/* ========================================
   AI Game DevTools - Main Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #111111;
    --bg-card: #0d0d0d;
    --bg-hover: #1a1a1a;

    --text-primary: #ffffff;
    --text-secondary: #888888;
    --text-muted: #555555;

    --accent-white: #ffffff;
    --accent-gray: #888888;
    --accent-dark-gray: #333333;

    --gradient-primary: linear-gradient(135deg, #ffffff, #888888);
    --gradient-secondary: linear-gradient(135deg, #cccccc, #666666);

    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.25);

    --shadow-glow: 0 0 40px rgba(255, 255, 255, 0.08);
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.6);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* Container */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   Navigation
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 16px 0;
    transition: var(--transition-normal);
    border-bottom: 1px solid transparent;
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    border-bottom-color: var(--border-color);
    padding: 12px 0;
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-logo img {
    height: 40px;
    width: auto;
}

.nav-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffffff, #888888);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(255, 255, 255, 0.1);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.nav-links a:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-links .nav-cta {
    background: linear-gradient(135deg, #ffffff, #888888);
    color: #000000 !important;
    margin-left: 8px;
    font-weight: 700;
}

.nav-links .nav-cta:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition-fast);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 120px 24px 80px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 8s ease-in-out infinite;
}

.orb-1 {
    width: 400px;
    height: 400px;
    background: #ffffff;
    top: -100px;
    left: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 300px;
    height: 300px;
    background: #888888;
    bottom: -50px;
    right: -50px;
    animation-delay: -3s;
}

.orb-3 {
    width: 250px;
    height: 250px;
    background: #555555;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -5s;
    opacity: 0.2;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 100px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: #ffffff;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

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

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.title-top {
    font-size: 0.5em;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.title-bottom {
    font-size: 1em;
    line-height: 1.2;
}

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

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 64px;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    transition: var(--transition-normal);
    border: none;
    cursor: pointer;
    font-family: inherit;
}

.btn-primary {
    background: #ffffff;
    color: #000000;
    box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
    font-weight: 700;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255, 255, 255, 0.25);
}

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

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 12px 24px;
}

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

/* Hero Stats */
.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
}

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

.stat-number, .stat-suffix {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-suffix {
    margin-left: 2px;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border-color);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.scroll-mouse {
    width: 24px;
    height: 36px;
    border: 2px solid var(--text-muted);
    border-radius: 12px;
    position: relative;
}

.scroll-wheel {
    width: 4px;
    height: 8px;
    background: var(--text-muted);
    border-radius: 2px;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollWheel 2s infinite;
}

@keyframes scrollWheel {
    0% { top: 6px; opacity: 1; }
    100% { top: 18px; opacity: 0; }
}

/* ========================================
   Section Headers
   ======================================== */
.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    padding: 6px 14px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #ffffff;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 800;
    line-height: 1.2;
}

/* ========================================
   Category Navigation
   ======================================== */
.category-nav {
    padding: 100px 0;
    background: var(--bg-secondary);
    position: relative;
}

.category-nav::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}

.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--card-accent, var(--gradient-primary));
    opacity: 0;
    transition: var(--transition-normal);
}

.category-card:hover::before,
.category-card.active::before {
    opacity: 1;
}

.category-card:hover,
.category-card.active {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
}

.category-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: var(--icon-bg, var(--bg-tertiary));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    font-size: 1.5rem;
}

.category-card h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.category-card p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ========================================
   Tools Section
   ======================================== */
.tools-section {
    padding: 100px 0;
    background: var(--bg-primary);
}

.tools-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 40px;
    flex-wrap: wrap;
    gap: 20px;
}

.tools-title-group {
    display: flex;
    align-items: baseline;
    gap: 12px;
}

.tools-title {
    font-size: 1.75rem;
    font-weight: 800;
}

.tools-count {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.tools-controls {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box svg {
    position: absolute;
    left: 12px;
    color: var(--text-muted);
}

.search-box input {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 10px 12px 10px 40px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    width: 240px;
    transition: var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: #ffffff;
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.1);
}

