex-start;
}

.tip-icon {
    color: var(--text-secondary);
    flex-shrink: 0;
    width: 18px;
    height: 18px;
    margin-top: 2px;
}

.tip-icon svg {
    width: 100%;
    height: 100%;
}

.tip-text {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* --- FOOTER --- */
.app-footer {
    text-align: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-tertiary);
    padding: 1.5rem 0;
    border-top: 1px solid var(--border-color);
}

/* --- KEYFRAME ANIMATIONS --- */
@keyframes outer-pulse {
    0% {
        transform: scale(1);
        opacity: 0.8;
    }
    100% {
        transform: scale(2.4);
        opacity: 0;
    }
}

@keyframes flash {
    0% { opacity: 0.3; }
    100% { opacity: 1; }
}

@keyframes pulse-logo {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.06); }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(6px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* --- RESPONSIVE DESIGN --- */
@media (max-width: 900px) {
    .app-main {
        grid-template-columns: 1fr !important;
    }
    
    .insights-grid {
        grid-template-columns: 1fr;
    }
    
    body {
        padding: 1rem;
    }
}

@media (max-width: 600px) {
    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .divider {
        display: none;
    }
    
    .bpm-control-group, .volume-control-group {
        width: 100%;
    }
    
    .sequencer-headers {
        display: none; /* Hide top steps numbers on small screens to save space */
    }
    
    .instrument-header-spacer {
        width: 80px;
        font-size: 0.7rem;
    }
    
    .instrument-control {
        width: 80px;
    }
    
    .playhead-track-overlay {
        left: 80px;
    }
    
    .playhead-track-overlay[style] {
        left: 70px !important; /* overrides inline styles on mobile for piano roll */
    }
    
    .piano-keyboard-spacer {
        width: 70px;
        font-size: 0.7rem;
    }
    
    .piano-key {
        width: 70px;
        font-size: 0.65rem;
    }
    
    .sequencer-footer {
        display: none;
    }
    
    .utility-buttons {
        justify-content: space-between;
        width: 100%;
    }
    
    .utility-buttons .btn {
        flex-grow: 1;
    }
}