/* ============================================
   CSS Variables & Reset
   ============================================ */

:root {
    /* Colors */
    --color-bg-primary: #000000;
    --color-bg-secondary: #0a0a0a;
    --color-bg-tertiary: #111111;
    --color-text-primary: #ffffff;
    --color-text-secondary: #aaaaaa;
    --color-text-tertiary: #808080;
    --color-accent: #0066ff;
    --color-accent-hover: #0052cc;
    --color-accent-light: #1a7fff;
    --color-border: #1a1a1a;
    --color-border-light: #2a2a2a;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 20px;
    --spacing-lg: 28px;
    --spacing-xl: 40px;
    --spacing-xxl: 56px;
    
    /* Container */
    --container-max-width: 1000px;
    --container-padding: var(--spacing-lg);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 102, 255, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 102, 255, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 102, 255, 0.2);
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

body {
    font-family: var(--font-primary);
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: clamp(36px, 4vw, 48px);
    font-weight: 700;
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(28px, 3.5vw, 36px);
    font-weight: 600;
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(20px, 2.5vw, 24px);
    font-weight: 600;
}

h4 {
    font-size: clamp(16px, 2vw, 18px);
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-secondary);
    line-height: 1.7;
    font-size: 15px;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ============================================
   Skip Link (Accessibility)
   ============================================ */

.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--color-accent);
    color: var(--color-text-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: 1000;
    border-radius: var(--radius-md);
}

.skip-link:focus {
    top: var(--spacing-md);
}

/* ============================================
   Container
   ============================================ */

    .container {
        max-width: var(--container-max-width);
        margin: 0 auto;
        padding: 0 var(--container-padding);
        width: 100%;
        box-sizing: border-box;
    }

/* ============================================
   Header & Navigation
   ============================================ */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: background var(--transition-base);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--container-padding);
    max-width: var(--container-max-width);
    margin: 0 auto;
}

.nav-brand .logo-text {
    font-family: var(--font-heading);
    font-size: clamp(16px, 1.8vw, 20px);
    font-weight: 700;
    color: var(--color-text-primary);
    background: linear-gradient(135deg, var(--color-text-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--color-text-secondary);
    font-size: 14px;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--color-text-primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition-base);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-cta {
    background: var(--color-accent);
    color: var(--color-text-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-weight: 600;
}

.nav-cta:hover {
    background: var(--color-accent-hover);
    color: var(--color-text-primary);
}

.nav-cta::after {
    display: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: all var(--transition-base);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    text-align: center;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    font-family: var(--font-primary);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    user-select: none;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-text-primary);
    box-shadow: var(--shadow-sm);
}

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

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

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

.btn-outline {
    background: transparent;
    color: var(--color-accent);
    border-color: var(--color-accent);
}

.btn-outline:hover {
    background: var(--color-accent);
    color: var(--color-text-primary);
}

.btn-large {
    padding: 14px 28px;
    font-size: 15px;
}

/* ============================================
   Hero Section
   ============================================ */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: calc(var(--spacing-xxl) + 80px) 0 var(--spacing-xxl);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(0, 102, 255, 0.1) 0%, transparent 70%);
    z-index: -1;
}

.hero-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
    animation: fadeInUp 0.8s ease-out;
    padding: 0 var(--spacing-md);
}

.hero-title {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.hero-description {
    font-size: 16px;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--spacing-xxl);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xxl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: clamp(24px, 3.5vw, 32px);
    font-weight: 700;
    color: var(--color-accent);
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    display: block;
    font-size: 12px;
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ============================================
   Section Styles
   ============================================ */

.section {
    padding: var(--spacing-xxl) 0;
    position: relative;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-xxl);
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: 15px;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   Generate Section
   ============================================ */

.generate {
    background: var(--color-bg-secondary);
    padding: var(--spacing-xxl) 0;
}

.generate-wrapper {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.generate-controls {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.generate-tabs {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tab-btn {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-primary);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    user-select: none;
    min-height: 40px; /* Touch-friendly */
}

