/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Fredoka', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    overflow-x: hidden;
    color: #333;
    transition: all 0.3s ease;
    -webkit-overflow-scrolling: touch; /* Smooth scrolling on iOS */
}

/* Mobile-specific optimizations */
@media (max-width: 768px) {
    body {
        background-attachment: scroll; /* Better mobile performance */
    }
    
    /* Prevent zoom on input focus */
    input, select, textarea {
        font-size: 16px;
    }
    
    /* Better touch targets */
    button, .menu-btn, .answer-btn, .control-btn {
        min-height: 44px;
        min-width: 44px;
    }
    
    /* Improve scrolling performance */
    .screen {
        -webkit-overflow-scrolling: touch;
    }
}

/* Theme Variables */
:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #ffd700;
    --text-color: #333;
    --bg-color: #fff;
    --card-bg: rgba(255,255,255,0.95);
    --border-color: #ddd;
    --shadow-color: rgba(0,0,0,0.1);
}

/* Dark Theme */
[data-theme="dark"] {
    --primary-color: #4a5568;
    --secondary-color: #2d3748;
    --accent-color: #f6ad55;
    --text-color: #f7fafc;
    --bg-color: #1a202c;
    --card-bg: rgba(45, 55, 72, 0.95);
    --border-color: #4a5568;
    --shadow-color: rgba(0,0,0,0.3);
    --youstn-color: rgba(0,241,255,1);
}

/* Background Gradients */
.gradient-blue { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); }
.gradient-purple { background: linear-gradient(135deg, #a855f7 0%, #7c3aed 100%); }
.gradient-green { background: linear-gradient(135deg, #10b981 0%, #059669 100%); }
.gradient-orange { background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%); }
.gradient-pink { background: linear-gradient(135deg, #ec4899 0%, #be185d 100%); }
.gradient-red { background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%); }

#app {
    width: 100vw;
    height: 100vh;
    position: relative;
    overflow: hidden;
}

/* Screen Management */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    overflow-y: auto;
    overflow-x: hidden;
}

.screen.hidden {
    opacity: 0;
    transform: translateX(100%);
    pointer-events: none;
}

.screen.active {
    opacity: 1;
    transform: translateX(0);
    pointer-events: all;
}

/* Loading Screen */
.loading-screen {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.loading-content {
    text-align: center;
    color: white;
    padding: 2rem;
}

.loading-logo {
    font-size: clamp(3rem, 8vw, 4rem);
    margin-bottom: 1rem;
    animation: bounce 2s infinite;
}

.loading-logo i {
    background: linear-gradient(45deg, #ffd700, #ffed4e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.loading-content h1 {
    font-size: clamp(2rem, 6vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 2rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.loading-bar {
    width: min(300px, 80vw);
    height: 8px;
    background: rgba(255,255,255,0.3);
    border-radius: 4px;
    margin: 0 auto 1rem;
    overflow: hidden;
}

.loading-progress {
    height: 100%;
    background: linear-gradient(90deg, #ffd700, #ffed4e);
    border-radius: 4px;
    animation: loading 2s ease-in-out infinite;
}

@keyframes loading {
    0% { width: 0%; }
    50% { width: 70%; }
    100% { width: 100%; }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-20px); }
    60% { transform: translateY(-10px); }
}

/* Authentication Screen */
#auth-screen {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.auth-container {
    background: var(--card-bg);
    border-radius: 25px;
    padding: clamp(1.5rem, 5vw, 3rem);
    box-shadow: 0 20px 40px var(--shadow-color);
    max-width: 500px;
    width: 100%;
    animation: slideIn 0.5s ease;
    color: var(--text-color);
    margin: 1rem;
}

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

.auth-logo {
    font-size: clamp(3rem, 8vw, 4rem);
    margin-bottom: 1rem;
    color: rgb(226, 230, 0);
}

.auth-header h1 {
    font-size: clamp(1.5rem, 5vw, 2rem);
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.auth-header p {
    color: var(--text-color);
    opacity: 0.7;
    font-size: clamp(1rem, 3vw, 1.1rem);
}

