/* ============================================
   AIR TRAFFIC LIGHT - STYLESHEET
   Modern Aviation Theme
   ============================================ */

/* === RESET & BASE === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

:root {
    /* Aviation Color Palette */
    --sky-blue: #4A90E2;
    --deep-blue: #1E3A5F;
    --navy: #0F1B2E;
    --cloud-white: #F5F7FA;
    --metallic-grey: #8B9DC3;
    --accent-gold: #FFD700;
    --success-green: #2ECC71;
    --danger-red: #E74C3C;
    --warning-orange: #F39C12;
    
    /* Gradients */
    --gradient-sky: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-day: linear-gradient(180deg, #87CEEB 0%, #E0F6FF 100%);
    --gradient-night: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
    --gradient-storm: linear-gradient(180deg, #2c3e50 0%, #34495e 100%);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px rgba(74, 144, 226, 0.5);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    background: url('images/background.png') center center / cover no-repeat fixed;
    background-color: #87CEEB; /* Fallback color if image doesn't load */
    color: var(--navy);
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    position: fixed;
    touch-action: none;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* === SCREEN MANAGEMENT === */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    flex-direction: column;
    opacity: 0;
    transition: opacity var(--transition-normal);
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    background: transparent; /* Transparent to show body background */
}

.screen.active {
    display: flex;
    opacity: 1;
}

/* === MAIN MENU === */
#mainMenu {
    justify-content: center;
    align-items: center;
    background: transparent; /* Transparent to show body background */
    position: relative;
    overflow: hidden;
}

#mainMenu::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 50%, rgba(74, 144, 226, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
    animation: skyShift 20s ease-in-out infinite;
}

@keyframes skyShift {
    0%, 100% { transform: translateX(0) translateY(0); }
    50% { transform: translateX(-20px) translateY(10px); }
}

.menu-container {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
    max-width: 500px;
    width: 90%;
}

.title-section {
    margin-bottom: 4rem;
    animation: fadeInDown 0.8s ease-out;
}

.game-title {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 900;
    letter-spacing: 0.1em;
    color: var(--deep-blue);
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
}

.game-subtitle {
    font-size: clamp(2rem, 6vw, 3.5rem);
    font-weight: 300;
    letter-spacing: 0.2em;
    color: var(--sky-blue);
    margin-bottom: 1rem;
    text-transform: uppercase;
}

/* Parachute Drop specific styles */
#gameCanvas {
    cursor: crosshair;
    touch-action: none;
}

.title-decoration {
    width: 100px;
    height: 4px;
    background: var(--gradient-sky);
    margin: 0 auto;
    border-radius: 2px;
    box-shadow: var(--shadow-glow);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scaleX(1); }
    50% { opacity: 0.7; transform: scaleX(1.1); }
}

.menu-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    animation: fadeInUp 0.8s ease-out 0.3s both;
}

.menu-btn {
    padding: 1.2rem 2.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.menu-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.menu-btn:hover::before {
    left: 100%;
}

.menu-btn.primary {
    background: var(--gradient-sky);
    color: white;
    box-shadow: var(--shadow-md);
}

.menu-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.menu-btn.secondary {
    background: rgba(255, 255, 255, 0.9);
    color: var(--deep-blue);
    border: 2px solid var(--sky-blue);
    box-shadow: var(--shadow-sm);
}

.menu-btn.secondary:hover {
    background: rgba(255, 255, 255, 1);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* === SCREEN HEADER === */
.screen-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.screen-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--deep-blue);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    flex: 1;
    text-align: center;
}

.back-btn {
    background: none;
    border: none;
    color: var(--sky-blue);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all var(--transition-fast);
}

.back-btn:hover {
    background: rgba(74, 144, 226, 0.1);
    transform: translateX(-3px);
}

/* === CHAPTER SELECT === */
#chapterSelect {
    background: var(--gradient-day);
}

.chapters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.chapter-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient-sky);
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.chapter-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--sky-blue);
}

.chapter-card:hover::before {
    opacity: 0.05;
}

.chapter-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
}

.chapter-card h3 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--deep-blue);
    margin-bottom: 0.5rem;
    position: relative;
    z-index: 1;
}

.chapter-card p {
    font-size: 0.95rem;
    color: var(--metallic-grey);
    margin-bottom: 1.5rem;
    position: relative;
    z-index: 1;
}

.chapter-progress {
    position: relative;
    z-index: 1;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(74, 144, 226, 0.2);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-sky);
    border-radius: 4px;
    transition: width var(--transition-slow);
    box-shadow: 0 0 10px rgba(74, 144, 226, 0.5);
}

.progress-text {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--deep-blue);
}

/* === LEVEL SELECT === */
#levelSelect {
    background: transparent; /* Transparent to show body background */
}

