:root {
    /* Playful Theme Variables (Kids Friendly) */
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;

    --primary-color: #4f46e5;
    --secondary-color: #ec4899;
    --accent-yellow: #f59e0b;
    --accent-green: #10b981;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;

    --font-family: 'Outfit', 'Fredoka', sans-serif;
    --radius: 24px;
    /* More rounded for kids */
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --card-shadow: 0 8px 0px rgba(0, 0, 0, 0.05);
    /* Chunky shadows */
}

/* Dark Mode Support (if user prefers, but default is light now for kids) */
[data-theme="dark"] {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
}

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    margin-bottom: 20px;
}

.logo {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    letter-spacing: -1px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo span {
    color: var(--secondary-color);
}

/* Old Nav Styles - Overridden by Bootstrap if used, but kept for legacy if needed */
nav a {
    text-decoration: none;
    color: var(--text-muted);
    margin-left: 20px;
    font-weight: 500;
    transition: color 0.2s;
}

nav a.active,
nav a:hover {
    color: var(--text-main);
    /* Highlight with white */
}

/* 
   BOOTSTRAP NAVBAR OVERRIDES (Dark Theme) 
   Used for tabbed navigation consistency 
*/
.navbar-nav.nav-tabs {
    border-bottom: none;
}

.navbar-nav.nav-tabs .nav-link {
    color: var(--text-muted);
    font-weight: 500;
    border: none;
    border-bottom: 3px solid transparent;
    margin-right: 5px;
    transition: all 0.2s;
    /* Reset margins from legacy nav a if conflicting */
    margin-left: 0;
}

.navbar-nav.nav-tabs .nav-link:hover {
    color: var(--text-main);
    background: rgba(255, 255, 255, 0.05);
    border-bottom-color: rgba(255, 255, 255, 0.3);
}

.navbar-nav.nav-tabs .nav-link.active {
    color: var(--primary-color) !important;
    border-bottom: 3px solid var(--primary-color);
    background-color: transparent;
    font-weight: 700;
}

/* Helper to reset login button color if needed */
.btn-reset-nav {
    color: inherit !important;
}

/* Main Layout */
main {
    display: flex;
    gap: 30px;
    flex: 1;
    overflow: hidden;
}

/* Controls Panel */
.controls-panel {
    flex: 0 0 350px;
    background: var(--card-bg);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
    overflow-y: auto;
}

.controls-panel h1 {
    font-size: 1.5rem;
    margin-bottom: 5px;
    color: var(--text-main);
}

.subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 30px;
}

/* Form Styling */
.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: flex;
    gap: 15px;
}

.form-row .form-group {
    flex: 1;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-muted);
    /* Softer label color */
}

input[type="number"],
select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    background-color: #404040;
    /* Input bg */
    border-radius: 6px;
    font-family: var(--font-family);
    font-size: 1rem;
    color: var(--text-main);
    transition: border-color 0.2s, box-shadow 0.2s;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

/* Checkbox Styling */
.form-check-group {
    margin-bottom: 15px;
}

.checkbox-container {
    display: flex;
    align-items: center;
    position: relative;
    padding-left: 30px;
    cursor: pointer;
    font-size: 0.95rem;
    user-select: none;
    color: var(--text-main);
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    height: 20px;
    width: 20px;
    background-color: #404040;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: all 0.2s;
}

.checkbox-container:hover input~.checkmark {
    background-color: #4a4a4a;
}

.checkbox-container input:checked~.checkmark {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked~.checkmark:after {
    display: block;
}

.checkbox-container .checkmark:after {
    left: 7px;
    top: 3px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

/* Button */
.btn-primary {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.2s;
    margin-top: 10px;
}

.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-secondary {
    padding: 8px 16px;
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
    border-radius: 6px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--text-main);
}



/* --- MATH ZONE STYLES (Moved from math-zone.html) --- */

.game-card {
    background-color: var(--card-bg);
    width: 100%;
    max-width: 800px;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-height: 450px;
    position: relative;
    border: 1px solid var(--border-color);
    margin: 0 auto;
}

.game-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 30px;
    border-bottom: 1px solid var(--border-color);
    color: #d4d4d4;
    font-size: 1.1rem;
}

.stat-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.center-timer {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 5px;
    border-radius: 50%;
    transition: color 0.2s, background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    color: white;
    background: rgba(255, 255, 255, 0.1);
}

.game-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 40px;
    position: relative;
}

.problem-wrapper {
    display: flex;
    align-items: center;
    gap: 20px;
    font-size: 3.5rem;
    font-weight: 500;
    color: #e5e5e5;
}

.input-box {
    background: transparent;
    border: 1px solid var(--border-color);
    color: white;
    font-size: 3.5rem;
    width: 140px;
    height: 90px;
    text-align: center;
    border-radius: 6px;
    outline: none;
    font-family: inherit;
    transition: border-color 0.2s;
}

.input-box:focus {
    border-color: var(--text-main);
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--card-bg);
    z-index: 10;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.btn-start {
    background: white;
    color: black;
    padding: 12px 30px;
    border-radius: 6px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    transition: opacity 0.2s;
}

.btn-start:hover {
    opacity: 0.9;
}

.difficulty-select {
    background: #404040;
    color: white;
    border: 1px solid var(--border-color);
    padding: 10px 15px;
    border-radius: 6px;
    margin-bottom: 30px;
    font-size: 1rem;
    outline: none;
    width: auto;
}