.auth-form {
    transition: all 0.3s ease;
}

.auth-form.hidden {
    display: none;
}

.auth-form h2 {
    font-size: clamp(1.2rem, 4vw, 1.5rem);
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 1.5rem;
    text-align: center;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
    background: var(--bg-color);
    color: var(--text-color);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.auth-btn {
    width: 100%;
    padding: 1rem 2rem;
    border: none;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    min-height: 44px;
}

.auth-btn.primary {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 8px 25px rgb(0, 89, 255);
}

.auth-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px rgba(0, 47, 255, 0.6);
}

.auth-switch {
    text-align: center;
}

.auth-switch p {
    color: var(--text-color);
    opacity: 0.7;
    font-size: 0.9rem;
}

.auth-switch a {
    color: rgb(0, 174, 255);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.auth-switch a:hover {
    color: var(--secondary-color);
}

/* Main Menu */
#main-menu {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: clamp(1rem, 3vw, 2rem);
}

.menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: clamp(2rem, 5vw, 3rem);
    flex-wrap: wrap;
    gap: 1rem;
}

.menu-header h1 {
    color: white;
    font-size: clamp(1.8rem, 6vw, 2.5rem);
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.menu-header h1 i {
    color: var(--accent-color);
    margin-right: 0.5rem;
}

.user-info {
    display: flex;
    align-items: center;
    background: rgba(255,255,255,0.2);
    padding: 1rem;
    border-radius: 15px;
    backdrop-filter: blur(10px);
    gap: 1rem;
    flex-wrap: wrap;
}

.avatar {
    width: 50px;
    height: 50px;
    background: linear-gradient(45deg, var(--accent-color), #ffed4e);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    overflow: hidden;
    background-size: cover;
    background-position: center;
    flex-shrink: 0;
}

.avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.user-details {
    color: white;
    flex: 1;
    min-width: 0;
}

.username {
    font-weight: 600;
    font-size: 1.1rem;
    display: block;
    margin-bottom: 0.5rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.level-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.level {
    font-size: 0.9rem;
    opacity: 0.9;
}

.xp-bar {
    width: 80px;
    height: 6px;
    background: rgba(255,255,255,0.3);
    border-radius: 3px;
    overflow: hidden;
    flex-shrink: 0;
}

.xp-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-color), #ffed4e);
    border-radius: 3px;
    transition: width 0.3s ease;
}

.user-controls {
    display: flex;
    gap: 0.5rem;
    flex-shrink: 0;
}

.profile-btn, .logout-btn {
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.profile-btn:hover, .logout-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.1);
}

.menu-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 0;
}

.menu-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    max-width: 500px;
    width: 100%;
}

.menu-btn {
    padding: 1.5rem;
    border: none;
    border-radius: 20px;
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: inherit;
    min-height: 80px;
}

.menu-btn.primary {
    background: linear-gradient(45deg, var(--accent-color), #ffed4e);
    color: #333;
    box-shadow: 0 8px 25px rgba(255, 215, 0, 0.4);
    grid-column: 1 / -1;
}

.menu-btn.secondary {
    background: rgba(255,255,255,0.2);
    color: white;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.3);
}

.menu-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 35px rgba(0,0,0,0.2);
}

.menu-btn.primary:hover {
    box-shadow: 0 12px 35px rgba(255, 215, 0, 0.6);
}

.menu-btn i {
    font-size: 2rem;
}

.menu-footer {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.stats {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.stat {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: white;
    font-weight: 600;
    background: rgba(255,255,255,0.2);
    padding: 0.75rem 1.5rem;
    border-radius: 25px;
    backdrop-filter: blur(10px);
}

.stat i {
    color: var(--accent-color);
    font-size: 1.2rem;
}

/* Profile Personalization */
#profile-screen {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: clamp(1rem, 3vw, 2rem);
    overflow-y: auto;
}

.profile-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 2rem;
    color: white;
    flex-wrap: wrap;
    gap: 1rem;
}

.profile-header h2 {
    font-size: clamp(1.5rem, 5vw, 2rem);
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.theme-toggle {
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    flex-shrink: 0;
}

.theme-toggle:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.1);
}

.profile-content {
    max-width: 800px;
    margin: 0 auto;
}

.profile-section {
    background: var(--card-bg);
    border-radius: 20px;
    padding: clamp(1.5rem, 4vw, 2rem);
    margin-bottom: 2rem;
    box-shadow: 0 10px 30px var(--shadow-color);
    color: var(--text-color);
}

