:root {
    --bg-color: #f8fafc;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f7f7f7;
    --text-primary: #000000;
    --text-secondary: #595959;
    --accent-primary: #8989eb;
    --accent-color: #8989eb;
    --accent-hover: #7575d6;
    --accent-glow: rgba(137, 137, 235, 0.2);
    --accent-electricity: #8989eb;
    --border-color: #f7f7f7;
    --font-heading: 'Oswald', sans-serif;
    --font-body: Arial, Calibri, sans-serif;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
    overflow-x: hidden;
}

/* Dynamic Background Effect */
.background-effect {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    background:
        radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(234, 179, 8, 0.1), transparent 25%);
    filter: blur(60px);
    animation: pulse 15s ease-in-out infinite alternate;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 0.8;
    }

    100% {
        transform: scale(1.1);
        opacity: 1;
    }
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Header */
.main-header {
    padding: 2rem 0;
}

.brand-logo {
    width: 85px;
    height: auto;
    object-fit: contain;
}

/* Hero Section */
.hero {
    margin: 6rem 0 4rem;
    text-align: center;
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: 4rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.hero h1 span {
    background: linear-gradient(135deg, #60a5fa, #3b82f6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Lessons Grid */
.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
    padding-bottom: 6rem;
}

.lesson-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    display: flex;
    flex-direction: column;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.lesson-card:hover:not(.coming-soon) {
    transform: translateY(-10px);
    background: var(--bg-surface-hover);
    border-color: var(--accent-primary);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1), 0 0 20px var(--accent-glow);
}

.card-visual {
    height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: rgba(37, 99, 235, 0.05);
    border-bottom: 1px solid var(--border-color);
}

.card-visual svg {
    width: 64px;
    height: 64px;
    color: var(--accent-primary);
    z-index: 2;
    transition: transform 0.5s ease;
}

.lesson-card:hover .card-visual svg {
    transform: scale(1.1);
}

.electricity-visual .glow-orb {
    position: absolute;
    width: 100px;
    height: 100px;
    background: var(--accent-electricity);
    border-radius: 50%;
    filter: blur(40px);
    opacity: 0.5;
    transition: all 0.5s ease;
}

.lesson-card:hover .electricity-visual .glow-orb {
    opacity: 0.8;
    transform: scale(1.5);
}

.card-content {
    padding: 2rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.badge {
    align-self: flex-start;
    padding: 0.25rem 0.75rem;
    background: rgba(37, 99, 235, 0.1);
    color: var(--accent-primary);
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.badge-outline {
    background: transparent;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
}

.card-content h2 {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
}

.card-content p {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 1.5rem;
    flex: 1;
}

.action-link {
    color: var(--accent-primary);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: gap 0.3s ease;
}

.lesson-card:hover .action-link {
    gap: 0.75rem;
}

.coming-soon {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Footer */
footer {
    margin-top: auto;
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        margin: 4rem 0 2rem;
    }

    .hero h1 {
        font-size: 3rem;
    }

    .lessons-grid {
        grid-template-columns: 1fr;
    }
}