/* ===========================
   CSS Variables & Theme
   =========================== */
:root {
    /* Dark Theme (Default) */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);

    --border-color: #334155;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);

    --glow-color: rgba(99, 102, 241, 0.3);
    --step-active: #6366f1;
    --step-inactive: #1e293b;
    --step-current: #8b5cf6;
}

[data-theme="light"] {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --accent-primary: #4f46e5;
    --accent-secondary: #7c3aed;
    --accent-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);

    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.05);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.05);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.05);

    --glow-color: rgba(79, 70, 229, 0.2);
    --step-active: #4f46e5;
    --step-inactive: #f1f5f9;
    --step-current: #7c3aed;
}

/* ===========================
   Base Styles
   =========================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
}

/* ===========================
   Glow Effects
   =========================== */
.glow {
    position: fixed;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.15;
    pointer-events: none;
    z-index: 0;
}

.glow-top-left {
    background: var(--accent-primary);
    top: -300px;
    left: -300px;
}

.glow-bottom-right {
    background: var(--accent-secondary);
    bottom: -300px;
    right: -300px;
}

/* ===========================
   Header
   =========================== */
.header {
    position: relative;
    z-index: 10;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-primary);
    text-decoration: none;
}

.logo-icon {
    width: 36px;
    height: 36px;
    color: var(--text-primary);
}

.logo-text-container {
    display: flex;
    flex-direction: column;
    gap: 0.125rem;
}

.logo-title-row {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.version-badge {
    background: var(--accent-gradient);
    color: white;
    font-size: 0.625rem;
    font-weight: 700;
    padding: 0.125rem 0.375rem;
    border-radius: 999px;
    letter-spacing: 0.05em;
    line-height: 1;
    box-shadow: 0 0 10px var(--glow-color);
}

.logo-text {
    font-weight: 700;
    font-size: 1.25rem;
    line-height: 1;
}

.logo-by {
    font-size: 0.625rem;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.theme-toggle {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: scale(1.05);
}

.theme-toggle .sun-icon,
.theme-toggle .moon-icon {
    transition: opacity 0.3s ease;
}

/* Default (Dark Theme) - Show Moon, Hide Sun */
.theme-toggle .sun-icon {
    display: none;
}

.theme-toggle .moon-icon {
    display: block;
}

/* Light Theme - Show Sun, Hide Moon */
[data-theme="light"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="light"] .theme-toggle .moon-icon {
    display: none;
}

/* ===========================
   Main Container
   =========================== */
.container {
    position: relative;
    z-index: 1;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem 4rem;
}

/* ===========================
   Visualizer
   =========================== */
.visualizer-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 2rem;
    height: 120px;
    box-shadow: var(--shadow-lg);
}

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

/* ===========================
   Controls
   =========================== */
.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.controls-left,
.controls-right {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 1.5rem;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    font-family: inherit;
    background: linear-gradient(to bottom, #3d4a5e 0%, #2d3748 50%, #1e293b 100%);
    color: var(--text-secondary);
    border: 1px solid #475569;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    transition: all 0.2s ease;
}

.btn-secondary:hover {
    background: linear-gradient(to bottom, #475569 0%, #3d4a5e 50%, #2d3748 100%);
    color: var(--text-primary);
}

.btn-danger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    font-family: inherit;
    background: linear-gradient(to bottom, #ef4444 0%, #dc2626 50%, #b91c1c 100%);
    color: white;
    border: 1px solid #991b1b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
    transition: all 0.2s ease;
}

.btn-danger:hover {
    background: linear-gradient(to bottom, #dc2626 0%, #b91c1c 50%, #991b1b 100%);
    transform: translateY(-1px);
}

.btn-play {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 0 20px var(--glow-color);
}

.btn-play:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px var(--glow-color);
}

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

.btn-play .stop-icon {
    display: none;
}

.btn-play.playing {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
}

.btn-play.playing .play-icon {
    display: none;
}

.btn-play.playing .stop-icon {
    display: block;
}

.step-selector {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
}

.selector-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.step-switch {
    position: relative;
    display: flex;
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 3px;
    border: 1px solid var(--border-color);
}

