/* Global Styles & Variables */
:root {
    --primary-color: #6c5ce7;       /* 主色调 - 紫色 */
    --primary-light: #a29bfe;     /* 浅紫色 */
    --primary-dark: #544ab0;      /* 深紫色 (新) */
    --secondary-color: #007f7b;     /* 次色调 - 深青色，确保白字对比度 */
    --accent-color: #fd79a8;       /* 强调色 - 粉色 */
    --light-bg: #f8f9fa;          /* 亮色背景 */
    --light-card-bg: #ffffff;     /* 亮色卡片背景 */
    --light-text: #2d3436;        /* 亮色文本 */
    --dark-bg: #1e272e;           /* 暗色背景 */
    --dark-card-bg: #2d3436;      /* 暗色卡片背景 */
    --dark-text: #dfe6e9;         /* 暗色文本 */
    --grey-color: #636e72;        /* 灰色，满足浅色背景文字对比度 */
    --light-grey: #dfe6e9;       /* 浅灰 (新) */
    --success-color: #00b894;     /* 成功色 */
    --warning-color: #fdcb6e;     /* 警告色 */
    --danger-color: #d63031;      /* 危险色 */
    --shadow-light: 0 6px 18px rgba(108, 92, 231, 0.15); /* 浅阴影 (新) */
    --shadow-strong: 0 10px 25px rgba(0, 0, 0, 0.1);   /* 强阴影 */
    --border-radius-sm: 6px;       /* 小圆角 (新) */
    --border-radius-md: 12px;      /* 中圆角 (调整) */
    --border-radius-lg: 20px;      /* 大圆角 (新) */
    --transition-fast: all 0.2s ease-out; /* 快速过渡 (新) */
    --transition-std: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1); /* 标准过渡 (调整) */

    /* Difficulty Colors */
    --difficulty-easy: #187a4a;
    --difficulty-medium: #8a5200;
    --difficulty-hard: #b42318;
    --difficulty-text: #ffffff;

    /* Subtle Background Gradient */
    --light-body-gradient: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    --dark-body-gradient: linear-gradient(135deg, #1e272e 0%, #2d3436 100%);

    /* Section Separator */
    --section-border: 1px solid rgba(0, 0, 0, 0.05);
    --dark-section-border: 1px solid rgba(255, 255, 255, 0.08);

    /* Typewriter caret color variable */
    --typewriter-caret-color: var(--primary-color);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 5.5rem;
    font-size: 16px; /* Base font size */
}

body {
    font-family: system-ui, -apple-system, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    line-height: 1.7;
    color: var(--light-text);
    background: var(--light-body-gradient); /* Use subtle gradient */
    transition: background-color var(--transition-std), color var(--transition-std);
    overflow-x: hidden; /* Prevent horizontal scroll */
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}
a:hover {
    color: var(--primary-color);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto; /* Maintain aspect ratio */
    display: block;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.6rem 1.5rem; /* 减小按钮padding */
    border: none;
    border-radius: var(--border-radius-md); /* 减小圆角 */
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-std);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.85rem; /* 减小字体大小 */
    box-shadow: var(--shadow-light);
    text-align: center;
    min-height: 44px;
}

.primary-btn {
    background: linear-gradient(45deg, var(--primary-color), var(--primary-light));
    color: white;
}

.primary-btn:hover {
    background: linear-gradient(45deg, var(--primary-light), var(--primary-color));
    transform: translateY(-3px) scale(1.02); /* 减小悬停效果 */
    box-shadow: 0 5px 15px rgba(108, 92, 231, 0.25); /* 减小阴影 */
}

.reset-btn {
    background-color: var(--secondary-color);
    color: white;
    padding: 0.6rem 1.2rem;
    font-size: 0.85rem;
    border-radius: var(--border-radius-md);
    display: flex;
    justify-content: center;
    align-items: center;
}
.reset-btn:hover {
    background-color: #00b894; /* Darker secondary color */
    transform: translateY(-2px);
}

/* Section Styling */
section {
    padding: 3rem 5%;
    max-width: 1400px;
    margin: 0 auto;
    position: relative; /* For potential pseudo-elements */
}

/* Add subtle separators between sections */
section:not(:first-child)::before {
    content: '';
    position: absolute;
    top: 0;
    left: 10%;
    right: 10%;
    height: 1px;
    background: var(--section-border);
    opacity: 0.7;
}


.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-header h2 {
    font-size: 2.8rem; /* Slightly larger */
    margin-bottom: 0.8rem;
    color: var(--primary-dark); /* Use darker primary */
    font-weight: 700;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--grey-color);
    max-width: 600px; /* Limit width */
    margin: 0 auto; /* Center */
}

