/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --success-hover: #059669;
    --background-dark: #0f0f1a;
    --background-light: #1a1a2e;
    --surface-color: #252541;
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
    --border-color: #3f3f5a;
    --gradient-1: linear-gradient(135deg, #6366f1, #8b5cf6);
    --gradient-2: linear-gradient(135deg, #f472b6, #ec4899);
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--background-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    text-align: center;
    padding: 2rem 1rem;
    background: var(--background-light);
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo-icon {
    width: 40px;
    height: 40px;
    color: var(--primary-color);
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Main Content */
.main-content {
    flex: 1;
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

/* Sections */
section {
    margin-bottom: 2rem;
}

section h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Hidden State */
.hidden {
    display: none !important;
}

/* Upload Section */
.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    text-align: center;
    background: var(--surface-color);
    transition: var(--transition);
    cursor: pointer;
}

.upload-area:hover,
.upload-area.drag-over {
    border-color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.upload-icon {
    margin-bottom: 1rem;
}

.upload-icon svg {
    width: 64px;
    height: 64px;
    color: var(--primary-color);
}

.upload-area h2 {
    margin-bottom: 0.5rem;
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.supported-formats {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem !important;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn svg {
    width: 20px;
    height: 20px;
}

.btn-primary {
    background: var(--gradient-1);
    color: white;
}

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

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

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

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: var(--success-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-icon {
    padding: 0.5rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-icon:hover {
    background: var(--border-color);
}

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

/* Video Preview Section */
.preview-section {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.video-container {
    margin-bottom: 1rem;
}

.video-container video {
    width: 100%;
    max-height: 400px;
    border-radius: var(--border-radius-sm);
    background: #000;
}

.video-info {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.file-name {
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-all;
}

/* Settings Section */
.settings-section {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.25rem;
}

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

.setting-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.setting-group select,
.setting-group input[type="range"] {
    width: 100%;
    padding: 0.75rem;
    background: var(--background-light);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
}

.setting-group select:focus,
.setting-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.setting-group input[type="range"] {
    padding: 0;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
}

.setting-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: 2px solid white;
}

.setting-group input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: 2px solid white;
}

.setting-group input[type="color"] {
    width: 50px;
    height: 40px;
    padding: 0;
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
}

.color-inputs {
    display: flex;
    gap: 0.5rem;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

/* Visualization Section */
.visualization-section {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.canvas-container {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background: var(--background-dark);
    border-radius: var(--border-radius-sm);
    overflow: hidden;
}

.canvas-container canvas {
    width: 100%;
    height: 100%;
    display: block;
}

.canvas-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.5);
    color: var(--text-secondary);
    font-size: 0.875rem;
    pointer-events: none;
}

.canvas-overlay.hidden {
    display: none;
}

.viz-controls {
    display: flex;
    justify-content: flex-end;
    margin-top: 0.75rem;
}

/* Conversion Section */
.conversion-section {
    background: var(--surface-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.format-options {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.format-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex: 1;
    min-width: 150px;
}

.format-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.format-group select {
    width: 100%;
    padding: 0.75rem;
    background: var(--background-light);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
}

.format-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Progress Bar */
.progress-container {
    margin-bottom: 1.5rem;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--background-light);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--gradient-1);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.action-buttons .btn {
    flex: 1;
    min-width: 200px;
}

/* Footer */
.footer {
    text-align: center;
    padding: 1.5rem 1rem;
    background: var(--background-light);
    border-top: 1px solid var(--border-color);
}

.footer p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.footer a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Fullscreen Mode */
.canvas-container.fullscreen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    aspect-ratio: unset;
    z-index: 1000;
    border-radius: 0;
}

.canvas-container.fullscreen .canvas-overlay {
    border-radius: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header {
        padding: 1.5rem 1rem;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    .tagline {
        font-size: 0.875rem;
    }

    .main-content {
        padding: 1rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .upload-icon svg {
        width: 48px;
        height: 48px;
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .action-buttons .btn {
        width: 100%;
    }

    .video-info {
        flex-direction: column;
        gap: 0.25rem;
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 0.5rem;
    }

    .logo h1 {
        font-size: 1.25rem;
    }

    section h2 {
        font-size: 1.125rem;
    }

    .btn-large {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }

    .format-options {
        flex-direction: column;
    }

    .format-group {
        min-width: 100%;
    }
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.processing {
    animation: pulse 1.5s ease-in-out infinite;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Focus Styles for Accessibility */
.btn:focus-visible,
select:focus-visible,
input:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .upload-section,
    .settings-section,
    .visualization-section,
    .conversion-section {
        display: none;
    }
}