:root {
    --bg-primary: linear-gradient(135deg, #0a0a12, #0d0d1a);
    --bg-secondary: #12121d;
    --bg-tertiary: #1a1a2a;
    --border-primary: #2a2a4a;
    --border-secondary: #2d2d4d;
    
    --text-primary: #e0e0ff;
    --text-secondary: #a0a0c0;
    --text-tertiary: #707090;
    
    --accent-primary: #00d2ff;
    --accent-secondary: #928dab;
    --accent-gradient: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    
    --success-color: #00ff88;
    --error-color: #ff6b6b;
    --warning-color: #ffb347;
    
    --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.4);
    --shadow-elevated: 0 14px 35px rgba(0, 0, 0, 0.5);
    --shadow-button: 0 4px 15px rgba(0, 210, 255, 0.25);
    --shadow-button-hover: 0 7px 20px rgba(0, 210, 255, 0.35);
    
    --transition-default: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    --transition-fast: all 0.2s ease;
    
    --border-radius-small: 6px;
    --border-radius-medium: 10px;
    --border-radius-large: 16px;
    --border-radius-xl: 18px;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 2.5rem;
}

[data-theme="light"] {
    --bg-primary: linear-gradient(135deg, #f8f9ff, #ffffff);
    --bg-secondary: #ffffff;
    --bg-tertiary: #f5f5f7;
    --border-primary: #e1e1e8;
    --border-secondary: #d1d1d8;
    
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-tertiary: #6a6a8a;
    
    --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-elevated: 0 14px 35px rgba(0, 0, 0, 0.15);
    --shadow-button: 0 4px 15px rgba(0, 210, 255, 0.15);
    --shadow-button-hover: 0 7px 20px rgba(0, 210, 255, 0.25);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.subtitle, .hint, .status, p, span {
    -webkit-user-select: text;
    -moz-user-select: text;
    -ms-user-select: text;
    user-select: text;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    padding: var(--spacing-xl) var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: var(--transition-default);
    line-height: 1.6;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    opacity: 0.4;
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.2) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.2) 1px, transparent 1px);
    background-size: 25px 25px;
    transition: var(--transition-default);
    animation: gridPulse 20s ease-in-out infinite;
}

[data-theme="light"] body::before {
    background-image: 
        linear-gradient(rgba(0, 0, 0, 0.15) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 0, 0, 0.15) 1px, transparent 1px);
    animation: gridPulseLight 20s ease-in-out infinite;
}

@keyframes gridPulse {
    0%, 100% {
        opacity: 0.15;
        background-size: 30px 30px;
    }
    50% {
        opacity: 0.08;
        background-size: 35px 35px;
    }
}

@keyframes gridPulseLight {
    0%, 100% {
        opacity: 0.4;
        background-size: 30px 30px;
    }
    50% {
        opacity: 0.2;
        background-size: 35px 35px;
    }
}

.container {
    width: 100%;
    max-width: 1200px;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xxl);
}

header {
    text-align: center;
    padding: var(--spacing-lg) 0;
    position: relative;
}

h1 {
    font-size: clamp(2rem, 5vw, 2.8rem);
    font-weight: 800;
    margin-bottom: 0.75rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    letter-spacing: -0.03em;
    text-shadow: 0 2px 10px rgba(0, 210, 255, 0.15);
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

.header-controls {
    position: absolute;
    top: 0;
    right: 0;
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.github-link {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-default);
    text-decoration: none;
    color: var(--text-secondary);
}

.github-link:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-card);
    color: var(--text-primary);
}

.github-link svg {
    transition: var(--transition-default);
}

.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition-default);
    font-size: 1.2rem;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-card);
}

.upload-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
}

.drop-zone {
    border: 2px dashed transparent;
    border-radius: var(--border-radius-large);
    padding: 3.5rem 2rem;
    text-align: center;
    cursor: pointer;
    background: var(--bg-secondary);
    border-image: var(--accent-gradient) 1;
    transition: var(--transition-default);
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.drop-zone::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at center, rgba(0, 210, 255, 0.08) 0%, transparent 70%);
    opacity: 0;
    transition: var(--transition-default);
    pointer-events: none;
}

.drop-zone:hover::before,
.drop-zone:focus-within::before {
    opacity: 1;
}

.drop-zone:hover,
.drop-zone:focus-within {
    transform: translateY(-3px);
    box-shadow: var(--shadow-elevated);
}