/* Header and Navigation */
header {
    background-color: rgba(255, 255, 255, 0.9); /* Slightly transparent */
    backdrop-filter: blur(10px); /* Glass effect */
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05); /* Softer shadow */
    position: sticky;
    top: 0;
    z-index: 1000; /* Ensure it's above everything */
    transition: background-color var(--transition-std);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.8rem 5%; /* Slightly reduced padding */
    max-width: 1400px;
    margin: 0 auto;
}

.logo h1 {
    font-size: 2rem; /* Larger logo */
    font-weight: 700;
    color: var(--light-text);
}

.logo span {
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 2.5rem; /* Increased gap */
}

.nav-links a {
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
    color: var(--light-text);
    font-size: 1rem;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px; /* Position slightly below */
    left: 0;
    width: 0%;
    height: 3px; /* Thicker underline */
    background-color: var(--primary-color);
    transition: width var(--transition-std);
    border-radius: 2px;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}
.nav-links a:hover {
    color: var(--primary-color); /* Hover color */
}
.nav-links a.active {
    color: var(--primary-color); /* Active color */
    font-weight: 600;
}


.nav-controls {
    display: flex;
    align-items: center;
    gap: 1rem; /* Reduced gap */
    padding: 5px 8px; /* Adjusted padding */
    background-color: transparent; /* Make transparent */
    border-radius: var(--border-radius-lg);
    /* Removed shadow */
}

/* Language Switch and Theme Toggle Styles */
.language-switch select {
    background-color: var(--light-bg);
    border: 1px solid var(--light-grey);
    border-radius: var(--border-radius-md); /* Match other elements */
    padding: 6px 28px 6px 12px; /* Adjusted padding */
    font-size: 0.9rem;
    color: var(--light-text);
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    outline: none;
    transition: var(--transition-std);
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
}

.language-switch {
    position: relative;
}

.language-switch::after { /* Custom arrow */
    content: '\f0d7';
    font-family: 'Font Awesome 6 Free'; /* Updated Font Awesome family */
    font-weight: 900;
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    pointer-events: none;
    color: var(--grey-color); /* Use grey for arrow */
    transition: color var(--transition-fast);
}

.language-switch select:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 5px rgba(108, 92, 231, 0.2);
}
.language-switch select:focus {
     border-color: var(--primary-color);
     box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
}

.theme-toggle {
    cursor: pointer;
    font-size: 1.3rem; /* Slightly larger icon */
    color: var(--grey-color); /* Start with grey */
    width: 40px; /* Larger touch target */
    height: 40px;
    padding: 0;
    appearance: none;
    font: inherit;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background-color: var(--light-bg);
    border: 1px solid var(--light-grey);
    transition: var(--transition-std);
}

.theme-toggle:hover {
    background-color: var(--primary-light);
    color: white;
    border-color: var(--primary-light);
    transform: rotate(15deg); /* Slight rotation on hover */
}
.theme-toggle:focus-visible {
    outline: 3px solid rgba(108, 92, 231, 0.25);
    outline-offset: 3px;
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    min-height: calc(100vh - 70px); /* Adjusted height slightly */
    padding: 3rem 5% 4rem; /* Adjusted padding */
    gap: 3rem; /* Add gap between content and image */
}

.hero-content {
    flex: 1.1; /* Give slightly more space to content */
    padding-right: 1rem;
    animation: slideInFromLeft 0.8s ease-out forwards; /* Entrance animation */
}

.hero-badge {
    display: inline-flex;
    gap: 0.5rem;
    align-items: center;
    margin-bottom: 1rem;
    padding: 0.45rem 0.8rem;
    border: 1px solid rgba(108, 92, 231, 0.22);
    border-radius: 999px;
    background: rgba(108, 92, 231, 0.08);
    color: var(--primary-dark);
    font-size: 0.86rem;
    font-weight: 700;
}

body.dark-theme .hero-badge {
    color: var(--primary-light);
    border-color: rgba(162, 155, 254, 0.3);
    background: rgba(162, 155, 254, 0.1);
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.85rem;
    align-items: center;
}

.source-btn,
.github-btn {
    display: inline-flex;
    gap: 0.5rem;
    align-items: center;
    justify-content: center;
    background: #24292f;
    color: #fff;
}

.share-btn {
    display: inline-flex;
    gap: 0.5rem;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(108, 92, 231, 0.24);
    background: var(--light-card-bg);
    color: var(--primary-dark);
}