.step-switch input[type="radio"] {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.step-switch label {
    position: relative;
    z-index: 2;
    padding: 0.375rem 0.875rem;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: color 0.3s ease;
    color: var(--text-secondary);
    user-select: none;
}

.step-switch input[type="radio"]:checked+label {
    color: white;
}

.switch-slider {
    position: absolute;
    top: 3px;
    left: 3px;
    width: calc(33.333% - 2px);
    height: calc(100% - 6px);
    background: var(--accent-gradient);
    border-radius: 6px;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    z-index: 1;
}

.step-switch input[type="radio"]:nth-of-type(1):checked~.switch-slider {
    transform: translateX(0);
}

.step-switch input[type="radio"]:nth-of-type(2):checked~.switch-slider {
    transform: translateX(100%);
}

.step-switch input[type="radio"]:nth-of-type(3):checked~.switch-slider {
    transform: translateX(200%);
}

.tempo-control {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
}

.tempo-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.tempo-slider {
    width: 140px;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(to bottom, #1a1f2e 0%, #0f1219 100%);
    border: 1px solid #334155;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5);
    outline: none;
    appearance: none;
    -webkit-appearance: none;
}

.tempo-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.tempo-slider::-moz-range-thumb {
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.tempo-value {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    min-width: 2.5rem;
    text-align: right;
}

/* Swing Control */
.swing-control {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
}

.swing-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.swing-slider {
    width: 100px;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(to bottom, #1a1f2e 0%, #0f1219 100%);
    border: 1px solid #334155;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5);
    outline: none;
    appearance: none;
    -webkit-appearance: none;
}

.swing-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.swing-slider::-moz-range-thumb {
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.swing-value {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    min-width: 3rem;
    text-align: right;
    color: var(--text-primary);
}

.btn-icon {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 10px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-icon:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border-color: var(--accent-primary);
}

.divider {
    width: 1px;
    height: 32px;
    background: var(--border-color);
}

/* ===========================
   Sequencer Grid
   =========================== */
.sequencer {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: var(--shadow-xl);
}

.grid-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.grid-row {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.instrument-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 160px;
    flex-shrink: 0;
}

.instrument-label {
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

/* Retro Mute Button - Slim Style */
.mute-btn {
    width: 24px;
    min-width: 24px;
    height: 40px;
    min-height: 40px;
    background: linear-gradient(to bottom, #3d4a5e 0%, #2d3748 50%, #1e293b 100%);
    border: 1px solid #475569;
    border-radius: 4px;
    position: relative;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    gap: 2px;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    transition: all 0.15s ease;
}

.mute-btn:hover {
    background: linear-gradient(to bottom, #475569 0%, #3d4a5e 50%, #2d3748 100%);
}

.mute-led {
    width: 6px;
    height: 6px;
    background: #1e293b;
    border-radius: 50%;
    box-shadow: inset 1px 1px 2px rgba(0, 0, 0, 0.5);
    transition: all 0.2s ease;
}

.mute-btn span {
    font-size: 8px;
    font-weight: 800;
    color: #94a3b8;
    line-height: 1;
}

.mute-btn.muted {
    background: linear-gradient(to bottom, #ef4444 0%, #dc2626 50%, #b91c1c 100%);
    border-color: #991b1b;
}

.mute-btn.muted .mute-led {
    background: #fff;
    box-shadow: 0 0 6px #fff, inset -1px -1px 2px rgba(0, 0, 0, 0.2);
}

.mute-btn.muted span {
    color: #fff;
}

.steps-row {
    display: grid;
    grid-template-columns: repeat(16, 1fr);
    gap: 0.5rem;
    flex: 1;
}

.step {
    height: 40px;
    border-radius: 8px;
    background: var(--step-inactive);
    border: 2px solid var(--border-color);
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
}

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

.step.active {
    background: var(--step-active);
    border-color: var(--step-active);
    box-shadow: 0 0 15px var(--glow-color);
}

.step.current {
    border-color: var(--step-current);
    box-shadow: 0 0 20px var(--glow-color);
}