.levels-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 1rem;
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.level-btn {
    aspect-ratio: 1;
    border-radius: 12px;
    border: none;
    font-size: 1.2rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    background: rgba(255, 255, 255, 0.9);
    color: var(--deep-blue);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.level-btn:hover:not(.locked) {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.level-btn.completed {
    background: var(--gradient-sky);
    color: white;
}

.level-btn.locked {
    opacity: 0.5;
    cursor: not-allowed;
    background: rgba(0, 0, 0, 0.1);
}

.level-btn .stars {
    position: absolute;
    top: 4px;
    right: 4px;
    font-size: 0.7rem;
    color: var(--accent-gold);
}

.level-btn .level-theme {
    position: absolute;
    top: 4px;
    left: 4px;
    font-size: 1rem;
}

.level-btn .level-progress {
    position: absolute;
    bottom: 4px;
    right: 4px;
    font-size: 0.7rem;
    color: var(--accent-gold);
}

.level-btn.last-played {
    border: 2px solid var(--sky-blue);
    box-shadow: 0 0 10px rgba(74, 144, 226, 0.5);
}

.level-btn .continue-badge {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.5rem;
    opacity: 0.7;
    pointer-events: none;
}

/* === GAME SCREEN === */
#gameScreen {
    background: transparent; /* Transparent to show body background */
    position: relative;
}

#gameCanvas {
    width: 100%;
    height: 100%;
    display: block;
    touch-action: none;
    cursor: crosshair;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
}

.game-hud {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 1.5rem;
    z-index: 10;
    pointer-events: none;
}

.hud-left {
    display: flex;
    gap: 1.5rem;
}

.hud-item {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 0.8rem 1.2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    min-width: 100px;
}

.hud-label {
    font-size: 0.75rem;
    color: var(--metallic-grey);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.hud-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--deep-blue);
}

.pause-btn {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 12px;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    pointer-events: auto;
    transition: all var(--transition-fast);
}

.pause-btn:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
}

.game-instructions {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 1rem 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    font-size: 0.9rem;
    color: var(--deep-blue);
    text-align: center;
    animation: fadeInUp 0.5s ease-out;
    pointer-events: none;
}

/* === OVERLAYS === */
.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5); /* More transparent to show background */
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    animation: fadeIn var(--transition-normal);
}

.overlay.active {
    display: flex;
}

.overlay-content {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 3rem;
    max-width: 400px;
    width: 90%;
    text-align: center;
    box-shadow: var(--shadow-lg);
    animation: scaleIn 0.3s ease-out;
}

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

.success-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-green);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.error-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--danger-red);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.success-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-green);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.error-message {
    color: var(--metallic-grey);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.stars-display {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.star {
    font-size: 2.5rem;
    color: var(--metallic-grey);
    transition: all var(--transition-normal);
}

.star.earned {
    color: var(--accent-gold);
    transform: scale(1.2);
    filter: drop-shadow(0 0 10px rgba(255, 215, 0, 0.5));
}

.level-stats {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    padding: 0.8rem;
    background: rgba(74, 144, 226, 0.1);
    border-radius: 8px;
    font-size: 1rem;
}

.stat-item span:first-child {
    color: var(--metallic-grey);
}

.stat-item span:last-child {
    font-weight: 700;
    color: var(--deep-blue);
}

/* === ACHIEVEMENTS SCREEN === */
#achievementsScreen {
    background: transparent; /* Transparent to show body background */
}

.achievements-content {
    padding: 2rem;
    max-width: 1000px;
    margin: 0 auto;
    width: 100%;
}

.achievements-section {
    margin-top: 3rem;
}

.achievements-section h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--deep-blue);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.achievement-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 1.2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    border: 2px solid transparent;
}

.achievement-card.achieved {
    border-color: var(--accent-gold);
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.1) 0%, rgba(255, 255, 255, 0.95) 100%);
}

.achievement-card.locked {
    opacity: 0.6;
    background: rgba(0, 0, 0, 0.05);
}

.achievement-card:hover:not(.locked) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.achievement-card-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.achievement-card-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.achievement-card-name {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--deep-blue);
}

.achievement-card-desc {
    font-size: 0.85rem;
    color: var(--metallic-grey);
}

.achievement-card-status {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.achievement-notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 10000;
    opacity: 0;
    transform: translateX(100%);
    transition: all var(--transition-normal);
}

.achievement-notification.show {
    opacity: 1;
    transform: translateX(0);
}

.achievement-notification-content {
    background: var(--gradient-sky);
    color: white;
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 1rem;
    min-width: 300px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.achievement-notification-content .achievement-icon {
    font-size: 3rem;
    flex-shrink: 0;
}

.achievement-notification-content .achievement-text {
    flex: 1;
}

.achievement-notification-content .achievement-text strong {
    display: block;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.achievement-notification-content .achievement-text div {
    font-size: 0.9rem;
    opacity: 0.9;
}

