/* Define CSS Variables for Light Mode (Default) */
:root {
    /* Colors derived from your logo: Blue, Purple, Pink */
    --color-primary-blue: #87CEEB; /* Sky Blue */
    --color-primary-purple: #DDA0DD; /* Plum */
    --color-primary-pink: #FF69B4; /* Hot Pink */
    --color-dark-purple-text: #7D3C98; /* Darker Purple for titles/accents */

    /* General Backgrounds & Text */
    --body-bg-gradient-start: var(--color-primary-blue);
    --body-bg-gradient-middle: var(--color-primary-purple);
    --body-bg-gradient-end: var(--color-primary-pink);
    --body-text-color: #333;
    --footer-text-color: #6a6a6a;

    /* Container/Card Backgrounds */
    --container-bg: rgba(255, 255, 255, 0.95);
    --container-border-color: rgba(255, 255, 255, 0.2);
    --card-bg: #fff;
    --card-shadow-color: rgba(0, 0, 0, 0.1);
    --nft-preview-bg: #FDF9F9;
    --nft-preview-border: #DDA0DD;

    /* Button Colors */
    --btn-primary-gradient-start: var(--color-primary-blue);
    --btn-primary-gradient-end: var(--color-primary-purple);
    --btn-primary-hover-gradient-start: var(--color-primary-purple);
    --btn-primary-hover-gradient-end: var(--color-primary-pink);
    --btn-secondary-gradient-start: var(--color-primary-pink);
    --btn-secondary-gradient-end: var(--color-primary-purple);
    --btn-secondary-hover-gradient-start: var(--color-primary-purple);
    --btn-secondary-hover-gradient-end: var(--color-primary-blue);
    --btn-text-color: #fff;
    --btn-shadow-color-primary: rgba(135, 206, 235, 0.4); /* Based on primary blue */
    --btn-shadow-color-primary-hover: rgba(221, 160, 221, 0.5); /* Based on purple */
    --btn-shadow-color-secondary: rgba(255, 105, 180, 0.4); /* Based on pink */
    --btn-shadow-color-secondary-hover: rgba(221, 160, 221, 0.5); /* Based on purple */

    /* Headings & Accents */
    --h1-color: var(--color-dark-purple-text);
    --h2-color: var(--color-primary-pink);
    --timer-color: var(--color-dark-purple-text);
    --progress-bg: #e0e0e0;
    --progress-fill-start: var(--color-primary-blue);
    --progress-fill-end: var(--color-primary-purple);

    /* Quiz Answers */
    --answer-btn-bg: #F8F8F8;
    --answer-btn-border: #ddd;
    --answer-btn-hover-bg: #EFEFEF;
    --answer-btn-text: #333;
    --answer-btn-shadow: rgba(0,0,0,0.05);
    --answer-btn-hover-shadow: rgba(0,0,0,0.1);

    /* Message Colors */
    --msg-success-bg: #E8F5E9;
    --msg-success-color: #2E7D32;
    --msg-success-border: #4CAF50;
    --msg-error-bg: #FFEBEE;
    --msg-error-color: #C62828;
    --msg-error-border: #F44336;
}

/* Dark Mode Variables */
body.dark-theme {
    /* General Backgrounds & Text */
    --body-bg-gradient-start: #1A0F2B; /* Darker Purple */
    --body-bg-gradient-middle: #2B1A4B; /* Even Darker Purple */
    --body-bg-gradient-end: #3D2C6D; /* Deepest Purple */
    --body-text-color: #e0e0e0; /* Light grey text */
    --footer-text-color: #a0a0a0;

    /* Container/Card Backgrounds */
    --container-bg: rgba(40, 40, 60, 0.95); /* Darker, slightly transparent */
    --container-border-color: rgba(255, 255, 255, 0.1);
    --card-bg: #2b2b45; /* Dark card background */
    --card-shadow-color: rgba(0, 0, 0, 0.3);
    --nft-preview-bg: #3a3a5a;
    --nft-preview-border: #8E44AD; /* Darker purple dashed border */