.profile-section h3 {
    font-size: clamp(1.2rem, 4vw, 1.5rem);
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.profile-section h3 i {
    color: var(--primary-color);
}

.profile-section h4 {
    font-size: clamp(1rem, 3vw, 1.2rem);
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
}

/* Avatar Section */
.avatar-upload {
    display: flex;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.avatar-preview {
    width: 100px;
    height: 100px;
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: white;
    overflow: hidden;
    background-size: cover;
    background-position: center;
    border: 3px solid var(--border-color);
    flex-shrink: 0;
}

.avatar-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.upload-btn {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 44px;
}

.upload-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
}

/* Background Section */
.background-options {
    margin-bottom: 2rem;
}

.color-presets {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.color-preset {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 1rem;
    border-radius: 15px;
    border: 2px solid transparent;
}

.color-preset:hover {
    background: rgba(102, 126, 234, 0.1);
    border-color: var(--primary-color);
}

.color-preset.active {
    background: rgba(102, 126, 234, 0.2);
    border-color: var(--primary-color);
}

.color-preview {
    width: 60px;
    height: 60px;
    border-radius: 15px;
    border: 3px solid var(--border-color);
    transition: all 0.3s ease;
}

.color-preset:hover .color-preview {
    transform: scale(1.1);
}

.color-preset span {
    font-weight: 600;
    color: var(--text-color);
    text-align: center;
    font-size: 0.9rem;
}

.image-upload {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.remove-btn {
    background: #ef4444;
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 44px;
}

.remove-btn:hover {
    background: #dc2626;
    transform: translateY(-2px);
}

.background-preview {
    width: 100%;
    height: 150px;
    border: 2px dashed var(--border-color);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-size: cover;
    background-position: center;
    color: var(--text-color);
    font-weight: 600;
}

/* Theme Section */
.theme-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1.5rem;
}

.theme-option {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 1rem;
    border-radius: 15px;
    border: 2px solid transparent;
}

.theme-option:hover {
    background: rgba(102, 126, 234, 0.1);
    border-color: var(--primary-color);
}

.theme-option.active {
    background: rgba(102, 126, 234, 0.2);
    border-color: var(--primary-color);
}

.theme-preview {
    width: 120px;
    height: 80px;
    border-radius: 15px;
    border: 3px solid var(--border-color);
    overflow: hidden;
    transition: all 0.3s ease;
}

.theme-option:hover .theme-preview {
    transform: scale(1.05);
}

.theme-demo {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.demo-header {
    height: 20px;
    background: var(--primary-color);
}

.demo-content {
    flex: 1;
    background: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.demo-content::before {
    content: '';
    width: 60%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
}

.theme-option span {
    font-weight: 600;
    color: var(--text-color);
    text-align: center;
}

/* Light Theme Preview */
.light-theme .demo-header {
    background: #667eea;
}

.light-theme .demo-content {
    background: #ffffff;
}

.light-theme .demo-content::before {
    background: #ddd;
}

/* Dark Theme Preview */
.dark-theme .demo-header {
    background: #4a5568;
}

.dark-theme .demo-content {
    background: #1a202c;
}

.dark-theme .demo-content::before {
    background: #4a5568;
}

/* Auto Theme Preview */
.auto-theme .demo-header {
    background: linear-gradient(45deg, #667eea, #4a5568);
}

.auto-theme .demo-content {
    background: linear-gradient(45deg, #ffffff, #1a202c);
}

.auto-theme .demo-content::before {
    background: linear-gradient(45deg, #ddd, #4a5568);
}

/* Profile Actions */
.profile-actions {
    text-align: center;
    margin-top: 2rem;
}

.save-btn {
    background: linear-gradient(45deg, #10b981, #059669);
    color: white;
    border: none;
    padding: 1rem 3rem;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 44px;
}

.save-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

/* Subject Selection */
#subject-selection {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: clamp(1rem, 3vw, 2rem);
}

.subject-header {
    text-align: center;
    margin-bottom: clamp(2rem, 5vw, 3rem);
    color: white;
}

