/* ============================================
   CONNECT 4 GAME - CSS3 STYLESHEET
   Production-Ready Gaming Interface
   ============================================ */

/* ============================================
   CSS VARIABLES - Design Tokens
   ============================================ */
:root {
    /* Colors - Light Clean Palette */
    --color-bg-primary: #f5f5f7;
    --color-bg-secondary: #ffffff;
    --color-bg-tertiary: #f0f0f3;
    --color-accent-primary: #0066ff;
    --color-accent-secondary: #ff3b30;
    --color-player: #ff3b30;
    --color-ai: #ffd700;
    --color-empty: #e8e8eb;
    --color-text-primary: #1d1d1f;
    --color-text-secondary: #666666;
    --color-border: #d5d5d7;
    --color-success: #00d989;
    --color-warning: #ff9500;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Footer */
    --footer-height: 60px;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-mono: 'Courier New', monospace;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 2.5rem;
    --font-weight-regular: 400;
    --font-weight-medium: 600;
    --font-weight-bold: 700;
    --font-weight-black: 900;
    
    /* Transitions */
    --transition-fast: 150ms ease-out;
    --transition-normal: 300ms ease-out;
    --transition-slow: 500ms ease-out;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);
    --shadow-glow: 0 0 20px rgba(0, 102, 255, 0.2);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
}

/* High Contrast Mode Support */
@media (prefers-contrast: more) {
    :root {
        --color-accent-primary: #00e5ff;
        --color-player: #ff3333;
        --color-ai: #ffdd00;
    }
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, #f0f0f3 0%, #ffffff 50%, #f5f5f7 100%);
    color: var(--color-text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    padding: var(--spacing-md) var(--spacing-md) calc(var(--footer-height) + var(--spacing-md)) var(--spacing-md);
}

button {
    cursor: pointer;
    border: none;
    font-family: inherit;
    transition: all var(--transition-fast);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Keyboard focus visible */
button:focus-visible {
    outline: 2px solid var(--color-accent-primary);
    outline-offset: 2px;
}

/* ============================================
   SCREEN CONTAINER
   ============================================ */
.screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
    z-index: 10;
    overflow-y: auto;
    padding-bottom: var(--footer-height);
}


/* .screen {
    position: relative;
    top: auto;
    left: auto;
    width: auto;
    height: auto;
    display: none;
    opacity: 1;
    pointer-events: auto;
    transition: opacity var(--transition-normal);
    z-index: 10;
    overflow-y: auto;
    padding-bottom: var(--footer-height);


} */

.screen.active {
    opacity: 1;
    pointer-events: auto;
    z-index: 20;
}

/* ============================================
   FOOTER STYLES
   ============================================ */
.site-footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: var(--footer-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(0, 0, 0, 0.08);
    padding: 0.85rem 1rem;
    z-index: 30;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.04);
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    height: 100%;
}

.footer-logo-link {
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: var(--font-weight-bold);
    white-space: nowrap;
}

.footer-logo-link:hover {
    color: var(--color-accent-primary);
    transition: color var(--transition-fast);
}

.footer-logo-link .logo {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.footer-logo-link .logo-icon {
    color: var(--color-accent-primary);
    font-size: 1.1rem;
}

.footer-text {
    display: flex;
    align-items: center;
    white-space: nowrap;
}

@media (max-width: 650px) {
    .footer-inner {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
    
    .footer-logo-link {
        font-size: 0.9rem;
    }
    
    .footer-text {
        font-size: 0.85rem;
        white-space: normal;
    }
    
    .site-footer {
        padding: 0.75rem 0.5rem;
        height: auto;
        min-height: var(--footer-height);
    }
}

/* ============================================
   CONTENT SECTION - GAME GUIDE
   ============================================ */
.content-section {
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.game-guide {
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid #e0e0e3;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    backdrop-filter: blur(10px);
}

.section-title {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: var(--font-weight-black);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-accent-primary) 0%, #ff6b9d 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 0.02em;
}

.guide-content {
    color: var(--color-text-primary);
    line-height: 1.8;
    font-size: 1.05rem;
}

.guide-content p {
    margin-bottom: var(--spacing-lg);
    color: var(--color-text-secondary);
    text-align: justify;
    hyphens: auto;
}

