:root {
    --bg-color: #0a0e14;
    --card-bg: #161b22;
    --accent-color: #00d4ff;
    --accent-glow: rgba(0, 212, 255, 0.5);
    --text-primary: #e6edf3;
    --text-secondary: #8b949e;
    --success: #238636;
    --danger: #da3633;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Animowane tło z cząsteczkami */
.lab-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: radial-gradient(circle at 50% 50%, #1a1f2b 0%, #0a0e14 100%);
    overflow: hidden;
}

.bubble {
    position: absolute;
    bottom: -100px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 50%;
    animation: rise 10s infinite ease-in;
}

@keyframes rise {
    0% { transform: translateY(0) rotate(0deg); opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { transform: translateY(-120vh) rotate(360deg); opacity: 0; }
}

/* Kontener główny */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 4rem;
}

h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 3rem;
    color: var(--accent-color);
    text-shadow: 0 0 20px var(--accent-glow);
    margin-bottom: 1rem;
    letter-spacing: 2px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.2rem;
}

/* Karty Lekcji */
.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.lesson-card {
    background: var(--card-bg);
    border: 1px solid #30363d;
    border-radius: 16px;
    padding: 1.5rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.lesson-card:hover {
    transform: translateY(-10px);
    border-color: var(--accent-color);
    box-shadow: 0 10px 30px rgba(0, 212, 255, 0.1);
}

.lesson-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-color);
    opacity: 0;
    transition: opacity 0.3s;
}

.lesson-card:hover::before {
    opacity: 1;
}

.lesson-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.lesson-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

.lesson-desc {
    color: var(--text-secondary);
    line-height: 1.5;
    flex-grow: 1;
}

.btn-start {
    margin-top: 1.5rem;
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: transparent;
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    border-radius: 8px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s;
}

.lesson-card:hover .btn-start {
    background: var(--accent-color);
    color: var(--bg-color);
}

/* Responsywność */
@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    .container { padding: 1rem; }
}