.share-btn:hover {
    border-color: var(--primary-color);
    background: rgba(108, 92, 231, 0.08);
    color: var(--primary-dark);
    transform: translateY(-2px);
}

body.dark-theme .share-btn {
    border-color: rgba(162, 155, 254, 0.28);
    background: var(--dark-card-bg);
    color: var(--primary-light);
}

.share-status {
    min-height: 1.5em;
    margin-top: 0.75rem;
    color: var(--grey-color);
    font-size: 0.9rem;
    font-weight: 600;
}

.source-btn:hover,
.github-btn:hover {
    background: #000;
    color: #fff;
    transform: translateY(-2px);
}

.hero-content h1 {
    font-size: clamp(2.5rem, 5vw, 4rem); /* Responsive font size */
    margin-bottom: 1.2rem;
    color: var(--primary-dark);
    font-weight: 700;
    line-height: 1.2;
}

.hero-content p { /* This is the .typewriter-text element */
    font-size: clamp(1rem, 2.5vw, 1.2rem);
    margin-bottom: 2.5rem;
    color: var(--grey-color);
    max-width: 550px;
    /* Typewriter specific styles are handled by .typewriter-text class below */
}

.hero-image {
    flex: 0.9;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative; /* Needed for absolute positioned shapes */
    animation: fadeIn 1s ease-out 0.3s forwards; /* Fade in animation */
    opacity: 0; /* Start hidden for animation */
}

/* Enhanced Hero Animation Container */
.hero-animation {
    width: clamp(300px, 80%, 500px); /* Responsive width */
    aspect-ratio: 1 / 1; /* Make it square */
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-lg); /* Smoother radius */
    position: relative;
    overflow: visible; /* Allow icons/shapes to peek out slightly */
    box-shadow: 0 15px 35px rgba(108, 92, 231, 0.25); /* Enhanced shadow */
    transform: rotate(-5deg); /* Slight tilt */
    transition: transform 0.5s ease-out;
}
.hero:hover .hero-animation {
    transform: rotate(0deg) scale(1.02); /* Straighten and scale slightly on hover */
}


/* Floating Icons Enhancement */
.floating-icon {
    position: absolute;
    width: clamp(50px, 12vw, 70px); /* Responsive size */
    height: clamp(50px, 12vw, 70px);
    background: white;
    border-radius: var(--border-radius-md);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: clamp(1.5rem, 4vw, 2rem);
    color: var(--primary-color);
    animation: floatEnhanced 6s infinite ease-in-out; /* Slower, smoother float */
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
    transition: transform 0.3s ease-out;
}
.floating-icon:hover {
    transform: scale(1.1) rotate(10deg); /* Scale and rotate on hover */
}

/* Adjusted icon positions */
.icon1 { top: -10%; left: 15%; animation-delay: 0s; }
.icon2 { top: 25%; right: -12%; animation-delay: 1.5s; }
.icon3 { bottom: -8%; left: 40%; animation-delay: 3s; }
.icon4 { bottom: 30%; left: -15%; animation-delay: 4.5s; }

@keyframes floatEnhanced {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    25% { transform: translateY(-15px) rotate(-5deg); }
    50% { transform: translateY(0) rotate(0deg); }
    75% { transform: translateY(15px) rotate(5deg); }
}

/* Subtle Background Shapes in Hero Animation */
.hero-bg-shape {
    position: absolute;
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; /* Organic shape */
    opacity: 0.1;
    background: white;
    animation: morph 15s infinite ease-in-out alternate;
}
.shape1 { width: 150px; height: 150px; top: 10%; left: 10%; animation-delay: 0s; }
.shape2 { width: 100px; height: 100px; bottom: 15%; right: 5%; animation-delay: -5s; }
.shape3 { width: 80px; height: 80px; top: 50%; left: 50%; transform: translate(-50%, -50%); animation-delay: -10s;}

@keyframes morph {
    0%, 100% { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; transform: rotate(0deg) scale(1); }
    50% { border-radius: 50% 50% 30% 70% / 60% 40% 60% 40%; transform: rotate(180deg) scale(1.1); }
}


/* Featured Section */
.featured-section {
    background-color: var(--light-bg); /* Ensure background color */
    padding-top: 3rem;
    border-top: var(--section-border);
}

.featured-game-container {
     display: flex;
     justify-content: center; /* Center the card */
}

.featured-game-card { /* Renamed from .featured-game */
    background-color: var(--light-card-bg);
    border-radius: var(--border-radius-lg); /* Larger radius */
    box-shadow: var(--shadow-strong); /* Stronger shadow */
    overflow: hidden;
    max-width: 760px;
    width: 100%;
    transition: transform var(--transition-std), box-shadow var(--transition-std);
}