.step.active.current {
    transform: scale(1.1);
    box-shadow: 0 0 25px var(--glow-color);
}

/* Step Numbers */
.step-numbers {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-top: 1rem;
}

.numbers-row {
    display: grid;
    grid-template-columns: repeat(16, 1fr);
    gap: 0.5rem;
    flex: 1;
}

.step-number {
    text-align: center;
    font-size: 0.625rem;
    font-family: 'JetBrains Mono', monospace;
    color: var(--text-muted);
    transition: all 0.2s ease;
}

.step-number.current {
    color: var(--accent-primary);
    font-weight: 700;
    transform: scale(1.2);
}

/* ===========================
   Footer
   =========================== */
.footer {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer p {
    margin: 0.25rem 0;
}

.footer a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer a:hover {
    color: var(--accent-secondary);
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 1024px) {
    .steps-row {
        gap: 0.375rem;
    }

    .numbers-row {
        gap: 0.375rem;
    }

    .step {
        border-radius: 6px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem 3rem;
    }

    .header {
        padding: 1rem;
    }

    .sequencer {
        padding: 1.5rem 1rem;
        overflow-x: auto;
    }

    .grid-container {
        min-width: 600px;
    }

    .step-numbers {
        min-width: 600px;
    }

    .instrument-controls {
        min-width: 90px;
        gap: 0.5rem;
    }

    .instrument-label {
        font-size: 0.625rem;
    }

    .mute-btn {
        width: 28px;
        height: 28px;
    }

    .steps-row {
        gap: 0.25rem;
    }

    .step {
        min-width: 32px;
        height: 36px;
        border-radius: 4px;
        border-width: 1px;
    }

    .numbers-row {
        gap: 0.25rem;
    }

    .controls {
        flex-direction: column;
        align-items: stretch;
    }

    .controls-left,
    .controls-right {
        justify-content: center;
        flex-wrap: wrap;
    }
}

@media (max-width: 480px) {
    .tempo-slider {
        width: 100px;
    }

    .step-number {
        font-size: 0.5rem;
    }
}

/* Mixer Button (4 Knobs Icon) */
.mixer-btn {
    width: 32px;
    height: 40px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    padding: 10px 6px;
    gap: 4px;
    transition: all 0.2s ease;
}

.mixer-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-primary);
}

.mixer-knob-icon {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 1px solid var(--text-muted);
    position: relative;
}

.mixer-knob-icon::after {
    content: '';
    position: absolute;
    top: 20%;
    left: 50%;
    width: 1px;
    height: 30%;
    background: var(--text-muted);
    transform: translateX(-50%);
}

.mixer-btn:hover .mixer-knob-icon {
    border-color: var(--accent-primary);
}

.mixer-btn:hover .mixer-knob-icon::after {
    background: var(--accent-primary);
}

/* Mixer Modal Layout */
.mixer-controls {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.mixer-knob-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg-tertiary);
    padding: 1rem;
    border-radius: 12px;
}

.mixer-knob-group label {
    font-size: 0.875rem;
    font-weight: 700;
    width: 60px;
    color: var(--text-secondary);
}

.mixer-slider {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 6px;
    background: var(--bg-primary);
    border-radius: 3px;
    outline: none;
}

.mixer-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-primary);
    cursor: pointer;
    transition: transform 0.2s;
}

.mixer-slider::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.mixer-value {
    width: 60px;
    text-align: right;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    color: var(--text-primary);
}

/* Rotary Knobs */
.knobs-row {
    display: flex;
    justify-content: space-around;
    gap: 1rem;
    padding: 1rem 0;
    background: var(--bg-tertiary);
    border-radius: 12px;
    margin-bottom: 1rem;
}

.fader-row {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.fader-row .mixer-knob-group {
    flex: 1;
    min-width: 200px;
}

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

.rotary-knob {
    width: 60px;
    height: 60px;
    cursor: grab;
    user-select: none;
}