.subject-header h2 {
    font-size: clamp(1.8rem, 6vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.subject-header p {
    font-size: clamp(1rem, 3vw, 1.2rem);
    opacity: 0.9;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.subject-item {
    background: rgba(255,255,255,0.2);
    border-radius: 25px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255,255,255,0.3);
    color: white;
    font-weight: 600;
    font-size: 1.3rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    min-height: 120px;
}

.subject-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    border-color: rgba(255,255,255,0.6);
}

.subject-item i {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

/* Level Selection */
#level-selection {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: clamp(1rem, 3vw, 2rem);
}

.level-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    color: white;
    flex-wrap: wrap;
    gap: 1rem;
}

.back-btn {
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    margin-right: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    flex-shrink: 0;
}

.back-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.1);
}

.level-header h2 {
    font-size: clamp(1.5rem, 5vw, 2rem);
    font-weight: 700;
    margin-right: auto;
}

.subject-info {
    background: rgba(255,255,255,0.2);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    backdrop-filter: blur(10px);
}

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

.level-item {
    aspect-ratio: 1;
    background: rgba(255,255,255,0.2);
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    border: 2px solid transparent;
    color: white;
    font-weight: 600;
    font-size: 1.2rem;
    min-height: 80px;
}

.level-item:hover {
    transform: scale(1.05);
    background: rgba(255,255,255,0.3);
}

.level-item.completed {
    background: linear-gradient(45deg, #4CAF50, #45a049);
    border-color: #4CAF50;
}

.level-item.current {
    background: linear-gradient(45deg, #ffd700, #ffed4e);
    color: #333;
    border-color: #ffd700;
    animation: pulse 2s infinite;
}

.level-item.locked {
    background: rgba(0,0,0,0.3);
    color: rgba(255,255,255,0.5);
    cursor: not-allowed;
}

.level-item.locked:hover {
    transform: none;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(255, 215, 0, 0.7); }
    70% { box-shadow: 0 0 0 10px rgba(255, 215, 0, 0); }
    100% { box-shadow: 0 0 0 0 rgba(255, 215, 0, 0); }
}

/* Game Screen */
#game-screen {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    flex-wrap: wrap;
    gap: 1rem;
}

.game-info {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: white;
    flex: 1;
    min-width: 0;
}

.level-number {
    font-weight: 600;
    font-size: 1.2rem;
    white-space: nowrap;
}

.progress-bar {
    width: min(200px, 30vw);
    height: 8px;
    background: rgba(255,255,255,0.3);
    border-radius: 4px;
    overflow: hidden;
    flex-shrink: 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #ffd700, #ffed4e);
    border-radius: 4px;
    transition: width 0.3s ease;
}

.game-controls {
    display: flex;
    gap: 0.5rem;
    flex-shrink: 0;
}

.control-btn {
    background: rgba(255,255,255,0.2);
    border: none;
    color: white;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
}

.control-btn:hover {
    background: rgba(255,255,255,0.3);
    transform: scale(1.1);
}

.game-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(1rem, 3vw, 2rem);
}

.game-question {
    background: var(--card-bg);
    border-radius: 25px;
    padding: clamp(2rem, 5vw, 3rem);
    text-align: center;
    box-shadow: 0 20px 40px var(--shadow-color);
    max-width: 600px;
    width: 100%;
    animation: slideIn 0.5s ease;
    color: var(--text-color);
}

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

.question-text {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 600;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.answer-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.answer-btn {
    padding: 1rem 2rem;
    border: 2px solid var(--border-color);
    border-radius: 15px;
    background: var(--bg-color);
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-color);
    min-height: 44px;
}

.answer-btn:hover {
    border-color: var(--accent-color);
    background: rgba(255, 249, 230, 0.1);
    transform: translateY(-2px);
}

.answer-btn.correct {
    border-color: #4CAF50;
    background: #e8f5e8;
    color: #4CAF50;
}

.answer-btn.incorrect {
    border-color: #f44336;
    background: #ffebee;
    color: #f44336;
}

.game-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(10px);
    color: white;
    flex-wrap: wrap;
    gap: 1rem;
}