.stats-section,
.chapters-progress-section {
    margin-bottom: 3rem;
}

.stats-section h3,
.chapters-progress-section h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--deep-blue);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    font-size: 2.5rem;
}

.stat-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--metallic-grey);
    margin-bottom: 0.25rem;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--deep-blue);
}

.chapter-progress-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-md);
}

.chapter-progress-card h4 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--deep-blue);
    margin-bottom: 1rem;
}

.progress-bar-large {
    width: 100%;
    height: 12px;
    background: rgba(74, 144, 226, 0.2);
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-percentage {
    font-size: 1rem;
    font-weight: 600;
    color: var(--deep-blue);
}

/* === PRIVACY POLICY SCREEN === */
#privacyScreen {
    background: transparent; /* Transparent to show body background */
}

.privacy-content {
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}

.privacy-text-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

.privacy-text-container h3 {
    color: var(--sky-blue);
    font-size: 1.3rem;
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.privacy-text-container h3:first-child {
    margin-top: 0;
}

.privacy-text-container p {
    color: var(--navy);
    line-height: 1.7;
    margin-bottom: 1rem;
    font-size: 1rem;
}

.privacy-text-container ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--navy);
}

.privacy-text-container li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.privacy-note {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid rgba(74, 144, 226, 0.2);
    font-weight: 600;
    color: var(--deep-blue);
}

/* === SETTINGS SCREEN === */
#settingsScreen {
    background: transparent; /* Transparent to show body background */
}

.settings-content {
    padding: 2rem;
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
}

.setting-item {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
}

.setting-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.setting-label {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--deep-blue);
    margin-bottom: 0.25rem;
}

.setting-desc {
    font-size: 0.85rem;
    color: var(--metallic-grey);
}

.toggle-switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--metallic-grey);
    transition: var(--transition-normal);
    border-radius: 34px;
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: var(--transition-normal);
    border-radius: 50%;
}

.toggle-switch input:checked + .toggle-slider {
    background-color: var(--sky-blue);
}

.toggle-switch input:checked + .toggle-slider:before {
    transform: translateX(26px);
}

.danger-btn {
    background: var(--danger-red);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.danger-btn:hover {
    background: #c0392b;
    transform: scale(1.05);
}

/* === ANIMATIONS === */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* === ACHIEVEMENT NOTIFICATION === */
.achievement-notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    z-index: 10000;
    opacity: 0;
    transform: translateX(100%);
    transition: all var(--transition-normal);
    max-width: 90%;
}

.achievement-notification.show {
    opacity: 1;
    transform: translateX(0);
}

.achievement-notification-content {
    background: var(--gradient-sky);
    color: white;
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 1rem;
    min-width: 250px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.achievement-notification-content .achievement-icon {
    font-size: 3rem;
    flex-shrink: 0;
}

.achievement-notification-content .achievement-text {
    flex: 1;
}

.achievement-notification-content .achievement-text strong {
    display: block;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.achievement-notification-content .achievement-text div {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
    /* Ensure all screens show background */
    .screen,
    #mainMenu,
    #levelSelect,
    #gameScreen,
    #achievementsScreen,
    #settingsScreen,
    #privacyScreen {
        background: transparent !important;
    }
    
    /* Privacy screen mobile optimizations */
    .privacy-content {
        padding: 1rem;
    }
    
    .privacy-text-container {
        padding: 1.5rem;
    }
    
    .privacy-text-container h3 {
        font-size: 1.1rem;
    }
    
    .privacy-text-container p {
        font-size: 0.9rem;
    }
    
    /* Mobile optimizations for game canvas */
    #gameCanvas {
        touch-action: none;
        -webkit-touch-callout: none;
        -webkit-user-select: none;
        user-select: none;
    }
    
    /* Smaller HUD for mobile */
    .game-hud {
        padding: 0.8rem;
        flex-wrap: wrap;
    }
    
    .hud-item {
        padding: 0.5rem 0.7rem;
        min-width: 70px;
    }
    
    .hud-label {
        font-size: 0.7rem;
    }
    
    .hud-value {
        font-size: 1.1rem;
    }
    
    /* Smaller buttons */
    .menu-btn {
        padding: 0.9rem 1.5rem;
        font-size: 0.95rem;
    }
    
    /* Optimize level grid for mobile */
    .levels-grid {
        grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
        gap: 0.8rem;
        padding: 1rem;
    }
    
    .level-btn {
        width: 60px;
        height: 60px;
        font-size: 1.2rem;
    }
    
    /* Smaller menu container */
    .menu-container {
        padding: 1.5rem;
    }
    