.guide-content h3 {
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 3px solid rgba(0, 102, 255, 0.15);
}

.guide-content h3:first-of-type {
    margin-top: var(--spacing-xl);
}

.guide-content h4 {
    font-size: 1.2rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-accent-primary);
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    position: relative;
    padding-left: var(--spacing-lg);
}

.guide-content h4::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-accent-primary);
}

.guide-content strong {
    color: var(--color-text-primary);
    font-weight: var(--font-weight-bold);
}

/* ============================================
   HOME CONTENT ADJUSTMENTS FOR SCROLLING
   ============================================ */
#homeScreen {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-lg) var(--spacing-lg) calc(var(--footer-height) + var(--spacing-lg)) var(--spacing-lg);
    overflow-y: auto;
}

/* .home-container {
    padding-top: var(--spacing-lg);
    animation: fadeIn 0.8s ease-out;
} */

.home-container {
    width: 100%;
    max-width: 100%;
    text-align: center;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* ============================================
   RESPONSIVE ADJUSTMENTS FOR CONTENT
   ============================================ */
@media (max-width: 768px) {
    .content-section {
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .game-guide {
        padding: var(--spacing-xl);
    }
    
    .guide-content {
        font-size: 1rem;
        line-height: 1.75;
    }
    
    .guide-content h3 {
        font-size: 1.3rem;
        margin-top: var(--spacing-xl);
    }
    
    .guide-content h4 {
        font-size: 1.1rem;
    }
    
    .guide-content p {
        text-align: left;
        margin-bottom: var(--spacing-md);
    }
}

.game-header {
    margin-bottom: var(--spacing-2xl);
    animation: slideDown 0.6s ease-out;
}

.game-title {
    font-size: clamp(2.5rem, 8vw, 4rem);
    font-weight: var(--font-weight-black);
    background: linear-gradient(90deg, #2563eb 0%, #6366f1 40%, #ec4899 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 0.1em;
    margin-bottom: var(--spacing-md);
}

.title-accent {
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, #2563eb 0%, #3b82f6 100%);
    margin: 0 auto var(--spacing-lg);
    border-radius: var(--radius-full);
    animation: expandWidth 0.8s ease-out 0.2s backwards;
}

@keyframes expandWidth {
    from {
        width: 0;
    }
    to {
        width: 100px;
    }
}

.game-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.02em;
}

.home-content {
    width: min(760px, 100%);
    max-width: 760px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid #e0e0e3;
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    margin: 0 auto var(--spacing-xl);
    backdrop-filter: blur(10px);
    animation: slideUp 0.6s ease-out;
}

.difficulty-section h2 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--color-text-primary);
}

.difficulty-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.difficulty-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg);
    background: linear-gradient(135deg, #f5f5f7 0%, #ffffff 100%);
    border: 2px solid #e0e0e3;
    border-radius: var(--radius-lg);
    color: var(--color-text-primary);
    font-weight: var(--font-weight-bold);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.difficulty-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 102, 255, 0.1), transparent);
    transition: left var(--transition-normal);
}

.difficulty-btn:hover {
    border-color: #7c3aed;
    background: linear-gradient(135deg, rgba(124, 58, 237, 0.08) 0%, rgba(124, 58, 237, 0.03) 100%);
    box-shadow: 0 0 30px rgba(124, 58, 237, 0.2);
    transform: translateY(-2px);
}

.difficulty-btn:focus-visible {
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.difficulty-btn.active {
    background: linear-gradient(135deg, #7c3aed, #6d28d9);
    border-color: #7c3aed;
    color: #ffffff;
    box-shadow: 0 0 30px rgba(124, 58, 237, 0.4);
    transform: scale(1.05);
}

.difficulty-icon {
    width: 2rem;
    height: 2rem;
    color: #8b5cf6;
    transition: all var(--transition-normal);
}

.difficulty-btn[data-difficulty="easy"] .difficulty-icon {
    color: #7c3aed;
}

.difficulty-btn[data-difficulty="medium"] .difficulty-icon {
    color: #ec4899;
}

.difficulty-btn[data-difficulty="hard"] .difficulty-icon {
    color: #a855f7;
}

.difficulty-name {
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.difficulty-desc {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    font-weight: var(--font-weight-regular);
}