.score, .timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1.1rem;
}

.score i, .timer i {
    color: var(--accent-color);
}

/* Results Screen */
#results-screen {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: clamp(1rem, 3vw, 2rem);
}

.results-content {
    background: var(--card-bg);
    border-radius: 25px;
    padding: clamp(2rem, 5vw, 3rem);
    text-align: center;
    box-shadow: 0 20px 40px var(--shadow-color);
    max-width: 500px;
    width: 100%;
    animation: slideIn 0.5s ease;
    color: var(--text-color);
}

.results-header {
    margin-bottom: 2rem;
}

.results-header h2 {
    font-size: clamp(1.5rem, 5vw, 2rem);
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.stars-earned {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-color);
}

.results-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.7;
    font-weight: 500;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
}

.results-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.btn {
    padding: 1rem 2rem;
    border: none;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    min-height: 44px;
}

.btn.primary {
    background: linear-gradient(45deg, var(--accent-color), #ffed4e);
    color: #333;
    box-shadow: 0 8px 25px rgba(255, 215, 0, 0.4);
}

.btn.secondary {
    background: rgba(102, 126, 234, 0.1);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 35px var(--shadow-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .menu-buttons {
        grid-template-columns: 1fr;
    }
    
    .menu-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .levels-grid {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }
    
    .subjects-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .color-presets {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }
    
    .theme-options {
        grid-template-columns: 1fr;
    }
    
    .avatar-upload {
        flex-direction: column;
        text-align: center;
    }
    
    .image-upload {
        flex-direction: column;
    }
    
    .game-question {
        padding: 2rem;
    }
    
    .question-text {
        font-size: 1.5rem;
    }
    
    .answer-options {
        grid-template-columns: 1fr;
    }
    
    .results-stats {
        grid-template-columns: 1fr;
    }
    
    .auth-container {
        padding: 2rem;
        margin: 1rem;
    }
    
    .user-info {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
    
    .user-controls {
        flex-direction: row;
        justify-content: center;
    }
    
    .game-header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .game-info {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .game-footer {
        flex-direction: column;
        gap: 1rem;
    }
}

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

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

.fade-in {
    animation: fadeIn 0.5s ease;
}

.slide-up {
    animation: slideUp 0.5s ease;
}

/* Utility */
.is-hidden { display: none; }

/* Question Enhancements */
.game-question .explanation {
    margin-top: 1rem;
    padding: 1rem 1.25rem;
    background: #fff8d6;
    border: 2px dashed #ffd24d;
    color: #5c4a00;
    border-radius: 12px;
    text-align: left;
}

/* Hints */
.game-question .hint {
    margin-top: 0.75rem;
}
.game-question .hint a {
    display: inline-block;
    background: #2563eb;
    color: #fff;
    padding: 0.5rem 0.75rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
}
.game-question .hint a:hover {
    background: #1d4ed8;
}

.game-question .question-image {
    max-width: 100%;
    border-radius: 12px;
    margin: 0 auto 1rem;
    display: block;
}

/* Second Chance System */
.second-chance-banner {
    background: linear-gradient(45deg, #ff6b6b, #ff8e8e);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 15px;
    margin-bottom: 1.5rem;
    font-weight: 600;
    font-size: 1.1rem;
    animation: pulse 2s infinite;
}

.second-chance-intro {
    background: var(--card-bg);
    border-radius: 25px;
    padding: 3rem;
    text-align: center;
    box-shadow: 0 20px 40px var(--shadow-color);
    max-width: 500px;
    width: 100%;
    animation: slideIn 0.5s ease;
    color: var(--text-color);
}

.second-chance-intro h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.second-chance-intro p {
    font-size: 1.1rem;
    color: var(--text-color);
    opacity: 0.7;
    margin-bottom: 1rem;
    line-height: 1.5;
}

/* Feedback Animations */
@keyframes shake {
    10%, 90% { transform: translateX(-1px); }
    20%, 80% { transform: translateX(2px); }
    30%, 50%, 70% { transform: translateX(-4px); }
    40%, 60% { transform: translateX(4px); }
}

.shake { animation: shake 0.4s linear; }

@keyframes popIn {
    0% { transform: scale(0.9); }
    60% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.pop { animation: popIn 0.35s ease; }