    /* Button Colors - adapt to be visible on dark */
    --btn-primary-gradient-start: var(--color-primary-blue); /* Keep vibrant from logo */
    --btn-primary-gradient-end: #7D3C98; /* Deeper purple */
    --btn-primary-hover-gradient-start: #DDA0DD;
    --btn-primary-hover-gradient-end: #FF69B4;
    --btn-secondary-gradient-start: #FF69B4;
    --btn-secondary-gradient-end: #7D3C98;
    --btn-secondary-hover-gradient-start: #DDA0DD;
    --btn-secondary-hover-gradient-end: var(--color-primary-blue);
    --btn-text-color: #fff; /* Keep white for readability */
    --btn-shadow-color-primary: rgba(135, 206, 235, 0.3);
    --btn-shadow-color-primary-hover: rgba(221, 160, 221, 0.4);
    --btn-shadow-color-secondary: rgba(255, 105, 180, 0.3);
    --btn-shadow-color-secondary-hover: rgba(221, 160, 221, 0.4);

    /* Headings & Accents */
    --h1-color: var(--color-primary-purple); /* Lighter purple for dark mode heading */
    --h2-color: var(--color-primary-pink); /* Keep vibrant pink */
    --timer-color: var(--color-primary-purple);
    --progress-bg: #555570; /* Darker background for progress bar */
    --progress-fill-start: var(--color-primary-blue);
    --progress-fill-end: var(--color-primary-purple);

    /* Quiz Answers */
    --answer-btn-bg: #3a3a5a; /* Darker answer buttons */
    --answer-btn-border: #555570;
    --answer-btn-hover-bg: #4a4a6a;
    --answer-btn-text: #e0e0e0;
    --answer-btn-shadow: rgba(0,0,0,0.1);
    --answer-btn-hover-shadow: rgba(0,0,0,0.2);

    /* Message Colors - adapt for dark background */
    --msg-success-bg: #2C5F2D; /* Darker green */
    --msg-success-color: #A3D8A5; /* Lighter green text */
    --msg-success-border: #4CAF50;
    --msg-error-bg: #7C2A2A; /* Darker red */
    --msg-error-color: #F0A0A0; /* Lighter red text */
    --msg-error-border: #F44336;
}

/* General Body and Container Styles - using variables */
body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--body-bg-gradient-start), var(--body-bg-gradient-middle), var(--body-bg-gradient-end));
    background-attachment: fixed;
    color: var(--body-text-color);
    overflow: hidden;
    position: relative;
    transition: background 0.5s ease-in-out, color 0.5s ease-in-out; /* Smooth transition for theme change */
}

/* Background animation - keep as is, it's cool */
.background-animation {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at top left, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
                radial-gradient(circle at bottom right, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    animation: pulseBackground 15s infinite alternate ease-in-out;
    pointer-events: none;
}

@keyframes pulseBackground {
    0% { transform: scale(1); opacity: 0.8; }
    100% { transform: scale(1.1); opacity: 1; }
}

/* Fixed Footer - using variables */
.fixed-footer {
    position: fixed;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    font-size: 0.9em;
    color: var(--footer-text-color);
    z-index: 999;
    background-color: transparent;
}

.footer-icon {
    width: 1em;
    height: 1em;
    vertical-align: middle;
    margin: 0 0.2em;
}

/* Main Container (the white card) - using variables */
.container {
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
    text-align: center;
    box-sizing: border-box;
    z-index: 10;
    max-width: 800px; /* reduced from 800px */
    width: 100%;
    position: relative;
    border: 1px solid var(--container-border-color);
    transition: background-color 0.5s ease-in-out, box-shadow 0.5s ease-in-out, border-color 0.5s ease-in-out;
}

/* Header Styles - using variables */
.main-header {
    margin-bottom: 30px;
}

.main-header .header-icon {
    width: 80px;
    height: 80px;
    margin-bottom: 5px;
    animation: float 3s ease-in-out infinite alternate;
}

@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
    100% { transform: translateY(0px); }
}

.main-header h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5em;
    color: var(--h1-color);
    margin-bottom: 5px;
    transition: color 0.5s ease-in-out;
}

