@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&display=swap');

/* CSS Custom Properties for Design System */
:root {
    --font-primary: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    
    /* Dark Theme (Default) */
    --bg-base: #080710;
    --bg-surface: rgba(255, 255, 255, 0.05);
    --bg-surface-hover: rgba(255, 255, 255, 0.09);
    --border-color: rgba(255, 255, 255, 0.1);
    --border-color-hover: rgba(255, 255, 255, 0.2);
    
    --text-primary: #ffffff;
    --text-secondary: #a0aec0;
    --text-muted: #718096;
    
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
    --accent-glow: 0 8px 32px 0 rgba(99, 102, 241, 0.2);
    
    --primary-color: #6366f1;
    --secondary-color: #a855f7;
    --accent-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.3);
    
    --glass-blur: 16px;
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    --ad-bg: rgba(255, 255, 255, 0.02);
}

/* Light Theme Variables */
[data-theme="light"] {
    --bg-base: #f8fafc;
    --bg-surface: rgba(255, 255, 255, 0.7);
    --bg-surface-hover: rgba(255, 255, 255, 0.95);
    --border-color: rgba(0, 0, 0, 0.08);
    --border-color-hover: rgba(0, 0, 0, 0.15);
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    
    --primary-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 50%, #ec4899 100%);
    --accent-glow: 0 8px 32px 0 rgba(59, 130, 246, 0.15);
    
    --primary-color: #3b82f6;
    --secondary-color: #8b5cf6;
    --ad-bg: rgba(0, 0, 0, 0.02);
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: var(--font-primary);
}

body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    padding-bottom: 40px;
    transition: background-color var(--transition-normal), color var(--transition-normal);
    position: relative;
}

/* Cosmic Background Decorative Blobs */
body::before, body::after {
    content: '';
    position: absolute;
    width: 35vw;
    height: 35vw;
    border-radius: 50%;
    filter: blur(120px);
    z-index: -1;
    opacity: 0.15;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}

body::before {
    top: -10%;
    left: -10%;
    background: var(--primary-color);
}

body::after {
    bottom: 10%;
    right: -10%;
    background: var(--secondary-color);
}

[data-theme="light"]::before, [data-theme="light"]::after {
    opacity: 0.08;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-base);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* --- HEADER --- */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
    transition: background-color var(--transition-normal), border var(--transition-normal);
}

header.scrolled {
    background: var(--bg-surface);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    box-shadow: var(--shadow-sm);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.9;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    background: var(--primary-gradient);
    color: #fff;
    -webkit-text-fill-color: #fff;
    font-size: 1.2rem;
    font-weight: 800;
    box-shadow: var(--accent-glow);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
    position: relative;
    padding: 6px 0;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-gradient);
    transition: width var(--transition-normal);
    border-radius: 2px;
}

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

.actions-group {
    display: flex;
    align-items: center;
    gap: 16px;
}

.theme-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-btn:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-color-hover);
    transform: scale(1.05);
}

.theme-btn svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

.theme-btn .sun {
    display: none;
}

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

[data-theme="light"] .theme-btn .sun {
    display: block;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* --- HERO BANNER --- */
.hero {
    padding: 40px 0 20px;
    text-align: center;
    position: relative;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.hero h1 span {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* --- WORKSPACE LAYOUT --- */
main {
    margin-top: 30px;
}

.workspace-layout {
    display: grid;
    grid-template-columns: 280px 1fr 280px;
    gap: 24px;
    align-items: start;
}

@media (max-width: 1200px) {
    .workspace-layout {
        grid-template-columns: 1fr;
    }
    .left-sidebar, .right-sidebar {
        order: 2;
    }
    .canvas-viewport {
        order: 1;
    }
}

/* --- SIDEBAR PANEL PANELS --- */
.left-sidebar, .right-sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.glass-panel {
    background: var(--bg-surface);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-md);
    transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}

.glass-panel:hover {
    border-color: var(--border-color-hover);
    background: var(--bg-surface-hover);
}

.panel-section-title {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
    border-left: 3px solid var(--primary-color);
    padding-left: 8px;
}

/* --- TOOLS & GRIDS --- */
.tool-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.tool-btn {
    padding: 10px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background: var(--bg-base);
    color: var(--text-primary);
    font-weight: 600;
    font-family: var(--font-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-size: 0.85rem;
    user-select: none;
    transition: all var(--transition-fast);
}

.tool-btn:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-color-hover);
}

.tool-btn.active {
    background: var(--primary-gradient);
    color: #fff;
    border-color: transparent;
    box-shadow: var(--accent-glow);
}

/* --- INPUTS & STEPPERS --- */
.form-group {
    margin-bottom: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.stepper-ctrl {
    display: flex;
    align-items: center;
    background: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.stepper-btn {
    background: transparent;
    border: none;
    color: var(--text-primary);
    width: 36px;
    height: 36px;
    font-weight: bold;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.stepper-btn:hover {
    background: var(--bg-surface-hover);
}