.search-box input::placeholder {
    color: var(--text-muted);
}

.filter-group select {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 10px 36px 10px 12px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b6b7b' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
}

.filter-group select:focus {
    outline: none;
    border-color: #ffffff;
}

/* Tools Grid */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 16px;
}

.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: var(--card-accent, #ffffff);
    opacity: 0;
    transition: var(--transition-normal);
}

.tool-card:hover::before {
    opacity: 1;
}

.tool-card:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-card);
}

.tool-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 12px;
}

.tool-name {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.tool-card:hover .tool-name {
    color: #ffffff;
}

.tool-badges {
    display: flex;
    gap: 6px;
    flex-shrink: 0;
}

.badge {
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.badge-engine {
    background: rgba(255, 255, 255, 0.1);
    color: #aaaaaa;
}

.badge-type {
    background: rgba(255, 255, 255, 0.08);
    color: #888888;
}

.badge-paper {
    background: rgba(255, 255, 255, 0.12);
    color: #cccccc;
}

.tool-description {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.tool-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.tool-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    color: #aaaaaa;
    transition: var(--transition-fast);
}

.tool-link:hover {
    color: #ffffff;
}

.tool-link:hover {
    gap: 8px;
}

.tool-link svg {
    width: 14px;
    height: 14px;
}

/* Load More */
.load-more {
    text-align: center;
    margin-top: 48px;
}

/* ========================================
   About Section
   ======================================== */
.about-section {
    padding: 100px 0;
    background: var(--bg-secondary);
    position: relative;
}

.about-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-content .section-tag {
    margin-bottom: 16px;
}

.about-content .section-title {
    margin-bottom: 24px;
}

.about-content p {
    color: var(--text-secondary);
    margin-bottom: 16px;
    font-size: 1rem;
    line-height: 1.7;
}

.about-features {
    margin-top: 40px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.feature-text p {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin: 0;
}

.about-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.visual-card {
    position: relative;
    padding: 48px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    text-align: center;
    min-width: 280px;
}

.visual-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
    opacity: 0.05;
    z-index: 0;
}

.card-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 250px;
    height: 250px;
    background: #ffffff;
    filter: blur(120px);
    opacity: 0.12;
    border-radius: 50%;
    animation: pulse-glow 4s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.15; }
    50% { transform: translate(-50%, -50%) scale(1.1); opacity: 0.25; }
}

.about-avatar {
    position: relative;
    z-index: 1;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffffff, #888888);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3.5rem;
    box-shadow: 0 8px 32px rgba(255, 255, 255, 0.15);
    border: 3px solid rgba(255, 255, 255, 0.15);
}

.about-title {
    position: relative;
    z-index: 1;
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #ffffff, #888888);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.about-subtitle {
    position: relative;
    z-index: 1;
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: 64px 0 32px;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand img {
    height: 48px;
    margin-bottom: 16px;
}

.footer-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffffff, #888888);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: 16px;
    box-shadow: 0 4px 16px rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.15);
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    max-width: 300px;
}

.footer-links h4 {
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition-fast);
}

.footer-links a:hover {
    color: #ffffff;
}

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ========================================
   Back to Top
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition-normal);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--bg-hover);
    border-color: #ffffff;
    color: #ffffff;
}

/* ========================================
   Animations
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }
    
    .about-visual {
        order: -1;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: var(--bg-secondary);
        flex-direction: column;
        padding: 80px 24px 24px;
        transition: var(--transition-normal);
        border-left: 1px solid var(--border-color);
    }
    
    .nav-links.active {
        right: 0;
    }
    
    .mobile-toggle {
        display: flex;
        z-index: 1001;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }
    
    .stat-divider {
        width: 40px;
        height: 1px;
    }
    
    .tools-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
        width: 100%;
    }
    
    .hero-cta .btn {
        width: 100%;
        justify-content: center;
    }
    
    .search-box input {
        width: 100%;
    }
}

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

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

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

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