:root {
    /* Primary Colors */
    --bg-main: #EAF6FF; /* Soft sky blue */
    --text-main: #2D3748;
    --text-light: #718096;
    --white: #FFFFFF;
    
    /* Pastel Accents */
    --pastel-blue: #BAE1FF;
    --pastel-pink: #FFB3BA;
    --pastel-yellow: #FFFFBA;
    --pastel-green: #BAFFC9;
    --pastel-orange: #FFDFBA;
    
    /* Shadows */
    --shadow-soft: 0 10px 25px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 15px 35px rgba(0, 0, 0, 0.1);
    
    /* Border Radius */
    --radius-lg: 20px;
    --radius-md: 16px;
    --radius-full: 999px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.header {
    background-color: var(--white);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-soft);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.logo span {
    font-size: 2rem;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 800;
    color: #4299E1;
    letter-spacing: -0.5px;
}

.nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.nav a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 600;
    font-size: 1.1rem;
    transition: color 0.2s ease;
}

.nav a:hover {
    color: #ED8936;
}

.header-contact {
    display: flex;
    gap: 1.5rem;
}

.contact-link {
    text-decoration: none;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

.contact-link:hover {
    color: #4299E1;
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 3rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.section {
    display: none;
    animation: fadeIn 0.4s ease forwards;
}

.section.active {
    display: block;
}

/* Home Section */
.welcome-banner {
    text-align: center;
    margin-bottom: 3rem;
}

.welcome-banner h2 {
    font-size: 2.5rem;
    font-weight: 800;
    color: #2B6CB0;
    margin-bottom: 0.5rem;
}

.welcome-banner p {
    font-size: 1.25rem;
    color: var(--text-light);
}

.home-cards {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.main-card {
    background-color: var(--white);
    padding: 3rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    text-align: center;
    cursor: pointer;
    width: 350px;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 4px solid transparent;
}

.main-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-hover);
}

.card-blue { border-color: var(--pastel-blue); background-color: #F0F8FF; }
.card-orange { border-color: var(--pastel-orange); background-color: #FFF5EB; }

.card-icon {
    font-size: 5rem;
    margin-bottom: 1rem;
    animation: float 3s ease-in-out infinite;
}

.main-card h3 {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.main-card p {
    font-size: 1.1rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Section Header */
.section-header {
    display: flex;
    align-items: center;
    margin-bottom: 2rem;
    gap: 2rem;
}

.btn-back {
    background-color: var(--white);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: 700;
    color: #4A5568;
    cursor: pointer;
    box-shadow: var(--shadow-soft);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
}

.btn-back:hover {
    background-color: #ED8936;
    color: var(--white);
    transform: translateX(-5px);
}

.section-header h2 {
    font-size: 2.25rem;
    font-weight: 800;
    color: #2D3748;
}

/* Grids */
.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1.5rem;
}

.numbers-grid {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
}

/* Item Cards (Alphabet & Numbers) */
.item-card {
    background-color: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    padding: 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 3px solid transparent;
}

.item-card:hover {
    transform: translateY(-8px) scale(1.05);
    box-shadow: var(--shadow-hover);
}

/* Bounce Animation for Clicks */
.bounce {
    animation: bounce 0.5s cubic-bezier(0.36, 0, 0.66, -0.56);
}

/* Alphabet Card Specifics */
.letter {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1;
    margin-bottom: 0.5rem;
    color: var(--text-main);
}

.emoji {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.word {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
}

/* Number Card Specifics */
.number {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1;
    color: var(--text-main);
}

/* Footer */
.footer {
    background-color: var(--white);
    padding: 2rem;
    text-align: center;
    border-top: 2px dashed #E2E8F0;
    margin-top: auto;
}

.text-danger { color: #FC8181; }

.footer-contact {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 1rem;
    margin-top: 1rem;
    font-weight: 500;
}

.footer-contact a {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-contact a:hover {
    color: #4299E1;
}

/* Colors for dynamic cards */
.bg-pastel-pink { background-color: var(--pastel-pink); }
.bg-pastel-blue { background-color: var(--pastel-blue); }
.bg-pastel-green { background-color: var(--pastel-green); }
.bg-pastel-yellow { background-color: var(--pastel-yellow); }
.bg-pastel-orange { background-color: var(--pastel-orange); }

/* Animations Keyframes */
@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes bounce {
    0% { transform: scale(1); }
    50% { transform: scale(1.15); }
    100% { transform: scale(1); }
}

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