.play-button {
    width: 50%;
    padding: var(--spacing-lg) var(--spacing-2xl);
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: #ffffff;
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-bold);
    border-radius: var(--radius-lg);
    letter-spacing: 0.05em;
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.3);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}


/* .play-button {
    width: 100%;
    padding: var(--spacing-lg) var(--spacing-2xl);
    background: linear-gradient(135deg, var(--color-accent-primary) 0%, #0052cc 100%);
    color: #ffffff;
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-bold);
    border-radius: var(--radius-lg);
    letter-spacing: 0.05em;
    box-shadow: 0 8px 24px rgba(0, 102, 255, 0.25);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
} */

.play-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.2);
    transition: left var(--transition-normal);
}

.play-button:hover::before {
    left: 100%;
}

.play-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(0, 102, 255, 0.35);
}

.play-button:active {
    transform: scale(0.98);
}

.home-footer {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.stats-preview {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    opacity: 0.8;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-value {
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-bold);
    color: var(--color-accent-primary);
    font-family: var(--font-mono);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: rgba(0, 0, 0, 0.1);
}

/* ============================================
   GAME SCREEN
   ============================================ */
.game-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
    min-height: 100vh;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.game-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

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

.turn-text {
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
}

.turn-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.2);
}

.difficulty-display {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(0, 102, 255, 0.05);
    border-radius: var(--radius-md);
}

.controls {
    display: flex;
    gap: var(--spacing-sm);
}

.control-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(0, 102, 255, 0.1);
    color: var(--color-accent-primary);
    border: 1px solid rgba(0, 102, 255, 0.2);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    transition: all var(--transition-fast);
}

.control-btn:hover {
    background: rgba(0, 102, 255, 0.15);
    border-color: var(--color-accent-primary);
}

.sound-btn {
    min-width: 44px;
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.sound-icon {
    font-size: 1.2rem;
}

/* ============================================
   GAME BOARD
   ============================================ */
.board-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 100%;
    background: rgba(255, 255, 255, 0.95);
    border-radius: var(--radius-xl);
    padding: 2rem;
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    min-height: 450px;
    flex-grow: 1;
    box-sizing: border-box;
}

.board {
    display: grid;
    grid-template-columns: repeat(7, minmax(0, 1fr));
    width: 100%;
    max-width: 100%;
    gap: 12px;
    padding: 2rem;
    background: linear-gradient(135deg, #1a3a52 0%, #2a4a62 100%);
    border-radius: var(--radius-lg);
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.15);
    box-sizing: border-box;
}

.cell {
    aspect-ratio: 1;
    background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.15), rgba(0, 0, 0, 0.2));
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.1);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    min-width: 0;
}

.cell:hover:not(.occupied) {
    background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.25), rgba(0, 0, 0, 0.3));
    transform: scale(1.08);
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.2);
}

.cell.player {
    background: radial-gradient(circle at 35% 35%, #ff5555, var(--color-player));
    box-shadow: inset -2px -2px 4px rgba(0, 0, 0, 0.3), 0 4px 12px rgba(255, 59, 48, 0.3);
    border-color: #cc0000;
}

.cell.ai {
    background: radial-gradient(circle at 35% 35%, #ffed4e, var(--color-ai));
    box-shadow: inset -2px -2px 4px rgba(0, 0, 0, 0.2), 0 4px 12px rgba(255, 215, 0, 0.3);
    border-color: #ffaa00;
}

.cell.occupied {
    cursor: default;
}

.cell.winning {
    animation: pulse 0.6s ease-out 3;
    box-shadow: inset 0 -2px 4px rgba(0, 0, 0, 0.1), 0 0 20px rgba(0, 102, 255, 0.4);
}

.cell.winning::after {
    content: '★';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: rgba(255, 255, 255, 0.95);
    font-size: 1.4rem;
    text-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
    pointer-events: none;
    z-index: 2;
}

.cell.winning.player::after {
    color: rgba(255, 255, 255, 0.95);
}

.cell.winning.ai::after {
    color: rgba(255, 255, 255, 0.95);
}

.cell.winning {
    z-index: 1;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}

.cell.drop {
    animation: drop 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

@keyframes drop {
    0% {
        transform: translateY(-300px);
        opacity: 0;
    }
    70% {
        opacity: 1;
    }
    100% {
        transform: translateY(0);
    }
}