.featured-game-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
}


.featured-game-card h3 {
    padding: 1rem 1.5rem;
    font-size: 1.6rem;
    background: linear-gradient(45deg, var(--primary-color), var(--primary-light)); /* Match button gradient */
    color: white;
    text-align: center;
}

.game-preview {
    padding: 1.25rem 1.5rem;
    min-height: 0;
}

.memory-game {
    width: 100%;
    height: 100%; /* 确保填满容器 */
}

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--light-grey);
}

.stats {
    display: flex;
    gap: 2rem;
    font-weight: 500;
    font-size: 1rem;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(4, 1fr); /* 固定4列 */
    gap: 0.75rem;
    margin-top: 0.75rem;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
    min-height: 300px; /* 确保游戏板有足够的高度 */
    width: 100%; /* 确保宽度充满容器 */
    background-color: rgba(108, 92, 231, 0.05); /* 更明显的背景色 */
    border-radius: var(--border-radius-md);
    padding: 0.75rem;
    border: 2px solid var(--primary-light); /* 添加边框 */
    box-shadow: var(--shadow-light); /* 添加阴影 */
    position: relative; /* 为加载指示器做准备 */
}

/* 添加加载指示器 */
.game-board::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: 4px solid rgba(108, 92, 231, 0.2);
    border-top-color: var(--primary-color);
    animation: spin 1s infinite linear;
    z-index: 0;
}

@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}

/* 卡片在加载指示器之上 */
.memory-card {
    aspect-ratio: 1 / 1; /* Make cards square */
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1); /* Smoother flip */
    cursor: pointer;
    border-radius: 10px;
    z-index: 1; /* 确保卡片在加载指示器之上 */
    background: transparent;
    box-shadow: 0 5px 14px rgba(45, 42, 74, 0.14);
}

.memory-card .front-face,
.memory-card .back-face {
    inset: 0;
    width: 100%;
    height: 100%;
    position: absolute;
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.memory-card .front-face {
    background: linear-gradient(145deg, #ffffff, #f0edff);
    transform: rotateY(180deg);
    border: 2px solid var(--primary-light);
}

.memory-card .front-face i {
    font-size: clamp(1.5rem, 5vw, 2.5rem); /* Responsive icon size */
    color: var(--primary-color);
}

.memory-card .back-face {
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color)); /* Gradient back */
    color: white;
    border: 2px solid transparent;
}

.memory-card .back-face i {
    font-size: clamp(1.5rem, 5vw, 2.5rem);
}

.memory-card.flip {
    transform: rotateY(180deg);
}

.memory-card:not(.flip):hover .back-face {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light)); /* Invert gradient on hover */
    transform: scale(1.03); /* Slight grow effect */
    box-shadow: 0 6px 12px rgba(0,0,0,0.2);
}

/* Matched card effect */
.memory-card.matched .front-face {
    background-color: rgba(46, 204, 113, 0.1); /* Light green background */
    border-color: var(--difficulty-easy); /* Green border */
}

.memory-card.matched .front-face i {
    color: var(--difficulty-easy); /* Green icon */
}

/* Dark theme support for memory cards */
body.dark-theme .memory-card .front-face {
    background-color: var(--dark-card-bg);
    border-color: var(--primary-color);
}

body.dark-theme .memory-card .front-face i {
    color: var(--primary-light);
}

body.dark-theme .memory-card .back-face {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

body.dark-theme .memory-card:not(.flip):hover .back-face {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

body.dark-theme .memory-card.matched .front-face {
    background-color: rgba(46, 204, 113, 0.2);
    border-color: var(--difficulty-easy);
}

.game-instructions {
    padding: 1rem 1.5rem;
    background-color: var(--light-bg);
    border-top: 1px solid var(--light-grey);
}

.memory-result {
    margin: 1rem;
    padding: 0.85rem 1rem;
    border: 1px solid rgba(24, 122, 74, 0.3);
    border-radius: var(--border-radius-md);
    background: rgba(24, 122, 74, 0.1);
    color: #125c38;
    font-weight: 700;
    text-align: center;
}

body.dark-theme .memory-result {
    border-color: rgba(85, 239, 196, 0.35);
    background: rgba(85, 239, 196, 0.1);
    color: #b8f7e8;
}

.game-instructions h4 {
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
    font-weight: 600;
}
.game-instructions p {
    color: var(--grey-color);
    font-size: 0.95rem;
}

