:root {
    --primary-color: #F7DF1E;
    --background-color: #282c34;
    --text-color: #FFFFFF;
    --accent-color: #61DAFB;
    --card-background: #3a3f47;
}

body {
    font-family: 'Roboto', 'Noto Sans KR', sans-serif;
    margin: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    scroll-behavior: smooth;
}

header {
    background-color: #20232a;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 700;
    transition: color 0.3s ease;
}

nav a:hover {
    color: var(--primary-color);
}

main {
    padding: 0 2rem;
}

section {
    padding: 4rem 0;
    border-bottom: 1px solid var(--card-background);
}

#hero {
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 80vh;
    background: linear-gradient(rgba(40, 44, 52, 0.8), rgba(40, 44, 52, 0.8)), url('https://source.unsplash.com/random/1600x900/?javascript,code') no-repeat center center/cover;
}

#hero h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 3rem;
    color: var(--primary-color);
}

.subtitle {
    font-size: 1.2rem;
    margin-top: 1rem;
    margin-bottom: 2rem;
}

.cta-button {
    background-color: var(--primary-color);
    color: #000;
    padding: 0.8rem 1.5rem;
    text-decoration: none;
    font-weight: 700;
    border-radius: 5px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(247, 223, 30, 0.4);
}

h2 {
    text-align: center;
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--accent-color);
}

#features .feature-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.card {
    background-color: var(--card-background);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.4);
}

.card h3 {
    color: var(--primary-color);
    margin-top: 0;
}

#curriculum .accordion {
    max-width: 800px;
    margin: 0 auto;
}

.accordion-item {
    background-color: var(--card-background);
    margin-bottom: 1rem;
    border-radius: 5px;
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    background-color: var(--card-background);
    border: none;
    padding: 1.5rem;
    font-size: 1.2rem;
    color: var(--text-color);
    text-align: left;
    cursor: pointer;
    font-weight: 700;
    border-bottom: 1px solid #282c34;
}

.accordion-content {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
}

#enroll {
    text-align: center;
}

.enroll-content .price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 1rem 0;
}

.refund-policy {
    margin-bottom: 2rem;
    font-size: 0.9rem;
    opacity: 0.8;
}

footer {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    background-color: #20232a;
}

@media (max-width: 768px) {
    nav {
        flex-direction: column;
        gap: 1rem;
    }

    nav ul {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    #hero h1 {
        font-size: 2.2rem;
    }
}