.game-footer {
    text-align: center;
    padding: var(--spacing-lg);
    background: rgba(255, 255, 255, 0.9);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0, 0, 0, 0.05);
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

.move-text {
    font-family: var(--font-mono);
    color: var(--color-accent-primary);
    font-weight: var(--font-weight-bold);
}

/* ============================================
   MODAL - WIN/DRAW
   ============================================ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
    z-index: 100;
    backdrop-filter: blur(2px);
}

.modal.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(224, 224, 227, 0.9);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    max-width: 500px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08), 0 0 20px rgba(0, 102, 255, 0.1);
    animation: modalAppear 0.4s ease-out;
    backdrop-filter: blur(8px);
}

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

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

.result-title {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    font-weight: var(--font-weight-black);
    background: linear-gradient(135deg, var(--color-accent-primary) 0%, #ff6b9d 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
    animation: slideDown 0.6s ease-out;
}

.result-message {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    animation: slideUp 0.6s ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-stats {
    background: rgba(0, 102, 255, 0.05);
    border: 1px solid rgba(0, 102, 255, 0.15);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

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

.stat-box-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-xs);
}

.stat-box-value {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-accent-primary);
    font-family: var(--font-mono);
}

.modal-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.btn-primary, .btn-secondary {
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-bold);
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
    letter-spacing: 0.05em;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent-primary) 0%, #0052cc 100%);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(0, 102, 255, 0.25);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 102, 255, 0.35);
}

.btn-secondary {
    background: linear-gradient(135deg, #f5f5f7 0%, #ffffff 100%);
    color: var(--color-text-primary);
    border: 1px solid #e0e0e3;
}

.btn-secondary:hover {
    border-color: var(--color-accent-primary);
    color: var(--color-accent-primary);
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.05) 0%, rgba(0, 102, 255, 0.02) 100%);
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-sm) var(--spacing-sm) calc(var(--footer-height) + 10px) var(--spacing-sm);
    }
    
    .home-content {
        width: 100%;
        max-width: 100%;
        padding: var(--spacing-xl) var(--spacing-md);
    }
    
    .play-button {
        width: 100%;
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: var(--font-size-base);
    }
    
    .game-container {
        gap: var(--spacing-md);
        padding: var(--spacing-lg) var(--spacing-md);
    }
    
    .top-bar {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .game-info {
        width: 100%;
        justify-content: space-between;
        flex-wrap: wrap;
    }
    
    .controls {
        width: 100%;
        justify-content: flex-end;
    }
    
    .board-wrapper {
        min-height: 500px;
        padding: 1.5rem;
    }
    
    .board {
        gap: 11px;
        padding: 1.5rem;
        max-width: 100%;
    }
    
    .difficulty-buttons {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        padding: var(--spacing-xl);
    }
    
    .modal-buttons {
        grid-template-columns: 1fr;
    }
    
    .difficulty-btn {
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    body {
        padding: var(--spacing-sm) var(--spacing-xs) calc(var(--footer-height) + 8px) var(--spacing-xs);
    }
    
    .home-content {
        padding: var(--spacing-lg);
    }
    
    .game-title {
        font-size: 2rem;
    }
    
    .stats-preview {
        gap: var(--spacing-md);
        flex-wrap: wrap;
    }
    
    .stat-divider {
        height: 30px;
    }
    
    .board-wrapper {
        min-height: 420px;
        padding: 1rem;
    }
    
    .board {
        gap: 8px;
        padding: 1rem;
        max-width: 100%;
    }
    
    .cell {
        min-width: 0;
    }
    
    .control-btn {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-xs);
    }
    
    .difficulty-display {
        font-size: var(--font-size-xs);
    }
    
    .site-footer {
        height: auto;
        min-height: 55px;
        padding: 0.5rem;
    }
    
    .footer-inner {
        gap: 0.25rem;
    }
}

/* ============================================
   ACCESSIBILITY - Reduced Motion
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ============================================
   DARK MODE (Explicit)
   ============================================ */
@media (prefers-color-scheme: dark) {
    /* Already dark mode primary - no changes needed */
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
    body {
        background: white;
        color: black;
    }
    
    .screen {
        display: none;
    }
    
    .site-footer {
        display: none;
    }
}