body {
    font-family: 'Fredoka', cursive;
    background-image: url('background.png');
    background-size: cover;
    background-position: center;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    color: #333;
    text-align: center;
    padding: 20px;
    box-sizing: border-box;
}

.quiz-container {
    background-color: rgba(255, 255, 255, 0.9);
    padding: 30px 40px;
    border-radius: 20px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    max-width: 800px;
    width: 100%;
    border: 5px solid #6cbe45; /* Nature-themed border color */
}

h1 {
    color: #4CAF50; /* Green theme */
    font-size: 2.8em;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
}

h2 {
    color: #795548; /* Brownish theme for sticker area */
    font-size: 1.8em;
    margin-top: 25px;
    margin-bottom: 15px;
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

#start-screen p {
    font-size: 1.3em;
    margin-bottom: 30px;
    color: #555;
}

.question {
    font-size: 1.6em;
    margin-bottom: 25px;
    color: #333;
    font-weight: 700;
}

.options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 25px;
}

.option-button, .action-button {
    background-color: #8BC34A; /* Lighter green for buttons */
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 10px;
    font-size: 1.2em;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    font-family: 'Fredoka', cursive;
}

.option-button:hover, .action-button:hover {
    background-color: #689F38; /* Darker green on hover */
    transform: translateY(-2px);
}

.option-button:active, .action-button:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.option-button.correct {
    background-color: #4CAF50; /* Green for correct */
    animation: pulseCorrect 0.5s forwards;
}

.option-button.incorrect {
    background-color: #F44336; /* Red for incorrect */
    animation: shake 0.3s forwards;
}

@keyframes pulseCorrect {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

@keyframes shake {
    0% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    50% { transform: translateX(5px); }
    75% { transform: translateX(-5px); }
    100% { transform: translateX(0); }
}

.feedback {
    font-size: 1.4em;
    font-weight: 700;
    margin-top: 15px;
    height: 40px; /* Reserve space to prevent layout shifts */
}

.feedback.correct {
    color: #4CAF50;
}

.feedback.incorrect {
    color: #F44336;
}

.sticker-area {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 2px dashed #aed581; /* Dotted line separator */
}

.stickers-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr); /* 5 stickers per row */
    gap: 10px;
    justify-items: center;
    margin-top: 15px;
}

.sticker-slot {
    width: 60px; /* Size for stickers */
    height: 60px;
    border: 2px dashed #9E9E9E; /* Placeholder border */
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 0.8em;
    color: #9E9E9E;
    background-color: #f0f0f0;
    box-sizing: border-box;
    position: relative;
    overflow: hidden;
}

.sticker-slot img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transform: scale(0.5);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.sticker-slot.filled img {
    opacity: 1;
    transform: scale(1);
}

#win-screen h2 {
    color: #4CAF50;
    font-size: 3em;
    margin-top: 20px;
    margin-bottom: 10px;
}

#win-screen p {
    font-size: 1.5em;
    color: #555;
    margin-bottom: 30px;
}

lottie-player {
    margin: 0 auto; /* Center the Lottie animation */
}

@media (max-width: 600px) {
    .quiz-container {
        padding: 20px;
    }
    h1 {
        font-size: 2em;
    }
    .options {
        grid-template-columns: 1fr;
    }
    .option-button, .action-button {
        font-size: 1em;
        padding: 12px 20px;
    }
    .question {
        font-size: 1.3em;
    }
    .feedback {
        font-size: 1.1em;
    }
    .stickers-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .sticker-slot {
        width: 50px;
        height: 50px;
    }
    #win-screen h2 {
        font-size: 2.2em;
    }
    #win-screen p {
        font-size: 1.2em;
    }
}