.drop-icon {
    font-size: 3.5rem;
    margin-bottom: 1.2rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.drop-text {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    color: var(--text-primary);
}

.drop-subtext {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 500px;
    margin: 0 auto;
    line-height: 1.6;
}

.strong {
    color: var(--accent-primary);
    font-weight: 700;
}

.canvas-container {
    position: relative;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    border-radius: var(--border-radius-large);
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.canvas-container:hover .remove-audio {
    opacity: 1;
    transform: scale(1);
}

#canvas {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius-large);
    background: #000;
    display: block;
    border: 1px solid var(--border-primary);
    margin: 0 auto;
}

.remove-audio {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 18px;
    z-index: 10;
    opacity: 0;
    transform: scale(0.8);
    transition: var(--transition-fast);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    border: none;
}

.remove-audio:hover {
    background: var(--error-color);
    transform: scale(1.1);
}

.export-progress {
    position: absolute;
    bottom: 20px;
    left: 20px;
    right: 20px;
    background: rgba(0, 0, 0, 0.8);
    border-radius: var(--border-radius-medium);
    padding: var(--spacing-md);
    backdrop-filter: blur(10px);
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    color: white;
    font-size: 0.9rem;
    font-weight: 500;
}

.controls-section {
    background: var(--bg-secondary);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-card);
    border: 1px solid var(--border-primary);
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: var(--text-primary);
}

.section-title::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent-primary));
    margin-left: var(--spacing-md);
}

.controls-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.7rem;
}

.control-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.value-display {
    background: var(--bg-tertiary);
    padding: 0.25rem 0.6rem;
    border-radius: var(--border-radius-small);
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
    min-width: 60px;
    text-align: right;
    color: var(--accent-primary);
    font-size: 0.85rem;
}

.control-input,
.control-color {
    width: 100%;
    padding: 0.85rem 1rem;
    border-radius: var(--border-radius-medium);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: var(--transition-default);
    cursor: pointer;
}

.control-input:focus,
.control-color:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 210, 255, 0.2);
}

.control-color {
    height: 48px;
    cursor: pointer;
    padding: 0;
}

.range-container {
    position: relative;
}

.control-range {
    -webkit-appearance: none;
    width: 100%;
    height: 8px;
    border-radius: 4px;
    background: var(--bg-tertiary);
    outline: none;
    margin: var(--spacing-sm) 0;
    cursor: pointer;
}

.control-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-gradient);
    cursor: pointer;
    transition: var(--transition-default);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
    border: none;
}

.control-range::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 0 10px rgba(0, 210, 255, 0.15);
}

.control-range::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-gradient);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

.button-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.2rem;
    margin-bottom: var(--spacing-lg);
}

.btn {
    padding: 0.95rem 1.4rem;
    border: none;
    border-radius: var(--border-radius-medium);
    font-weight: 700;
    font-size: 1.05rem;
    cursor: pointer;
    transition: var(--transition-default);
    position: relative;
    overflow: hidden;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    text-decoration: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: var(--shadow-button);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
}

.btn::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -60%;
    width: 20px;
    height: 200%;
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(30deg);
    transition: all 0.6s;
}

.btn:hover::after {
    left: 120%;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary:hover {
    box-shadow: var(--shadow-button-hover);
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-small {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9rem;
}

.btn-loading {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s linear infinite;
}

.preset-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-primary);
    border-radius: var(--border-radius-medium);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition-default);
}

.preset-btn:hover {
    background: var(--accent-primary);
    color: white;
}

.export-options {
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    border-radius: var(--border-radius-large);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-card);
    position: relative;
    overflow: hidden;
}

.export-options::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--accent-gradient);
}

.export-options h3 {
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    font-size: 1.3rem;
    font-weight: 700;
    text-align: center;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.export-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.export-grid .control-group {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-secondary);
    border-radius: var(--border-radius-medium);
    padding: var(--spacing-md);
    transition: var(--transition-default);
}

.export-grid .control-group:hover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 210, 255, 0.15);
}

.export-grid .control-group label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.export-grid .control-group select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-secondary);
    border-radius: var(--border-radius-small);
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: var(--transition-default);
}

.export-grid .control-group select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: none;
    padding: var(--spacing-sm);
}