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

.tab-btn.active {
    background: var(--color-bg-secondary);
    border-color: var(--color-accent);
    color: var(--color-text-primary);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.control-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.control-label-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.control-toggles {
    display: flex;
    gap: var(--spacing-md);
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--color-text-secondary);
    cursor: pointer;
}

.toggle-label input[type="checkbox"] {
    width: 14px;
    height: 14px;
    cursor: pointer;
}

/* Model selector removed - using custom dropdown instead */

/* Custom Dropdown */
.custom-dropdown-wrapper {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.custom-dropdown {
    position: relative;
    width: 100%;
}

.dropdown-selected {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
    min-height: 60px;
}

.dropdown-selected:hover {
    border-color: var(--color-accent);
}

.dropdown-selected.active {
    border-color: var(--color-accent);
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
}

.dropdown-arrow {
    color: var(--color-text-secondary);
    transition: transform var(--transition-base);
    flex-shrink: 0;
    margin-left: var(--spacing-sm);
}

.dropdown-selected.active .dropdown-arrow {
    transform: rotate(180deg);
}

.dropdown-options {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-accent);
    border-top: none;
    border-radius: var(--radius-md);
    border-top-left-radius: 0;
    border-top-right-radius: 0;
    max-height: 400px;
    overflow-y: auto;
    z-index: 1000;
    display: none;
    box-shadow: var(--shadow-lg);
}

/* Custom scrollbar for dropdown */
.dropdown-options::-webkit-scrollbar {
    width: 6px;
}

.dropdown-options::-webkit-scrollbar-track {
    background: var(--color-bg-tertiary);
}

.dropdown-options::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

.dropdown-options::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}

.dropdown-options.active {
    display: block;
}

.model-option {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-base);
    border-bottom: 1px solid var(--color-border);
    min-height: 60px;
}

.model-option:last-child {
    border-bottom: none;
}

.model-option:hover {
    background: var(--color-bg-tertiary);
}

.model-option.selected {
    background: rgba(0, 102, 255, 0.1);
}

.model-item-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
}

.model-icon {
    width: 32px;
    height: 32px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.model-info {
    flex: 1;
    min-width: 0;
}

.model-name-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: 4px;
    flex-wrap: wrap;
}

.model-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.model-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 500;
    white-space: nowrap;
}

.audio-tag {
    background: rgba(170, 170, 170, 0.2);
    color: var(--color-text-secondary);
}

.coming-soon-tag {
    background: rgba(255, 152, 0, 0.2);
    color: #ff9800;
}

.model-tag svg {
    width: 10px;
    height: 10px;
}

.model-desc {
    font-size: 12px;
    color: var(--color-text-secondary);
    margin: 0;
    line-height: 1.4;
}

.check-icon {
    color: var(--color-accent);
    flex-shrink: 0;
    margin-left: var(--spacing-sm);
    display: none;
}

.model-option.selected .check-icon {
    display: block;
}

.model-audio {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.audio-label {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 36px;
    height: 20px;
    cursor: pointer;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-border);
    transition: var(--transition-base);
    border-radius: 20px;
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 14px;
    width: 14px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: var(--transition-base);
    border-radius: 50%;
}

.toggle-switch input:checked + .toggle-slider {
    background-color: var(--color-accent);
}

.toggle-switch input:checked + .toggle-slider:before {
    transform: translateX(16px);
}

.model-description {
    font-size: 12px;
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-xs);
}

.upload-area {
    position: relative;
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
    background: var(--color-bg-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
}

.upload-area:hover {
    border-color: var(--color-accent);
    background: rgba(0, 102, 255, 0.05);
}

.upload-area svg {
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
}

.upload-text {
    font-size: 14px;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.upload-formats {
    font-size: 12px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-sm);
}

.upload-counter {
    position: absolute;
    top: var(--spacing-xs);
    right: var(--spacing-xs);
    font-size: 11px;
    color: var(--color-text-tertiary);
}

.prompt-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 14px;
    font-family: var(--font-primary);
    resize: vertical;
    min-height: 80px;
    transition: all var(--transition-base);
    -webkit-appearance: none;
    appearance: none;
}