.rotary-knob:active {
    cursor: grabbing;
}

.knob-body {
    width: 100%;
    height: 100%;
    background: linear-gradient(145deg, #3d4a5e, #1e293b);
    border-radius: 50%;
    border: 3px solid #4a5568;
    position: relative;
    box-shadow:
        0 4px 8px rgba(0, 0, 0, 0.4),
        inset 0 2px 4px rgba(255, 255, 255, 0.1),
        inset 0 -2px 4px rgba(0, 0, 0, 0.3);
}

.knob-indicator {
    position: absolute;
    width: 4px;
    height: 18px;
    background: var(--accent-primary);
    border-radius: 2px;
    top: 8px;
    left: 50%;
    margin-left: -2px;
    transform-origin: center 22px;
    box-shadow: 0 0 6px var(--accent-primary);
}

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

.knob-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--text-primary);
}

/* Retro Fader Thumb */
.mixer-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.mixer-slider::-moz-range-thumb {
    width: 16px;
    height: 28px;
    background: linear-gradient(to bottom, #64748b 0%, #475569 50%, #334155 100%);
    cursor: pointer;
    border-radius: 3px;
    border: 1px solid #1e293b;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

/* Smaller Modal */
.modal-sm {
    max-width: 400px;
}

/* Instrument Selection Grid */
.instrument-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

.instrument-option {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--text-primary);
}

.instrument-option:hover {
    border-color: var(--accent-primary);
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

.instrument-icon {
    width: 2.5rem;
    height: 2.5rem;
}

/* Add Track Button */
.add-track-row {
    display: flex;
    justify-content: center;
    padding: 1rem 0;
}

.add-track-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-tertiary);
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.875rem;
    font-weight: 600;
}

.add-track-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

/* Remove Track Button - Slim Retro Style */
.remove-btn {
    width: 20px;
    height: 40px;
    flex-shrink: 0;
    border: none;
    border-radius: 4px;
    background: linear-gradient(to bottom, #3d4a5e 0%, #2d3748 50%, #1e293b 100%);
    color: #94a3b8;
    cursor: pointer;
    font-size: 1.2rem;
    font-weight: bold;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid #475569;
    box-shadow:
        0 2px 4px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    transition: all 0.15s ease;
}

.remove-btn:hover {
    background: linear-gradient(to bottom, #ef4444 0%, #dc2626 50%, #b91c1c 100%);
    color: white;
    border-color: #991b1b;
}

/* ===========================
   About Page & Navigation
   =========================== */

/* Header Navigation */
.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.header-nav-link {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.2s ease;
    padding: 0.5rem 1rem;
    border-radius: 8px;
}

.header-nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.btn-bmc {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: #FFDD00;
    color: #000000;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.875rem;
    text-decoration: none;
    transition: all 0.2s ease;
}

.btn-bmc:hover {
    background: #FFEA5E;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(255, 221, 0, 0.3);
}

[data-theme="light"] .btn-bmc {
    background: #FFDD00;
    color: #000000;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .btn-bmc:hover {
    background: #FFEA5E;
}


/* About Hero */
.about-container {
    max-width: 1000px;
    padding-top: 4rem;
}

.about-hero {
    text-align: center;
    margin-bottom: 4rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.text-gradient {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 6rem;
}

.feature-card {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-primary);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 0.95rem;
}

/* Copy Section */
.about-copy {
    max-width: 700px;
    margin: 0 auto 4rem;
}

.copy-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 0.5rem;
}

.copy-subtitle {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 2rem;
}

.copy-content p {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.copy-content strong {
    color: var(--text-primary);
}

.highlight-box {
    background: rgba(99, 102, 241, 0.1);
    border-left: 4px solid var(--accent-primary);
    padding: 1.5rem;
    margin: 2.5rem 0;
    border-radius: 0 12px 12px 0;
}

.highlight-box strong {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--accent-primary);
    font-size: 1.1rem;
}

.highlight-box p {
    margin-bottom: 0;
    font-size: 1rem;
}

/* Footer Links */
.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1.5rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 600;
}

.footer-links a:hover {
    color: var(--text-primary);
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        /* Hide nav on small screens for now, or make hamburger */
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .about-container {
        padding-top: 2rem;
    }

    .copy-title {
        font-size: 2rem;
    }
}