:root {
    --primary-color: #3485E4;
    --secondary-color: #6833E4;
    --accent-color: #F26207;
    --background-color: #0E1525;
    --card-background: #1C2333;
    --text-color: #F5F9FC;
    --error-color: #E84D3D;
    --success-color: #2ECC71;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    min-height: 100vh;
}

.game-container {
    padding: 1.5rem;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
}

.game-title {
    font-weight: 700;
    font-size: clamp(1.5rem, 5vw, 2.5rem);
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.table-selection {
    text-align: center;
    margin-bottom: 2rem;
    background-color: var(--card-background);
    border-radius: 15px;
    padding: clamp(1rem, 3vw, 2rem);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.table-selection h2 {
    font-size: clamp(1.1rem, 4vw, 1.5rem);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.table-buttons {
    max-width: 600px;
    margin: 0 auto;
}

.table-btn {
    width: 100%;
    padding: clamp(0.5rem, 2vw, 1rem);
    font-size: clamp(0.9rem, 3vw, 1.2rem);
    font-weight: 600;
    border: none;
    border-radius: 10px;
    background-color: var(--primary-color);
    color: white;
    transition: transform 0.2s, background-color 0.2s;
    box-shadow: 0 4px 6px rgba(52, 152, 219, 0.2);
}

.table-btn:hover {
    transform: translateY(-2px);
    background-color: var(--accent-color);
}

.game-board {
    background-color: var(--card-background);
    border-radius: 15px;
    padding: clamp(1rem, 3vw, 2rem);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.1);
    max-width: 800px;
    margin: 0 auto;
}

.character-container {
    text-align: center;
    margin-bottom: clamp(1rem, 3vw, 2rem);
}

.teacher-character {
    font-size: clamp(2.5rem, 8vw, 4rem);
    color: var(--accent-color);
}

.problem-container {
    text-align: center;
    font-size: clamp(1.5rem, 6vw, 2.5rem);
    font-weight: 700;
    margin-bottom: clamp(1rem, 3vw, 2rem);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.operation, .equals {
    color: var(--primary-color);
    margin: 0 0.5rem;
}

.question-mark {
    color: var(--accent-color);
}

.answers-container {
    max-width: 600px;
    margin: 0 auto;
}

.answer-btn {
    width: 100%;
    padding: clamp(0.7rem, 2vw, 1rem);
    font-size: clamp(1rem, 4vw, 1.5rem);
    font-weight: 600;
    border: none;
    border-radius: 10px;
    background-color: var(--secondary-color);
    color: white;
    transition: transform 0.2s, background-color 0.2s;
    box-shadow: 0 4px 6px rgba(46, 204, 113, 0.2);
    -webkit-tap-highlight-color: transparent; /* Remove tap highlight on iOS */
    touch-action: manipulation; /* Optimize for touch */
    user-select: none; /* Prevent text selection */
}

.answer-btn:hover {
    transform: translateY(-2px);
    background-color: var(--success-color);
}

.answer-btn:active {
    background-color: var(--success-color);
    transform: translateY(-1px);
}

.answer-btn.clicked {
    background-color: var(--secondary-color);
    transform: translateY(0);
}

.score-container {
    text-align: center;
    margin-top: clamp(1rem, 3vw, 2rem);
    font-size: clamp(1rem, 3vw, 1.2rem);
    font-weight: 600;
}

.back-btn {
    margin-top: clamp(1rem, 3vw, 2rem);
    padding: 0.8rem 1.5rem;
    font-size: clamp(0.9rem, 3vw, 1.1rem);
    font-weight: 600;
    border: none;
    border-radius: 10px;
    background-color: var(--accent-color);
    color: white;
    transition: transform 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 4px 6px rgba(155, 89, 182, 0.2);
}

.back-btn:hover {
    transform: translateY(-2px);
    background-color: var(--primary-color);
}

.navigation-container {
    text-align: center;
    margin-top: clamp(1rem, 3vw, 2rem);
}

.celebration-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 1000;
}

.celebration-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
}

.celebration-star {
    font-size: clamp(3rem, 10vw, 5rem);
    color: var(--secondary-color);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

/* Improved responsive breakpoints */
@media (max-width: 576px) {
    .game-container {
        padding: 1rem;
    }

    .answers-container .row {
        gap: 0.5rem;
    }

    .col-6 {
        width: 100%;
    }
}

@media (min-width: 577px) and (max-width: 768px) {
    .col-6 {
        width: 50%;
    }
}

@media (min-width: 769px) {
    .game-container {
        padding: 2rem;
    }
}

.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--background-color);
    z-index: 2000;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

.loading-overlay.active {
    display: flex;
    opacity: 1;
}

.loading-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.math-characters {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.math-char {
    font-size: clamp(2rem, 6vw, 3rem);
    color: var(--primary-color);
    animation: bounceChar 1.5s infinite;
}

.math-char:nth-child(2) {
    animation-delay: 0.2s;
    color: var(--secondary-color);
}

.math-char:nth-child(3) {
    animation-delay: 0.4s;
    color: var(--accent-color);
}

.math-char:nth-child(4) {
    animation-delay: 0.6s;
    color: var(--secondary-color);
}

.math-char:nth-child(5) {
    animation-delay: 0.8s;
    color: var(--primary-color);
}

.loading-text {
    font-size: clamp(1.2rem, 4vw, 1.5rem);
    font-weight: 600;
    color: var(--text-color);
    margin-top: 1rem;
    animation: pulse 1.5s infinite;
}

@keyframes bounceChar {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px) scale(1.1);
    }
}

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