.prompt-input:focus {
    outline: none;
    border-color: var(--color-accent);
}

.prompt-input::placeholder {
    color: var(--color-text-tertiary);
}

.char-counter {
    text-align: right;
    font-size: 11px;
    color: var(--color-text-tertiary);
    margin-top: 4px;
}

.resolution-buttons,
.aspect-ratio-buttons {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
}

.res-btn,
.aspect-btn {
    padding: 8px 16px;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-primary);
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
    user-select: none;
    min-height: 36px; /* Touch-friendly */
}

.res-btn:hover,
.aspect-btn:hover {
    border-color: var(--color-accent);
    color: var(--color-text-primary);
}

.res-btn.active,
.aspect-btn.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-text-primary);
}

.duration-slider-wrapper {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.duration-slider {
    flex: 1;
    height: 4px;
    background: var(--color-border);
    border-radius: 2px;
    outline: none;
    -webkit-appearance: none;
    touch-action: manipulation;
    cursor: pointer;
}

.duration-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    touch-action: manipulation;
}

.duration-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    touch-action: manipulation;
}

.duration-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
}

.duration-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--color-accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

.duration-value {
    font-size: 13px;
    color: var(--color-text-primary);
    min-width: 30px;
    text-align: right;
}

.advanced-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    font-size: 13px;
    cursor: pointer;
    padding: var(--spacing-xs) 0;
    transition: color var(--transition-fast);
    font-family: var(--font-primary);
}

.advanced-toggle:hover {
    color: var(--color-text-primary);
}

.advanced-toggle svg {
    transition: transform var(--transition-base);
}

.btn-generate {
    width: 100%;
    margin-top: var(--spacing-sm);
    padding: var(--spacing-md);
    font-size: 15px;
}

.generate-preview {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.video-player {
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    aspect-ratio: 16 / 9;
    position: relative;
    cursor: pointer;
}

.preview-video {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: none;
}

.preview-video.loaded {
    display: block;
}

.video-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    color: var(--color-text-tertiary);
    z-index: 1;
    transition: opacity var(--transition-base);
}

.video-placeholder.hidden {
    opacity: 0;
    pointer-events: none;
    z-index: -1;
}

.video-placeholder svg {
    margin-bottom: var(--spacing-sm);
    opacity: 0.5;
}

.video-placeholder p {
    font-size: 13px;
    color: var(--color-text-tertiary);
    margin: 4px 0;
}

.upload-hint {
    font-size: 11px;
    color: var(--color-text-tertiary);
    opacity: 0.7;
    margin-top: var(--spacing-xs);
}

.video-controls {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.play-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all var(--transition-base);
}

.play-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.video-time {
    font-size: 12px;
    color: var(--color-text-primary);
    min-width: 70px;
}

.video-progress {
    flex: 1;
    height: 2px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 1px;
    position: relative;
    cursor: pointer;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: var(--color-accent);
    border-radius: 1px;
    transition: width 0.1s linear;
}

.control-btn {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    color: var(--color-text-primary);
    cursor: pointer;
    opacity: 0.8;
    transition: all var(--transition-base);
}

.control-btn:hover {
    opacity: 1;
    transform: scale(1.1);
}

.video-dots {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xs);
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-border);
    cursor: pointer;
    transition: all var(--transition-base);
}

.dot.active {
    background: var(--color-accent);
    width: 24px;
    border-radius: 4px;
}

/* ============================================
   Features Section
   ============================================ */

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

.feature-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
    transform: translateX(-100%);
    transition: transform var(--transition-slow);
}

.feature-card:hover::before {
    transform: translateX(100%);
}

.feature-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 102, 255, 0.1);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    color: var(--color-accent);
}

.feature-title {
    margin-bottom: var(--spacing-sm);
    font-size: clamp(16px, 2vw, 20px);
}

.feature-description {
    color: var(--color-text-secondary);
    line-height: 1.6;
    font-size: 14px;
}

/* ============================================
   Use Cases Section
   ============================================ */

.use-cases {
    background: var(--color-bg-secondary);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