.main-header p {
    font-size: 1.1em;
    color: var(--body-text-color); /* General body text color */
    line-height: 1.6;
    
}

/* Section Card Styles - using variables */
.card {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 20px var(--card-shadow-color);
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;     /* reduce from 30px */
    max-width: 100%;
    margin-top: 20px;
    
    transition: opacity 0.5s ease-in-out, background-color 0.5s ease-in-out, box-shadow 0.5s ease-in-out;
}

.card h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.8em;
    color: var(--h2-color);
    margin-bottom: 1px;
    margin-top: 1px;
    transition: color 0.5s ease-in-out;
}

.card p {
    font-size: 1em;
    color: var(--body-text-color); /* General body text color */
    margin-bottom: 10px;
}

/* Button Styles - using variables */
.btn {
    display: inline-block;
    padding: 12px 25px;
    border: none;
    border-radius: 8px;
    font-family: 'Montserrat', sans-serif;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    color: var(--btn-text-color);
    text-shadow: 1px 1px 2px rgba(0,0,0,0.2);
}

.primary-btn {
    background: linear-gradient(to right, var(--btn-primary-gradient-start), var(--btn-primary-gradient-end));
    box-shadow: 0 4px 15px var(--btn-shadow-color-primary);
}

.primary-btn:hover {
    background: linear-gradient(to right, var(--btn-primary-hover-gradient-start), var(--btn-primary-hover-gradient-end));
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--btn-shadow-color-primary-hover);
}

.secondary-btn {
    background: linear-gradient(to right, var(--btn-secondary-gradient-start), var(--btn-secondary-gradient-end));
    box-shadow: 0 4px 15px var(--btn-shadow-color-secondary);
    margin-left: 15px;
}

.secondary-btn:hover {
    background: linear-gradient(to right, var(--btn-secondary-hover-gradient-start), var(--btn-secondary-hover-gradient-end));
    transform: translateY(-3px);
    box-shadow: 0 6px 20px var(--btn-shadow-color-secondary-hover);
}

.actions-grid {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
    flex-wrap: wrap;
}

/* Quiz Specific Styles - using variables */
.quiz-header {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
}

.progress-bar {
    width: 70%;
    background-color: var(--progress-bg);
    border-radius: 5px;
    height: 10px;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
    transition: background-color 0.5s ease-in-out;
}

.progress {
    height: 100%;
    width: 0%;
    background: linear-gradient(to right, var(--progress-fill-start), var(--progress-fill-end));
    border-radius: 5px;
    transition: width 0.3s ease-in-out, background 0.5s ease-in-out;
}

.timer {
    font-weight: 600;
    color: var(--timer-color);
    font-size: 1.1em;
    transition: color 0.5s ease-in-out;
}

#questionText {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.6em;
    color: var(--body-text-color);
    margin-bottom: 30px;
    text-align: center;
    line-height: 1.4;
    transition: color 0.5s ease-in-out;
}

.answers-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
    width: 100%;
}

.answer-btn {
    background-color: var(--answer-btn-bg);
    color: var(--answer-btn-text);
    border: 1px solid var(--answer-btn-border);
    box-shadow: 0 2px 5px var(--answer-btn-shadow);
    padding: 15px 20px;
    font-size: 1.1em;
    font-weight: 500;
    text-align: left;
    width: 100%;
    transition: all 0.2s ease, background-color 0.5s ease-in-out, color 0.5s ease-in-out, border-color 0.5s ease-in-out, box-shadow 0.5s ease-in-out;
}

.answer-btn:hover:not(:disabled) {
    background-color: var(--answer-btn-hover-bg);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--answer-btn-hover-shadow);
}

.answer-btn.correct {
    background-color: var(--msg-success-bg);
    border-color: var(--msg-success-border);
    color: var(--msg-success-color);
}

.answer-btn.incorrect {
    background-color: var(--msg-error-bg);
    border-color: var(--msg-error-border);
    color: var(--msg-error-color);
}