/* About Section */
.about-section {
    padding: 3rem 5%;
    background-color: var(--light-card-bg);
    border-top: var(--section-border);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    color: var(--grey-color);
    font-size: 1.05rem;
    line-height: 1.9;
}


/* Games Section */
.games-section {
    padding: 3rem 5%;
    background-color: var(--light-bg); /* Ensure background */
    border-top: var(--section-border);
}

.progress-section {
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.08), rgba(0, 127, 123, 0.08));
}

.progress-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
}

.progress-card {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 0.25rem 0.75rem;
    align-items: center;
    padding: 1.1rem;
    border: 1px solid rgba(108, 92, 231, 0.14);
    border-radius: var(--border-radius-md);
    background: var(--light-card-bg);
    box-shadow: var(--shadow-light);
}

.progress-icon {
    grid-row: 1 / 4;
    font-size: 1.75rem;
}

.progress-card h3 {
    color: var(--grey-color);
    font-size: 0.86rem;
    line-height: 1.35;
}

.progress-card strong {
    color: var(--primary-dark);
    font-size: 1.2rem;
    line-height: 1.25;
}

.progress-achievement {
    justify-self: start;
    padding: 0.18rem 0.5rem;
    border-radius: 999px;
    background: rgba(99, 110, 114, 0.12);
    color: var(--grey-color);
    font-size: 0.72rem;
    font-weight: 700;
    line-height: 1.35;
}

.progress-achievement.unlocked {
    background: rgba(0, 127, 123, 0.14);
    color: #00695c;
}

.progress-privacy {
    margin-top: 1rem;
    color: var(--grey-color);
    text-align: center;
    font-size: 0.9rem;
}

body.dark-theme .progress-section {
    background: linear-gradient(135deg, rgba(162, 155, 254, 0.08), rgba(0, 127, 123, 0.08));
}

body.dark-theme .progress-card {
    border-color: rgba(162, 155, 254, 0.18);
    background: var(--dark-card-bg);
}

body.dark-theme .progress-card strong {
    color: var(--primary-light);
}

body.dark-theme .progress-achievement.unlocked {
    background: rgba(85, 239, 196, 0.14);
    color: #55efc4;
}

.category-filter {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem; /* More space below filters */
}

.filter-btn {
    padding: 0.6rem 1.6rem; /* Adjusted padding */
    background-color: var(--light-card-bg);
    border: 1px solid var(--light-grey);
    border-radius: var(--border-radius-lg); /* Match primary button */
    cursor: pointer;
    transition: var(--transition-std);
    font-weight: 500;
    color: var(--grey-color); /* Start greyed out */
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    min-height: 44px;
}

.filter-btn:hover {
    background-color: var(--primary-light);
    color: white;
    border-color: var(--primary-light);
    transform: translateY(-2px);
}
.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 4px 10px rgba(108, 92, 231, 0.2);
    transform: translateY(-2px);
}

.games-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); /* Slightly smaller min size */
    gap: 2.5rem; /* Increased gap */
}

.game-card {
    background-color: var(--light-card-bg);
    border-radius: var(--border-radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-light);
    transition: var(--transition-std);
    display: flex; /* Use flexbox for better control */
    flex-direction: column; /* Stack thumb and info vertically */
}

.game-card:hover {
    transform: translateY(-10px) scale(1.02); /* Lift and scale */
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1); /* Stronger hover shadow */
}

.game-thumb {
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--light-grey); /* Separator */
    isolation: isolate; /* Ensure overlay stacks above preview artwork */
}


.game-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(rgba(45, 52, 54, 0.2), rgba(45, 52, 54, 0.8)); /* Darker gradient */
    display: flex;
    flex-direction: column; /* Stack elements */
    justify-content: center;
    align-items: center;
    opacity: 0;
    z-index: 10;
    transition: opacity var(--transition-std); /* Only transition opacity */
}

.game-card:not(.coming-soon) .game-overlay {
    opacity: 1;
    background: linear-gradient(rgba(45, 52, 54, 0.0), rgba(45, 52, 54, 0.65));
    justify-content: flex-end;
    padding-bottom: 1rem;
}

.game-card:hover .game-overlay {
    opacity: 1;
}

.play-btn {
    background: var(--primary-color);
    color: white;
    padding: 0.8rem 1.8rem;
    border-radius: var(--border-radius-lg);
    transform: translateY(20px);
    transition: transform 0.4s cubic-bezier(0.25, 0.8, 0.25, 1) 0.1s, opacity 0.3s ease-out 0.1s; /* Delayed transform */
    opacity: 0;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.game-card:not(.coming-soon) .play-btn {
    opacity: 1;
    transform: translateY(0);
}

