:root {
    --bg-color: #050510;
    --card-bg: rgba(255, 255, 255, 0.05);
    --primary-color: #00efff;
    --secondary-color: #ff00ff;
    --text-color: #ffffff;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Noto Sans KR', sans-serif;
    margin: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    text-align: center;
    padding: 60px 20px;
}

header h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 3rem;
    margin: 0;
    background: linear-gradient(90deg, #00efff, #ff00ff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 20px rgba(0, 239, 255, 0.5);
}

header p {
    color: #888;
    margin-top: 10px;
    font-size: 1.1rem;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    width: 100%;
    max-width: 1200px;
    padding: 0 40px;
    box-sizing: border-box;
}

.card {
    background: var(--card-bg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 30px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    backdrop-filter: blur(10px);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 239, 255, 0.1);
    border-color: var(--primary-color);
}

.card-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    background: rgba(255, 255, 255, 0.1);
    width: 100px;
    height: 100px;
    line-height: 100px;
    border-radius: 50%;
}

.card-content h2 {
    font-family: 'Orbitron', sans-serif;
    margin: 10px 0;
    color: #fff;
}

.card-content p {
    color: #aaa;
    margin-bottom: 25px;
    min-height: 40px;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    text-decoration: none;
    font-weight: bold;
    border-radius: 25px;
    font-family: 'Orbitron', sans-serif;
    transition: filter 0.2s;
}

.btn:hover {
    filter: brightness(1.2);
    box-shadow: 0 0 15px var(--secondary-color);
}

.card.puyo:hover {
    border-color: #ff0055;
    box-shadow: 0 10px 30px rgba(255, 0, 85, 0.2);
}

.card.tetris:hover {
    border-color: #00ff00;
    box-shadow: 0 10px 30px rgba(0, 255, 0, 0.2);
}

footer {
    margin-top: auto;
    padding: 40px;
    color: #555;
    font-size: 0.9rem;
}