.card-footer {
    text-align: center;
    padding: 15px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

.icon {
    width: 20px;
    height: 20px;
    stroke-width: 2;
}

.page-header {
    text-align: center;
    margin-bottom: 30px;
}

.page-title {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.page-subtitle {
    color: var(--text-muted);
    font-size: 1rem;
    margin-bottom: 15px;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 15px;
    color: var(--text-muted);
    font-size: 0.9rem;
    align-items: center;
}

.social-links a {
    color: var(--text-muted);
    text-decoration: none;
}

/* Utility */
.hidden {
    display: none !important;
}



/* Override Bootstrap text-muted to use our theme variable for visibility */
.text-muted {
    color: var(--text-muted) !important;
}

.score-box {
    background: #4ade80;
    color: #064e3b;
    padding: 2px 8px;
    border-radius: 4px;
    margin-left: 8px;
    font-weight: 800;
    display: inline-block;
}

/* Responsive Adjustments */
@media (max-width: 991px) {
    .navbar-brand {
        font-size: 1.5rem !important;
    }

    main {
        flex-direction: column;
        overflow: visible;
    }

    .controls-panel {
        flex: none;
        width: 100%;
        margin-bottom: 20px;
    }

    .preview-panel {
        padding: 0;
    }

    .worksheet-paper {
        padding: 20px;
    }

    .questions-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 15px;
    }
}

@media (max-width: 576px) {
    .questions-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .problem-wrapper {
        font-size: 2rem;
        gap: 10px;
    }

    .input-box {
        font-size: 2rem;
        width: 100px;
        height: 60px;
    }

    .game-bar {
        padding: 15px;
        font-size: 0.9rem;
    }
}

/* Kids Specific UI Components */

.kids-btn {
    border-radius: 100px;
    padding: 15px 40px;
    font-weight: 700;
    font-size: 1.1rem;
    border: none;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 4px 0 rgba(0, 0, 0, 0.1);
    text-decoration: none;
    display: inline-block;
    cursor: pointer;
}

.kids-btn:active {
    transform: translateY(4px);
    box-shadow: 0 0 0 rgba(0, 0, 0, 0.1);
}

.kids-btn-primary {
    background-color: var(--primary-color);
    color: white !important;
}

.kids-btn-secondary {
    background-color: var(--secondary-color);
    color: white !important;
}

.kids-btn-yellow {
    background-color: var(--accent-yellow);
    color: white !important;
}

.kids-btn:hover {
    transform: scale(1.05) translateY(-2px);
    filter: brightness(1.1);
}

.feature-card-kids {
    background: var(--card-bg);
    border-radius: 30px;
    padding: 2rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 4px solid var(--border-color);
    box-shadow: 0 10px 0 var(--border-color);
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.feature-card-kids:hover {
    transform: translateY(-10px) rotate(1deg);
    box-shadow: 0 20px 0 var(--border-color);
}

.feature-card-kids.blue {
    --border-color: var(--accent-blue);
}

.feature-card-kids.pink {
    --border-color: var(--secondary-color);
}

.feature-card-kids.green {
    --border-color: var(--accent-green);
}

.feature-card-kids.yellow {
    --border-color: var(--accent-yellow);
}

.feature-card-kids.purple {
    --border-color: var(--accent-purple);
}

.kids-icon-circle {
    width: 80px;
    height: 80px;
    background: #f1f5f9;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    transition: transform 0.3s ease;
}

.feature-card-kids:hover .kids-icon-circle {
    transform: scale(1.2) rotate(-10deg);
}

.floating {
    animation: floating 3s ease-in-out infinite;
}

@keyframes floating {
    0% {
        transform: translateY(0px);
    }

    50% {
        transform: translateY(-15px);
    }

    100% {
        transform: translateY(0px);
    }
}

.kids-badge {
    padding: 0.5rem 1rem;
    border-radius: 100px;
    font-weight: 700;
    font-size: 0.8rem;
    text-transform: uppercase;
    margin-bottom: 1rem;
}

/* Navbar Kids Style */
.navbar-kids {
    background: white;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    border-radius: 0 0 30px 30px;
    padding: 1rem 0;
}

.nav-link-kids {
    font-weight: 700;
    font-size: 1.1rem;
    margin: 0 10px;
    color: var(--text-main) !important;
    border-radius: 15px;
    padding: 8px 15px !important;
    transition: all 0.2s;
}

.nav-link-kids:hover,
.nav-link-kids.active {
    background: #f1f5f9;
    color: var(--primary-color) !important;
}

/* Force dark text in navbar-kids regardless of global theme for now */
.navbar-kids .navbar-brand,
.navbar-kids .nav-link-kids {
    color: var(--text-main) !important;
}

.navbar-kids .logo span {
    color: var(--secondary-color) !important;
}


/* Hero Kids Style */
.hero-kids {
    padding: 6rem 0;
    background: radial-gradient(circle at 10% 20%, rgba(79, 70, 229, 0.05) 0%, rgba(236, 72, 153, 0.05) 90%);
    border-radius: 50px;
    margin: 2rem 0;
}

.hero-kids h1 {
    font-family: 'Fredoka', 'Outfit', sans-serif;
    font-weight: 800;
    font-size: 4rem;
    color: var(--text-main);
}

@media (max-width: 768px) {
    .hero-kids h1 {
        font-size: 2.5rem;
    }
}