.use-case-card {
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    text-align: center;
    transition: all var(--transition-base);
}

.use-case-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.use-case-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.use-case-title {
    margin-bottom: var(--spacing-sm);
    font-size: clamp(16px, 2vw, 18px);
}

.use-case-description {
    color: var(--color-text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

/* ============================================
   How It Works Section
   ============================================ */

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-lg);
    max-width: 900px;
    margin: 0 auto;
}

.step-item {
    text-align: center;
    position: relative;
}

.step-number {
    font-size: clamp(40px, 5vw, 56px);
    font-weight: 700;
    color: var(--color-accent);
    font-family: var(--font-heading);
    opacity: 0.3;
    margin-bottom: var(--spacing-md);
    line-height: 1;
}

.step-title {
    margin-bottom: var(--spacing-sm);
    font-size: clamp(18px, 2vw, 20px);
}

.step-description {
    color: var(--color-text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

/* ============================================
   Testimonials Section
   ============================================ */

.testimonials {
    background: var(--color-bg-secondary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

.testimonial-card {
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: all var(--transition-base);
}

.testimonial-card:hover {
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.testimonial-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.testimonial-avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--color-accent);
}

.testimonial-name {
    font-size: clamp(14px, 1.8vw, 16px);
    margin-bottom: 4px;
}

.testimonial-role {
    font-size: clamp(12px, 1.5vw, 14px);
    color: var(--color-text-tertiary);
}

.testimonial-text {
    color: var(--color-text-secondary);
    font-style: italic;
    line-height: 1.6;
    font-size: 14px;
}

/* ============================================
   FAQ Section
   ============================================ */

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    transition: all var(--transition-base);
}

.faq-item:hover {
    border-color: var(--color-accent);
}

.faq-question {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    background: transparent;
    border: none;
    text-align: left;
    color: var(--color-text-primary);
    font-size: clamp(14px, 1.8vw, 16px);
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    font-family: var(--font-primary);
}

.faq-question:hover {
    color: var(--color-accent);
}

.faq-icon {
    flex-shrink: 0;
    transition: transform var(--transition-base);
    color: var(--color-accent);
}

.faq-item[aria-expanded="true"] .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base), padding var(--transition-base);
    padding: 0 var(--spacing-lg);
}

.faq-item[aria-expanded="true"] .faq-answer {
    max-height: 500px;
    padding: 0 var(--spacing-lg) var(--spacing-md);
}

.faq-answer p {
    color: var(--color-text-secondary);
    line-height: 1.6;
    padding-top: var(--spacing-sm);
    font-size: 14px;
}

/* ============================================
   Pricing Section
   ============================================ */

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

.pricing-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    position: relative;
    transition: all var(--transition-base);
}

.pricing-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.pricing-card.featured {
    border-color: var(--color-accent);
    border-width: 2px;
    background: linear-gradient(135deg, var(--color-bg-secondary) 0%, rgba(0, 102, 255, 0.05) 100%);
}

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-accent);
    color: var(--color-text-primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: clamp(12px, 1.5vw, 14px);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.pricing-name {
    font-size: clamp(18px, 2vw, 20px);
    margin-bottom: var(--spacing-md);
}

.pricing-price {
    margin-bottom: var(--spacing-lg);
}

.price-amount {
    font-size: clamp(32px, 4vw, 40px);
    font-weight: 700;
    color: var(--color-accent);
    font-family: var(--font-heading);
}

.price-period {
    font-size: 14px;
    color: var(--color-text-tertiary);
    margin-left: var(--spacing-xs);
}

.pricing-features {
    list-style: none;
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.pricing-features li {
    padding: var(--spacing-sm) 0;
    color: var(--color-text-secondary);
    position: relative;
    padding-left: var(--spacing-lg);
}

.pricing-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: 700;
}

/* ============================================
   CTA Section
   ============================================ */

.cta {
    background: linear-gradient(135deg, var(--color-bg-secondary) 0%, rgba(0, 102, 255, 0.1) 100%);
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.cta-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.cta-title {
    margin-bottom: var(--spacing-md);
    font-size: clamp(24px, 3.5vw, 32px);
}