.answer-btn:disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

/* NFT Preview Styles - using variables */
.nft-preview-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    
    padding: 15px;
    background-color: var(--nft-preview-bg);
    border-radius: 18px;
    border: 1px dashed var(--nft-preview-border);
    width: 100%;
    box-sizing: border-box;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: background-color 0.5s ease-in-out, border-color 0.5s ease-in-out;
}

.nft-preview-image {
    max-width: 160px;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    margin-bottom: 20px;
}

.nft-preview-text {
    font-size: 1.1em;
    color: var(--body-text-color);
    text-align: center;
    line-height: 1.5;
    transition: color 0.5s ease-in-out;
    margin-bottom: 10px;
}

/* Message Display - using variables */
.message {
    padding: 15px;
    margin-top: 20px;
    border-radius: 8px;
    font-weight: 600;
    text-align: center;
    display: none;
    font-size: 1em;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: background-color 0.5s ease-in-out, color 0.5s ease-in-out, border-color 0.5s ease-in-out;
}

.message.success {
    background-color: var(--msg-success-bg);
    color: var(--msg-success-color);
    border: 1px solid var(--msg-success-border);
}

.message.error {
    background-color: var(--msg-error-bg);
    color: var(--msg-error-color);
    border: 1px solid var(--msg-error-border);
}

/* Hidden Utility Class */
.hidden {
    display: none;
}

/* Fade-in Animation */
.fade-in {
    animation: fadeIn 0.8s ease-out forwards;
}

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

/* Responsive Adjustments */
@media (min-width: 600px) {
    .answers-grid {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
    .main-header h1 {
        font-size: 3em;
    }
    .card h2 {
        font-size: 2.2em;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
        border-radius: 10px;
    }
    .main-header h1 {
        font-size: 2em;
    }
    .main-header .header-icon {
        width: 60px;
        height: 60px;
    }
    .btn {
        width: 100%;
        margin-left: 0 !important;
        margin-top: 5px;

    }
    .actions-grid {
        flex-direction: column;
        gap: 10px;
    }
    .quiz-header {
        flex-direction: column;
        gap: 15px;
    }
    .progress-bar {
        width: 100%;
    }
}

/* Theme Toggle Button Styles */
.theme-toggle-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--container-bg); /* Use theme-aware background */
    color: var(--body-text-color); /* Use theme-aware text color */
    border: 1px solid var(--container-border-color);
    border-radius: 50%;
    width: 45px;
    height: 45px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease-in-out;
    z-index: 1000; /* Ensure it's above other content */
}
.footer-author-link {
    /* Make text transparent to apply background as text fill */
    color: transparent; 
    /* Apply gradient from theme colors */
    background: linear-gradient(to right, var(--color-primary-blue), var(--color-primary-purple), var(--color-primary-pink));
    -webkit-background-clip: text; /* For WebKit browsers */
    background-clip: text;
    text-decoration: none; /* Remove default underline */
    font-weight: 600; /* Make it bolder */
    transition: all 0.3s ease; /* Smooth transitions for hover effects */
    display: inline-block; /* Essential for transform to work properly */
}

.footer-author-link:hover {
    /* Slightly shift the gradient on hover, or apply a different background */
    background: linear-gradient(to right, var(--color-primary-pink), var(--color-primary-purple), var(--color-primary-blue));
    -webkit-background-clip: text;
    background-clip: text;
    /* Optional: subtle scale or text shadow */
    transform: scale(1.05); /* Slightly enlarge on hover */
    text-shadow: 0 0 8px rgba(var(--color-primary-purple), 0.5); /* Subtle glow */
}

/* Ensure the default footer link style doesn't override this, or keep it */
.fixed-footer a {
    /* Remove any conflicting styles from .fixed-footer a if they exist */
    /* For example, if it had a specific 'color' that overrides transparent */
    color: var(--footer-text-color); /* Fallback for browsers that don't support background-clip: text */
}
.theme-toggle-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

/* Optional: Icon specific styling if you use an SVG or font icon */
.theme-toggle-btn .icon {
    font-size: 1em; /* Adjust if using font awesome or similar */
}