.stepper-ctrl input,
.stepper-ctrl select {
    flex: 1;
    width: 100%;
    border: none;
    background: transparent;
    color: var(--text-primary);
    text-align: center;
    outline: none;
    font-size: 0.85rem;
    height: 36px;
    font-family: var(--font-primary);
    transition: all var(--transition-fast);
}

.stepper-ctrl select option,
.color-picker-wrapper select option {
    background-color: var(--bg-base);
    color: var(--text-primary);
}

.stepper-ctrl select {
    padding: 0 8px;
    cursor: pointer;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    cursor: pointer;
    user-select: none;
    margin-top: 4px;
}

.checkbox-label input {
    accent-color: var(--primary-color);
    width: 16px;
    height: 16px;
}

/* --- VIEWPORT TRUNG TÂM --- */
.canvas-viewport {
    background: #0f0f12;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    height: 620px;
    position: relative;
    overflow: hidden;
    user-select: none;
    cursor: crosshair;
    box-shadow: var(--shadow-lg);
}

.canvas-container-wrapper {
    position: absolute;
    transform-origin: 0 0;
    will-change: transform;
}

.pixel-canvas-element {
    display: block;
    image-rendering: pixelated;
    background-color: #fff;
    background-image: linear-gradient(45deg, rgba(0, 0, 0, 0.08) 25%, transparent 25%, transparent 75%, rgba(0, 0, 0, 0.08) 75%),
        linear-gradient(45deg, rgba(0, 0, 0, 0.08) 25%, transparent 25%, transparent 75%, rgba(0, 0, 0, 0.08) 75%);
    background-size: var(--bg-caro-size, 16px) var(--bg-caro-size, 16px);
    background-position: 0 0, calc(var(--bg-caro-size, 16px) / 2) calc(var(--bg-caro-size, 16px) / 2);
    box-shadow: var(--shadow-lg);
}

[data-theme="dark"] .pixel-canvas-element {
    background-image: linear-gradient(45deg, #18181c 25%, transparent 25%, transparent 75%, #18181c 75%),
        linear-gradient(45deg, #18181c 25%, transparent 25%, transparent 75%, #18181c 75%);
    background-color: #24242b;
}

.viewport-badges {
    position: absolute;
    bottom: 12px;
    left: 12px;
    right: 12px;
    display: flex;
    justify-content: space-between;
    pointer-events: none;
}

.status-badge {
    background: rgba(10, 10, 12, 0.85);
    backdrop-filter: blur(4px);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--success-color);
    font-family: monospace;
}

/* --- BẢNG MÀU THÔNG MINH --- */
.color-picker-wrapper {
    display: flex;
    gap: 12px;
    align-items: center;
}

input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    background: none;
}

input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
}

.smart-palette-container {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.palette-slot {
    flex: 1;
    height: 38px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: bold;
    color: #fff;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.8);
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 2px solid transparent;
}

.palette-slot:hover {
    transform: scale(1.06);
}

.selected-slot {
    border-color: var(--primary-color) !important;
    box-shadow: var(--accent-glow);
    transform: scale(1.04);
}

/* --- ANIMATION PREVIEW --- */
.animation-preview-box {
    width: 100%;
    height: 120px;
    background-color: var(--bg-base);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    border: 1px solid var(--border-color);
    margin-bottom: 8px;
}

.animation-preview-box canvas {
    max-width: 100%;
    max-height: 100%;
    image-rendering: pixelated;
}

/* --- SEO & FAQ BOTTOM SECTIONS --- */
.seo-section {
    margin-top: 80px;
    border-top: 1px solid var(--border-color);
    padding-top: 60px;
}

.seo-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-bottom: 60px;
}

@media (max-width: 768px) {
    .seo-grid {
        grid-template-columns: 1fr;
    }
}

.seo-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 32px;
}

.seo-card h2, .faq-section h2 {
    font-size: 1.75rem;
    font-weight: 800;
    margin-bottom: 20px;
}

.seo-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.faq-section {
    margin-bottom: 80px;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
    background: var(--bg-surface);
}

.faq-question {
    width: 100%;
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.1rem;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
    outline: none;
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--primary-color);
    transition: transform var(--transition-normal);
}

.faq-item.active .faq-question::after {
    content: '-';
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal) ease-out, padding var(--transition-normal) ease-out;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding: 0 24px 24px 24px;
}

/* --- FOOTER --- */
footer {
    margin-top: auto;
    border-top: 1px solid var(--border-color);
    padding: 60px 0 40px 0;
    background: rgba(0, 0, 0, 0.05);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .footer-col:first-child {
        grid-column: span 2;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-col:first-child {
        grid-column: span 1;
    }
}

.footer-col h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-col p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 0.9rem;
    color: var(--text-muted);
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: var(--bg-base);
        flex-direction: column;
        justify-content: center;
        gap: 40px;
        font-size: 1.5rem;
        z-index: 99;
        transition: all var(--transition-normal);
        border-top: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-toggle {
        display: block;
    }
}