.cta-description {
    font-size: 15px;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xxl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-title {
    font-size: clamp(20px, 2.5vw, 24px);
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-text-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-description {
    color: var(--color-text-secondary);
    font-size: 14px;
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    transition: all var(--transition-base);
}

.social-link:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
    transform: translateY(-2px);
}

.footer-heading {
    font-size: clamp(14px, 1.8vw, 16px);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--color-text-secondary);
    font-size: 14px;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer-copyright {
    color: var(--color-text-tertiary);
    font-size: 13px;
}

/* ============================================
   Animations
   ============================================ */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    :root {
        --container-padding: var(--spacing-sm);
        --container-max-width: 100%;
        --spacing-xs: 6px;
        --spacing-sm: 12px;
        --spacing-md: 16px;
        --spacing-lg: 24px;
        --spacing-xl: 32px;
        --spacing-xxl: 40px;
    }
    
    html {
        font-size: 14px;
    }
    
    body {
        font-size: 14px;
        line-height: 1.5;
    }
    
    p {
        font-size: 14px;
    }
    
    h1 {
        font-size: clamp(28px, 8vw, 36px);
    }
    
    h2 {
        font-size: clamp(24px, 7vw, 32px);
    }
    
    h3 {
        font-size: clamp(18px, 5vw, 22px);
    }
    
    /* Navigation */
    .nav {
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--color-bg-primary);
        flex-direction: column;
        padding: var(--spacing-md);
        border-top: 1px solid var(--color-border);
        transform: translateX(-100%);
        transition: transform var(--transition-base);
        gap: var(--spacing-sm);
        max-height: calc(100vh - 60px);
        overflow-y: auto;
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .nav-link {
        padding: var(--spacing-sm) 0;
        font-size: 15px;
    }
    
    /* Hero Section */
    .hero {
        min-height: auto;
        padding: calc(var(--spacing-xl) + 60px) var(--spacing-sm) var(--spacing-lg);
    }
    
    .hero-content {
        padding: 0;
    }
    
    .hero-title {
        margin-bottom: var(--spacing-sm);
        line-height: 1.2;
    }
    
    .hero-description {
        font-size: 14px;
        margin-bottom: var(--spacing-lg);
        line-height: 1.6;
    }
    
    .hero-cta {
        flex-direction: column;
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-lg);
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding-top: var(--spacing-md);
        margin-top: var(--spacing-lg);
    }
    
    .stat-number {
        font-size: 24px;
    }
    
    .stat-label {
        font-size: 11px;
    }
    
    /* Generate Section */
    .generate {
        padding: var(--spacing-lg) 0;
    }
    
    .generate-wrapper {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding: var(--spacing-md);
        border-radius: var(--radius-md);
        margin: 0 var(--spacing-xs);
    }
    
    .generate-preview {
        order: -1;
    }
    
    .video-player {
        min-height: 200px;
        aspect-ratio: 16 / 9;
        width: 100%;
    }
    
    .video-controls {
        padding: var(--spacing-xs) var(--spacing-sm);
        gap: var(--spacing-xs);
    }
    
    .play-btn {
        width: 28px;
        height: 28px;
    }
    
    .video-time {
        font-size: 11px;
        min-width: 60px;
    }
    
    .control-btn {
        width: 24px;
        height: 24px;
    }
    
    .video-dots {
        margin-top: var(--spacing-xs);
    }
    
    .generate-tabs {
        gap: var(--spacing-xs);
        margin-bottom: var(--spacing-sm);
    }
    
    .tab-btn {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 13px;
    }
    
    .control-group {
        gap: var(--spacing-xs);
        margin-bottom: var(--spacing-sm);
    }
    
    .control-label {
        font-size: 12px;
        margin-bottom: 6px;
    }
    
    .control-label-row {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
    
    .control-toggles {
        flex-direction: column;
        gap: var(--spacing-xs);
        width: 100%;
    }
    
    .custom-dropdown-wrapper {
        gap: var(--spacing-xs);
    }
    
    .dropdown-selected {
        padding: var(--spacing-xs) var(--spacing-sm);
        min-height: 56px;
    }
    