[data-theme="light"] .export-grid .control-group select {
    background: #ffffff;
    border: 2px solid #e1e1e8;
    color: #1a1a2e;
}

[data-theme="light"] .export-grid .control-group select option {
    background: #ffffff;
    color: #1a1a2e;
}

[data-theme="light"] .export-grid .control-group label {
    color: #1a1a2e;
}

.export-grid .control-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(0, 210, 255, 0.2);
}

.export-grid .hint {
    margin-top: var(--spacing-xs);
    font-size: 0.8rem;
    color: var(--text-tertiary);
    font-style: italic;
}

.export-controls {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    align-items: center;
}

.export-controls .btn {
    min-width: 140px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.export-controls .btn-primary {
    background: var(--accent-gradient);
    border: none;
    color: white;
    box-shadow: var(--shadow-button);
}

.export-controls .btn-primary:hover {
    box-shadow: var(--shadow-button-hover);
    transform: translateY(-2px);
}

.export-controls .btn-secondary {
    background: linear-gradient(135deg, #ff4757, #ff3742);
    border: none;
    color: white;
    box-shadow: 0 4px 15px rgba(255, 71, 87, 0.25);
}

.export-controls .btn-secondary:hover {
    box-shadow: 0 7px 20px rgba(255, 71, 87, 0.35);
    transform: translateY(-2px);
}

.status {
    text-align: center;
    padding: 0.7rem;
    border-radius: var(--border-radius-medium);
    background: rgba(0, 0, 0, 0.2);
    font-size: 0.95rem;
    color: var(--text-secondary);
    border: 1px solid var(--border-primary);
}

.status.success {
    color: var(--success-color);
    border-color: var(--success-color);
    background: rgba(0, 255, 136, 0.1);
}

.status.error {
    color: var(--error-color);
    border-color: var(--error-color);
    background: rgba(255, 107, 107, 0.1);
}

.status.warning {
    color: var(--warning-color);
    border-color: var(--warning-color);
    background: rgba(255, 179, 71, 0.1);
}

.hint {
    font-size: 0.85rem;
    color: var(--text-tertiary);
    opacity: 0.9;
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(20px) saturate(1.2);
    -webkit-backdrop-filter: blur(20px) saturate(1.2);
    animation: modalBackdropFade 0.3s ease-out;
}

.modal-content {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(15px) saturate(1.8);
    -webkit-backdrop-filter: blur(15px) saturate(1.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-large);
    width: 90%;
    max-width: 500px;
    max-height: 70vh;
    overflow: hidden;
    box-shadow: 
        0 25px 50px -12px rgba(0, 0, 0, 0.5),
        0 0 0 1px rgba(255, 255, 255, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
    transform: translateZ(0);
    will-change: transform;
}

.modal-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
}

.modal-header h3 {
    color: var(--text-primary);
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.modal-close:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.02);
}

.preset-list {
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: var(--spacing-lg);
}

.preset-item {
    padding: var(--spacing-md);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius-medium);
    margin-bottom: var(--spacing-sm);
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(5px);
    -webkit-backdrop-filter: blur(5px);
}

.preset-item:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-primary);
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(0, 210, 255, 0.15);
}

.preset-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.preset-actions input {
    flex: 1;
    padding: var(--spacing-sm);
    border: 1px solid var(--border-secondary);
    border-radius: var(--border-radius-small);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    outline: none;
}

.preset-actions input:focus {
    border-color: var(--accent-primary);
}

button, .btn, .control-input, .control-range, .theme-toggle, .github-link, .drop-zone {
    outline: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

button:focus-visible, .btn:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

@media (hover: none) and (pointer: coarse) {
    .btn, .theme-toggle, .github-link, .remove-audio, .modal-close {
        min-width: 44px;
        min-height: 44px;
    }
    
    .control-input, .control-range {
        min-height: 44px;
    }
}

button:active, .btn:active {
    transform: scale(0.98);
    transition: transform 0.1s ease;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
}

.mobile-footer {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-primary);
    padding: var(--spacing-md);
    z-index: 100;
    backdrop-filter: blur(10px);
    box-shadow: 0 -2px 20px rgba(0, 0, 0, 0.1);
}

.mobile-footer-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    max-width: 300px;
    margin: 0 auto;
}

.hidden {
    display: none !important;
}

.loading {
    position: relative;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid var(--accent-primary);
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}