    .game-title {
        font-size: 2.5rem;
    }
    
    .game-subtitle {
        font-size: 1.8rem;
    }
    
    /* Optimize instructions */
    .game-instructions {
        font-size: 0.8rem;
        padding: 0.6rem 1rem;
        bottom: 1rem;
        max-width: 90%;
    }
    
    /* Smaller overlay content */
    .overlay-content {
        padding: 1.5rem;
        max-width: 90%;
        max-height: 90%;
        overflow-y: auto;
    }
    
    /* Optimize stat cards */
    .stat-card {
        padding: 1rem;
    }
    
    .stat-icon {
        font-size: 2rem;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    /* Smaller achievement cards */
    .achievements-grid {
        grid-template-columns: 1fr;
        gap: 0.8rem;
    }
    
    .achievement-card {
        padding: 1rem;
    }
    
    .achievement-card-icon {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .chapters-grid {
        grid-template-columns: 1fr;
        padding: 1rem;
        gap: 1.5rem;
    }
    
    .levels-grid {
        grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
        gap: 0.75rem;
        padding: 1rem;
    }
    
    .overlay-content {
        padding: 2rem 1.5rem;
        max-width: 90%;
    }
    
    .game-hud {
        padding: 0.75rem;
        flex-wrap: wrap;
    }
    
    .hud-left {
        display: flex;
        gap: 0.5rem;
        flex-wrap: wrap;
        flex: 1;
    }
    
    .hud-item {
        padding: 0.5rem 0.75rem;
        min-width: 70px;
        flex: 1 1 auto;
    }
    
    .hud-label {
        font-size: 0.65rem;
    }
    
    .hud-value {
        font-size: 1rem;
    }
    
    .pause-btn {
        width: 45px;
        height: 45px;
        font-size: 1.2rem;
    }
    
    .game-instructions {
        bottom: 1rem;
        padding: 0.75rem 1.5rem;
        font-size: 0.8rem;
    }
    
    .menu-btn {
        padding: 1rem 2rem;
        font-size: 1rem;
    }
    
    .chapter-card {
        padding: 1.5rem;
    }
    
    .chapter-icon {
        font-size: 3rem;
    }
    
    .chapter-card h3 {
        font-size: 1.5rem;
    }
    
    .stat-card {
        padding: 1.2rem;
    }
    
    .stat-icon {
        font-size: 2rem;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .achievements-grid {
        grid-template-columns: 1fr;
    }
    
    .achievement-notification {
        right: 1rem;
        left: 1rem;
        max-width: none;
    }
    
    .achievement-notification-content {
        min-width: auto;
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .menu-container {
        padding: 1rem;
    }
    
    .game-title {
        font-size: 2rem;
    }
    
    .game-subtitle {
        font-size: 1.5rem;
    }
    
    .menu-btn {
        padding: 0.9rem 1.5rem;
        font-size: 0.9rem;
    }
    
    .hud-item {
        padding: 0.4rem 0.6rem;
        min-width: 60px;
    }
    
    .hud-label {
        font-size: 0.6rem;
    }
    
    .hud-value {
        font-size: 0.9rem;
    }
    
    .levels-grid {
        grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
        gap: 0.5rem;
    }
    
    .level-btn {
        font-size: 1rem;
    }
    
    .screen-header {
        padding: 1rem;
    }
    
    .screen-header h2 {
        font-size: 1.2rem;
    }
    
    .back-btn {
        font-size: 0.9rem;
        padding: 0.4rem 0.8rem;
    }
}

/* === TOUCH OPTIMIZATIONS === */
@media (hover: none) and (pointer: coarse) {
    .menu-btn:hover,
    .chapter-card:hover,
    .level-btn:hover {
        transform: none;
    }
    
    .menu-btn:active,
    .chapter-card:active,
    .level-btn:active {
        transform: scale(0.95);
    }
    
    /* Larger touch targets for mobile */
    .menu-btn {
        min-height: 48px;
    }
    
    .level-btn {
        min-height: 48px;
    }
    
    .pause-btn {
        min-width: 48px;
        min-height: 48px;
    }
    
    /* Prevent text selection on touch */
    * {
        -webkit-user-select: none;
        -moz-user-select: none;
        -ms-user-select: none;
        user-select: none;
        -webkit-touch-callout: none;
    }
    
    /* Optimize canvas rendering */
    #gameCanvas {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
    }
}

/* === PERFORMANCE OPTIMIZATIONS === */
@media (max-width: 768px) {
    /* Reduce animations on mobile for better performance */
    * {
        animation-duration: 0.3s !important;
        transition-duration: 0.2s !important;
    }
    
    /* Simplify shadows on mobile */
    .menu-btn,
    .chapter-card,
    .hud-item {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    }
    
    /* Reduce backdrop blur on mobile */
    .menu-btn,
    .hud-item,
    .overlay-content {
        backdrop-filter: blur(5px);
        -webkit-backdrop-filter: blur(5px);
    }
}