.game-card:hover .play-btn {
    transform: translateY(0);
    opacity: 1;
}
.play-btn:hover {
    background: var(--primary-light);
}

.coming-soon-label {
    background-color: var(--accent-color);
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: var(--border-radius-md);
    font-weight: 500;
    font-size: 0.9rem;
    transform: translateY(20px);
    transition: transform 0.4s cubic-bezier(0.25, 0.8, 0.25, 1) 0.1s, opacity 0.3s ease-out 0.1s;
    opacity: 0;
}
.game-card:hover .coming-soon-label {
    transform: translateY(0);
    opacity: 1;
}

.game-info {
    padding: 1.2rem 1.5rem; /* Adjusted padding */
    flex-grow: 1; /* Allow info to take remaining space */
    display: flex;
    flex-direction: column;
    justify-content: space-between; /* Push meta to bottom */
}

.game-info h3 {
    margin-bottom: 0.8rem;
    color: var(--light-text);
    font-size: 1.25rem; /* Slightly smaller title */
    font-weight: 600;
}

.game-meta {
    display: flex;
    justify-content: space-between;
    align-items: center; /* Align items vertically */
    margin-top: 1rem; /* Add space above meta */
}

.category {
    background-color: var(--primary-color);
    color: white;
    padding: 0.3rem 0.9rem; /* Adjusted padding */
    border-radius: var(--border-radius-lg);
    font-size: 0.75rem; /* Smaller font */
    font-weight: 500;
    text-transform: uppercase;
}

.difficulty {
    padding: 0.3rem 0.9rem;
    border-radius: var(--border-radius-lg);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    color: var(--difficulty-text);
}
/* Difficulty specific colors */
.difficulty.easy { background-color: var(--difficulty-easy); }
.difficulty.medium { background-color: var(--difficulty-medium); }
.difficulty.hard { background-color: var(--difficulty-hard); }


/* Footer */
footer {
    --grey-color: #b2bec3;
    background-color: var(--dark-bg);
    color: var(--light-grey); /* Use lighter grey */
    padding: 5rem 5% 2rem; /* More top padding */
    margin-top: 4rem; /* Space above footer */
    border-top: 4px solid var(--primary-color); /* Accent border */
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    max-width: 1400px;
    margin: 0 auto 3rem;
}

.footer-logo h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: white; /* White logo text */
}

.footer-logo span {
    color: var(--primary-light);
}

.footer-logo p {
    color: var(--grey-color);
}

.footer-links h3,
.footer-newsletter h3 {
    margin-bottom: 1.5rem;
    position: relative;
    display: inline-block;
    color: white; /* White headings */
    font-size: 1.2rem;
}

.footer-links h3::after,
.footer-newsletter h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px; /* Lower underline */
    width: 50px;
    height: 3px; /* Thicker underline */
    background-color: var(--primary-light);
    border-radius: 2px;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-links a {
    color: var(--grey-color);
    transition: var(--transition-fast);
}

.footer-links a:hover {
    color: var(--primary-light);
    padding-left: 5px; /* Indent on hover */
}

.footer-newsletter p {
    color: var(--grey-color);
    margin-bottom: 1rem;
}

.footer-newsletter .github-btn {
    margin-top: 0.5rem;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    padding-top: 2.5rem; /* More padding */
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: var(--grey-color);
    font-size: 0.9rem;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition-std);
    color: var(--light-grey);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-4px) scale(1.1); /* Enhanced hover */
    color: white;
}

/* Dark Theme */
body.dark-theme {
    --grey-color: #b2bec3;
    background: var(--dark-body-gradient); /* Use dark gradient */
    color: var(--dark-text);
    --typewriter-caret-color: var(--primary-light); /* Typewriter caret color for dark theme */
}

body.dark-theme a:hover {
    color: var(--primary-light); /* Lighter hover color in dark theme */
}

body.dark-theme header {
    background-color: rgba(30, 39, 46, 0.85); /* Darker transparent header */
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2); /* Darker shadow */
}

body.dark-theme .logo h1 {
    color: var(--dark-text);
}
body.dark-theme .nav-links a {
    color: var(--dark-text);
}
body.dark-theme .nav-links a:hover {
    color: var(--primary-light);
}
body.dark-theme .nav-links a.active {
    color: var(--primary-light);
}
body.dark-theme .nav-links a::after {
    background-color: var(--primary-light);
}

