/* =====================
   CSS Variables & Reset
   ===================== */
:root {
    /* Colors */
    --bg-primary: #0a0e1a;
    --bg-secondary: #0f172a;
    --bg-tertiary: #1e293b;
    --bg-card: rgba(15, 23, 42, 0.8);
    
    --blue-primary: #3b82f6;
    --blue-secondary: #2563eb;
    --blue-dark: #1e40af;
    --blue-light: #60a5fa;
    --blue-glow: rgba(59, 130, 246, 0.3);
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-tertiary: #94a3b8;
    
    --border-color: rgba(59, 130, 246, 0.2);
    --border-hover: rgba(59, 130, 246, 0.4);
    
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Space Grotesk', var(--font-primary);
    
    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 30px var(--blue-glow);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* =====================
   Background Animation
   ===================== */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
    pointer-events: none;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--blue-primary), transparent);
    top: -250px;
    left: -250px;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--blue-secondary), transparent);
    bottom: -200px;
    right: -200px;
    animation-delay: -7s;
}

.orb-3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, var(--blue-dark), transparent);
    top: 50%;
    left: 50%;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(50px, -50px) scale(1.1); }
    50% { transform: translate(-30px, 30px) scale(0.9); }
    75% { transform: translate(-50px, -30px) scale(1.05); }
}

/* =====================
   Container & Layout
   ===================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* =====================
   Navigation
   ===================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 14, 26, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-links a:hover {
    color: var(--blue-light);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--blue-primary);
    transition: width var(--transition-base);
}

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

/* =====================
   Hero Section
   ===================== */
.hero {
    padding: calc(80px + var(--spacing-2xl)) 0 var(--spacing-2xl);
    text-align: center;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--blue-light), var(--blue-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

/* =====================
   Generator Section
   ===================== */
.generator-section {
    padding: var(--spacing-2xl) 0;
}

.generator-card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-xl);
    max-width: 900px;
    margin: 0 auto;
}

.card-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.card-header h2 {
    font-family: var(--font-display);
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.card-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* =====================
   Upload Section
   ===================== */
.upload-section {
    margin-bottom: var(--spacing-lg);
}

.upload-area {
    position: relative;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    transition: all var(--transition-base);
    overflow: hidden;
    min-height: 300px;
    cursor: pointer;
}

.upload-area:hover {
    border-color: var(--border-hover);
    background: var(--bg-tertiary);
}

.upload-area.dragover {
    border-color: var(--blue-primary);
    background: rgba(59, 130, 246, 0.1);
    transform: scale(1.02);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    text-align: center;
    min-height: 300px;
}

.upload-content svg {
    color: var(--blue-primary);
    margin-bottom: var(--spacing-md);
}

.upload-content h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

.upload-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.file-types {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.image-preview {
    position: relative;
    min-height: 300px;
}

.image-preview img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: var(--radius-lg);
}

.remove-image {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: rgba(239, 68, 68, 0.9);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
    color: white;
}

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

/* =====================
   Input Groups
   ===================== */
.input-group {
    margin-bottom: var(--spacing-lg);
}

.input-group label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-primary);
}

.label-badge {
    background: var(--blue-primary);
    color: white;
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-weight: 500;
}

textarea,
select {
    width: 100%;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    resize: vertical;
    transition: all var(--transition-base);
}

textarea {
    min-height: 120px;
}

textarea:focus,
select:focus {
    outline: none;
    border-color: var(--blue-primary);
    box-shadow: 0 0 0 3px var(--blue-glow);
}

textarea::placeholder {
    color: var(--text-tertiary);
}

.char-counter {
    text-align: right;
    font-size: 0.875rem;
    color: var(--text-tertiary);
    margin-top: var(--spacing-xs);
}

/* =====================
   Advanced Options
   ===================== */
.advanced-options {
    margin-bottom: var(--spacing-lg);
}

.toggle-advanced {
    width: 100%;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    color: var(--text-primary);
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: all var(--transition-base);
}

.toggle-advanced:hover {
    background: var(--bg-tertiary);
    border-color: var(--border-hover);
}

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

.toggle-advanced.active svg {
    transform: rotate(180deg);
}

.advanced-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.advanced-content.active {
    max-height: 300px;
    margin-top: var(--spacing-md);
}

.option-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

/* =====================
   Buttons
   ===================== */
.submit-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--blue-primary), var(--blue-secondary));
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.4);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.6);
}

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

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.secondary-btn {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    color: var(--text-primary);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
}

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

/* =====================
   Progress Section
   ===================== */
.progress-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    color: var(--blue-light);
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top-color: var(--blue-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.time-estimate {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.progress-bar-container {
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    height: 8px;
    overflow: hidden;
    margin-bottom: var(--spacing-lg);
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--blue-primary), var(--blue-light));
    border-radius: var(--radius-sm);
    width: 0;
    transition: width var(--transition-slow);
    box-shadow: 0 0 10px var(--blue-glow);
}

.progress-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
}

.step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    opacity: 0.5;
    transition: opacity var(--transition-base);
}

.step.active {
    opacity: 1;
}

.step.complete .step-icon {
    background: var(--success);
}

.step-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    transition: all var(--transition-base);
}

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

.step span {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-align: center;
}

/* =====================
   Result Section
   ===================== */
.result-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.result-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.result-header h3 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-xs);
    color: var(--success);
}

.result-header p {
    color: var(--text-secondary);
}

.video-container {
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: black;
}

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

.result-actions {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.download-btn {
    flex: 1;
    min-width: 200px;
    background: var(--success);
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-md) var(--spacing-lg);
    color: white;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    text-decoration: none;
    transition: all var(--transition-base);
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

.result-actions .secondary-btn {
    flex: 1;
    min-width: 200px;
}

/* =====================
   Features Section
   ===================== */
.features {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 4vw, 3rem);
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--border-hover);
    box-shadow: var(--shadow-glow);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

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

/* =====================
   Footer
   ===================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand p {
    color: var(--text-secondary);
    margin-top: var(--spacing-sm);
}

.footer-links {
    display: flex;
    gap: var(--spacing-xl);
}

.footer-column h4 {
    margin-bottom: var(--spacing-md);
    font-size: 1.1rem;
}

.footer-column a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    margin-bottom: var(--spacing-xs);
    transition: color var(--transition-fast);
}

.footer-column a:hover {
    color: var(--blue-light);
}

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

/* =====================
   Responsive Design
   ===================== */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero {
        padding: calc(80px + var(--spacing-xl)) 0 var(--spacing-xl);
    }
    
    .generator-card {
        padding: var(--spacing-lg);
    }
    
    .option-row {
        grid-template-columns: 1fr;
    }
    
    .progress-steps {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .result-actions {
        flex-direction: column;
    }
    
    .download-btn,
    .result-actions .secondary-btn {
        width: 100%;
    }
    
    .footer-links {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .upload-content {
        padding: var(--spacing-lg);
    }
    
    .progress-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* =====================
   Accessibility
   ===================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus visible for keyboard navigation */
*:focus-visible {
    outline: 2px solid var(--blue-primary);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .navbar,
    .footer,
    .background-animation {
        display: none;
    }
}