    .model-item-content {
        gap: var(--spacing-xs);
    }
    
    .model-icon {
        width: 28px;
        height: 28px;
    }
    
    .model-name {
        font-size: 13px;
    }
    
    .model-tag {
        font-size: 10px;
        padding: 2px 6px;
    }
    
    .model-desc {
        font-size: 11px;
    }
    
    .dropdown-options {
        max-height: 300px;
    }
    
    .model-option {
        padding: var(--spacing-xs) var(--spacing-sm);
        min-height: 56px;
    }
    
    .model-audio {
        justify-content: space-between;
        padding: var(--spacing-xs) var(--spacing-sm);
        background: var(--color-bg-secondary);
        border: 1px solid var(--color-border);
        border-radius: var(--radius-md);
    }
    
    .model-description {
        font-size: 11px;
    }
    
    .upload-area {
        padding: var(--spacing-lg) var(--spacing-sm);
        min-height: 120px;
        touch-action: manipulation;
    }
    
    .upload-area svg {
        width: 24px;
        height: 24px;
        margin-bottom: var(--spacing-xs);
    }
    
    .upload-text {
        font-size: 13px;
    }
    
    .upload-formats {
        font-size: 11px;
    }
    
    .prompt-input {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 14px;
        min-height: 80px;
    }
    
    .char-counter {
        font-size: 10px;
    }
    
    .resolution-buttons,
    .aspect-ratio-buttons {
        gap: var(--spacing-xs);
    }
    
    .res-btn,
    .aspect-btn {
        padding: 8px 12px;
        font-size: 12px;
        flex: 1;
        min-width: 0;
    }
    
    .aspect-ratio-buttons {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
    }
    
    .duration-slider-wrapper {
        gap: var(--spacing-sm);
    }
    
    .duration-slider {
        height: 6px;
    }
    
    .duration-slider::-webkit-slider-thumb {
        width: 20px;
        height: 20px;
    }
    
    .duration-slider::-moz-range-thumb {
        width: 20px;
        height: 20px;
    }
    
    .duration-value {
        font-size: 12px;
        min-width: 28px;
    }
    
    .advanced-toggle {
        font-size: 12px;
    }
    
    .btn-generate {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 14px;
        margin-top: var(--spacing-sm);
    }
    
    /* Sections */
    .section {
        padding: var(--spacing-lg) 0;
    }
    
    .section-header {
        margin-bottom: var(--spacing-lg);
        padding: 0 var(--spacing-sm);
    }
    
    .section-title {
        margin-bottom: var(--spacing-sm);
    }
    
    .section-description {
        font-size: 14px;
    }
    
    /* Grids */
    .features-grid,
    .use-cases-grid,
    .testimonials-grid,
    .pricing-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
        padding: 0 var(--spacing-sm);
        max-width: 100%;
    }
    
    .steps {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding: 0 var(--spacing-sm);
        max-width: 100%;
    }
    
    /* Cards */
    .feature-card,
    .use-case-card,
    .testimonial-card,
    .pricing-card {
        padding: var(--spacing-md);
    }
    
    .feature-icon {
        width: 48px;
        height: 48px;
        margin-bottom: var(--spacing-sm);
    }
    
    .feature-title,
    .use-case-title {
        font-size: 16px;
        margin-bottom: var(--spacing-xs);
    }
    
    .feature-description,
    .use-case-description {
        font-size: 13px;
    }
    
    .step-number {
        font-size: 36px;
    }
    
    .step-title {
        font-size: 16px;
    }
    
    .step-description {
        font-size: 13px;
    }
    
    .testimonial-header {
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-sm);
    }
    
    .testimonial-avatar {
        width: 50px;
        height: 50px;
    }
    
    .testimonial-name {
        font-size: 14px;
    }
    
    .testimonial-role {
        font-size: 11px;
    }
    
    .testimonial-text {
        font-size: 13px;
    }
    
    .pricing-name {
        font-size: 18px;
    }
    
    .price-amount {
        font-size: 28px;
    }
    
    .price-period {
        font-size: 13px;
    }
    
    .pricing-features li {
        font-size: 13px;
        padding: var(--spacing-xs) 0;
    }
    