body.dark-theme .language-switch select {
    background-color: var(--dark-card-bg);
    color: var(--dark-text);
    border-color: var(--grey-color);
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.2);
}
body.dark-theme .language-switch::after {
    color: var(--grey-color);
}
body.dark-theme .language-switch select:hover {
    border-color: var(--primary-light);
    box-shadow: 0 0 5px rgba(162, 155, 254, 0.2);
}
body.dark-theme .language-switch select:focus {
     border-color: var(--primary-light);
     box-shadow: 0 0 0 3px rgba(162, 155, 254, 0.15);
}


body.dark-theme .theme-toggle {
    color: var(--grey-color);
    background-color: var(--dark-card-bg);
    border-color: var(--grey-color);
}
body.dark-theme .theme-toggle:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

body.dark-theme .section-header h2 {
    color: var(--primary-light); /* Lighter primary for headers */
}
body.dark-theme .section-header p {
    color: var(--grey-color);
}

/* Dark theme section separators */
body.dark-theme section:not(:first-child)::before {
    background: var(--dark-section-border);
}

body.dark-theme .featured-section,
body.dark-theme .games-section,
body.dark-theme .about-section {
    background-color: var(--dark-bg); /* Match body background */
    border-top: var(--dark-section-border);
}

body.dark-theme .featured-game-card,
body.dark-theme .game-card {
    background-color: var(--dark-card-bg);
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.2); /* Dark theme shadow */
}
body.dark-theme .featured-game-card:hover,
body.dark-theme .game-card:hover {
     box-shadow: 0 12px 28px rgba(0, 0, 0, 0.3);
     border-color: var(--primary-color); /* Use darker primary for hover border */
}


body.dark-theme .game-info h3 {
    color: var(--dark-text);
}
body.dark-theme .filter-btn {
    background-color: var(--dark-card-bg);
    color: var(--grey-color);
    border-color: var(--grey-color);
    box-shadow: 0 2px 5px rgba(0,0,0,0.15);
}
body.dark-theme .filter-btn:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}
body.dark-theme .filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 4px 10px rgba(162, 155, 254, 0.2);
}

body.dark-theme .game-instructions {
    background-color: var(--dark-bg); /* Match section bg */
    border-top: 1px solid var(--dark-section-border);
}
body.dark-theme .game-instructions h4 {
     color: var(--primary-light);
}
body.dark-theme .game-instructions p {
     color: var(--grey-color);
}

body.dark-theme .memory-card .front-face {
    background-color: var(--dark-card-bg);
}
body.dark-theme .memory-card .front-face i {
    color: var(--primary-light);
}
body.dark-theme .memory-card .back-face {
     background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}
body.dark-theme .memory-card:not(.flip):hover .back-face {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

body.dark-theme .controls {
    border-bottom: 1px solid var(--dark-section-border);
}

body.dark-theme .game-thumb {
     border-bottom: 1px solid var(--dark-section-border);
}


/* Animation Keyframes */
@keyframes slideInFromLeft {
    from { opacity: 0; transform: translateX(-50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

/* Animate on Scroll Logic */
.reveal-pending {
    transform: translateY(30px);
    transition: transform 0.7s ease-out;
}
.reveal-pending.animate {
    transform: translateY(0);
}
/* Stagger animation for grid items */
.games-grid .game-card {
    transition-delay: calc(var(--card-index) * 0.1s); /* Slower stagger */
}


/* Responsive Design */
@media (max-width: 992px) {
    html { font-size: 15px; } /* Slightly smaller base font */
    .hero {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
        min-height: auto; /* Remove min-height */
        padding: 4rem 5%;
    }
    .hero-content {
        padding-right: 0;
        order: 2; /* Content below image */
    }
     .hero-image {
        order: 1;
        margin-bottom: 2rem;
    }
    .hero-content p { /* This includes .typewriter-text */
        margin: 0 auto 2rem;
    }
    .hero-animation {
        transform: rotate(0deg); /* No tilt on smaller screens */
    }
    .floating-icon { display: none; } /* Hide floating icons on smaller screens */

}

@media (max-width: 768px) {
    html { font-size: 14px; }
    #featured-game { scroll-margin-top: 5rem; }
    .nav-links {
        order: 3;
        width: 100%;
        display: flex;
        justify-content: center;
        gap: 1.25rem;
        overflow-x: auto;
        padding-top: 0.35rem;
        scrollbar-width: none;
    }
    .nav-links::-webkit-scrollbar { display: none; }
    .nav-links a { white-space: nowrap; }
    nav {
        padding: 0.8rem 4%;
        flex-wrap: wrap;
        row-gap: 0.35rem;
    }

    .hero-content h1 { line-height: 1.3; }
    .section-header h2 { font-size: 2.2rem; }