    /* FAQ */
    .faq-list {
        padding: 0 var(--spacing-sm);
        max-width: 100%;
    }
    
    .faq-item {
        margin-bottom: var(--spacing-sm);
    }
    
    .faq-question {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 14px;
        min-height: 44px; /* Touch-friendly */
        display: flex;
        align-items: center;
    }
    
    .faq-answer {
        padding: 0 var(--spacing-md);
    }
    
    .faq-item[aria-expanded="true"] .faq-answer {
        padding: 0 var(--spacing-md) var(--spacing-sm);
    }
    
    .faq-answer p {
        font-size: 13px;
    }
    
    /* CTA */
    .cta {
        padding: var(--spacing-lg) 0;
    }
    
    .cta-title {
        font-size: clamp(20px, 6vw, 28px);
    }
    
    .cta-description {
        font-size: 14px;
    }
    
    /* Footer */
    .footer {
        padding: var(--spacing-lg) 0 var(--spacing-md);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        padding: 0 var(--spacing-sm);
    }
    
    .footer-title {
        font-size: 18px;
    }
    
    .footer-description {
        font-size: 13px;
    }
    
    .footer-heading {
        font-size: 14px;
        margin-top: var(--spacing-md);
    }
    
    .footer-heading:first-child {
        margin-top: 0;
    }
    
    .footer-links a {
        font-size: 13px;
    }
    
    .footer-social {
        gap: var(--spacing-sm);
    }
    
    .social-link {
        width: 36px;
        height: 36px;
    }
    
    .footer-copyright {
        font-size: 12px;
    }
    
    /* Buttons */
    .btn {
        width: 100%;
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 14px;
        min-height: 44px; /* Touch-friendly */
    }
    
    .btn-large {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 15px;
    }
}

@media (max-width: 480px) {
    :root {
        --container-padding: var(--spacing-xs);
    }
    
    html {
        font-size: 13px;
    }
    
    .hero {
        padding: calc(var(--spacing-lg) + 50px) var(--spacing-xs) var(--spacing-md);
    }
    
    .hero-title {
        font-size: 24px;
    }
    
    .hero-description {
        font-size: 13px;
    }
    
    .generate-wrapper {
        padding: var(--spacing-sm);
    }
    
    .video-player {
        min-height: 180px;
    }
    
    .section {
        padding: var(--spacing-md) 0;
    }
    
    .section-header {
        margin-bottom: var(--spacing-md);
        padding: 0 var(--spacing-xs);
    }
    
    .section-title {
        font-size: 20px;
    }
    
    .section-description {
        font-size: 13px;
    }
    
    .feature-card,
    .use-case-card,
    .testimonial-card,
    .pricing-card {
        padding: var(--spacing-sm);
    }
    
    .tab-btn {
        font-size: 12px;
        padding: 8px 10px;
        min-height: 36px;
    }
    
    .res-btn,
    .aspect-btn {
        padding: 8px 10px;
        font-size: 11px;
        min-height: 32px;
    }
    
    .aspect-ratio-buttons {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .model-dropdown {
        min-height: 40px;
        padding-right: 40px;
        font-size: 13px;
    }
    
    .model-audio {
        min-height: 40px;
    }
    
    .upload-area {
        min-height: 100px;
        padding: var(--spacing-md) var(--spacing-xs);
    }
    
    .prompt-input {
        min-height: 70px;
        font-size: 13px;
    }
    
    .btn-generate {
        min-height: 44px;
    }
    
    .nav {
        padding: var(--spacing-xs) var(--spacing-sm);
    }
    
    .nav-brand .logo-text {
        font-size: 16px;
    }
}

@media (min-width: 1920px) {
    :root {
        --container-max-width: 1100px;
    }
}

/* ============================================
   Print Styles
   ============================================ */

@media print {
    .header,
    .footer,
    .nav,
    .btn,
    .hero-cta {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
}