    .game-board {
        max-width: 90%; /* Wider board on mobile */
    }

    .controls {
        flex-direction: column;
        gap: 1rem;
        align-items: center; /* Center controls */
    }
    .stats { justify-content: center; }


    .footer-content { grid-template-columns: 1fr; text-align: center; }
    .footer-links ul { align-items: center; }
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    .social-links { justify-content: center; }

    .progress-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .nav-controls { gap: 0.5rem; }

    .hero-image { display: none; }
    .hero-content { order: 1; }
    .hero-badge { margin-inline: auto; }
    .hero-actions { justify-content: center; }

    .typewriter-text {
        letter-spacing: 0.1em; /* Reduce letter spacing on smaller screens */
        margin: 0 auto;
        text-align: center;
    }

    .hero-content .primary-btn {
        margin-top: 1.5rem;
        padding: 0.5rem 1.2rem;
        font-size: 0.8rem;
        max-width: 120px;
    }
}

@media (max-width: 576px) {
    .section-header h2 { font-size: 2rem; }
    .games-grid {
        grid-template-columns: 1fr; /* Single column */
        gap: 2rem;
    }

    .category-filter {
        gap: 0.8rem;
    }
    .filter-btn {
        padding: 0.5rem 1.2rem;
        font-size: 0.85rem;
    }

    .game-board {
        grid-template-columns: repeat(4, 1fr);
        gap: 0.5rem;
        max-width: 100%;
    }
    
    .memory-card .front-face i,
    .memory-card .back-face i {
        font-size: 1.2rem;
    }
}

@media (max-width: 360px) {
    .logo h1 {
        font-size: 1.6rem;
    }

    .language-switch select {
        max-width: 96px;
        padding: 5px 22px 5px 8px;
        font-size: 0.8rem;
    }

    .theme-toggle {
        width: 40px;
        height: 40px;
    }

    .nav-controls {
        gap: 0.35rem;
        padding-inline: 3px;
    }

    .nav-links {
        gap: 1rem;
    }

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

@media (orientation: landscape) and (max-height: 500px) {
    .hero {
        min-height: auto;
        padding: 2rem 5% 2.5rem;
    }

    .hero-image {
        display: none;
    }

    .hero-content {
        order: 1;
        padding-right: 0;
        text-align: center;
    }

    .hero-badge {
        margin-inline: auto;
    }

    .hero-content p {
        margin-inline: auto;
    }

    .hero-actions {
        justify-content: center;
    }
}

/* Accessibility: Screen Reader Only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.game-card[hidden] {
    display: none;
}

.memory-card {
    border: 0;
    padding: 0;
    font: inherit;
    color: inherit;
}

.memory-card:focus-visible,
.filter-btn:focus-visible,
.play-btn:focus-visible,
.btn:focus-visible,
.nav-links a:focus-visible,
.social-links a:focus-visible {
    outline: 3px solid var(--secondary-color);
    outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        transition-delay: 0ms !important;
    }
    .reveal-pending {
        transform: none;
    }
}

.typewriter-text {
    margin-left: auto;
    margin-right: auto;
    letter-spacing: 0.15em;
}

.hero-content .primary-btn {
    margin: 0 auto;
    margin-top: 2rem;
    padding: 0.6rem 1.5rem;
    font-size: 0.85rem;
    min-width: auto;
    width: auto;
    max-width: 150px;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-actions .primary-btn {
    margin: 0;
}
/* styles.css */
/* Add this new rule or modify your existing .game-board::before styles if you have them */

/* Styling for the loading spinner on the game board */
/* This spinner is shown by default if the .game-board element exists before JS loads cards */
.game-board::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50px; /* Size of the spinner */
    height: 50px;
    border-radius: 50%;
    border: 5px solid rgba(162, 155, 254, 0.3); /* Light purple, semi-transparent border */
    border-top-color: var(--primary-color); /* Solid primary color for the spinning part */
    animation: spin 1s infinite linear;
    z-index: 0; /* Behind cards */
}

/* Hide the CSS spinner once JavaScript has initialized the game and added the 'js-active' class */
.game-board.js-active::before {
    display: none;
}

/* Ensure memory cards are displayed above the spinner if it's briefly visible */
.memory-card {
    /* ... other memory-card styles ... */
    position: relative; /* Needed if not already set, for z-index to work effectively against absolute positioned pseudo-elements */
    z-index: 1; 
}

/* Keyframes for the spinning animation */
@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Ensure the game board has a position context if not already set, for the absolute spinner */
.game-board {
    position: relative; /* This is important for the ::before pseudo-element's positioning */
    /* ... other .game-board styles ... */
}